UV/PS降解水中2,4-二氯苯酚的特性研究

Study on the characteristics of 2, 4-dichlorophenol in water degraded by UV/PS

比较采用PS,UV和UV/PS工艺降解2,4-DCP的去除效果及一级动力学常数,研究光解反应中OH·和SO_4·^-的贡献率,计算SO_4·^-与2,4-DCP反应的二级动力学反应常数,考察实际水体中UV/PS光解2,4-DCP的效果,以及两种有效工艺UV和UV/PS经济性计算和比较.结果表明,分别单独采用PS,UV降解,降解率是4%和46.2%,而采用UV/PS去除率高达96.4%,大大提高单独PS系统降解2,4-DCP的效率,表明UV/PS系统可高效去除2,4-DCP.采用PS,UV和UV/PS降解2,4-DCP基本遵循拟一级反应动力学,一级反应动力学常数分别为0.4×10^(-3),6.2×10^(-3)和35.1×10^(-3)min^(-1).光解反应中起主作用的是自由基SO_4·^-.SO_4·^-与2,4-DCP二级动力学反应常数是7.07×109(mol/L)-1s-12,4-DCP在3种实际水体(锡东水厂,西氿水库,横山水库)中降解率比在超纯水中的高.经济计算中UV/PS协同系统的能量利用率最高.

The study compared the removal effects and the first order reaction kinetics constants of2,4-DCP with PS、UV and UV/PS processes,respectively.Investigated the contribution rate of OH?and SO4?-in the photolysis reaction,calculated the two order kinetics constants for SO4?-with2,4-DCP reactions.Meanwhile,the degradation rates in actualwater conditions were tested and the economic budge of UV and UV/PS processes were calculated and compared.Theresults showed that the removal rate of2,4-DCP was only4%in the PS process alone,46.2%in UV process.Thedegradation percentage can reach as high as96.4%with UV/PS process,which effectively improved the degradationeffect of2,4-DCP,meanwhile2,4-DCP degradation by PS,UV and UV/PS fitted the pseudo-first-order reaction equationand the kobs(reaction rate constant)was0.4×10-3,6.2×10-3and35.1×10-3min-1,respectly.The main contribution functionof the photolysis reaction was SO4?-,the second-order-reaction constants for SO4?-with2,4-DCP was7.07×109(mol/L)-1s-1.The photo-degradation rates of2,4-DCP in three actual water conditions(Xidong water works,Xijiu reservoir,Hengshanreservoir)were higher than in the ultrapure water.The energy utilization rate of UV/PS cooperative system is the highestduring economic calculation.