酸化吹气-重铬酸钾法测定高氯地表水中化学需氧量
达莉芳,范丽华,施玉格,段小燕,李刚,李媛,贺承启
新疆维吾尔自治区生态环境监测总站,乌鲁木齐 830011
Determination of chemical oxygen demand in high chlorine surface water by blow-acidizing-dichromate method
达莉芳,范丽华,施玉格,段小燕,李刚,李媛,贺承启
Xinjiang Uygur Autonomous Ecological Environmental Monitoring Station, Urumqi 830011, China
摘要:建立酸化吹气-重铬酸钾法测定高氯地表水化学需氧量(CODCr)的方法。通过在高氯水样中加入适宜浓度的硫酸,在加热及吹气条件下使干扰物氯离子以氯化氢的形式释放出,并用氢氧化钠溶液吸收,再采用重铬酸盐法对驱氯后的样品进行CODCr的测定。结果表明,在优化条件下,当取样体积为10.0 mL时,本方法的检出限为4 mg/L,测定结果的相对标准偏差为5.2%~13.5%(n=6),与理论值的相对误差为-2.0%~4.3%。该方法适用于氯离子质量浓度为1000~100000 mg/L的地表水中化学需氧量的测定。
Abstract:A method was developed for determination of the chemical oxygen demand(CODCr) in high chlorine surface water by blow-acidizing-dichromate method. By adding sulfuric acid of specific concentration to the water sample with high concentration of chloride ion, the interfering chloride ion was released in the form of hydrogen chloride under heating and air blow conditions, and absorbed by sodium hydroxide solution. CODCr of the sample was determined by dichromate method after chloride removal. The results show that the detection limit of this method was 4 mg/L, the relative standard deviation of determination results was 5.2%-13.5%(n=6) and the relative error with the theoretical value was from -2.0% to 4.3% when the sample volume was 10.0 mL under optimized conditions. The method is suitable for the determination of CODCr in surface water with the mass concentration of chloride ion between 1000 mg/L and 100000 mg/L.
关键词:氯;地表水;化学需氧量;酸化吹气-重铬酸钾法
Keywords:chlorine; surface water; chemical oxygen demand; blow-acidizing-dichromate method
本文引用格式:
达莉芳,范丽华,施玉格,等.酸化吹气-重铬酸钾法测定高氯地表水中化学需氧量[J].化学分析计量,2021,30(6):62.
Da Lifang,Fan Lihua,Shi Yuge,et al. Determination of chemical oxygen demand in high chlorine surface water by blow-acidizing-dichromate method[J]. Chemical Analysis and Meterage,2021,30(6):62.
相似文章: