The biogas generated from anaerobic digestion (AD) also includes undesirable by-product such as hydrogen sulfide (H2S), which must be removed before the biogas can be used as a clean energy source. Therefore, it is necessary to find an appropriate strategy to simultaneously enhance the methane yield and reduce H2S production. An efficient strategy-pretreating sludge at pH 10 for 8d and adjusting the system at neutral pH to produce methane for 20d-is reported for the synchronous enhancement of methane production and reduction of H2S production during AD. The experimental results showed that the cumulative methane yield was 861.2±6.1mL/g volatile solids (VS) of sludge pretreated at pH 10 in semi-continuous stirred anaerobic reactors for 84d, an increase of 49.6% over the yield in the control. Meanwhile, the cumulative production of H2S was 144.1×10-4mL/g VS, 54.2% lower than that in the control.
Keywords: Hydrogen sulfide (H(2)S) production; Methane yield; Methane-producing archaea; Sulfate-reducing bacteria; Waste activated sludge (WAS).
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