A new thermophoretic particle precipitator has been developed for representative and efficient collection of aerosol particles from the ambient air and technological pipelines. The device consists of hot and cold plates (5 × 5 cm²) capable of operation at temperature gradients ranging from 20 000 to 100 000 K/m. A gas sample is made to pass through a 1-mm slot between the plates at a flow rate of up to 1.5 L/min, which makes the device suitable for operation in conjunction with common aerosol instruments including DMA and diffusion batteries with similar operational flow rates. It was shown that the efficiency of the device was highest for the lowest gas flow rate used (0.3 L/min) reaching a level of above 99%. The efficiency was decreased reaching its minimal values at the highest flow rate investigated (1.5 L/min). However, even for highest flow rate, the average efficiency for removal of particle smaller than 60 nm was around 50%.

A new efficient thermophoretic precipitator has been designed and tested for collection of NaCl and Mo nanoparticles at three sample flow rates. The TEM images of the particles collected at 100 K show partial separation of polydisperse aerosols into monodisperse fractions.

This paper deals with kinetics and equilibrium studies on the adsorption of arsenic species from simulated groundwater containing arsenic (As(III)/As(V), 1:1), Fe, and Mn in concentrations of 0.188, 2.8, and 0.6 mg/L, respectively, by Ca²⁺ impregnated granular activated charcoal (GAC-Ca). Effects of agitation period and initial arsenic concentration on the removal of arsenic species have also been described. Although, most of the arsenic species are adsorbed within 10 h of agitation, equilibrium reaches after ∼24 h. Amongst various kinetic models investigated, the pseudo second order model is more adequate to explain the adsorption kinetics and film diffusion is found to be the rate controlling step for the adsorption of arsenic species on GAC-Ca. Freundlich isotherm is adequate to explain the adsorption equilibrium. However, empirical polynomial isotherm gives more accurate prediction on equilibrium specific uptakes of arsenic species. Maximum specific uptake (q_max) for the adsorption of As(T) as obtained from Langmuir isotherm is 135 µg/g.

Kinetics and equilibrium studies on the adsorption of arsenic species from simulated groundwater containing As(III), As(V), Fe, and Mn by Ca²⁺ impregnated granular activated charcoal (GAC-Ca) are investigated. The results show that the Freundlich isotherm is adequate to explain the adsorption equilibrium.

Sulfur removal using adsorption requires a proper process parametric study to determine its optimal performance characteristics. In this study, response surface methodology was employed for sulfur removal from model oil (dibenzothiophene; DBT dissolved in iso-octane) using commercial activated carbon (CAC) as an adsorbent. Experiments were carried out as per central composite design with four input parameters such as initial concentration (C₀: 100–900 mg/L), adsorbent dosage (m: 2–22 g/L), time of adsorption (t: 15–735 min), and temperature (T: 10–50°C). Regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination R²-value of 0.9390 and Fisher F-value of 16.5. The highest removal of sulfur by CAC was obtained with m = 20 g/L, t = 6 h, and T = 30°C.

The adsorption of DBT onto commercial activated carbon was investigated here. 3D surface methodology by the central composite design was used to examine the role of four process factors on adsorptive desulfurization process. It could be shown that a second-order polynomial regression model could properly interpret the experimental data.

Sorption behavior of Lanaset Red (LR) G on lentil straw (LS) was studied as a function of particle size, adsorbent dose, initial pH value, initial dye concentration, and contact time. Sorption kinetics data was well described by logistic model. Modified logistic equation can be used to explain effects of initial dye concentrations and contact time on the sorption of LR G with high R² value. Freundlich model was found to be excellent in representing the equilibrium data. Thermodynamic parameters like free energy (ΔG⁰), enthalpy (ΔH⁰), and entropy (ΔS⁰) were calculated by the use of Langmuir constant. Thermodynamic data showed that the sorption processes were spontaneous and endothermic in nature. Desorption process suggested that strong binding and weak interactions could be formed between adsorbent surface and dye molecules. Results revealed that LS has a remarkable potential for the sorption of LR G.

This study revealed that lentil straw can be used as an effective adsorbent for dye removal from aquatic ecosystems at several environmental conditions. Thermodynamic data indicated that the sorption processes are spontaneous and of endothermic nature.

Feasibility of photocatalytic dechlorination of PCB-138 and Aroclor-1254 using platinum loaded TiO₂ (P25) in an alkaline 2-propanol medium has been investigated. Experiments were conducted in batch mode using a Rayonet photo-reactor under aerated and deaerated conditions with black lamps emitting around 350 nm as light source. Two forms of platinum deposition were investigated: Photochemically loaded P25 as well as addition of potassium hexachloroplatinate into the reaction medium. Partial dechlorination of PCBs was observed after 7 h of irradiation with pure TiO₂ as catalyst when the reaction vessel was kept open to air. Complete dechlorination was observed after 5 h of irradiation in a deaerated environment. Enhanced photocatalytic efficiency was observed when platinum deposited P25 was used as catalyst, with the best result being obtained when aqueous potassium hexachloroplatinate was added into the reaction medium. Lower potassium hexachloroplatinate concentration (0.1 mM) yielded better performance.

The processes at the TiO₂ surface demonstrate that the species required for the chain reaction that follows direct photolysis of PCBs can be generated photocatalytically. Both PCB-138 and a commercial mixture (Aroclor-1254) were dechlorinated successfully in an alkaline IPA medium.

Gallium arsenide (GaAs) has both high saturated electron velocity and high electron mobility, making it useful as a semiconductor material in a variety of applications, including light-emitting diodes (LEDs), integrated circuits (ICs), and microwave appliances. A side effect of the use of gallium (Ga) is the production of a relatively large amount of hazardous waste. This study aimed at the recovery of Ga and arsenic (As) from GaAs waste using hydrometallurgical methods involving leaching and coagulation and a dry annealing process that involves annealing, vacuum separation, and sublimation by heating. Our research has shown that GaAs can be leached using nitric acid (HNO₃) to obtain 100% Ga and As with a leaching solution at pH 0.1, with subsequent adjustment of the leaching solution to pH 3 with sodium hydroxide (NaOH). Another method used a leaching solution at pH 2, then adjusting to pH 11 using NaOH. Ferric hydroxide (FeO(OH)) was added at 90°C after NaOH was added to the leaching solution. At pH 2 and 11, 55.5 and 21.9% of the As could be removed from the hazardous waste, respectively. The Ga could also be precipitated. When GaAs powder was heated to 1000°C over 3 h, 100% As removal was achieved, and 92.6% of the Ga was removed by formation of 99.9% gallium trioxide (Ga₂O₃). Arsenic was vaporized when the temperature was elevated to 1000°C, allowing arsenic trioxide (As₂O₃) to condense with 99.2% purity. The Ga₂O₃ powder produced was then dissolved and electrolyzed, allowing for 95.9% recovery of Ga with a purity of 99.9%.

Gallium arsenide (GaAs), a semiconductor material, can serve as a source of Ga and As by using hydrometallurgical methods. The results show that Ga and As could be recovered in high quality and high purity.

Acid violet 19 (AV) belongs to the triphenylmethane (TPM) class of dyes which are potentially mutagenic or carcinogenic. However, very little studies on biodegradation of AV were reported as compared to other TPM dyes such as malachite green and crystal violet. In this study, AV was decolorized up to 98% within 30 min by Pseudomonas aeruginosa BCH. The decolorization depends on the initial dye concentration, pH, and temperature. However, the dye was decolorized under wide pH and temperature ranges with an optimum of pH 7 and 30°C. Up to 250 mg L⁻¹ of dye was found to be tolerated and decolorized by this strain. It showed decolorization ability for seven repeated dye addition cycles. The effect of additional carbon sources on dye decolorization was studied in which mannitol containing medium showed decolorization in 15 min. Induction in the enzyme activities of laccase, NADH-DCIP reductase, and veratryl alcohol oxidase (VAO) indicates their involvement in AV degradation. Various analytical studies viz. UV–VIS, HPTLC, HPLC, and FTIR confirmed the biodegradation of AV by the bacterium. Based on GC-MS analysis, a possible degradation pathway for AV was proposed. The phytotoxicity studies using Phaseolus mungo and Sorghum vulgare revealed the less toxic nature of metabolites formed after AV degradation.

The bacterium Pseudomonas aeruginosa BCH efficiently decolorized and detoxified the triphenylmethane dye Acid violet 19 at a very fast rate. Induction in activities of laccase, NADH-DCIP reductase, and VAO indicated their combined action in AV biodegradation.

