Comparative Kinetics of Bacterial Reduction of Chromium

The treatment of textile wastewater including chromium(VI) and reactive dye by sulfate-reducing bacterial enrichment

“…In these previous experiments, it was shown that the chromium(VI) reduction capacity of the microbial biomass varied with the pH values of the culture medium, where the optimum pH values were found to be 7 in bacterial cultures (Schmieman et al, 1998;Ram et al, 1999;Nepple et al, 2000;Zouboulis et al, 2004). In the experiments with SRB, chromium(VI) reduction was also investigated at pH 7 (Tebo and Obratzsova, 1998;Smith and Gadd, 2000;Lloyd et al, 2001;Battaglia-Brunet et al, 2002).…”

“…Hexavalent chromium is known to be toxic to many plants, animals and microorganisms inhabiting aquatic environments, but if reduced to chromium(III) it may be significantly less harmful. The studies performed with chromium(VI) bioaccumulating microorganisms (Schmieman et al, 1998;Ram et al, 1999;Do¨nmez and Aksu, 2002;Dursun et al, 2003;Baldrian, 2003;Zouboulis et al, 2004;Do¨nmez and Koc -berber, 2005) have shown that microbial chromium(VI) removal from solutions typically included the following stages: (1) the binding of chromium to cell surfaces, (2) translocation of chromium into the cell, and (3) reduction of chromium(VI) to chromium(III). Intracellular reduction of chromium(VI) to chromium(III) is known to be the main detoxification mechanism.…”

Performance evaluation of various bioreactors for the removal of Cr(VI) and organic matter from industrial effluent

“…The bio-reduction of Cr(VI) to Cr(III) was possible by pure and enriched mixed cultures of microorganisms under aerobic and anaerobic conditions [14][15][16]. Most of the biological systems for treatment of Cr(VI) containing wastewater are operated in batch mode [17][18][19], probably due to eventual loss of active biomass as a result of metal toxicity.…”

Modeling nonlinearly transient zero-order bioreduction and transport of Cr(VI) in groundwater

“…In equation (15) q is equal to wDx with w as the wave number, Cn is the mesh Courant number, and I is equal to ffiffiffiffiffiffi ffi À1 p . It can be shown that ª!…”