改进快速消解分光光度法测定高盐垃圾渗滤液中COD

Detection of COD content in high-salt landfill leachate based on rapid digestion spectrophotometry

为消除高含盐垃圾渗滤液中Cl-对COD测定的干扰,改进了快速消解分光光度法,降低K2Cr2O7浓度并讨论了HgSO4与Cl-质量比对测定结果的影响。研究结果显示,改进后方法的标准曲线为y=0.0033x+0.0416,R2=0.9912,检出限8.54mg·L^(-1),精密度0.512%;加标回收率96.83%~116.93%,且在Cl-含量低浓度(500mg·L^(-1))条件下,掩蔽剂与Cl-质量比为40∶1时,在高浓度Cl-含量(2000mg·L^(-1))条件下,掩蔽剂与Cl-质量比为50∶1时,掩蔽剂的效果都较好,检测结果与现行国家标准COD测定方法结果接近。该方法标准曲线线性度较好,方法可以有效掩蔽Cl-影响,具有推广应用价值。

The interference of determination of COD in landfill leachate by potassium dichromate digestion method was eliminated.The results showed that the standard curve of the improved method was y=0.0033x+0.0416,R2=0.9912,and the detection limit was 8.54 Under the condition of low concentration of chlorine(500mg·L^(-1)),the mass ratio of masking agent to chloride ion is 40∶1,and under the condition of high concentration of chlorine(2000mg·L^(-1)),the mass ratio of masking agent to chloride ion is 50∶1,the effect of masking agent is better,and the detection results are close to the results of the current national standard COD determination method.The linearity of the standard curve of the method is good,and the method can effectively mask the influence of chloride ion,which has the value of popularization and application.