The effects of plant species richness (SR; i.e., 1, 2, 4, 8, and 16 species per plot) on substrate nitrate and ammonium retention and ecosystem productivity in a full-scale constructed wetland (CW) with high nitrogen (N) input were studied. Substrate nitrate (0.1–16.4 mg kg⁻¹) and ammonium concentrations (1.3–9.2 mg kg⁻¹) in this study were higher than those in other comparable biodiversity experiments. Substrate nitrate concentration significantly increased while ammonium concentration significantly decreased with the increase of plant SR (p = 0.008 and 0.040, respectively). The response of ecosystem productivity to increasing SR was unimodal with four species per plot achieving the greatest productivity. Transgressive overyielding, which was compared to the most productive of corresponding monocultures, did not occur in most polycultures. We conclude that substrate N retention was enhanced by plant SR even with high N input, and plant SR could be managed to improve the efficiency of N removals in CWs for wastewater treatment.

This study offers a case study on the relationship between species richness (SR) and ecosystem functioning in an environment with high N input: Plant SR should be considered in designing constructed wetland to enhance nutrient retention and productivity and improve the removal efficiencies of N from wastewater.

Degradation of an anthraquinone dye, disperse blue E-4R, by zero-valent iron (ZVI)/ozone (O₃) was carried out in a series of laboratory-scale experiments. The obtained results indicated that this method was much more effective than single ZVI or single O₃ at removal of color, chemical oxygen demand, total organic carbon, and adsorbable organic halogen. The effect of several related operational parameters, including O₃ dosage, zero valent iron dosage, temperature, pH value, and ZVI particle size were also discussed. Finally, we tried to decontaminate some actual samples with this method, which showed high treatment efficiency to the sample pretreated by conventional activated sludge.

An efficient and convenient procedure for the degradation of E-4R by a zero-valent iron/ozone (ZVI/O₃) method is proposed. This method showed higher degradation efficiency, compared with ZVI or O₃ alone. ZVI/O₃ showed promising efficiency for dye wastewater treatment.

Leachate treatment using a membrane bioreactor is an effective method. This study presents a configuration including an anaerobic bioreactor and a membrane module, called submerged anaerobic membrane bioreactor (SAnMBR), for treating influent with leachate/acetate rations (L/A), that were kept to be 10, 25, 50, 75, and 100% at a constant SRT (100 days). COD removal decreased from 85 to 75% when the L/A ratio increased from 10 to 100. To prevent membrane fouling, a SAnMBR was operated in the case of circulation of mixed liquor under continuous and intermittent suction. The average fluxes were 2.60 and 0.40 L/m² h at the periods of intermittent and continuous suction, respectively. The methane production varied between 0.25 and 0.32 L CH₄/g COD_removed.

The behavior results of a submerged anaerobic membrane bioreactor at different leachate/acetate ratios reveal, e.g., that the concentration polarization on the membrane surface was eliminated due to cutting the force applied to membrane and that ammonium concentration in the influent did not affect the performance of the bioreactor.

Soil air permeability plays a decisive role in the effectiveness of soil vapour extraction (SVE) for the removal of volatile organic contaminants (VOCs) from soil. The objective of this work is to study the change of the soil air permeability during continuous venting and removal of contaminant from a polluted soil. SVE pilot experiments were conducted to investigate the interaction of soil air permeability with total liquids saturation. Oppositely to previous studies, air permeability was measured by fitting pressure data measured in a 3D laboratory venting pilot to an analytical airflow solution. The experimental correlation was compared with two different correlations published previously. A difference was observed between measured and calculated air relative air permeabilities especially for low water saturation degrees. The importance of the correct estimate of relative permeability was then illustrated by comparing vacuums and streamlines calculated using measured permeability and permeability values estimated with the two correlations tested here. Results show that an inappropriate assessment of relative permeability may engender significant errors in designing an SVE system. The second part of this work reports on the influence of air permeability change on the prediction capability of an SVE mathematical model. A significant difference between simulated breakthrough curves, estimated using firstly the relationship established experimentally and secondly the two other correlations, was observed. These results lead us to say that inadequate characterization of the air permeability change may generate significant errors in removal rate and closure time estimates.

Soil air permeability plays a decisive role in the effectiveness of soil vapour extraction (SVE) for the removal of volatile organic contaminants (VOCs) from soil. The results indicate that air relative permeability variation as a function of liquid saturation should be determined experimentally as existed correlations do not give good estimation.

The runoff in Songhuajiang River catchment has experienced a decreasing trend during the second half of the 20th century. Serially complete daily rainfall data of 42 rainfall stations from 1959 to 2002 and daily runoff data of five meteorological stations from 1953 to 2005 were obtained. The Mann–Kendall trend test and the sequential version of Mann–Kendall test were employed in this study to test the monthly and annual trends for both rainfall and runoff, to determine the start point of abrupt runoff declining, and to identify the main driving factors of runoff decline. The results showed an insignificant increasing trend in rainfall but a significant decreasing trend in runoff in the catchment. For the five meteorological stations, abrupt runoff decline occurred during 1957–1963 and the middle 1990s. Through Mann–Kendall comparisons for the area-rainfall and runoff for the two decreasing periods, human activity, rather than climatic change, is identified as the main driving factor of runoff decline. Analysis of land use/cover shows that farmland is most related with runoff decline among all the land use/cover change in Nenjiang catchment. From 1986 to 1995, the area of farmland increased rapidly from 6.99 to 7.61 million hm². Hydraulic engineering has a significant influence on the runoff decline in the second Songhuajiang catchment. Many large-scale reservoirs and hydropower stations have been built in the upstream of the Second Songhuajiang and lead to the runoff decline. Nenjiang and the Second Songhuajiang are the two sources of mainstream of Songhuajiang. Decreased runoff in these two sub-catchments then results in runoff decrease in mainstream of Songhuajiang catchment. It is, therefore, concluded that high percent agricultural land and hydraulic engineering are the most probable driving factors of runoff decline in Songhuajiang River catchment, China.

Mann–Kendall trend test versions were employed to analyze monthly and annual trends for rainfall and runoff, to determine the start point of abrupt runoff declining and to identify the main driving factors of runoff decline. The results showed that high percent agricultural land and hydraulic engineering are the most probable driving factors of runoff decline.

The ultrasound-assisted emulsification–microextraction (USAEME) method was combined with graphite furnace atomic absorption spectrometry (GFAAS) for the determination of trace Pb using dithizone (H²DZ) as chelating reagent. Some effective parameters influenced the detection and microextraction, such as ashing temperature and atomization temperature, pH, extraction solvent, sample volume, extraction time, and extraction temperature were selected and optimized. After extraction, the calibration curves for Pb was in the concentration range of 0.1–10 ng mL⁻¹, and the linear equation was y = 0.097 x + 0.023 (R = 0.99). Under the optimized conditions, the detection limit of the method was 20 pg mL⁻¹ with an enrichment factor of 70 and the relative standards deviation (RSD) for seven determinations of 1 ng mL⁻¹ Pb was 11%. The proposed method was successfully applied to determine trace Pb in Yueya Lake water, pond water, and spiked samples. Furthermore, a certified reference material of Environment Water (GBW08607) was analyzed and the determined value was in good agreement with the certified value, which showed the accuracy, recovery, and applicability of the reported method.

The combination of ultrasound-assisted emulsification–microextraction with graphite furnace atomic absorption spectrometry has been used to determine trace Pb in water. This method is environmental friendly, simple, rapid, sensitive, and practical and can be applied for metal pollution analysis in future.

A systematic approach was used to characterize the biosorption of copper(II) onto two biosorbents, Posidonia oceanica and peat, focusing on the interaction mechanisms, the copper(II) sorption–desorption process and the thermal behavior of the biosorbents. Sorption isotherms at pH 4–6 were obtained and the experimental data were fitted to the Langmuir model with a maximum uptake (q_max) at pH 6 of 85.78 and 49.69 mg g⁻¹, for P. oceanica and peat, respectively. A sequential desorption (SD) with water, Ca(NO₃)₂, and EDTA was applied to copper-saturated biosorbents. Around 65–70% copper(II) were desorbed with EDTA, indicating that this heavy metal was strongly bound. The reversibility of copper(II) sorption was obtained by desorption with HCl and SD. Fourier transform IR spectroscopy (FTIR) analysis detected the presence of peaks associated with OH groups in aromatic and aliphatic structures, CH, CH₂, and CH₃ in aliphatic structures, COO⁻ and COOH groups and unsaturated aromatic structures on the surface of both biosorbents, as well as peaks corresponding to SiO groups on the surface of peat. The results of SEM-EDX and FTIR analysis of copper-saturated samples demonstrated that ion exchange was one of the mechanisms involved in copper(II) retention. Thermal analysis of biosorbent samples showed that copper(II) sorption–desorption processes affected the thermal stability of the biosorbents.

A comprehensive combination of analytical techniques (SEM-EDX and FTIR) allowed concluding that ion exchange is one of the mechanisms involved in copper(II) retention by Posidonia oceanica and peat, and that carboxylic and hydroxyl groups were involved in the sorption process.

