摘要
土壤重金属污染成为食品安全的重大隐患,农林废弃物生物炭来源广泛,成本低,已被广泛用于土壤重金属污染修复。本文综述了农林废弃物生物炭的制备方法及影响其性能的关键因素,并重点探讨了利用农林废弃物生物炭钝化土壤典型重金属的作用机制。发现木质、竹、秸秆、稻壳和动物粪便等材料被广泛用于生物炭制备,热解温度、热解停留时间以及原材料种类均会影响生物炭的性能,其中植物生物炭比表面积的增加、吸附性能和重金属固定性能的提高均高于牛粪生物炭,在300℃高温热解制得的生物炭含有更多的含氧官能团,而在500~700℃高温热解制得的生物炭含有更多的微孔和更大的表面积,高热解温度下适当的停留时间有助于生物炭结构的形成。此外,生物炭还可以影响土壤微生物的多样性和种类来提高吸附能力,通过络合沉淀固定汞(Hg)、镉(Cd)和铜(Cu),通过静电吸附、络合作用和阳离子交换来固定铬(Cr)、砷(As)、锌(Zn)和铅(Pb)。最后,为确保生物炭的安全生产和可持续利用提出了未来的研究方向。
Heavy metal pollution in soils has become a major challenge for food safety.Biochar derived from agricultural and forestry wastes has a wide range of sources and low cost,which has been widely used for the soil remediation.In this study,we summarized the methods of biochar preparation from agricultural and forestry wastes and the key factors affecting its performance.In addition,the mechanisms of heavy metals passivation in soils by biochar were also studied.We found that the wood,bamboo,straw,rice husk,animal feces,etc.were frequently used for biochar preparation.The physicochemical characteristics of biochar were affected by pyrolysis temperature,residence time,and type of raw materials.The increases of surface area and improvement of adsorption performance as well as heavy metal passivation in biochar derived from plants are superior to the one made from animal manure.Besides,more oxygen-containing functional groups are found in biochar with pyrolysis temperature at 300℃,while the biochar produced at 500~700℃contains more micropores and larger surface areas.Given that,the appropriate residence time at high pyrolysis temperature is conducive to the formation of biochar structure.Additionally,the adsorption capacity of biochar can be improved via changes of diversity and species of soil microorganisms.The Hg,Cd,and Cu could be immobilized by biochar through complex-precipitation.For immobilization of Cr,As,Zn and Pb,electrostatic adsorption,complexation and cation exchange should be the predominant manner.Taken together,to ensure the safe production and sustainable utilization of biochar,we pointed out the existing issues and prospected the further direction.
作者
宗大鹏
田稳
李韦钰
张梦妍
徐武美
向萍
Zong Dapeng;Tian Wen;Li Weiyu;Zhang Mengyan;Xu Wumei;Xiang Ping(Yunnan Province Innovative Research Team of Environmental Pollution,Food Safety and Human Health,Southwest Forestry University,Kunming 650224,China;School of Ecology and Environment/Institute of Environmental Remediation and Human Health,Southwest Forestry University,Kunming 650224,China;School of Energy and Environmental Sciences,Yunnan Normal University,Kunming 650500,China)
出处
《生态毒理学报》
CAS
CSCD
北大核心
2023年第1期232-245,共14页
Asian Journal of Ecotoxicology
基金
云南省农业联合专项重点项目(202101BD070001-023)
国家林业和草原局林草科技创新青年拔尖人才项目(2020132613)
国家自然科学基金资助项目(41967026)
云南省高层次人才引进计划青年人才项目(YNQR-QNRC-2018-049)。
关键词
土壤重金属
生物炭
钝化机制
农林废弃物
微生物
soil heavy metals
biochar
passivation mechanism
agricultural and forestry waste
microorganism
