水溶液中氯代苯酚的电子束辐射降解研究

利用电子束辐射降解水中的2-氯苯酚(2-CP),4-氯苯酚(4-CP)和2,4-2氯苯酚(2,4-DCP),研究了辐照剂量对初始浓度各为200mg/L的三种氯代苯酚以及浓度各为50mg/L的三种混合物辐射降解、去除有机氯及溶液pH值的影响。用HPLC测定了辐照溶液中2-CP、4-CP和2,4-DCP的含量,测试结果表明,随着辐照剂量的增加氯代苯酚的降解增加,溶液中的氯离子增加,pH值减小。浓度为200mg/L的三种溶液,在同样的辐射剂量率下,其辐射降解速度和氯离子产率的顺序为2,4-DCP>4-CP>2-CP;对浓度各为50mg/L氯代苯酚的混合物溶液,2,4-DCP的辐射降解速度最大,4-CP和2-CP的降解速度几乎相同。在辐照剂量为21kGy时,对浓度为200mg/L的三种溶液,其辐射降解率分别为93.0%(2-CP)、98.5%(4-CP)和99.4%(2,4-DCP),氯离子产率为55.4%、71.3%和69.0%,降解率为90%所需剂量(D90)分别为18.0kGy(2-CP)、11.4kGy(4-CP)和6.1kGy(2,4-DCP)。浓度各为50mg/L混合体系中的D90值分别为16.1kGy(2-CP)、15.6kGy(4-CP)和12.8kGy(2,4-DCP)。

Degradation of chlorophenols in aqueous solution by electron beam irradiation

Electron beam was used for degradation of aqueous solutions of 2?chlorophenol (2?CP), 4?chlorophenol (4?CP), and 2,4?dichlorophenol (2,4?DCP) in this research. The effect of absorbed dose on substrate degradation, dechlorination and pH of solutions with an initial concentration of 200mg/L each and another solution containing 50mg/L each of the three solutes mixed together were investigated. The results show that increased dose leads to increased degradation of the chlorophenols, increased Cl- yield and decreasing pH value of the solutions. For the individual solutions containing 200mg/L of solutes, the rate of degradation and chloride ion yield was in the order of 2,4?DCP>4?CP>2?CP, while for the mixed 50mg/L solution, while 2,4?DCP still has the highest degrada- tion rate, the degradation of 4?CP and 2?CP proceeded almost at the same rate. At a dose of 21kGy, the rate of deg- radation were 93.0% for 2?CP, 98.5% for 4?CP and 99.4% for 2,4?DCP (200mg/L individual solutions), and the chloride yield was 55.4%, 71.3% and 69.0% for 2?CP, 4?CP and 2,4?DCP respectively. The calculated dose required for 90% degradation of the original solute (D90) are 18.0kGy (2?CP), 11.4kGy (4?CP) and 6.1kGy (2,4?DCP) for the 200mg/L solutions and 16.1kGy (2?CP), 15.6kGy (4?CP) and 12.8kGy (2,4?DCP) for the 50mg/L mixed solution.