摘要
以市政污泥为原料、纳米零价铁(nZVI)为添加剂,采用热解法制备污泥生物炭,考察了nZVI添加量、热解温度和升温速率对生物炭中Zn、Cu、Pb形态分布及其生态风险的影响。结果显示:高nZVI添加量、高热解温度及低升温速率可提高稳定态(BCR法)Zn、Cu和Pb的含量;高nZVI添加量可促使Zn、Cu和Pb向可氧化态转化,而高热解温度和低升温速率有利于残渣态Zn、Cu和Pb的生成;最优nZVI添加量、热解温度和升温速率分别为2000 mg/kg,800℃和4℃/min。此外,当nZVI添加量为800 mg/kg、热解温度为800℃和升温速率为2℃/min时有利于降低Zn、Cu和Pb的生态风险;Zn、Cu和Pb总体生态风险等级分别为低风险、低风险和无风险,与Cu和Pb相比,Zn的生态风险较高;以RI值为评价指标,nZVI/污泥基生物炭的优化制备工艺为:nZVI添加量为200 mg/kg,热解温度为800℃,升温速率为5℃/min。
The biochars were prepared by pyrolysis using municipal sludge as the raw material and nano-zero-valent iron(nZVI)as the additive.The effect of nZVI addition,pyrolysis temperature and heating rate on speciation distribution and ecological risk of Zn,Cu and Pb in biochars was investigated.The results showed that the higher nZVI addition,higher pyrolysis temperature and lower heating rate could increase the contents of Zn,Cu and Pb in the steady state(BCR method).The higher nZVI addition could promote the conversion of Zn,Cu and Pb to the oxidizable state,while the higher pyrolysis temperature and lower heating rate were favorable for the formation of residual Zn,Cu and Pb.The optimized nZVI addition,pyrolysis temperature and heating rate were 2000 mg/kg,800℃and 4℃/min,respectively.In addition,when the addition amount of nZVI was 800 mg/kg,the pyrolysis temperature was 800℃and the heating rate was 2℃/min,which was conducive to reduce the ecological risk of Zn,Cu and Pb.The approximate ecological risk levels of Zn,Cu and Pb were low risk,low risk and no risk,respectively.Compared with Cu and Pb,the ecological risk of Zn was higher.If the RI value was used as the evaluation index,the optimized preparation process of nZVI/sludge-based biochar was as follow:nZVI dosage of 200 mg/kg,pyrolysis temperature of 800℃,heating rate of 5℃/min.
作者
汤传武
刘立恒
黄蓉
何东薇
TANG Chuan-wu;LIU Li-heng;HUANG Rong;HE Dong-wei(College of Environmental Sciences and Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology,Guilin University of Technology,Guilin 541004,China;Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area,Guilin University of Technology,Guilin 541004,China)
出处
《环境工程》
CAS
CSCD
北大核心
2020年第10期216-221,共6页
Environmental Engineering
基金
国家自然科学基金重点项目(51638006)
桂林理工大学人才项目(002401003489)
广西高等学校高水平创新团队及卓越学者计划项目(002401013001)
广西矿冶与环境科学实验中心(KH2012ZD004)
广西“八桂学者”项目。
关键词
nZVI/污泥基生物炭
制备工艺
重金属
形态分布
生态风险
nZVI/sludge based biochars
preparation technology
heavy metal
morphology distribution
ecological risk
作者简介
第一作者:汤传武(1992-),男,硕士研究生,主要研究方向为固体废弃物的处置及其资源化利用。813702685@qq.com;通信作者:刘立恒(1980-),男,博士,副研究员,主要研究方向为固体废弃物资源化利用和环境功能材料。deanhenry_liu01@126.com。
