铁炭微电解+EF-Feox+混凝沉淀预处理增塑剂生产废水

Pretreatment of Plasticizer Production Wastewater by the Combined Process of Iron-carbon Micro-electrolysis,EF-Feox and Coagulation-Sedimentation

选用铁炭微电解+EF-Feox+混凝沉淀组合工艺,对增塑剂生产废水进行预处理。结果表明:微电解控制pH=3.0、HRT=120 min、m(Fe)/m(C)=3、气水比=8:1,EF-Feox控制pH=3.5、U=8 V、H2O2(3%)投加量20 m L/L、HRT=80 min,混凝沉淀控制p H=10、PAM(2‰)投加量1.5 m L/L、HRT=30 min,工艺稳定运行后COD从13 000mg/L左右降解到500 mg/L以下,去除率达到95%以上,出水BOD5、SS皆在200 mg/L以下,达到了污水综合排放标准(GB 8978-1996)的三级标准。同时,出水B/C提高到0.35左右,可生化性增强,有利于后续接生化反应器,以进一步降解有机物。微电解产生的Fe2+对EF-Feox反应能起到强化作用,在一定程度上可以加快EF-Feox反应。

The integrated process of iron-carbon micro-electrolysis, EF-Feox and coagulation-sedimentation was used for pretreating plasticizer production wastewater. Experimental results show that COD is degraded from about 13 000 mg/L to below 500 mg/L, COD removal efficiency is above95%, and BOD5 and SS are all removed to below 200 mg/L, which reach the third level of Sewage Discharge Standard（GB 8978-1996） when control conditions of iron-carbon micro-electrolysis are as follows： effluent p H is 3, HRT is 120 min, iron-carbon mass ratio is 3, gas-water ratio is 8,control conditions of EF-Feox are as follows： effluent p H is 3.5, voltage is 8 V, dosage of H_2O_2（3%） is 20 m L/L, HRT is 80 min, and control conditions of coagulation-sedimentation are as follows： effluent p H is 10, dosage of PAM（2‰） is 1.5 m L/L, HRT is 30 min and under the circumstance of stable operation of processes. At the same time, the effluent B/C is increased to about 0.35, which shows that the biodegradability of wastewater is improved.The result is conducive to add biological reactor subsequently to degrade further organic matter. Fe2＋produced by micro-electrolysis reaction can play a strengthening effect on EF-Feox and speed up the reaction rate of EF-Feox in a certain extent.