混凝沉淀-微电解预处理再生造纸废水实验研究

STUDY ON PRETREATMENT OF REGENERATED PAPERMAKING WASTEWATER WITH COAGULATION- MICRO-ELECTROLYSIS PROCESS

采用混凝沉淀-微电解组合工艺预处理再生造纸废水。通过实验,考察了混凝单元药剂选择、药剂投量以及沉淀时间、微电解单元的初始pH、铁炭用量、铁炭比、反应时间以及出水pH对预处理效果的影响,确定了该工艺的最佳条件。结果表明,选择氢氧化钙为混凝剂,用量为4 g/L,沉淀时间为40 min,微电解的初始pH为3.0,铁炭总量为20g/L,铁炭比为3:1,反应时间为40 min,出水pH为8.0时再生造纸废水的COD、氨氮、总磷、SS和BOD5的去除率分别达到52.88%、43.08%、93.61%、91.64%和33.19%。同时可生化性由0.32提高到0.46,减小了后续生化处理工艺负荷。

In this paper, iron-carbon micro-electrolysis process combined with coagulation was used to pretreat wastewater of regenerate paper. The types of coagulants,pharmaceutical dosage, coagulation time in coagulation unit and the effect of initial pH of raw water, total iron and carbon, proportion of iron and carbon, hydraulic retention time as well as after the reaction of the pH in micro-electrolysis unit were investigated. The optimal condition of the process was determined. The results show that the best coagulant was Ca（OH）2, the pharmaceutical dosage was 4 g/L, the coagulation time was 40 min, the dosage of iron and carbon was 20 g/L, the proportion of iron and carbon was 3：1, the initial pH was 3.0, the effluent pH was 8.0 and the reaction time was 40 rain. Under these conditions, the removal rates of COD, ammonia nitrogen, total phosphorus, SS and BOD5 were reached to 52.88%, 43.08%, 93.61%, 91.64% and 33.19%. Biodegradability increased from 0.32 to 0.46 at the same time, the pollution load of subsequent biochemical treatment process was reduced.