次氯酸钠废水结晶盐回用对盐水质量影响程度的探讨

Influence of sodium hypochlorite wastewater crystallization salt on the quality of brine

根据次氯酸钠废水结晶盐中硫酸根离子、微量金属元素和TOC的测定结果,分析了次氯酸钠废水结晶盐回用到化盐工序对盐水质量的影响程度。结果表明,结晶盐中的硫酸根离子和微量金属元素对盐水质量影响很小;结晶盐中的TOC含量相对较高,少量回收的结晶盐对盐水质量的影响有限。同时,对结晶磷酸盐进行了EDX能谱分析和pH分析,发现其主要成分为磷酸氢二钠;又通过其他定性和定量方法,测得了结晶磷酸盐还含有质量分数为5%~10%的亚磷酸钠或次磷酸钠和质量分数为1%的氯酸钠。最后,讨论了在粗盐水中加入结晶磷酸盐的除钙效果,结晶磷酸盐除钙效果不及碳酸钠,但可以混合使用。

Based on the determination results of sulfate ion,trace metal elements and TOC in the crystallization salt from sodium hypochlorite wastewater,the impact of sodium hypochlorite wastewater crystallization salt on the quality of brine was analyzed.The result showed that the sulfate ion and trace metal elements in crystalline salt had little impact on the quality of brine,the TOC content in the crystalline salt was relatively high,but the impact of a small amount of recovered crystalline salt on the quality of brine was limited.At the same time,EDX spectrum analysis and pH analysis were conducted on the crystalline phosphate,and it was found that its main component was disodium hydrogen phosphate.Through other qualitative and quantitative methods,it was determined that crystalline phosphate also contained sodium phosphite or sodium hypophosphate with a mass fraction of 5%to 10% and sodium chlorate with a mass fraction of 1%.Finally,the calcium removal effect of adding crystalline phosphate to crude brine was discussed.The calcium removal effect of crystalline phosphate was not as good as that of sodium carbonate,but the crystalline phosphate could be used in combination.