二氧化锰催化二氧化氯氧化酸性铬蓝K模拟废水

Manganese dioxide catalytic oxidation with chlorine dioxide as an oxidant of simulated wastewater containing acid chrome blue K

以活性炭为载体,采用浸渍法制备了活性炭-MnO2催化剂,并将其应用于催化氧化降解酸性铬蓝K模拟废水。对于COD为2418mg/L的原废水,在最佳pH值为1.2,经1200mg/L二氧化氯和4g活性炭-MnO2催化剂催化氧化50min后,COD去除率和脱色率分别为72.0%和87.8%。并且对水样COD去除率,催化氧化法比化学氧化法提高了42.6%,所制备的催化剂循环使用8次后,以COD去除率权衡催化剂的活性,催化剂活性仅降低10.5%。经红外光谱分析,催化剂有效成份二氧化锰与活性炭载体之间是以化学键相连,不是简单的机械混合。在线红外光谱机理分析表明酸性铬蓝K经化学氧化或催化氧化后,分子中苯环和萘环被氧化降解为醌和羧酸,并进一步降解为二氧化碳和水。

The activated carbon-MnO2 catalyst was prepared by the dipping method with activated carbon as the carrier.The catalyst was used for catalyzing/degrading simulated acid chrome blue K wastewater with chlorine dioxide as the oxidant.The COD removal efficiency and decolor efficiency by catalytic oxidation were 72.0% and 87.8%,respectively,when the condition of wastewater＇s COD was 2 418 mg/L,the optimum pH value was 1.2,and the dosage of chlorine dioxide was 1 200 mg/L,and the dosage of activated carbon-MnO2 catalyst was 4 g after reacting 50 min.The COD removal efficiency by catalytic oxidation was increased by 42.6% compared with that of the chemical oxidation.The COD removal efficiency decreased only 10.5% after the catalyst was used 8 times.The IR spectra indicated that the active ingredient of manganese dioxide was linked with activated carbon by a chemical bond,not merely by mechanical blending.The benzene ring and naphthalin ring in the acid chrome blue K were degraded into quinone and carboxylic acid,and finally changed into carbon dioxide and water during chemical oxidation or catalytic oxidation as shown by on-line infrared spectrum mechanism analysis.