重铬酸盐法中回流时间对COD测定值影响的探讨

Effect of reflux time on COD measurement value by dichromate method

为便于批量工业废水的快速测定,探讨了不同回流时间对COD测定值的影响,得出结论如下:当水样的COD值在500～800mg/L时,回流时间需要大于90min;当COD值在300～500mg/L时,回流时间需大于60min;当COD值小于300mg/L时,回流时间仅需大于30min。

In order to analyse quickly the Chemical Oxygen Demand(COD) of lar ge amount of industrial wastewater samples,the effect of reflux time on COD meas urement value was studied.The results show that the reflux time must be more tha n 90min and 60min when COD is in the range of 500-800mg/L and 300-500mg/L re spectively. When COD is lower than 300mg/L, the reflux time needed only more tha n 30min.