微波消解光度法快速测定无挥发性废水的化学需氧量

Rapid photometric determination of COD in no-volatility in waste water with microwave heating sample digestion

介绍了一种微波消化制样、分光光度快速测定无挥发性废水化学需氧量的新方法,确定了微波功率250 W,硫酸-硫酸银溶液10 mL,消解时间为10 min为最佳消解条件,并于351 nm波长处分光光度测定过量Cr(Ⅵ)的浓度,结果表明,吸光度与COD值在0～400 mg/L范围内呈良好的线性关系,能有效排除Cl-的干扰,实际水样测定结果的准确度达到99%,精密度小于4%,加标回收率达到98.7%.并与经典重铬酸钾回流法进行了对比,证实了两种方法处于同一种水平.

This paper introduced a new spectrophotometric method for high-speed measurement of COD of no-volatility waste water by using microwave-heating. The optimal condition of digestion was obtained,which indicated that the power of microwave is 250 W, the volume of sulfuric acid and argentine sulfate is 10 mL and the time of digestion is 10 min. The surplus Cr（Ⅵ） was determined in 351 nm wavelength by spectrophotometric method and the results showed that values of absorbance and COD are in good linear relation when COD value is 0 -400 mg/L, the interference of Cl^- can be removed efficiently, the accuracy is 99% , the precision of the method is less than 4% , and the recovery is 98.7%. The comparison between this method and conventional refluxing method was carried out and testified that two methods are on the same level.