Fenton氧化与树脂吸附组合工艺对化工废水的深度处理研究

Advanced treatment of chemical industrial wastewater by combination of Fenton oxidation and resin adsorption

化工废水经过生化处理后,仍含有成分复杂的有机污染物,其毒性一般较大,需要进行深度处理.目前单一的处理方法效果欠佳,本文在优化Fenton氧化处理条件的基础上,考察了系列磁性超高交联树脂对Fenton氧化出水的处理效果.结果表明,对于化学需氧量(COD)为145.5mg·L-1的化工废水生化出水,在Fenton氧化优选条件(4mmol·L-1 FeSO4、8mmol·L-1 H2O2、pH为5、反应时间为90min)处理后,其出水COD去除率达62%,但处理后的出水中仍然含有较多的溶解性有机物质.具有一定含量阴离子交换基团的超高交联树脂对Fenton氧化出水具有较好的处理效果,这是由于Fenton氧化过程所产生小分子有机酸,易于与树脂发生静电作用引起的.优选出的GMA-5树脂(强碱交换量0.89mmol·g-1,比表面积668m2·g-1),对UV254去除率达53%,COD去除率达59%;树脂再生后可重复使用,稳定性较好.组合工艺研究表明Fenton氧化与磁性树脂吸附组合方法能够有效对化工废水进行深度处理,其组合工艺对UV254和COD去除率均达75%以上,处理后的出水COD低于40mg·L-1.

Chemical industrial wastewater treated by biochemical treatment is difficult to meet discharge standards due to its complex and refractory components.Thus advanced treatment of chemical industrial wastewater is important.Nonetheless,single treatment method after biochemical treatment is not sufficient.This work investigated the combination of optimized Fenton oxidation and magnetic hyper-crosslinked resin adsorption for the advanced treatment of the biochemical effluent of chemical industrial wastewater.Results showed that 62% of chemical oxygen demand（COD）was removed after Fenton treatment under the optimized conditions（4mmol·L^-1 FeSO4,8mmol·L^-1 H2O2 at pH 5with the contact time of 90min）for a biochemical effluent with the COD value of 145.5mg·L^-1.However,the dissolved or-ganic matter in Fenton effluent was still at a high concentration.This Fenton effluent was better treated by hypercrosslinked resin modified with anion exchange functional groups,which can be explained by the electrostatic interaction between resin and small molecular organic acid generated during Fenton oxidation.The removal rate of UV254 and COD were 53%and 59%,respectively,by the optimized resin（GMA-5）with a strong base exchange capacity of 0.89mmol·g^-1 and a specific surface area of 668m^2·g^-1.GMA-5could be reused with high adsorption capacity after regeneration.The combination of Fenton oxidation and magnetic resin adsorption was proved to be a feasible method for the advanced treatment of chemical industrial wastewater with removal rates of both UV254 and COD higher than 75%.The COD values after this combination method were lower than 40mg·L^-1.