分级氧化-絮凝耦合工艺同步降解焦化废水

Simultaneous Degradation of Coking Wastewater by Fractional Oxidation-Flocculation Coupling Process

针对湖北某焦化废水处理厂出水水质不稳定的现象,对该厂深度处理工艺进行改造。将原有混凝反应池改为氧化反应池,投加高铁酸盐-次氯酸钠-碳酸钠的复合氧化药剂,充分利用反应过程中的中间产物、最终产物以及药剂间的协同作用。通过对复合药剂配比、碳酸钠浓度和投加量的优化,以及不同阶段pH值的调试,在同一池体内实现分级氧化-絮凝耦合,从而同步去除COD、氨氮、氰化物、硫氰化物以及挥发酚等多重污染物质。结果表明,经改造后的处理系统具有较强的抗冲击负荷能力,出水COD、氨氮、氰化物、挥发酚稳定达到《炼焦化学工业污染物排放标准》(GB 16171—2012)表2中的直接排放限值。

Due to the unstable effluent quality of a coking wastewater treatment plant in Hubei Province,the original advanced treatment process was modified.The original coagulation tank was transformed into an oxidation tank,and the composite oxidant containing ferrate,NaClO and Na2 CO3 was added to make full use of the intermediate products,the final products and the synergistic effect between agents in the reaction process.By optimizing the ratio of compound agents,the concentration and dosage of Na2 CO3,and the adjustment of p H at different stages,the fractional oxidization-flocculation coupling was realized in the same tank,so as to remove multiple pollutants such as COD,NH3-N,cyanide,thiocyanide,and volatile phenol simultaneously.The operation result showed that the modified treatment process had a strong impact load resistance capability,and the effluent COD,NH3-N,cyanide,and volatile phenols reached the direct discharge limits in table 2 of the Emission Standard of Pollutants for Coking Chemical Industry(GB 16171-2012).