利用微波消解-无银催化法检测水中化学需氧量

Detection of chemical oxygen demand(CODCr) in water with silver-free catalyst by microwave digestion method

研究了采用微波消解-无银催化测定CODCr的新方法,并探讨了该方法测定CODCr时样品消解条件对检测结果的影响;实验还采用硫酸锰、硫酸镍、硫酸铜、硫酸镁、硫酸铁分别作催化剂,微波加热快速消解后测定CODCr,同时与国家标准方法测定结果进行比较,确定了最佳催化剂、最佳投加量和消解时间。对比结果表明:当试样体积为5 mL时,0.250 mol/L K2 Cr2 O7的用量为5 mL,硫酸锰催化剂用量为3 mg,微波消解时间仅为3 min,检测结果最佳。该方法具有快速准确、节约试剂、降低耗电成本等优点。

This paper studied a new method for determining CODCr with silver-free catalyst by microwave digestion method and discussed the influences of digestion conditions on the detection results.This experiment used manganese sulfate,nickel sulfate,cupric sulfate,magnesium sulfate and ferric sulfate as catalyst respectively,and determined CODCr after microwave fast digestion.By comparing the obtained CODCr value with that determined by the national standard method,the optimal catalyst,dosage and digestion time was determined.Comparative results showed that： when the volume of the sample was 5 mL,the volume of 0.250 mol/L K2Cr2O7 was 5 mL,the amount of manganese sulfate catalyst was 3 mg and the microwave digestion time was 3 min,the results were the best.The method was quick,accurate,low consumption of reagent and power.