改进膜法深度处理工艺对焦化废水的处理效果研究

针对焦化废水成分复杂、难降解等特点,对某化工厂焦化废水采用预处理并结合组合膜工艺进行深度处理,通过测定各工艺出水COD、总硬度、总碱度、电导率、浊度和pH值等指标,探究该改进膜法深度处理工艺对焦化废水的处理效果。结果表明,该膜法深度处理工艺对COD的去除率为99.8%,对总硬度的去除率约为99.5%,对总碱度的去除率达到99.1%~99.5%,对浊度的去除率达到100%,电导率下降99.7%。经改进膜法深度处理工艺处理后,出水COD、总硬度、总碱度、电导率和浊度等满足循环水水质标准和除盐水水质标准,pH值较标准偏低。超滤对浊度去除效果显著,对COD、总碱度、总硬度的去除和电导率降低效果不好,纳滤对COD、总碱度、总硬度的去除和电导率降低均有一定效果但均弱于反渗透。

Effect of an Advanced Treatment of Coking Wastewater by an Improved Membrane-Process

Aiming at the characteristics of complex components and difficult degradation of coking wastewater, an advanced treatment consisting of a pretreatment and a hybrid membrane process was adopted for the coking wastewater in a chemical plant. The processing effect by this method was explored based on the measurement of the COD, total hardness, total alkalinity, conductivity, turbidity and pH of the effluent from each process. Results show that this advanced processing technique can result in the removal rates of COD, total hardness, total alkalinity, turbidity and conductivity up to 99.8%, 99.5%, 99.1%~99.5%, 100% and 99.7% respectively. And the effluent after this advanced treatment has its COD, total hardness, total alkalinity, conductivity and turbidity all up to the standards for the quality of circulating water and desalted water, and the pH lower than the standard. It is also found that ultrafiltration can bring a significant effect to turbidity removal, but little effect to COD, total alkalinity, total hardness removal and conductivity reduction; nanofiltration can also bring a certain effect to COD, total alkalinity, total hardness removal and conductivity reduction, which, however, is weaker than the effect by reverse osmosis.