Selected dark sides of biomass-derived biochars as environmental amendments

作     者：Zien Chen Lei Luo Diyi Xiao Jitao Lv Bei Wen Yibing Ma Shuzhen Zhang 

作者机构：State Key Laboratory of Environmental Chemistry and EcotoxicologyResearch Center for Eco-Environmental SciencesChinese Academy of Sciences Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2017年第29卷第4期

页      面：13-20页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 082803[工学-农业生物环境与能源工程] 080703[工学-动力机械及工程] 08[工学] 0828[工学-农业工程] 09[农学] 0807[工学-动力工程及工程热物理] 0903[农学-农业资源与环境] 

基　　金：supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB14020202) the National Natural Science Foundation of China(Nos.41471269 and 21277157) the National Basic Research Program(973) of China(No.2014CB441102) 

主　　题：Biochar Swine manure Heavy metal Free radical Dissolved biochar 

摘      要：With the rapid increase in the application of biochars as amendments, studies are needed to clarify the possible environmental risks derived from biochars to use safely the biomass resources. This work reported selected dark sides of maize straw-and swine manurederived biochars pyrolyzed at 300 and 500°C. During the pyrolysis processes, total heavy metals in the biochars were enriched greatly accompanying with considerable emission of the heavy metals into atmosphere and the trends became increasingly obvious with pyrolysis temperature. Meanwhile, the biochars showed distinctly decreased available heavy metals compared with raw feedstocks, which could be mainly attributed to the sorption by the inorganics in the biochars. The water-and acid-washing treatments significantly increased the releasing risks of heavy metals from biochars into the environments. Electron paramagnetic resonance analysis indicated that persistent free radicals, emerged strongly in the biochars as a function of the aromatization of biomass feedstocks, were free from the influence of water-, acid-, or organic-washing of the biochars and could remain stable even after aged in soils for 30 days. Dissolved biochars, highly produced during pyrolysis processes, showed distinct properties including lower molecular weight distribution while higher aromaticity compared with soil dissolved organic *** results of this study provide important perspectives on the safe usage of biochars as agricultural/environmental amendments.