Excessive amounts of mineral fertilizers are unnecessarily applied to agricultural soils in Egypt to increase crop yield. The current study aims at assessing the impacts of fertilization with different mineral fertilizers for different cultivation periods on the accumulation of heavy metals in soils and plants grown thereon. In addition, human risks resulted due to the exposure to these metal ions through ingestion, and dermal routes were evaluated. Soil and plant samples were collected from several locations in El-Behira Governorate, Egypt and their heavy metal contents were measured. The result indicated that there is a continuous accumulation of heavy metals in the soils and the plants grown thereon. Calculation of the hazard index (HI) revealed that humans, especially children, have a potential health risk for both Pb and Cd, which have levels greater than the safe level (1). Finally, the obtained results showed that the continuous application of mineral fertilizers containing high levels of heavy metals pose a potential health threat.

Mineral fertilizers containing varying concentrations of heavy metals are commonly used. Soil and plant samples were collected and tested for heavy metal contents. Calculation of the hazard index revealed that especially children have a potential health risk for both Pb and Cd with levels greater than the safe level.

Chemical speciation of vanadium is important to understand the true nature of this element in the environment as well as its biochemical pathways. Sample pretreatment, preparation, and chemical speciation methods were applied for vanadium in coal bottom ash here. Two-stage microwave acid digestion was used to preparation of samples. Determination of vanadium was performed using inductively coupled plasma-optical emission spectrometry (ICP-OES). Speciation of vanadium was carried out using a seven-step sequential extraction procedure of the coal bottom ash each releasing species of vanadium: Water soluble, exchangeable, carbonate, reducible, oxidizable, sulfide, and residual fractions. Total vanadium concentration in the coal bottom ash is 701 mg kg⁻¹ d.w. The most abundant form of vanadium in coal bottom ash is residual fraction of vanadium (196 mg kg⁻¹ d.w.). Relative abundances of the remaining vanadium fractions in coal bottom ash are as follows: Reducible (176 mg kg⁻¹ d.w.) > sulfide (176 mg kg⁻¹ d.w.) > carbonate (85 mg kg⁻¹ d.w.) > oxidizable (50 mg kg⁻¹ d.w.) > water soluble (10.6 mg kg⁻¹ d.w.) > exchangeable (9.0 mg kg⁻¹ d.w.).

The determination and speciation of vanadium in coal bottom ash using inductively coupled plasma-optical emission spectrometer has been reported here. This work focuses on determining the leachability of V (water soluble, exchangeable, carbonate, reducible, oxidizable, sulfide, and residual fractions).

Soil salinization due to saltwater incursion, is a major threat to microbial population and thus strongly alters biogeochemical processes in a freshwater riparian of coastal estuary region. An incubation experiment was conducted to investigate the effects of simulated saltwater treatments with different percentages of artificial seawater on biodegradation dynamics of herbicide bensulfuron-methyl (BSM) and microbial ecophysiological parameters in a riparian soil in Chongming Island, China. The results showed that saltwater addition with 10% seawater significantly increased the biodegradation efficiency of BSM with the lowest residual concentration among all the treatments. However, BSM degradation was markedly decreased in the riparian soil with high levels of saltwater treatment. The half-lives for 20% and 50% seawater treatments were prolonged by 4.9% and 21.1%, respectively, as compared to no saltwater treatment. Throughout the incubation period, 10% seawater treatment showed significantly stimulating effects on microbial parameters in the BSM-spiked riparian soil. At the end of incubation experiment, flourescein diacetate (FDA) hydrolysis rate, soil microbial adenosine triphosphate (ATP), and basal soil respiration (BSR) in the BSM-spiked riparian soil with 10% seawater were 64.2%, 48.9%, and 39.4% higher than those with no saltwater treatment, respectively. In contrast, saltwater treatment with 50% seawater significantly inhibited microbial activities, relative to no saltwater treatment. Especially, FDA hydrolysis rate, microbial ATP, and BSR were decreased by 74.1%, 69.8%, and 63.4%, respectively, as compared to no saltwater treatment. Our data indicate that different levels of simulated saltwater incursion can exert variable effects on microbial ecophysiological parameters, and consequently resulted in the difference in biodegradation dynamics of herbicide in the herbicide-spiked riparian soil.

Laboratory incubation experiment results showed that degradation kinetics of bensulfuron-methyl in riparian soils well fit to a first-order kinetic model despite the levels of saltwater treatments. Low level of saltwater treatment with 10% seawater significantly stimulated biological and biochemical activities in the riparian soil.

An assessment of water quality measurements during a spring flood in the Elbe River is presented. Daily samples were taken at a site in the middle Elbe, which is part of the network of the International Commission for the Protection of the Elbe River (IKSE/MKOL). Cluster analysis (CA), principal components analysis (PCA), and source apportionment (APCS apportioning) were used to assess the flood-dependent matter transport. As a result, three main components could be extracted as important to the matter transport in the Elbe River basin during flood events: (i) re-suspended contaminated sediments, which led to temporarily increased concentrations of suspended matter and of most of the investigated heavy metals; (ii) water discharge related concentrations of pedogenic dissolved organic matter (DOM) as well as preliminary diluted concentrations of uranium and chloride, parameters with stable pollution background in the river basin; and (iii) abandoned mines, i.e., their dewatering systems, with particular influence on nickel, manganese, and zinc concentrations.

It could be shown that the application of cluster analysis, principal components analysis, and source apportionment can considerably improve the understanding of flood-dependent matter transport in large rivers. The paper identifies of three main pollution sources as sediment re-suspension, water discharge, and mining supply.

The present study was undertaken to investigate the accumulation of microcystins (MCYST) in the various tissues of an endemic and protected fish species (Rutilus panosi). We also tried to identify any differences in sensitivity and accumulation of MCYST, for various specimens of the same fish species related to body length. MCYST concentrations in lake water and fish tissues were determined by a commercial Microcystin ELISA kit. Results showed that considerable amount of toxins were found to be accumulated in tissues of R. panosi throughout the year. Among them, liver had the highest MCYST concentrations (407.97 ± 32.43 ng/g). This study confirmed the accumulation of high MCYST concentrations in fish brain (308.75 ± 26.49 ng/g). Our results suggest, that MCYST accumulation in R. panosi tissues is size depended. High MCYST concentration in the muscle of the fish increases the risk of unsafe consumption, thus threatening human health.

The accumulation of microcystins in various tissues of an endemic and protected fish species (Rutilus panosi) was investigated. The results showed that liver had the highest concentrations. Furthermore, body size is an important factor for the accumulation of free MCYST in R. panosi tissues.

The objective of this study was to investigate the effect of salt concentration on performance of a membrane bioreactor (MBR) for treating an olefin plant wastewater. For this purpose, a lab-scale submerged MBR with a flat-sheet ultrafiltration membrane was used for treatment of synthetic wastewater according to oxidation and neutralization unit of olefin plant. The synthetic wastewater was adjusted to have 500 mg/L chemical oxygen demand (COD). Trials on different concentrations of sodium sulfate (Na₂SO₄) (0–20 000 ppm) in the feed were conducted under aerobic conditions in the MBR. The results showed that increasing the salt concentrations causes an increase in the effluent COD, phenol, and oil concentrations. These results are due to reduction of the membrane filtration efficiency and also decline in the microbial activity that it is indicated by decreasing the sOUR in MBR. But in all the trials, the effluent COD and oil concentration was well within the local discharge limit of 100 and 10 mg/L, respectively. These results indicate that the MBR system is highly efficient for treating the olefin plant wastewater, and although high salt concentrations decreased organic contaminant removal rates in the MBR, the effluent still met the discharge limits for treating the olefin plant wastewater.

The effect of salt concentration on performance of a membrane bioreactor (MBR) for treating an olefin plant wastewater was investigated. For this purpose, a lab-scale submerged MBR with a flat-sheet ultrafiltration membrane was used. The results indicated that MBR is a high promising process for biological treatment of olefin plant wastewater.

In the Pearl River Delta (PRD), river water quality deteriorates continually due to the population increase and ongoing industrialization and urbanization. In this study, a water quality management paradigm based on the seasonal variation is proposed. For better exploring the seasonal change of water quality, wavelet analysis was used to analyze the division of dry and wet seasons in the PRD during 1952–2009. Then water quality seasonal variation in 2008 and relevant impact factors were analyzed by multivariate statistic methods as a case to make some management measures. The results show that there are some differences of dry and wet seasons division among different years. Wet season mainly appear from April to September, which occupy the largest proportion among the 58 years (about 70%) and then followed by the wet season from May to October (about 13.8% of the total years). As to the water quality of 2008, significant differences exist between dry and wet seasons for 17 water quality parameters except TP, , Fe²⁺, and Zn²⁺. Levels of parameters pH, EC, COD_Mn, BOD₅, , , and Cl⁻ in dry season are much higher than those in wet season. In dry season the variations of river water quality are mainly influenced by domestic sewage, industrial effluents, and salt water intrusion. While in wet season, except the aforementioned pollution sources, drainages from cultivated land and livestock farm are also the main factors influencing water pollution. Thus, water quality management measures are proposed in dry and wet seasons, respectively. The results obtained from this study would further facilitate water quality protection and water resources management in the PRD.

