Lead removal through biological sulfate reduction process

Heavy metals removal from acid mine drainage water using biogenic hydrogen sulphide and effluent from anaerobic treatment: Effect of pH

“…Specifically, the effluent from a UASB reactor containing sulphide in the range of 30-50 mg/L and a lead-containing solution of 45-50 mg/L were fed continuously into the precipitation chamber in which the optimum pH for lead sulphide precipitation of 7.5-8.5 was maintained. Lead removal of 85-95% was attained by these authors [16]. On the other hand, mid-acidic metal (Cu, Zn, Ni, Fe, Al and Mg), arsenic and sulphate contaminated waters were treated, over a 14-day period at 25 • C in a bench-scale up flow anaerobic packed bed reactor filled with silica sand and employing a mixed population of sulphate reducing bacteria (SRB) [8].…”

“…A sulphide-rich effluent from the biological process was used to remove lead as lead sulphide precipitate [16]. Specifically, the effluent from a UASB reactor containing sulphide in the range of 30-50 mg/L and a lead-containing solution of 45-50 mg/L were fed continuously into the precipitation chamber in which the optimum pH for lead sulphide precipitation of 7.5-8.5 was maintained.…”

“…The heavy metal removal by biological and chemical processes involves two stages: the production of H 2 S by SRB and the precipitation of heavy metals by the biologically produced H 2 S [1,8,10,[12][13][14][15][16][17][18][19][20][21][22][23]. The raw AMDW is fed into the chemical reactor where biogenic hydrogen sulphide is added to precipitate the heavy metals.…”

“…This deposit represents 3.2% of the total area and 15.5% of the hydraulic resources of the watershed. Several procedures for AMDW depuration at laboratory, pilot and full scales have been developed based on biological processes [1,[3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Anaerobic processes based on the use of sulphate reducing bacteria (SRB) are able to use sulphate as an electron acceptor and to form hydrogen sulphide which leads to an increase in the pH of the water and the precipitation of heavy metal sulphides.…”

Temperature Effects on Methanogenesis and Sulfidogenesis during Anaerobic Digestion of Sulfur-Rich Macroalgal Biomass in Sequencing Batch Reactors

“…Highly comparable electron flows to methanogenesis and sulfidogenesis were observed in a down-flow digester treating a synthetic mixture of acid mine drainage and vinasse at mesophilic temperature [13]. Mesophilic studies in up-flow anaerobic sludge blanket (UASB) reactors reported that methanogenesis was more competitive when treating a mixture of acetate and ethanol [4,14], while sulfidogenesis is predominant when treating methanol [15] or ethanol [16]. The observations on the competition between methanogenesis and sulfidogenesis at thermophilic temperature also varied.…”