Engineering in Life Sciences

Marine organisms metabolize inorganic toxic arsenic species to harmless organo-arsenicals such as arsenobetaine (AsB) via methylation. In the presence of natural zeolites, often used as feed additives, AsB is degraded to harmful arsenic species mediated by Thiobacillus bacteria. The degradation products could be detected and identified by using ion chromatography coupled in parallel with electrospray ionization mass spectrometry and inductively coupled plasma mass spectrometry.

A new analytical method was developed to separate and detect different hydrophobic organoarsenicals using hydrophilic interaction chromatography with a zwitterionic stationary phase (ZIC^®-HILIC) in parallel coupled with electro spray ionization mass spectrometry (ESI-MS) and inductively coupled plasma mass spectroscopy (ICP-MS).

A risk assessment for the bioavailability of redox sensitive arsenic is essential for arsenic contaminated floodplain soils which are used for agricultural applications. Here, a new experimental approach was conducted to study the influence of changing redox conditions on the solubility of arsenic in soil.

Wastewater from a crystal glass factory can contain arsenic as hexafluoroarsenate. On the basis of a case study, an optimized treatment procedure for a hexafluoroarsenate-containing surface water is presented using a strong basic anion exchanger. The ion exchange process has proven to be capable of cleaning waters contaminated with hexafluoroarsenate.

This study demonstrated the feasibility of applying horizontal subsurface-flow constructed wetlands, which seemed to be viable alternatives for an effective elimination of elevated arsenic concentration from secondary domestic wastewater effluents. Both systems (planted and unplanted) were suitable to treat wastewater containing As, particularly under sulfate reducing conditions.

To characterize the redox dynamics of As species and the transformation processes particularly in the root-near environment of the helophytes in treatment wetlands were the prime focus of this study. A specially designed macro-gradient-free rooted gravel bed reactor, planted with Juncus effusus, was used to treat an artificial wastewater containing As.

Understanding the fundamentals of processes yielding arsenic release into the environment is crucial for the optimization of remediation technologies. This article reports valuable information on the possible determinant but actually not fully understood impact of As-carbonate complexes on the arsenic transport in the environment.

At the ancient mining site of Ehrenfriedersdorf at the Erzgebirge mountains, an area of high geogenic and anthropogenic levels of arsenic and the sources of arsenic input into the mine waters were identified. It could be shown that the greater part of dissolved arsenic does not originate from flooded underground excavations, but from the infiltration of water into soil layers by ancient tailings.

Bog iron ores are wide-spread accumulations of mainly hydroxidic iron minerals which have a strong affinity towards arsenic. An occurrence of paleo bog iron ore, known to be responsible for elevated arsenic concentrations in the study area, is compared with recent deposits. Their mineralogical evolution and potential impact on arsenic dynamics is discussed.

In some biotechnological processes, e.g., wastewater treatment and biotransformation, substances are involved which are inhibitory or even toxic to microorganisms. A two-stage continuous-flow stirred tank reactor (CSTR) cascade was developed where the potentially toxic substance is supplied only to the second reactor. Identical growth conditions are created in both reactors by using a special set of process parameters.

The scientific basics of the coproduction of an intracellular biopolyester and a protector molecule using the strain Halomonas elongata are reported. It was found that bifactoral stress initiates the fast simultaneous synthesis of ectoine and poly-β-hydroxyalkanoates (PHA). Based on these results, the economic balance of both PHA and ectoine synthesis can be potentially improved.