Water quality management measures are proposed to manage river water quality in the Pearl River Delta. For better exploring the seasonal change of water quality, wavelet analysis was used to analyze the division of dry and wet seasons during 1952–2009. Contaminant sources were also identified.

The electrochemical oxidation (EO) of diethyl phthalate (DEP) in aqueous solution was studied at Pb/PbO₂ and Ti/SnO₂ anode materials under galvanostatic-experimental conditions. Results obtained clearly demonstrated that the anode plays a significant role for the optimization of the oxidation process, deciding the mechanisms and by-products formed. DEP and by-products of oxidation were also analyzed during various stages of the electrolysis reaction by HPLC and GC/MS techniques. Before the analysis by GC/MS technique, the samples were treated by solid phase microextraction (SPME) in order to concentrate the compounds from the reaction solution and identify all electrolysis intermediates. Current efficiencies (instantaneous current efficiency; ICE and total current efficiency; TCE) achieved during EO experiments were dependent on anode used and current density (20–40 mA cm⁻²) at 40°C. The results obtained demonstrated that the environmental electrochemical methods can be a feasible alternative for the wastewater treatment containing hazardous phthalates.

The aim of the present work was to evaluate the applicability of the electrochemical oxidation (EO) process for removing DEP from aqueous solutions. Comparing the results obtained with biological and photocatalytic degradation methods for DEP elimination, EO employs short treatment times and it generates minor hazardous by-products than other ones.

Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro-, trace- and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long-term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Paraná State, in the South-Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP-OES, ICP-MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed.

Spatial characterization of the watershed and their concentrations during a given time period was evaluated. The results show that there are no significant chemical changes that indicate recent anthropogenic contribution to the reservoir or its tributaries. The data are useful for future geochemical and environmental investigations.

Utilization of cheap renewable carbon feedstock for polyhydroxyalkanoate (PHA) production not only brings down its production cost but also ensures sustainability. The scope of this study was to evaluate the potential of sap extracted from felled oil palm trunk (OPT) as a novel inexpensive renewable carbon source for PHA production. OPT sap was found to be nutritionally rich and contained various fermentable sugars (5.5% w/v) as its major constituent. Termite gut isolate, Bacillus megaterium MC1 grew profoundly in mineral medium with OPT sap as carbon source and a cell density of 10.9 g/L was attained after 16 h of cultivation in shake flask cultures. A maximum poly-3-hydroxybutyrate [P(3HB)] content (% cell dry weight; CDW) of 30 wt% and a P(3HB) concentration of 3.28 g/L was recorded. Additionally, OPT sap extracted from younger tree trunks with prolonged storage had higher sugar content (10.8% w/v) and, when used as a growth medium without the addition of any nutrients, supported bacterial growth comparable to commercially available media.

Oil palm tree trunks sap represents almost all the macro- and micronutrients required for good bacterial growth. The results for Bacillus megaterium demonstrate the potential of OPT sap as a promising renewable carbon feedstock for bioplastic production and also as a bacterial growth medium.

In the present study, effects of operational parameters on the electrical energy consumption for photooxidative process (UV/H₂O₂) for the decolorization of C. I. Acid Red 88 (AR88) have been investigated. In a series of experiments, 20 mg L⁻¹ of AR88 solution were irradiated in the presence of different concentrations of H₂O₂ (to find out optimum amount of H₂O₂) by UV light intensity of 30 W m⁻² for certain irradiation times. The decolorization of the dye followed pseudo first-order kinetics, and hence, the figure-of-merit electrical energy per order (E_EO) is appropriate for estimating the electrical energy efficiency. The electrical energy consumption was determined during the variation of some parameters such as initial H₂O₂ concentration, initial dye concentration, UV light intensity, pH, and the gap size of solution. Results showed that electrical energy could be reduced by optimizing operational parameters.

This work proved that the photooxidative process is a powerful method to decolorize AR88. The decolorization efficiency depends on operational parameters as initial H₂O₂ and AR88 concentrations, UV light intensity, reactor gap size, and initial pH. The H₂O₂ concentration has a critical effect.

The present paper deals with the modeling of the removal of total arsenic As(T), trivalent arsenic As(III), and pentavalent arsenic As(V) from synthetic solutions containing total arsenic (0.167–2.0 mg/L), Fe (0.9–2.7 mg/L), and Mn (0.2–0.6 mg/L) in a batch reactor using Fe impregnated granular activated charcoal (GAC-Fe). Mass ratio of As(III) and As(V) in the solution was 1:1. Multi-layer neural network (MLNN) has been used and full factorial design technique has been applied for the selection of input data set. The developed models are able to predict the adsorption of arsenic species with an error limit of −0.3 to +1.7%. Combination of MLNN with design of experiment has been able to generalize the MLNN with less number of experimental points.

This paper shows that artificial neural network is able to predict the adsorption of arsenic species with an error limit of −0.3 to +1.7%. In addition, application of experimental design technique to a selected data set for training of neural network reduces the number of experiments for developing models.

In this paper, a novel composite material the silica grafted by poly(N-vinyl imidazole) (PVI), i.e., PVI/SiO₂, was prepared using 3-methacryloxypropyl trimethoxysilane (MPS) as intermedia through the “grafting from” method. The adsorption behavior of metal ions by PVI/SiO₂ was researched by both static and dynamic methods. Experimental results showed that PVI/SiO₂ possessed very strong adsorption ability for metal ions. For different metal ions, PVI/SiO₂ exhibited different adsorption abilities with the following order of adsorption capacity: Cu²⁺ > Cd²⁺ > Zn²⁺. The adsorption material PVI/SiO₂ was especially good at adsorbing Cu(II) ion and the saturated adsorption capacity could reach up to 49.2 mg/g. The empirical Freundlich isotherm was found to describe well the equilibrium adsorption data. Higher temperatures facilitated the adsorption process and thus increased the adsorption capacity. The pH and grafting amount of PVI had great influence on the adsorption amount. In addition, PVI/SiO₂ particles had excellent eluting and regenerating property using diluted hydrochloric acid solution as eluent. The adsorption ability trended to steady during 10 cycles.

Poly(N-vinyl imidazole) (PVI) was grafted onto silica surfaces by the “grafting from” method resulting in a novel composite adsorption material PVI/SiO₂. PVI/SiO₂ has strong adsorption ability for metal ions, especially for Cu²⁺ ion, which could be applied in removal, enrichment, and separation of Cu²⁺ ion.

There are many problems for the reclaimed soil in opencast-mining areas of the Loess Plateau of China such as poor soil structure and extreme poverty in soil nutrients and so on. For the sake of finding a better way to improve soil quality, the current study was to apply the weathered coal for repairing soil media and investigate the physicochemical properties of the reclaimed soil and the changes in enzyme activities after planting Robinia pseucdoacacia. The results showed that the application of the weathered coal significantly improved the quality of soil aggregates, increased the content of water stable aggregates, and the organic matter, humus, and the cation exchange capacity of topsoil were significantly improved, but it did not have a significant effect on soil pH. Planting R. pseucdoacacia significantly enhanced the activities of soil catalase, urease, and invertase, but the application of the weathered coal inhibited the activity of catalase. Although the application of appropriate weathered coal was able to significantly increase urease activity, the activities of catalase, urease, or invertase had a close link with the soil profile levels and time. This study suggests that applying weathered coals could improve the physicochemical properties and soil enzyme activities of the reclaimed soil in opencast-mining areas of the Loess Plateau of China and the optimum applied amount of the weathered coal for reclaimed soil remediation is about 27 000 kg hm⁻².

This study revealed that application of weathered coal significantly improved the quality of soil aggregates, increased the content of water stable aggregates, and the organic matter, humus, and the cation exchange capacity of topsoil were significantly improved, but without a significant effect on soil pH.

Glycerol is a low-cost and renewable resource, and its utilization is of great interest for chemical industry and sustainable development. In this work, a series of Ru–Cu bimetallic catalysts were prepared using different supports in an attempt to develop highly efficient catalysts. Hydrogenolysis of aqueous solution of glycerol was performed with the supported Ru–Cu catalysts. The bimetallic catalysts were very efficient for catalyzing the hydrogenolysis of glycerol compared with the corresponding monometallic catalysts. One hundred percent of glycerol conversion and 78.5% of 1,2-propanediol yield could be achieved at 180°C and 8 MPa.

