硫酸锰催化法快速测定水中COD_(Cr)

Rapid Determination of COD_(Cr)in Water by Manganese Sulfate Catalysis

文章建立了一种以硫酸锰为催化剂的分光光度法,可快速测定水中化学需氧量(COD_(Cr))含量。选用售价仅为硫酸银1/5的硫酸锰作为催化剂,显著降低分析成本的同时,使催化反应效率得到了显著提升,仅需10 min即可完成消解。该方法采用高温密闭消解法,试剂用量小,单个样品危险废物产生量仅为7.5 mL,有助于环境保护。在此条件下,COD_(Cr)质量浓度为4~1000 mg/L时线性关系良好,相关系数不低于0.999,方法检出限为1.13 mg/L,不同浓度样品重复测定相对标准偏差(RSD)为1.03%~7.30%,加标回收率为86.0%~114.0%。试验结果表明,该方法测定范围广、分析成本低、分析时间短、危废产生量小,适用于大批量不同浓度的生活污水、地表水、地下水等样品COD_(Cr)的快速测定。

A spectrophotometric method using manganese sulfate as catalyst for the rapid determination of chemical oxygen demand(COD_(Cr))in water was developed.Manganese sulfate,whose price is only 1/5 of silver sulfate,was selected as the catalyst,which significantly reduced the analysis cost and significantly improved the catalytic reaction efficiency,and the digestion could be completed in only 10 minutes:The method adopted high temperature closed digestion method,the amount of reagent was small,and the amount of hazardous waste produced by a single sample was only 7.5 mL,which was conducive to environmental protection.Under these conditions,the linear relationship of chemical oxygen demand was good in the mass concentration of 4~1000 mg/L,and the correlation coefficient was no less than 0.999.The detection limit of the method was 1.13 mg/L,the relative standard deviation(RSD)of repeated determination of different concentrations was 1.03%~7.30%,and the recovery rate of standard addition was 86.0%~114.0%.The experimental results show that the method has wide determination range,low analysis cost,short analysis time and small hazardous waste generation,and is suitable for the rapid determination of chemical oxygen demand of large quantities of domestic sewage,surface water,groundwater and other samples with different concentrations.