pH6.0酸性条件下产甲烷EGSB反应器的运行研究

采用中性颗粒污泥接种,运行一个3.1L的EGSB反应器共345d,通过逐步降低pH值,获得了耐酸的产甲烷颗粒污泥并实现厌氧反应器在低pH、低碱度条件下的稳定运行.在pH 6.0,进水COD 3000mg/L,COD容积负荷5kg/(m³·d)时,反应器的COD平均去除率为95.0%,出水总碱度(以CaCO₃计)仅为328.5mg/L,每g去除COD的沼气产量为372.2mL,沼气中甲烷含量约为57.6%;在进水COD 4 000mg/L,COD容积负荷7.5kg/(m³·d)时,COD平均去除率为90.9%,出水总碱度仅为404.8mg/L,每g去除COD的沼气产量为446.3mL,甲烷含量约为55.9%.EGSB反应器在pH6.0～6.1的范围内共运行112d,表明在低pH、低碱度下实现稳定的产甲烷过程是可行的.

Study on the Operation of a Methanogenic EGSB Reactor under Acid Condition at pH 6.0

In this paper the methanogenic process under acid condition at pH 6.0 was studied. Inoculated with neutral granular sludge, a 3.1 L EGSB reactor was operated for 345 days, the pH value in the reactor was gradually lowered down, and the acid-tolerant methanogenic granular sludge was achieved, and the anaerobic EGSB reactor was operated stably under lower pH and lower alkalinity. At pH 6.0, influent COD 3000 mg/L, COD OLR 5 kg/(m3 x d), the average COD removal efficiency of the EGSB reactor was 95.0%, while the effluent alkalinity (CaCO3) was only 328.5 mg/L, the biogas production per gram removal COD was 372.2 mL with 57.6% methane content. At pH 6.0, influent COD 4000 mg/L, COD OLR 7.5 kg/(m3 x d), the average COD removal efficiency was 90.9%, and the effluent alkalinity (CaCO3) was 404.8 mg/L, the biogas production per gram removal COD was 446.3 mL with 55.9% methane content. The EGSB reactor was operated at pH 6.0-6.1 for 112 days, which showed the stable methanogenic process was feasible at low pH and low alkalinity.