Hydrogenolysis of glycerol was performed with the supported Ru–Cu catalysts. The bimetallic catalysts were very efficient for catalyzing the reaction compared with the corresponding monometallic catalysts. One hundred percent of glycerol conversion and 78.5% of 1,2-propanediol yield could be achieved at 180°C and 8 MPa.

Nano-alumina modified by 9-aminoacridine was used as a sorbent for separation and determination of dichromate ions from water. Statistical method, based on surface response design, has been used for the optimization of dichromate ions elution from 9-aminoacridine nano-alumina. The adsorbed dichromate ions were found to be eluted quantitatively with 0.8 mol L⁻¹ KCl in 1.6 mol L⁻¹ NaOH which optimized by response surface design. Under optimum conditions, the accuracy, precision (relative standard deviation, RSD%) and R-square of the method were calculated as >98, <3, and >94%, respectively. Remarkable agreement between experimental and theoretical data was confirmed the predicted assumption. The method was applied to the simultaneous determination of dichromate in natural and industrial water samples. We also examined the retention of dichromate anions in the presence of Cl⁻, , and anions at pH 3.

The present methodology was applied for the analysis of dichromate on nano-alumina in environmental matrices. To investigate the accuracy and applicability of the method, natural and industrial water samples were analyzed. The results indicated that the dichromate recovery is almost quantitative.

This study evaluates the performance of two low cost and high performance adsorption materials, i.e., activated carbon produced from two natural waste products: Bamboo and coconut shell, in the removal of three pesticides from drinking water sources. Due to the fact that bamboo and coconut shell are abundant and inexpensive materials in many parts of the world, they respond to the “low-cost” aspect. The adsorption capacities of two local adsorbents have been compared with commercial activated carbon to explore their potential to respond to the “high quality” aspect. Two pesticides were selected, namely dieldrin and chlorpyrifos, because they are commonly used in agriculture activities, and may remain in high concentrations in surface water used as drinking water sources. The results indicate that the adsorption of pesticides on activated carbons is influenced by physico-chemical properties of the activated carbon and the pesticides such as the presence of an aromatic ring, and their molar mass. The activated carbon produced from bamboo can be employed as low-cost and high performance adsorbent, alternative to commercial activated carbon for the removal of pesticides during drinking water production. The performance of activated carbon from bamboo was better due to its relatively large macroporosity and planar surface. The effect of adsorbent and pesticide characteristics on the performance was derived from batch experiments in which the adsorption behavior was studied on the basis of Freundlich isotherms.

Activated carbons from waste materials were explored as alternative adsorbents for drinking water protection. The results indicated that the activated carbon made from waste bamboo could be used as low-cost high performance adsorbent alternative to commercial activated carbon in drinking water treatment for the removal of pesticides.

The dynamic changes in the sediment discharge over 90 years from 1919 to 2008 in the Yellow River in China were assessed on the basis of annual rainfall series and annual sediment series in Shan County hydrological station. The key factors affecting sediment discharge, such as rainfall, and human activities were studied. Anomaly accumulation method and double mass curve were employed to test the stage changes of sediment discharge, and to determine the main factors of sediment decline. Results showed that the annual average sediment discharge under natural conditions was about 16 × 10⁸ t, but the measured annual average sediment during 1919–2008 was 12.71 × 10⁸ t. The highest annual average during the study period was 39.10 × 10⁸ t in 1933 while the lowest was 1.77 × 10⁸ t in 2008. Sediment discharge in the Yellow River experienced two low sediment stages (1924–1931 and 1979–2008) and a high sediment stage (1932–1971), respectively. Since 1979, there was a significant decreasing trend in the sediment discharge, and the main influencing factor was fierce human activities. Annual average sediment discharge in the post-development period (1979–2008) was 69.7% lower than that in the pre-development period (1919–1978), with average reduction of 81 and 19% caused by human activities and rainfall, respectively. These results provide important evidence for making protecting policy for water resources quality and environmental safety of the Yellow River.

Key factors affecting sediment discharge were studied for the Yellow River and the results showed two low and a high sediment stage. Since 1979 a significant decrease in sediment discharge could be observed due to fierce human activities. These results provide important evidence for making protecting policy for water resources quality and environmental safety.

In this research, the bioremediation of dispersed crude oil, based on the amount of nitrogen and phosphorus supplementation in the closed system, was optimized by the application of response surface methodology and central composite design. Correlation analysis of the mathematical-regression model demonstrated that a quadratic polynomial model could be used to optimize the hydrocarbon bioremediation (R² = 0.9256). Statistical significance was checked by analysis of variance and residual analysis. Natural attenuation was removed by 22.1% of crude oil in 28 days. The highest removal on un-optimized condition of 68.1% were observed by using nitrogen of 20.00 mg/L and phosphorus of 2.00 mg/L in 28 days while optimization process exhibited a crude oil removal of 69.5% via nitrogen of 16.05 mg/L and phosphorus 1.34 mg/L in 27 days therefore optimization can improve biodegradation in shorter time with less nutrient consumption.

The effectiveness of nutrient supplementation in increasing the biodegradation rate of the dispersed crude oil was investigated using response surface methodology. A removal of 69.5% could be observed in reasonable agreement with the predicted value. It can be concluded that process variable optimization can improve the biodegradation rate.

The purpose of this work is the removal of basic dyes (Safranine T and Brilliant Green) from aqueous media by depolymerization products (DP) obtained from aminoglycolysis of waste poly(ethylene terephthalate) (PET). The surface morphology and physical properties of depolymerization product were also determined. Adsorption behaviors (adsorption capacities, adsorption kinetics and adsorption isotherms) of these samples were realized at room temperature. Then, the amounts of residual dye concentrations were measured using Visible Spectrophotometer at 530 and 618 nm for Safranine T (ST) and Brilliant Green (BG), respectively. All adsorption experiments were carried out for different depolymerization products (DP1, DP2, DP3, and DP4). Adsorption capacities of depolymerization products for both of dyes decrease with following order: DP2 > DP4 > DP1 > DP3. The maximum adsorption capacities for ST and BG onto DP2 sample were found to be 29 and 33 mg g⁻¹, respectively. In addition, the adsorption kinetic results show that the pseudo-second-order kinetic model is more suitable than pseudo-first-order model for the adsorption of basic dyes onto DP samples. Adsorption data were evaluated using Langmuir and Freundlich adsorption isotherm models. The results revealed that the adsorption of basic dyes onto DP sample fit very well Langmuir isotherm model. In conclusion, the depolymerization products of post-consumer PET bottles can be used as low cost adsorbent for the removal of basic dyes from wastewaters.

The results showed that the depolymerization products of waste PET are an alternative, low-cost, and easily available adsorbent. This adsorbent can be used effectively for dye removal process from aqueous media.

A method for the determination of nickel in water was developed. The procedure involves preconcentration of nickel by using dispersive liquid–liquid microextraction. The Ni(II) ions were extracted in chloroform in the form of complex with the reagent 2-(2′-benzothiazolylazo)-p-cresol. Ethanol was used as the disperser solvent. After injection of the extracting mixture in a solution of nickel, a cloudy mixture was observed. A quick centrifugation induces phase separation and thus the settling of rich phase. The nickel content in the rich phase is measured by flame atomic absorption spectrometry. Under optimal conditions, the limit of detection and quantification obtained were 1.4 and 4.7 µg L⁻¹, respectively. Some parameters used to characterize preconcentration systems, such as enrichment factor and consumption index were calculated and resulted in 29 and 0.34 mL, respectively. After optimization of variables and determination of analytical characteristics, the method was used for the analysis of certified reference materials (BCR-713: wastewater, effluent and BCR-414: plankton) and real water samples.

A newly developed method for nickel determination in water is presented here. BTAC is used as a complexing reagent in dispersive liquid–liquid microextraction. Simplicity, ease of handling and economy characterize the method and moreover, the procedure is fast and uses small quantities of reagents and samples.

A novel, simple, fast, and efficient ionic liquid-based dispersive liquid–liquid extraction (IL-DLLE) has been applied to extract and remove Congo Red (CR; a carcinogenic textile dye) from aqueous solutions. In this methodology a binary solution, containing the extraction solvent (1-hexyl-3-methylimmidazolium bis(trifluormethylsulfonyl) imid) and a suitable disperser solvent, was rapidly injected into the water sample containing CR dye. Therewith, a cloudy solution was formed, and most of the dye molecules were extracted into fine IL droplets and removed from aqueous phase. The effects of pH, type, and amount of IL, initial concentration of the dye, type and volume of the dispersant, and concentrations of salt on the extraction of the dye were studied. Experimental surveys were also accomplished for recovery of the IL by applying a reverse dispersive liquid–liquid extraction using acidic stripping solutions.

