Heavy metal removal from synthetic wastewaters in an anaerobic bioreactor using stillage from ethanol distilleries as a carbon source

Evaluating the microbial community and gene regulation involved in crystallization kinetics of ZnS formation in reduced environments

“…Eh measurements were in the range of -150 mV to -330 mV and coincide with peak hydrogen sulfide generation just prior to the formation of the ZnS aggregates across treatments. This observation supports other research with similar redox conditions noted in biogenic ZnS investigations (Castillo et al, 2012, Gonçalves et al, 2007. As stated previously, no ZnS phases were observed in the Abiotic Control that was amended with Zn but with no addition of cells, thus it is unlikely that any metal-sulfide generation can be attributed to abiotic factors.…”

“…This was proposed in this experiment, where mass balance calculations showed an overwhelming large sulfate removal compared to measured hydrogen sulfide production. Sulfur transformation from sulfate to sulfide is considered a 1:1 stoichiometric conversion, thus in control treatments where no metals are present to react with sulfide species, the moles of sulfate reacted is expected to equal the moles of sulfide produced (Edwards et al, 1992 (Gonçalves et al, 2007;Jong et al, 2003;Nagpal et al, 2000).…”

Assessment of solid reactive mixtures for the development of biological permeable reactive barriers

“…This procedure was repeated 5 times for each sample. H 2 S production, pH, E h , SO 4 2− and Cd concentrations were determined on collected samples. Each test was performed twice and average values were reported.…”

“…Biological remediation using sulphate reducing bacteria (SRB) can be performed in active systems such as off-line sulphidogenic bioreactors [4] or passive systems such as biological permeable reactive barriers (PRB) [2]. PRB has been successfully used for the treatment of a variety of contaminants, including the treatment of AMD and the remediation of streams polluted by heavy metals.…”

Anaerobes in Industrial- and Environmental Biotechnology

“…Continuous reactor systems for heavy metal removal with freely suspended cells require high residence time to prevent washout of the cells, although the use of immobilized cells on carrier matrix with high surface area allows short residence times and maintains high biomass retention and reaction rates [102]. Various types of bioreactors have been used for studying the process including (semi-)continuous stirred tank reactors (CSTR) [100,103], upflow anaerobic sludge blanket reactors (UASB) [104][105][106], fluidized bed reactors (FBR) [107], permeable reactive barriers (PRB) [108], etc.…”