浸渍热解法制备铁改性生物炭活化过硫酸盐去除2,4-二硝基甲苯  

REMOVAL OF 2,4-DINITROTOLUENE BY PERSULFATE ACTIVATED WITH IRON MODIFIED BIOCHAR PREPARED BY DIPPING-PYROLYSIS PROCESS

作　　者：曹媛 李晓东[2] 彭昌盛[1] 孙宗全 沈佳伦 马福俊[2,3] 谷庆宝 CAO Yuan;LI Xiao-dong;PENG Chang-sheng;SUN Zong-quan;SHEN Jia-lun;MA Fu-jun;GU Qing-bao(Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Research Institute of Solid Waste Pollution Control Technology,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;National Engineering Laboratory for Site Remediation Technologies,Beijing 100015,China)

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100 [2]中国环境科学研究院固体废物污染控制技术研究所,北京100012 [3]污染场地安全修复技术国家工程实验室,北京100015

出　　处：《环境工程》2021年第11期135-142,178,共9页Environmental Engineering

基　　金：污染场地安全修复技术国家工程实验室开放基金项目(NEL-SRT201706);国家重点研发计划项目“东北重工业区场地复合污染综合治理技术与集成工程示范”(2019YFC3800)。

摘　　要：为探究并优化浸渍热解法制备铁改性生物炭(MBC)活化过硫酸盐(PS)对有机污染物去除的试验条件及影响因素,以2,4-二硝基甲苯(2,4-DNT)为目标污染物,考察了热解参数(热解温度、升温速率和停留时间)、FeCl_(3)浸渍浓度及初始pH值对2,4-DNT去除的影响,并采用电子自旋共振波谱技术及自由基猝灭试验鉴定了PS/MBC体系中生成的自由基。结果表明:1)热解温度对MBC活化PS去除2,4-DNT的影响最显著,其次为升温速率和停留时间;当热解温度、停留时间和升温速率分别为300℃、3 h和10℃/min时,热解制备的MBC对活化PS去除2,4-DNT的效果最佳;2)FeCl_(3)浸渍浓度是影响MBC活化性能的重要因素,随着FeCl_(3)浸渍浓度的升高,2,4-DNT的去除率先增后减,当FeCl_(3)的浸渍浓度为100 mmol/L时,5 h内2,4-DNT的去除率可达到100%,2,4-DNT去除的准一级动力学常数(k_(obs))为1.373 min^(-1);3)当初始pH值为5.0~9.0时,2,4-DNT均具有较好的去除效果,其去除率为94.5%~83.6%,k_(obs)为0.606~0.345 min^(-1);4)PS/MBC体系中生成的·OH是2,4-DNT去除的主要原因,其强度随MBC的热解温度和FeCl_(3)浸渍浓度的不同差异较大。研究结果表明,浸渍热解法制备的MBC可有效活化PS实现污染物的高效去除,为PS化学氧化处理有机污染水体提供了新思路。To explore and optimize the experimental conditions and influence factors of the removal of organic pollutants by persulfate activated with iron modified biochar prepared by the dipping-pyrolysis process, 2,4-dinitrotoluene(2,4-DNT) was selected as the target pollutant to investigate the effects of pyrolysis parameters(pyrolysis temperature, heating rate, and residence time), FeCl_(3)concentration and initial pH values on 2,4-DNT removal. The electron spin resonance and free radical quenching test were used to assess the intensity of SO_(4)^(-)· and ·OH in the PS/MBC system. The results showed that: 1) The pyrolysis temperature had the most significant influence on removal of 2,4-DNT by PS activated with MBC, followed by heating rate and residence time. When the pyrolysis parameters were retained at 300 ℃, 3 h, and 10 ℃/min, the best removal of 2,4-DNT was obtained by PS/MBC oxidation. 2) The concentration of FeCl_(3)was an important factor of MBC activation. The removal of 2,4-DNT first increased and then decreased with the increase of the FeCl_(3)concentration. When the concentration of FeCl_(3)was retained at 100 mmol/L, the removal efficiency of 2,4-DNT reached 100% after the reaction of 5 h, and the pseudo-first-order kinetic constant(k_(obs)) of 2,4-DNT removal was determined to be 1.373 min^(-1). 3)When the initial pH ranged from 5.0 to 9.0, 2,4-DNT had a good removal by PS/MBC oxidation, the removal efficiencies were 94.5%~83.6%, and the k_(obs)values were 0.606~0.345 min^(-1). 4) ·OH was the main factor for the removal of 2,4-DNT by PS/MBC oxidation. The signals of ·OH with different strengths were observed, with the addition of MBC prepared by different pyrolysis temperatures and FeCl_(3)concentrations. The results showed that MBC prepared by dipping-pyrolysis could effectively activate PS to achieve the removal of organic pollutants, which provided a new idea for treatment of organically polluted water by PS based-advanced chemical oxidation.

关 键 词：过硫酸盐 铁改性生物炭 浸渍热解法 2 4-二硝基甲苯 

分 类 号：X703[环境科学与工程—环境工程]