木薯酒精废水厌氧消化液的后续处理试验研究

Experimental study on follow-up treatment of anaerobically digested effluent of cassava alcohol wastewater

木薯酒精废水经两级厌氧发酵处理后排出的消化液CODCr的质量浓度为1300～1500mg／L，NH3-N的质量浓度为400～500mg／L，m（BOD5）／m（CODCr）值较低，采用铁炭微电解-固定化微生物技术-混凝沉淀-Fenton试剂组合工艺对该废水进行处理。结果表明：在铁炭质量比为2，pH值为2．0．微电解反应时间为9h。好氧生化反应时间为24h，混凝沉淀单元pH值为9．0，反应时间为0.5h，Fenton试剂反应时间为1．0h，pH值为3．0，H2O2（30％）的投加量为1.8mL/LL，FeSO4·7H2O的投加量为0．91g/L的最佳工艺条件下，CODCr的去除率可达98．8％，NH3-N的去除率也高达98．1％，出水CODCr的质量浓度为20mg／L左右，NH3-N的质量浓度在10mg／L以下，符合GB8978—1996《污水综合排放标准》中酒精废水一级排放标准的要求。

The mass concentration of CODCr and NH3-N in the effluent of cassava alcohol wastewater after two-stage anaerobic fermentation were 1 300 - 1 500 and 400 - 500 mg/L respectively, the value of m（BOD5）/ m（CODCr） was relatively low. A combined process of iron-carbon microelectrolysis-immobilized microorganism technology-coagulation sedimentation-Fenton reagent was used to treat the said effluent. The results of the test showed that, under the optimal condition： the mass ratio of iron to carbon was 2, the pH value was 2.0, the reac- tion time of microelectrolysis was 9 h, the time of aerobic biochemical reaction was 24 h, the pH value and reaction time of coagulation sedimentation unit was 9.0 and 0.5 h respectively, the time and pH value of Fenton reaction were 1.0 h and 3.0 respectively, the dosage of H2O2（30%） and FeSO4·7H2O were 1.8 mL/L and 0.91 g/L respectively, the removal rates of CODCr and NH3-N by the said combined process reached 98.8% and 98.1% respectively, the mass concentration of CODa in the effluent water was about 20 mg/L, and the mass concentration of NH3-N was lower than 10 mg/L, which indicated that, through the treatment, the effluent water quality could meet the specification for grade 1 in GB 8978--1996 Integrated wastewater discharge standard.