高氯低COD废水中COD的测定

以某污水厂的高氯低COD生化出水为研究对象,探讨了硫酸汞加入量、K2Cr2O7溶液浓度、反应酸度、取水样量等参数对COD测定的影响,探讨消除该厂Cl-干扰最简单有效方法,结果表明:控制硫酸汞与氯离子比为15∶1(质量比)、K2Cr2O7浓度为0.18 mol/L、水样稀释0.75倍、Ag2SO4-H2SO4加入量为28mL,皆可有效减少氯离子的干扰。该方法相对氯气校正法,操作简单、准确可靠。

The Determination of COD in High Chlorine and Low COD Waste Water

Studying the high chlorine and low COD biotreated effluent of certain sewage plant,this paper discusses the influence of mercury sulfate dosage,K2Cr2O7 concentration,reaction acidity and water sample volume on COD determination.Furthermore,the most simple and effective way for eliminating the Cl-interference is presented in this paper and the results show that: The ratio between mercury sulfate and chloride ion 15∶1(mass ratio),K2Cr2O7 concentration 0.18 mol/L,water sample dilution 0.75-fold and Ag2SO4-H2SO4 dosage 28 mL,chloride ion interference can be effectively reduced.Compared with chlorine correction approach,this method is simpler,more accurate and reliable as well as expands the serviceable range of potassium dichromate method.