环氧丙烷废水COD测定方法研究

A study of determination method for epoxypropane wastewater COD

环氧丙烷废水COD质量浓度在100 mg/L以下时,采用HJ/T 70—2001《高氯废水化学需氧量的测定氯气校正法》测定会产生较大偏差。通过改进氯气校正法,采用0.025 mol/L重铬酸钾,并以相近Cl-浓度的空白盐水作为空白值进行扣除,来测定环氧丙烷废水COD浓度,相对偏差小于2%,COD平均回收率为96.9%~102.2%,测定结果准确可靠。

Using HJ/T 70—2001 Determination of Chemical Oxygen Demand in High Chlorine WastewaterChlorine Correction Method to determine epoxypropane wastewater with COD mass concentration below 100 mg/L may produce great deviation. The COD concentration of epoxypropane wastewater was determined by modifying chlorine correction method using 0.025 mol/L potassium dichromate, and using blank brine with similar Clconcentration as a blank value, the relative deviation was less than 2%. The average recovery rate of COD was96.9%-102.2%, the measurement result was accurate and reliable.