超声消化在连续流动分析法测定COD_(Mn)中的应用

Application of ultrasonic digestion in determination COD_(Mn) by continuous flow analysis

文中选定澄清样、混合沉淀30 min的水样、超声30 min、不超声等几种因素做连续流动分析法(CFA法)测定高锰酸盐指数的交叉实验,结果表明:超声波对含有多相液体的作用是多元复杂的,对澄清样上清液主要为絮凝作用,而对悬浮物较多的水样则主要是水氧化和机械剪切作用;同时也显示混合沉淀30 min+超声30 min的水样预处理方式,其结果与国家标准方法检测结果最为接近,且通过F检验和t检验,证明该方法误差可接受。

In this paper,several factors such as clarified sample,water sample with mixed precipitation for 30 min,ultrasonic for 30 min and no ultrasonic were selected to do the cross experiment of continuous flow analysis method(CFA)for the determination of permanganate index.The results show that the effects of ultrasonic on the liquid containing multiphase are multiple and complex.The effect on the supernatant of the clarified sample is mainly flocculation,while the effect on the water sample with more suspended solids is mainly water oxidation and mechanical shearing.At the same time,the pretreatment method of mixed precipitation for 30 min and ultrasonic for 30 min is also shown.The results are closest to those of the national standard method,and the error of this method is proved to be acceptable by F test and T test.