微波消解法测定工业废水中的化学需氧量

Determination of COD in Industrial Wastewater with Microwave Digestion

化学需氧量(COD)是工业废水和环境水质监测中重要的项目之一。文章采用微波消解—分光光度法测定工业废水中COD,并对此方法进行条件实验。确定最佳消解条件为:催化剂为0.05 mol/L硫酸镍-硫酸溶液,催化剂用量为3 m L,消解时间为4 min,于350nm波长处测定过量Cr(Ⅵ)的浓度。结果表明:吸光度与COD值在10~100 mg/L范围内呈良好的线性关系。实际水样测定结果相对偏差小于2%,平均加标回收率达到98.02%,该方法具有消解时间短、准确度高、操作简单等特点。

Chemical oxygen demand(COD) is one of the important indexes in the industrial wastewater and environmental water quality monitoring. In this paper, We choose microwave digestion-spectrophotometry to determine COD in industrial wastewater, and carry out this method in conditional experiment. Experiment shows that the optimal digestion conditions are below: As Nickel sulfate-Sulfuric acid solution cost 3m L which concentration is 0.05 mol/L; digestion time is 4 min; At 350 nm wavelength to determine excess Cr( Ⅵ) concentration; The results show that: The absorbancy has a linear relation with COD figure in the range of 10 ~100 mg/L; The relative deviation of real water samples determination results were less than2%; The average recovery rate reached 98.02%; the method has the features of short digestion time, high accuracy and simple operation.