铜均相和非均相催化氯化消毒反应研究

在不同的入水pH值条件下,考察了铜离子存在时的均相情况和铜氧化物存在时的非均相情况下,水中余氯的分解和消毒副产物的生成规律.结果表明,与不含铜的情况相比,铜的存在,无论是均相还是非均相,对余氯的分解均有促进作用.不同的pH值条件下,铜均相和非均相对挥发性氯化消毒副产物三卤甲烷(THMs)的生成和非挥发性氯化消毒副产物二氯乙酸(DCAA)和三氯乙酸(TCAA)生成的影响不同,这主要是由于pH值影响了水中可溶性铜离子的浓度造成的.随着pH值的升高,在铜均相和非均相催化下,水中可溶性铜离子的浓度均降低.可溶性铜离子的浓度会影响水中消毒副产物的生成.对于挥发性氯化消毒副产物THMs来说,当铜离子浓度小于2.5 mg·L-1时,随着铜离子浓度增加,对THMs生成的促进作用加强;当铜离子浓度大于2.5 mg·L-1后,对THMs生成的促进作用减弱;对于非挥发性氯化消毒副产物DCAA和TCAA,随着铜离子浓度增加,DCAA的生成量逐渐增加,TCAA的生成量逐渐减少.

Study on catalytic effects of copper homogeneous and heterogeneous system on chlorinated disinfection reaction

The chlorine consumption and formation of disinfection by-products (DBPs) were studied in copper homogeneous and heterogeneous systems under different pH condition. The rate of chlorine consumption was faster in copper homogeneous and heterogeneous systems than that in the absence of copper, which meant the presence of copper enhanced the depletion of chlorine. Due to the effect of pH value on concentration of dissolved copper ion in the system, the influence of copper homogeneous and heterogeneous systems on formation of volatile disinfection by-products (THMs) and non-volatile disinfection by-products (DCAA and TCAA) was different. The concentration of dissolved copper ion both decreased with the increasing of pH value in homogeneous and heterogeneous systems. The concentration of dissolved copper had an influence on the formation of DBPs. In the case of volatile disinfection by-products, the formation of THMs increased with the increasing of dissolved copper concentration when dissolved copper concentration was below 2.5 mg·L-1 and decreased when it was above 2.5 mg ·L-1. In the case of non-volatile disinfection by-products, the formation of DCAA increased with the increasing of dissolved copper concentration and the formation of TCAA decreased with the increasing of dissolved copper concentration.