摘要
以超声波(US)和Fenton试剂联用对氯苯(CB)的脱氯降解作用进行了研究。采用单因素法,重点考察了Fenton试剂配比(n(H_2O_2):n(Fe^(2+)))、Fenton试剂用量、CB初始浓度、溶液初始pH值和超声波功率等因素对脱氯降解效果的影响,研究了CB浓度与反应时间的变化关系。结果表明,US/Fenton试剂对CB具有良好的脱氯降解作用,当CB初始质量浓度为100 mg·L^(-1)、H_2O_2与Fe^(2+)的物质的量比为40:1、H_2O_2的浓度为10 mmol·L^(-1)、溶液初始pH值为3、超声波功率为250 W时,CB脱氯率最大可达93.5%。US/Fenton试剂对于CB的脱氯降解反应符合1级衰减模型,速率常数k’=0.266 min^(-1)。
This paper is aimed at introducing its authors＇ investiga- tion of the dechlorination of chlorobenzene （CB） by using ultrasonic （US） technology and Fenton reagent. Since the organic chlorinated chemicals are pollutants highly dangerous to the environment due to their low biodegradability and accumulation tendency, it is worthy for the researchers to take troubles in finding ways to develop new tech- niques for cleaning-up the sewage containing chlorinated organic con- tents. Thus, we have done a lot of efforts to study the influence of the ratio of H202 to Fe2＋ , the total amount of Fenton reagent, initial concentrations of CB, initial pH values of solutions and the power of US on the dechlorination efficiencies of CB by using the single factor method. Then, we have also investigated the kinetics of dechlorina- tion. Actually, the US/Fenton system may have significant effect on the dechlorination of CB, whose dechlorination efficiency tends to first of all rise and then drop down with the ratio of H202 to Fe2＋ turning from 10：1 to 100：1. However, if the total amount of Fenton reagent （H202） is larger than 10 mmol·L-1, the dechlorination would be leveled off basically. Given the initial concentrations of CB rising from 60 mg·L-1 to 140 mg·L-1, the dechlorination efficiency would be likely to rise up and then get to its maximum value and then tends to drop down. Thus, the deehlorination process can be found chang- ing remarkably when the pH value of the reaction system reaches 3. In addition, the process of dechlorination can be enhanced with the increase of ultrasonic strength. The efficiency of the dechlorination would come to its maximum value of 93.5 % in the following condi- tions, such as 100 mg·L-1 of CB concentration, the ratio of H202 to Fe2＋ 40：1, and H202 concentration getting to 10 mmol·L-1, with its initial pH value being 3 and US power reaching 250 W. In such opti- mal reaction conditions, the relationship between chlorobenzene con- centrations and the reaction time would follow a sequence of first order decay and the apparent rate constant k＇ was 0.266 min-1. The above results can thus naturally be made an implication for the physical-chemical treatment of sewage containing chlorinated hydrocarbons.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2010年第1期22-25,共4页
Journal of Safety and Environment
基金
教育部"春晖"计划项目(Z2005-1-62010)
甘肃省自然科学基金项目(3ZS051-A25-039)
兰州交通大学"青蓝"人才工程项目
关键词
环境工程学
水处理
超声波
FENTON试剂
氯苯
脱氯
environmental engineering
water treatment
ultrasound
Fenton reagent
chlorobenzene
dechlorination