A dispersive liquid–liquid extraction method based on ionic liquid (IL-DLLE) was developed and adapted for the separation and removal of Congo Red. The simplicity in regeneration of the IL and the dye recovery may make this IL-DLLE suitable for practical application in the industry.

In order to improve the growing environment of root zone, and investigate the effects of different rhizosphere ventilation environments on soil enzyme activities, we supplied gas for potted tomato by air compressor, and set three irrigation levels (70–90% field capacity). Each irrigation level has different ventilation volume coefficient (0.4, 0.8, 1.2, and 1.6) with the reference standard as 50% soil porosity. The results showed that the changing trend of soil catalase, urease, and dehydrogenase activity showed the first increase and then the decrease in the tomato growth period, and activities of soil catalase, urease, and dehydrogenase under the ventilation treatment are higher than those of the non-ventilation. When the irrigation level was 80% the field capacity and the ventilation coefficient was 0.8, the activities of three soil enzyme reached the highest value. Their activities of soil catalase, urease, and dehydrogenase were particularly sensitive to rhizosphere ventilation in fruit expanding process. Tomato had more dry matter accumulation and output under the ventilation treatment than that of the non-ventilation. The results prove that rhizosphere ventilation can improve the potted tomato root zone environment, increase the soil enzyme activity, and promote the nutrients uptake, thus promoting plant growth and fruit output and improving soil quality.

The results indicated that a suitable amount of ventilation volume can improve the tomato rhizosphere soil environment, increase the soil enzyme activity, promote uptake of nutrients, improve plant growth, and increase fruit yield and soil quality.

Bezafibrate (BZF), a widely used lipid regulator, is a potential threat to ecosystems and human health in water, and the recent research showed that advanced oxidation processes (AOPs) are much more effective for BZF degradation. In this study, we investigated the photochemical decomposition of BZF in surface water and effluent from waste water treatment plants (WWTP) by UV/H₂O₂ process. The results showed that the UV/H₂O₂ process was a promising method to remove BZF at low concentration, generally at µg L⁻¹ level. When initial concentrations reach 100 µg L⁻¹ in the deionized water, >99.8% of BZF could be removed in 16 min under UV intensity of 61.4 µm cm⁻², at the H₂O₂ concentration of 0.1 mg L⁻¹, and neutral pH condition. Moreover, BZF degradation was inhibited in this process when humic acid (HA) and inorganic solution anions were added to the deionized water solutions, including chloride, nitrate, bicarbonate, and sulfate, significantly. In the surface water and effluent of WWTP, however, the removal efficiency of BZF was lower than that in the deionized water because of the interference of complex constituents in the surface water and effluent. Some main intermediates at the m/z range of 100–400 were observed by high performance LC-MS (HPLC/MS) and a simple pathway of BZF degradation by UV/H₂O₂ was proposed.

The UV/H₂O₂ process exhibited high removal efficiency of bezafibrate (BZF), similar to, e.g., UV-catalytic and photo-Fenton processes. In this process, H₂O₂ concentration, temperature, and initial pH showed significant influences on BZF degradation. Most intermediates of BZF were not completely removed within 120 min illumination.

Feasibility of effluent reclamation for the Futian municipal WWTP in Taichung Taiwan was evaluated using an “SF-UF-RO” pilot plant. The optimal parameters of each unit were obtained during the pilot plant test. The pilot plant started the operation in late October 2008 and operated until January 2011. The reverse osmosis (RO) system produces 75 m³ water daily, and the produced water quality was comparable to the city water in Taichung. Chlorine dosed in the sand filtration (SF) inlet and ultrafiltration (UF) backwash had the most significant effect on the stability of system performance. When the chlorine was underdosed, biofilm clogged the bag filter (prefilter of UF) and led to the flow rate decay of the UF. The prefilter needed replacement every 1 or 2 weeks resulting in increased process cost. On the other hand, when the chlorine dosage was increased to mitigate the biofilm growth, the residual chlorine not only reacted with TOC and derived trihalomethanes (THMs) in the RO product water (more than 20 µg/L), but it also damaged the RO membrane. After trial and error, the chlorine concentration was optimized as 0.7 mg/L in SF inlet to prevent growth of biofilm as well as to control the residual chlorine in the RO inlet and THMs in the RO product water. It is suggested that cautiously adjusting chlorine dosage is essential for stably operating such a hybrid membrane system to reclaim the municipal wastewater.

An effluent reclamation pilot plant was installed to evaluate water quality safety, performance assessment, and cost analysis. The results revealed that an overdose of chlorine not only increased the risk of damaging the reverse osmosis (RO), but also raised the total trihalomethanes in the RO effluent.

A novel method has been put forward to retrofit the wet ammonia desulfurization process to realize the combined removal of sulfur dioxide and nitric oxide by introducing soluble cobalt(II) salt into aqueous ammonia solution. The active constituent of scrubbing NO from the flue gases is the produced by ammonia coordinating with Co²⁺. The regeneration of can be realized under the catalysis of activated carbon so as to sustain a high NO removal efficiency for a long time. In this paper, the adsorption–reduction behavior of on activated carbon has been researched using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. A conclusion can be drawn from the results that cobalt ions in the aqueous solution are adsorbed by activated carbon and most of them are reduced to Co²⁺ ions, and some of the Co²⁺ ions are further reduced into metallic cobalt. The results also demonstrate that the functional groups on the surface of carbon take part in this redox reaction. The CH groups on the carbon surface are oxidized into COH, and then some of the hydroxyl groups are further oxidized into carbonyl or carboxyl groups.

The adsorption–reduction behavior of on activated carbon has been investigated to retrofit the wet ammonia desulfurization process to realize the combined sulfur dioxide and nitric oxide removal. In such catalytic reaction, activated carbon acts not only as a catalyst but also as a reactant.

Selected volatile organic compounds (VOCs) emitted from commercial activities and industrial processes have been classified as hazardous air pollutants, posing a potential health risk in the urban environment. In this respect, perchloroethylene (PCE), a suspected human carcinogen, is the most noticeable compound because it is widely used in laundries and hotels as a dry-cleaning solvent. The objective of this paper was to quantify the emissions of PCE and other petroleum-based solvents from dry cleaning business in illustration of the regulatory infrastructure of reducing PCE exposure in the environment of Taiwan. Based on the Emission Factors (AP-42) method, the emissions of the non-methane hydrocarbons (NMHCs) from dry cleaning business had decreased from 5100 metric tons in 1997 to 2800 metric tons in 2007. The success of significant reduction of NMHCs in Taiwan has been ascribed to the fact that Taiwan established the relevant regulations at the end of the 1990s. From the data on the industrial/commercial demand for PCE and the emission inventories of NMHCs from dry cleaning business, the reduction of PCE emissions will show a declining trend in the near future.

Here, the emissions of PCE and other petroleum-based solvents from dry cleaning business in Taiwan were quantified. Based on the Emission Factors (AP-42) method, the emissions of the non-methane hydrocarbons (NMHCs) from dry cleaning business had decreased from 5100 metric tons in 1997 to 2800 metric tons in 2007.

Due to serious degradation of typical Stipa bungeana steppe community on the Loess Plateau, a 26-year (1982–2007) experiment has been carried out by methods of forbidden grazing, cutting, and rotational grazing. Our results show that the process of succession of long-term enclosed S. bungeana community can be divided into two stages: 1980–1996, the forward succession stage, when the species diversity and biomass reach the peak (33.7 species/m² and 1349.41 g/m², respectively); 1997–2007, the slow succession stage, when the gradually thickening of litter layer (litter depth reaches 3–5 cm) directly causes the reduction of species diversity and biomass to 19.1 species/m² and 863.19 g/m², respectively. While under the cutting and rotational grazing methods, grassland succession can be divided into four stages: 1st–5th year, the continuing growth stage; 6th–9th year, the vigorous competing stage; 10th–15th year, the aggregation growth stage of constructive species with biomass reaching the peak (1444.19 g/m²); and 16th–23rd year, stable growth stage of constructive species, which form sub-climax and are eventually dominated by S. bungeana, with the species diversity and biomass of 25–27 species/m² and 956.76–1165.35 g/m², respectively. The constructive species suddenly change in the 24th year, and the population of S. grandis increases rapidly to 21 m⁻² accounting for 25% of the total plant population. Long-term enclosure leads to decreased species diversity and biomass and is not beneficial for grassland renewing. The species diversity and biomass of degraded grassland continuously decrease to 10 species/m² and 392.1 g/m² due to long-term artificial failure and transitionally grazing, leading to harden soil with slow rainfall infiltration, where plants can only sustain life under the drought condition. Therefore, reasonable cutting and rotational grazing are the methods of choice for the gradual increase of species diversity and promotion of the natural renewal and forward succession of the grassland on Loess Plateau. These results provide reliable information for the diversity dynamic change as better indictors of soil quality and sustainable utilization mode.

