CLEAN – Soil, Air, Water

Research Articles: Conventional methods for removing heavy metals from water have many disadvantages including incomplete metal removal, high energy requirements, or the generation of toxic sludges. The present study provides an electrochemical coagulation process for the removal of Cr from water. The effects of several parameters on Cr removal were investigated. The results showed that a removal efficiency of 98.6% could be achieved.

Research Articles: The concept of managing environmental problems by methods such as removing a waste by using another waste source is of economic interest and environmentally important. This study shows the ability of wastewater from a liming and unhairing unit in a leather factory to remove sulfur dioxide (SO₂), and consequently, demonstrates the ability to eliminate environmental problems using wastewater.

Research Articles: The successful application of the MBfR membrane biofilm reactor (MBfR) in the effective removal of nitrate from drinking water or nitrified water is demonstrated. The results indicate that the MBfR based on a H₂-gas permeable membrane is an attractive unit for reducing nitrate in many water-treatment sectors such as drinking water, groundwater, wastewater, and agricultural drainage.

Research Articles: Catalytic wet air oxidation is a potential method for treating waste streams containing high concentrations of phenol (over 70 mg/L). The reaction was conducted at low temperature (90°C) and atmospheric pressure, and at moderate operating conditions (T ⪇ 160°C and total pressure ⪇0.8 MPa). The effect of pH, catalyst concentration, pressure and temperature on phenol and COD reduction is reported.

Research Articles: Selected aquatic plants are cultivated in a constructed wetland, the Pingyin wetland on the East Route of the South-to-North Water Transfer Project in China, and their biomass, total nitrogen and total phosphorus contents and accumulation are studied to assess whether the selected plants are suitable for cultivation in reclaimed water environments and to determine their nutrient removal rates. The nutrient accumulation by the local species is compared to that of the introduced plants.

Research Articles: The use of adsorbents of biological origin has emerged in the last decade as one of the most promising alternatives to conventional heavy metal management strategies. The factors affecting the biosorption of Hg(II) from aqueous solutions using Bacillus subtilis biomass was investigated in this study and it was found that Bacillus subtilis biomass could serve as an effective low cost adsorbent to remove Hg(II).

Research Articles: Traditional methods for lead removal are too expensive to be economical for lower concentrations, so raw biological materials have been investigated as alternates. They can be chemically modified to increase metal uptake. A new material has been prepared from widely available wheat straw and urea, and its biosorptive behavior was studied. It appeared to be a cost effective material for Pb (II) sorption.

Research Articles: This new approach for the quantification of the sum of short chain polychlorinated alkanes in mixtures allows standardized analysis according to the European Water Framework Directive in unfiltered surface water, ground water, drinking water and waste water. The method was independent of chlorine content and robust against changes in C-number distribution.

Research Articles: Benzene, toluene, ethylbenzene and xylene isomers (BTEX) are hazardous because of their fast migration in soil and water bodies and their acute and chronic toxicity. In this study, a natural zeolite was modified by two cationic surfactants for use as an adsorbent. The prepared adsorbents were characterized, and their adsorptive capabilities for BTEX were examined using different experimental conditions.

Research Articles: The textile industry worldwide is well-known for its extensive water consumption and discharges. Cleaner Production (CP) implementation options are developed and compared for a wool and blends textile enterprise in an attempt to achieve optimum water management. The CP approach may constitute a sustainable solution for water stress concerns by means of conservation of valuable high quality water resources in the long term.

Research Articles: An enrichment method for trace amounts of Ni(II), as 8-hydroxyquinoline chelates, is established on a cellulose acetate membrane filter. Ni(II)-8-hydroxyquinoline chelates adsorbed on a membrane filter are eluted using HNO₃ and the eluent nickel concentration is determined by a flame atomic absorption spectrometer. This enrichment method has the following advantages: simple, accurate, and low analysis cost.

Research Articles: An artificial neural network (ANN) model was developed to predict the decolorization of MG solution by algae and it was found to provide good predictive performance (R ² = 0.98). The influence of each parameter on decolorization was assessed, and reaction time and initial pH were found to be the most significant factors. The reusability and efficiency of the algae were also examined.