高级氧化法中H_2O_2对COD的测定影响及消除

Interference of H_2O_2 on COD Test and Removal Method for Advanced Oxidation Process

通过测定含不同H2O2浓度的纯水体系及硝基苯类化合物水样体系的废水化学需氧量(COD),分析发现硝基苯类化合物水样中H2O2对COD的测量存在正干扰,且具有很好的线性关系。在不引入新的干扰前提下,探讨了相应的H2O2消除方法。结果表明,当水样中H2O2浓度475 mg·L-1,COD值为747.6 mg·L-1时,改变水样p H值为碱性有利于H2O2的去除;添加二氧化锰催化剂虽然能在较短时间内去除H2O2,但可能引入新的干扰物;添加过氧化氢酶在不引入新的干扰情况下可快速去除H2O2。当反应时间3 min,分别调节水样p H为12、添加二氧化锰、添加过氧化氢酶,水样中H2O2去除率为1.2%、45.6%、100%。在相同酶量下处理含不同浓度H2O2的水样,H2O2均可在短时间内被除净。分析表明,添加过氧化氢酶可为快速、高效消除废水中未知浓度H2O2对CODCr测定的影响提供一条新的途径。

The chemical oxygen demand（ COD）for pure water and nitrobenzene waste water sample containing different content of H2 O2 was measured and the linear interference of H2 O2 concentration on COD test was studied. It shows that with increase of the H2 O2 ,the COD increases. Without new interference,the ways to suppress interference of H2 O2 on COD test were discussed including pH value,manganese dioxide catalyst,and catalase. Results show that the catalase eliminates the influence of H2O2on COD determination effectively,and the alkaline environment is in favor of removing the H2O2 to some extent,and manganese di-oxide catalyst can remove H2 O2 in short time but it may introduce new interferences. When the reaction time is 3 min,by adjus-ing initial liquid pH value of 12,adding manganese dioxide catalyst and catalase,respectively,the H2O2 removal rate can reach 1.2%,45.6% and 100%,indicating that catalase can conveniently remove H2O2 with unknown concentration,and suppress the interference of H2 O2 on COD test.