适于GB 21900-2008标准的废水处理后六价铬的判定方法

Method for determination of hexavalent chromium in treated wastewater complied with the GB 21900-2008 standard

介绍了一种用于简单判定废水中六价铬含量是否达到GB21900-2008《电镀污染物排放标准》限值(0.2mg/L)的方法。采用150°C干燥后的分析纯重铬酸钾制备不同六价铬质量浓度的标准溶液。以硫酸溶液酸化后加入二苯碳酰二肼指示剂,用目视比色法对经化学法处理的废水中六价铬的含量进行判定。该方法操作简单,适用于无仪器分析手段的电镀厂。

A method for easily determining whether the content of hexavalent chromium in wastewater meets the discharge limit（0.2 mg/L） stipulated by the GB 21900-2008 Emission Standard of Pollutants for Electroplating was introduced.Several standard solutions with different mass concentrations of hexavalent chromium are prepared with A.R.-grade potassium dichromate previously dried at 150 °C.The content of hexavalent chromium in chemically treated wastewater is determined by visual colorimetry with diphenylcarbazide as indicator after acidification with sulfuric acid solution.The method is easy to operate and suitable for use in the plating factories without related analysis instruments.