焦化废水COD的无汞快速测定

Rapid Determination of Coking Wastewater with Non-mercury Salt

以硝酸银为Cl-掩蔽剂 ,以硫酸银为催化剂 ,在 11mol/L的硫酸及 0 .0 5mol/L(1/ 6K2 Cr2 O7)K2 Cr2 O7介质中 ,COD测定的回流时间可缩短至 10min ,样品的分析周期约为 30min。此方法避免了使用剧毒硫酸汞产生的二次污染 ,回收、再用了废液中的银 ,进一步降低了分析费用 ,用于焦化废水COD的测定 ,结果与标准方法基本吻合。

A new method for COD-determining has been developed using silver nitrate as shelter of Cl\+- and silver sulphate as catalyst in the medium of 11 mol/L H\-2 SO\-4 and 0.05 mol/L(1/6 mol/L K\-2Cr\-2O\-7)K\-2Cr\-2O\-7,with the result that the reflowing time has been decreased to 10 min. and analytical cycle of sample is reduced to 30 min.The secondary pollution from toxic mercury sulphate has been avoided and the remained silver in wastewater has also been recovered and reused,thus the analytical cost further reduced. The method has been used in determining COD in coking wastewater,the result of which virtually agrees with that of the standard method.