铁炭耦合Fenton试剂-混凝沉淀法预处理DMAC废水

N，N-二甲基乙酰胺(DMAC)危害大，是化纤废水中的主要污染物之一. 采用铁炭微电解-Fenton试剂-混凝沉淀工艺预处理DMAC废水. 结果表明:在海绵铁投加量为30 g/L，铁炭体积比为1，pH为2，微电解反应1 h，H₂O₂投加量为5 mL/L，pH为3，Fenton试剂反应2.0 h，混凝沉淀pH为9.0，沉淀40 min的最佳工艺条件下，COD_Cr的去除率可稳定在70%以上；紫外可见分光光计测定证明，经微电解反应后DMAC的助色基团—CH₃和CO被破坏，经过Fenton 氧化后，—NH—基团才能被破坏，废水中的大分子物质被破坏，最终转变成小分子物质，为后续处理奠定了基础. 

Pretreatment of DMAC Wastewater by Iron-Carbon Micro-electrolysis Process Combined with Fenton Reagent and Coagulation-Sedimentation

Dimethylacetamide (DMAC) is a main pollutant of chemical fiber wastewater which has a great impact on the environment. A new process for DMAC wastewater pretreatment, iron-carbon micro-electrolysis combined with Fenton and coagulation-sedimentation, was developed. The results showed that at the optimum conditions of iron filings dosage of 30 g/L, ratio of iron filings to carbon of 1, pH of 2, hydraulic retention time of micro-electrolysis process of 1 h, H₂O₂ dosage of 5 mL/L, pH of 3, hydraulic retention time of Fenton process of 2.0 h, coagulation pH of 9.0, and hydraulic retention time of sedimentation of 40 min, the removal rate of COD_Cr was more than 70%. Through Vis-UV spectral analysis, it was shown that the chromophoric groups —CH₃ and CO were destroyed after the micro-electrolysis reaction, and after the Fenton oxidization, the amino group was destroyed. With this pretreatment process, the macromolecular substances in the wastewater were destroyed and transformed into small molecules, thus laying the foundation for further treatment.