低温下Ni^+和EDTA对厌氧产甲烷的影响

Effects of Ni^+ and EDTA on the Anaerobic Methane Production at Low Temperature

采用上流式厌氧污泥床(UASB)反应器,研究了低温条件下Ni^+、EDTA对厌氧产甲烷反应效能及活性的影响。结果表明,低温下Ni^+和EDTA生成的螯合化合物对厌氧产甲烷反应效能及活性具有强化作用。通过投加外源促进剂(0.2 mmol/L的Ni^+和8μmol/L的EDTA),COD去除率由67%提高到82%,平均COD去除负荷由1.44 kg/(m^3·d)增加到1.65 kg/(m^3·d);产气量由0.55 L/d增加到1.2 L/d;pH和VFA的质量浓度维持在7.3～7.4和54～65 mg/L,没有出现的酸化现象;MLVSS含量和ρ(VSS)/ρ(SS)比较稳定,污泥沉降性能较好,颗粒粒径逐渐变小并趋于稳定。

The effects of Ni^+ and EDTA on the reaction efficiency and the activity of anaerobic methane production were studied through the UASB reactor at low temperatures. The results showed that the chelated compounds produced by Ni^+ and EDTA at low temperature had an enhanced effect on the reaction efficiency and activity of anaerobic methane production. By adding exogenous accelerant(0.2 mmol/L of Ni^+ and 8 μmol/L of EDTA), the removal rate of COD was increased from 67% to 82%. And the average removal load of COD increased from 1.44 kg/(m^3·d) to 1.65 kg/(m^3·d), and the daily gas production increased from 0.55 L/d to 1.2 L/d. The PH and VFA were maintained at 7.3~7.4 and 54~65 mg/L respectively, and there was no phenomenon of acidification. The values of MLVSS content and ρ(VSS)/ρ(SS) were stable, the sludge sedimentation performance was better, and particle size became smaller and tends to be stable.