组合纳滤在煤化工废水分盐改造中的工程应用研究

Research on engineering application of combined nanofiltration in salt separation transformation of coal chemical wastewater

为实现结晶盐资源化,对某煤化工零排放项目采用组合纳滤技术+重结晶工艺进行改造。结果表明,组合纳滤可有效实现分盐及浓缩功能,当进水中Cl-/SO_(4)^(2-)=0.37~0.98时,组合纳滤产水Cl-/SO_(4)^(2-)=30.7~298.5(均值117.9),浓水中Cl-/SO_(4)^(2-)=0.09~0.28(均值0.15),浓水中SO_(4)^(2-)浓度可达80 000 mg/L以上,截留率>99%,Cl-平均截留率为-18.9%;产出合格NaCl及Na2SO4结晶盐,纯度均在98.5%以上,有效地实现了混盐资源化。

In response to the current situation of mixed salt production in a zero emission coal chemical project,in order to achieve the re-utilization of crystalline salt,a combined nanofiltration technology and recrystallization process is employed to renovate the original project.The results show that the combined nanofiltration process can effectively achieve salt separation and concentration functions.When Cl-/SO_(4)^(2-)=0.37-0.98 in the inlet water,the combined nanofiltration process generates water with a Cl-/SO_(4)^(2-) ratio of 30.7-298.5(mean value 117.9),and a concentrated water with a Cl-/SO_(4)^(2-) ratio of 0.09-0.28(mean value 0.15)and a SO_(4)^(2-) concentration of 80000 mg·L^(-1).The retention exceeds 99%,and the average retention rate of Cl-is-18.9%.The qualified NaCl and Na2SO4 crystalline salts with a purity over 98.5%are generated,effectively achieving the re-utilization of mixed salt.