COD快速测定新法的研究

该方法以测定COD值的重铬酸钾标准法为基础,在复合催化剂存在的条件下,对具有确定COD理论值的系列邻苯二钾酸氢钾标准溶液,进行恒温密封消解--分光光度法比色定量溶液的COD值,以最小二乘法拟合得到不同适用范围的标准曲线.以此标准曲线法测定实际水样的COD值,与重铬酸钾标准法测定得到的水样COD值相比较,相对误差≤±5%,且消解时间仅为10 min,从而形成具有快捷、简便而高效的测定水样COD值的新方法.

Study on a new quick method for determination of chemical oxygen demand

On the basis of the standard determination of chemical oxygen demand(COD) using potassium dichromate as oxidant, the seal temperature-visible light spectrophotometry in the existence of recombination catalyst has been applied to determination of COD in the serial standard liquor of potassium acid phthalate which has accurate academic COD.The serial standard curves which has different suitable range have obtained by least square method.The COD of actual waters has been determined by standard curve method and potassium dichromate method,their relative error less than or amount to 5%,and the digestion time of the standard curve method only needs 10 minutes. So the new determination of COD is quick,simple and efficient.