Reasonable cutting and rotational grazing are the methods of choice for the gradual increase of species diversity and thus, promotion of natural renewal and forward succession of grassland. The results described here, provide reliable information for the diversity dynamic change as better indictors of soil quality and sustainable utilization mode.

The objective of this work was to describe a method for isolating meaningful and measurable soil organic matter (SOM) pools that differ in the mechanisms by which they are protected from decomposition. The proposed method is appropriate for soil C stabilization and sequestration studies. Unlike previous fractionation schemes, this procedure allows free SOM located between aggregates (unprotected C pool) and SOM occluded within both macroaggregates and microaggregates (C weakly and strongly protected by physical mechanisms, respectively) to be recovered separately, freed from the soil mineral matrix and the mineral-associated SOM pool (C pool protected by chemical mechanisms) and thus well suited to advanced chemical characterization by ¹³C-NMR. Briefly, free SOM is isolated by an initial density separation. Stable macroaggregates are broken up into stable microaggregates and intra-macroaggregate SOM, which is then separated by density. Finally, intra-microaggregate SOM is isolated from mineral-associated SOM by a third density separation after ultrasonic disruption. The SOM dissolved during the fractionation procedure is also recovered. Results obtained on soil samples with contrasting textures suggested that clay content induces a decrease of the proportion of free organic C and an increase of mineral-associated organic C content. Free SOM is characterized by a marked presence of undecayed organic material and biologically labile substances, such as carbohydrates and proteins. In contrast, SOM occluded within aggregates, especially within microaggregates, represents a more decomposed fraction, relatively enriched in unsubstituted-aliphatic material, most probably lipid biopolymers.

The fractionation procedure described here will be a useful tool for soil organic matter research, especially for characterizing SOM structures and functions, as well as for developing a better understanding of the mechanisms of C stabilization and sequestration in soils under diverse management scenarios.

The paper presents a study by taking the soil seed banks and vegetation successions of the forests in Ziwuling Mountain as indicators to analyze the effects of the ages, and the litter layers and soil depths at growing locations in seven types of forest communities on their seed bank formations and soil quality. The results showed that the seed banks at different growing locations in the communities increased in the order of upper slope, middle slope, and lower slope; the seed storages of the seed banks in the different layers of the communities varied, much more higher in the litter layers than in 0–15 cm, and the seed storages of the seed banks in the seven types of forest communities ranked in the increasing order of Pinus tabulaeformis forest, Pinus shenkaneusis forest, Quercus liaotungensis forest, Populus davidiana forest, Betula platyphylla forest, scrub communities, and grassland communities; in the meantime, the seed storage of seed banks peaked in 30–50 years old P. shenkaneusis forest, 30–40 years old P. tabulaeformis forest, 15–30 years old Q. liaotungensis, and P. davidiana and B. platyphylla forests, and 10–15 years old scrub and grassland communities, and the ages of the communities varied with the seed storages of the seed banks in a significantly correlative manner following a fitted exponential equation. In addition, the soil seed banks of the seven types of communities consisted of rich and diverse species with the herbaceous and shrub species greatly outnumbering the arbor species; in general, the coniferous forests were composed of 31 kinds of plants, the deciduous and broadleaf forests consisted of 20–29 plant species, the shrubs contained 27 plant species, and the herbaceous plants numbered 20 plant species; The various species compositions contained only 4–6 arbor species with most being foreign species. In each of the compositions, Bothriochloa ischemum was the grassland plant with the highest occurrence frequency, Sophora viciifolia and Hippophae reamnoides were the shrub plants with the highest occurrence frequencies, and Q. liaotungensis was the arbor plant with the highest occurrence frequency, and they followed by P. shenkaneusis and P. tabulaeformis. These results showed that soil seed banks and forest successions are better indicators for soil quality from natural successions.

This study takes soil seed banks and vegetation successions of the forests in Ziwuling Mountain as indicators to analyze the effects of ages, and litter layers and soil depths at growing locations. The results showed that soil seed banks and vegetation succession status are good indicators for soil quality, which can provide important reference for ecological restoration globally.

In the semi-arid region of the Loess Plateau in China, a portable photosynthesis system (Li-6400) and a portable steady porometer (Li-1600) were used to study the quantitative relation between the soil water content (SWC) and trees' physiological parameters including net photosynthesis rate (P_n), carboxylation efficiency (CE), transpiration rate (T_r), water use efficiency of leaf (WUE_L), stomatic conductivity (G_s), stomatal resistance (R_s), intercellular CO₂ (C_i), and stomatal limitation (L_s). These are criteria for grading and evaluating soil water productivity and availability in forests of Black Locust (Robinia pseudoacacia) and Oriental Arborvitae (Platycladus orientalis). The results indicated: To the photosynthesis of Locust and Arborvitae, the SWC of less than 4.5 and 4.0% (relative water content (RWC) 21.5 and 19.0%) belong to “non-productivity and non-efficiency water”; the SWC of 4.5–10.0% (RWC 21.5–47.5%) and 4.0–8.5% (RWC 19.0–40.5%) belong to “low productivity and low efficiency water”; the SWC of 10.0–13.5% (RWC 47.5–64.0%) and 8.5–11.0% (RWC 40.5–52.0%) belong to “middle productivity and high efficiency water”; the SWC of 13.5–17.0% (RWC 64.0–81.0%) and 11.0–16.0% (RWC 52.0–76.0%) belong to “high productivity and middle efficiency water”; the SWC of 17.0–19.0% (RWC 81.0–90.5%) and 16.0–19.0% (RWC 76.0–90.5%) belong to “middle productivity and low efficiency water”; the SWC of more than 19.0% (RWC 90.5%) belongs to “low productivity and low efficiency water”. The SWC of about 13.5 and 11.0% (RWC 64.0 and 52.0%) are called “high productivity and high efficiency water”, which provides the further evidence for Locust and Arborvitae to get both higher productivity (P_n and CE) and the highest WUE_L and adaptation to the local environment, respectively.

The soil water content of about 13.5 and 11.0% (relative water content: 64.0 and 52.0%) are called “high productivity and high efficiency water”, which provides the further evidence for Locust and Arborvitae to get both higher productivity and the highest water use efficiency and the adaptation to the local environment.

Surface water quality can vary a lot with fluctuating discharge during a Rainfall – runoff event. This paper uses a set of hydrological and hydrochemical variables to explain concentration–discharge loops and hysteresis of , and total suspended solids in a brook dewatering a small upland agricultural catchment in the Czech Republic. Our study is based on data collected by a continuous monitoring approach provided by an automatic ISCO sampler both from snow thawing and rainfall – runoff events. Methods of correlation, regression and principal component analysis (PCA) were employed to reveal possible relationships among the variables. For and , we found several types of concentration–discharge loops due to the loop rotation direction and also the loop curvature shape, in mutual combinations, no matter which type of a hydrological event it was related to. PCA indicated that loops correlated mostly with the length of a rising hydrograph limb and with the slope of the initial phase of a falling hydrograph limb, 5-day amount of precipitation and runoff coefficient. In case of , the concentrations usually increased with elevated discharge, whereas PCA did not detect any closer linkages. For suspended solids, an unambiguous positive monotonic relationship was discovered. Although no definite pattern was found, this study showed the necessity of a continuous water quality monitoring system as an approach for capturing and understanding relationships between solute concentrations and runoff formation for tracing and modelling catchment pollution sources and describing transport processes.

This study showed the necessity of a continuous water quality monitoring system as an approach for capturing and understanding relationships between solute concentrations and runoff formation for tracing and modelling catchment pollution sources and describing transport processes – although no definite pattern was found.

If spread in excess of crop requirements, incidental phosphorus (P) losses from agriculture can lead to eutrophication of receiving waters. The use of amendments in targeted areas may help reduce the possibility of surface runoff of nutrients. The aim of this study was to identify amendments which may be effective in reducing incidental dissolved reactive phosphorus (DRP) losses in surface runoff from land applied pig slurry. For this purpose, the DRP losses under simulated conditions across the surface of intact grassland soil cores, loaded with unamended and amended slurry at a rate equivalent to 19 kg P ha⁻¹, were determined over a 30 h period. The effectiveness of the amendments at reducing DRP in overlying water were (in decreasing order): alum (86%), flue gas desulfurization by-product (FGD) (74%), poly-aluminum (Al) chloride (PAC) (73%), ferric chloride (71%), fly ash (58%), and lime (54%). FGD was the most costly of all the treatments (€7.64/m³ for 74% removal). Ranked in terms of feasibility, which takes into account effectiveness, cost, and other potential impediments to use, they were: alum, ferric chloride, PAC, fly ash, lime, and FGD.

