摘要
重金属生态风险问题一直制约着污泥及污泥热解生物炭的资源化利用,而重金属生态风险在很大程度上取决于其化学形态.近年来,污泥及其生物炭的重金属形态分布研究得到了广泛关注,已成为当前环境科学的研究热点.本文首先综述分析了市政污水污泥的重金属含量及其形态分布特征,然后从预处理方式(常规干燥、水热)、热解条件(温度、时间)以及添加剂(农林废弃物、催化剂)三方面分析了影响污泥热解生物炭的重金属形态分布关键因子及机理,通过调控这些影响因素可以促进污泥生物炭中的重金属由不稳定形态(酸提取态F1及可还原态F2)向稳定形态(可氧化态F3和残渣态F4)转变,从而降低污泥生物炭的重金属潜在生态风险.最后,基于研究现状提出了未来的研究方向.本文可为进一步研究污泥热解生物炭的重金属固定化提供重要参考.
The ecological risk of heavy metals has been restricting the resource utilization of sludge and its pyrolytic biochar.And the risk depends on the chemical speciation of heavy metals.Recently,the research on the speciation distribution of heavy metals in sludge and biochar has received extensive attention,which becomes a research hotspot in environmental science.This paper reviewed the analysis of the heavy metal content of sewage sludge and its distribution characteristics.And then the key factors and mechanism affecting the speciation distribution of heavy metals in sludge pyrolysis biochar were analyzed from three aspects:pretreatment methods(conventional drying,hydrothermal pretreatment),pyrolysis conditions(temperature,time)and additives(agricultural,forestry wastes and catalysts).By adjusting these influencing factors,the heavy metal speciation of sludge biochar can be changed from unstable forms(exchangeable and acid soluble fraction F1 and reducible fraction F2)to stable forms(oxidizable fraction F3 and residual fraction F4).So this reduces the potential ecological risk of heavy metals in sludge biochar.Finally,the future research direction was proposed based on the current research.This paper provides an important reference for the further study on the immobilization of heavy metals in sludge pyrolysis biochar.
作者
张洁
张少逸
梁学峰
冀苗
薛彤宇
赵林
杨永奎
ZHANG Jie;ZHANG Shaoyi;LIANG Xuefeng;JI Miao;XUE Tongyu;ZHAO Lin;YANG Yongkui(School of Environmental Science and Engineering,Tianjin University,Tianjin,300350,China;Agro-Environmental Protection Institute,Ministry of Agriculture and Rural Affairs,Tianjin,300191,China)
出处
《环境化学》
CAS
CSCD
北大核心
2022年第10期3254-3266,共13页
Environmental Chemistry
基金
国家自然科学基金(21407112)
天津市生态环境治理科技重大专项(18ZXSZSF00240)资助.
关键词
污泥生物炭
热解
重金属
化学形态
机理.
sludge biochar
pyrolysis
heavy metal
chemical speciation
mechanism
作者简介
通信联系人:杨永奎,Tel:18202661713,E-mail:ykyang@tju.edu.cn。
