摘要
采用超声波降解模拟废水中四环素类抗生素(TCs):土霉素(OTC)、四环素(TC)和金霉素(CTC),考查废水初始浓度、初始pH、超声波输入功率密度、曝气量和自由基清除剂(正丁醇)对降解效率的影响。结果表明,超声波可以快速高效地降解废水中的TCs,CTC最易被降解,TC和OTC次之;在OTC、TC和CTC初始浓度0.25mg/L,初始pH=8.2,声功率密度1.2W/mL,气水体积比30:1的条件下,超声波辐照20min后去除率分别达到76.8%、84.0%和94.4%。在实验研究条件下,TCs去除率均随初始浓度(0.25~2.00ing/L)的增大而降低,但总去除浓度升高;碱性条件有利于TCs降解,去除率随初始pH(6—11)升高而升高;功率密度(0.24~1.96W/mL)越高,TCs去除率也越高;曝气后TCs的去除率明显升高,随着气水比(10:1~60:1)的增大,去除率逐渐上升;正丁醇有效抑制TCs超声波降解,可推断TCs主要降解途径为自由基氧化。TCs超声波降解过程符合伪一级动力学反应特征。
This study investigated the tetracyclines ( oxytetracycline, OTC ; tetracycline, TC ; chlortetracy- cline, CTC) degradation upon ultrasonic action under different experimental conditions. The effects of initial con- centration (0.25 -2.00 rag/L) ,initial pH(6 - 11 ) of the solution,power density (0.24 -1.96 W/mL) ,aera- tion volume and hydroxyl radical scavenger (normal butanol) were evaluated. It was found that tetracyclines could be degraded rapidly by ultrasonic irradiation,the removal rates were CTC 〉 TC 〉 OTC and CTC was more easily degraded than TC and OTC. When the concentration was 0.25 rag/L, pH was 8.2,power density was 1.2 W/mL and aeration volume was 30 : 1 [ air/water, (V/V) ] , the removal efficiencies of OTC, TC and CTC were 76.8% 84.0% and 94.4% after 20 min irradiation,respectively. All the impact factors mentioned above had re- marked effects on tetracyclines removal efficiencies,which increased with increasing initial pH, power density and aeration volume,but decreased with increasing concentrations of teracyclines and volumes of normal butanol add- ed. Pseudo-first order reaction model can be used for the fitness of TCs degradation by ultrasonic action.
出处
《环境工程学报》
CAS
CSCD
北大核心
2014年第4期1503-1509,共7页
Chinese Journal of Environmental Engineering
基金
重庆市科技攻关重点项目(CSTC2009AB7027)
中央高校基本科研业务费专项资金资助项目(XDJK2011C081)
关键词
四环素
超声波
高级氧化
降解
tetracycline
ultrasound
advanced oxidation
degradation