The aim of this study was to identify amendments which may be effective in reducing incidental dissolved reactive phosphorus (DRP) losses in surface runoff from land applied pig slurry. The effectiveness of the amendments at reducing DRP in overlying water ranked in terms of feasibility, taking into account effectiveness, cost, and other potential impediments to use, is: alum, ferric chloride, PAC, fly ash, lime, and FGD.

The effluents of wastewater treatment plants in small sized communities of less than 2000 population equivalent (PE), which are discharged into sensitive receiving water environments, must receive “appropriate treatment” according to the EU Urban Wastewater Treatment Directive. Appropriate treatment depends on the quality objectives of the receiving waters as well as the relevant provisions of the member states. In this study, wastewater treatment options, such as vegetated land treatment (VLT), constructed wetlands (CW), and activated sludge treatment (AST), by which effluents are discharged to sensitive and less sensitive areas are evaluated by the life cycle assessment (LCA) approach. For this purpose, data related to energy usage, land requirement, raw material consumption, and released emissions from the life phases were collected with an inventory study and the environmental impacts were assessed by using SimaPro 7.1 LCA software. The results obtained from the assessments were compared with each other, which indicated that for small-scale communities VLT and CW are the most environmentally friendly wastewater treatment option.

Environmental impacts of collected data related to energy usage, land requirement, raw material consumption, and released emissions from the life phases were assessed by SimaPro 7.1 LCA. The results indicated that for small-scale communities vegetated land treatment and constructed wetlands are the most environmentally friendly wastewater treatment options.

The oxidation of organophosphorus pesticides (OPPs), such as malathion and parathion, in aqueous solution was studied using conventional ozonation (O₃), photolytic ozonation (O₃/UV, O₃/UV/H₂O₂), and heterogeneous catalytic ozonation (O₃/TiO₂/UV) processes. Experiments were performed in batch mode at laboratory scale and processes were compared in terms of disappearance kinetics. The best results of pesticide mineralization were obtained when TiO₂ particles in combination with ozone (O₃) and UV photolysis (λ = 254 nm) were applied. Decomposition of 99% of parent compounds were achieved in 10 min and oxon derivatives were completely removed in 30 min. The initial reaction rate increases linearly with increasing catalyst amount. Toxicity measurements of the treated solutions were carried out in order to evaluate the efficiency of the treatment methods. No detoxification was achieved for O₃ and O₃/UV applications. Heterogeneous photocatalytic ozonation was shown to be feasible for achieving complete decomposition of OPPs and their oxon intermediates.

It could be shown that heterogeneous catalytic ozonation processes (O₃/TiO₂/UV) is feasible for achieving complete decomposition of organophosphorus pesticides, such as malathion and parathion, and their toxic oxon intermediates.

This paper discusses about the adsorption of metal ions such as Cu(II), Cd(II), Zn(II), and Ni(II) from aqueous solution by sulfuric acid treated cashew nut shell (STCNS). The adsorption process depends on the solution pH, adsorbent dose, contact time, initial metal ions concentration, and temperature. The adsorption kinetics was relatively fast and equilibrium was reached at 30 min. The adsorption equilibrium follows Langmuir adsorption isotherm model. The maximum adsorption capacity values of the modified cashew nut shell (CNS) for metal ions were 406.6 mg/g for Cu(II), 436.7 mg/g for Cd(II), 455.7 mg/g for Zn(II), and 456.3 mg/g for Ni(II). The thermodynamic study shows the adsorption of metal ions onto the STCNS was spontaneous and exothermic in nature. The kinetics of metal ions adsorption onto the STCNS followed a pseudo-second-order kinetic model. The external mass transfer controlled metal ions removal at the earlier stages and intraparticle diffusion at the later stages of adsorption. A Boyd kinetic plot confirms that the external mass transfer was the slowest step involved in the adsorption of metal ions onto the STCNS. A single-stage batch adsorber was designed using the Langmuir adsorption isotherm equation.

A surface modified cashew nut shell adsorbent was studied for metal ions removal such as Cu(II), Cd(II), Zn(II), and Ni(II) from aqueous solution. The results show that the adsorption equilibrium follows the Langmuir adsorption isotherm model and the kinetics of metal ions adsorption onto the STCNS followed a pseudo-second-order kinetic model.

This study investigates structural and adsorption properties of the powdered waste shells of Rapana gastropod and their use as a new cheap adsorbent to remove reactive dye Brilliant Red HE-3B from aqueous solutions under batch conditions. For the powder shells characterization, solubility tests in acidic solutions and X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform IR spectroscopy (FT-IR) and thermogravimetric analyses were performed. The results revealed that the adsorbent surface is heterogeneous consisting mainly from calcium carbonate layers (either calcite or aragonite) and a small amount of organic macromolecules (proteins and polysaccharides). The dye adsorptive potential of gastropod shells powder was evaluated as function of initial solution pH (1–5), adsorbent dose (6–40 g L⁻¹), dye concentration (50–300 mg L⁻¹), temperature (5–60°C), and contact time (0–24 h). It was observed that the maximum values of dye percentage removal were obtained at the initial pH of solution 1.2, shells dose of 40 g L⁻¹, dye initial concentration of 50–50 mg L⁻¹ and higher temperatures; the equilibrium time decreases with increasing of dye concentration. It is proved that the waste seashell powder can be used as low cost bioinorganic adsorbent for dyes removal from textile wastewaters.

Here, the characterization of powdered waste shells of Rapana venosa gastropod and their use as adsorbent for removal of reactive dye Brilliant Red HE-3B from aqueous solutions is reported. The results showed that acid treatment of the seashell powder yields a rougher, more eroded, and richer in organic component, with a higher capacity to adsorb anionic reactive dye.

This paper presents a new environmental approach for reducing environmental impacts of two local Palestinian industries: It implements the principle of “treating waste by waste.” The technical feasibility of chromium removal from wastewater in leather making by its treatment with solid waste from stone cutting industry is demonstrated experimentally, and found to be an efficient approach. Nearly full removal of chromium is obtained at optimum operating conditions using sufficient mass of solid waste (limestone) and allowing enough contact time between the two wastes. This study investigated effects of various parameters on the percentage relative decrease in concentration by using ultra violet (UV)/Vis spectrophotometry. Kinetic curves showed that percentage relative decrease in concentration increased with time until approaching a plateau (adsorption capacity). The adsorption capacity increased with increasing limestone to liquid ratio (solid content), until nearly full removal of chromium was obtained when the solid content was 5 g/100 mL or higher. This was accomplished within few days when the particles were settled. The adsorption capacity was pH dependent; adsorption at pH < 5 was obtained, as a finding which was not reported by previous investigators for Cr(III) adsorption using other particles. The percentage removal was nearly doubled at higher pH values (>5). Further research work is proposed to distinguish between the contributions of the two removal mechanisms of precipitation and adsorption.

This paper demonstrates that limestone is very efficient in treating wastewater from tanneries. A >99% relative decrease in concentration was obtained when limestone solid content >5 g solid/100 mL, and when sufficient contact time was allowed (nearly 2 days).

A new separation and preconcentration technique based on coprecipitation of Cu(II) and Ni(II) ions by the aid of Mo(VI)/di-tert-butyl{methylenebis[5-(chlorobenzyl)-4H-1,2,4-triazol-3,4-diyl]}biscarbamate (BUMECTAC) precipitate has been established. The Mo(VI)/BUMECTAC precipitate was dissolved by concentrated HNO₃ and the solution was completed to 5.0 mL with distilled/deionized water. The levels of the analyte ions were determined by flame atomic absorption spectrometer. The effects of experimental conditions like HNO₃ concentration, amount of BUMECTAC and Mo(VI), sample volume, etc. and also the influences of some foreign ions were investigated in detail on the quantitative recoveries of analyte ions. The preconcentration factors were found to be 40 for Cu(II) and 100 for Ni(II) ions. The detection limits for Cu(II) and Ni(II) ions based on 3σ (N:10) were 0.43 and 0.70 µg L⁻¹, respectively. The relative standard deviations were found to be lower than 4.0% for both analyte ions. The accuracy of the method was checked by spiked/recovery tests and the analysis of two certified reference materials (Environment Canada TM-25.3 and CRM-SA-C Sandy Soil C). The procedure was successfully applied to sea water and stream water as liquid samples and baby food as solid sample in order to determine the levels of Cu(II) and Ni(II) ions.

The developed method, based on coprecipitation of Cu(II) and Ni(II) ions by the aid of Mo(VI)/BUMECTAC precipitate, offers a simple, rapid, and low cost separation and preconcentration technique for accurate and precise determination of Cu(II) and Ni(II) ions in environmental solid and liquid samples.