Distribution and transformation behaviors of heavy metals during liquefaction process of sewage sludge in ethanol-water mixed solvents  

基于乙醇-水混合溶剂污泥液化过程中重金属的迁移和转化（英文）

作　　者：PAN Zi-qian HUANG Hua-jun ZHOU Chun-fei LAI Fa-ying HE Xiao-wu XIONG Jiang-bo XIAO Xiao-feng 潘紫倩;黄华军;周春飞;赖发英;何小武;熊江波;肖晓峰(School of Land Resources and Environment,Key Laboratory of Agricultural Resource and Ecology in the Poyang Lake Basin of Jiangxi Province,Jiangxi Agricultural University,Nanchang 330045,China;School of Gardening and Landscape Design,Jiangxi Agricultural University,Nanchang 330045,China)

机构地区：[1]School of Land Resources and Environment,Key Laboratory of Agricultural Resource and Ecology in the Poyang Lake Basin of Jiangxi Province,Jiangxi Agricultural University,Nanchang 330045,China [2]School of Gardening and Landscape Design,Jiangxi Agricultural University,Nanchang 330045,China

出　　处：《Journal of Central South University》2019年第10期2771-2784,共14页中南大学学报（英文版）

基　　金：Project(21707056) supported by the National Natural Science Foundation of China;Project(20151BAB213024) supported by the Natural Science Foundation of Jiangxi Province,China;Project(GJJ14302) supported by the Scientific Research Fund of Jiangxi Provincial Education Department,China

摘　　要：Liquefaction of sewage sludge(SS)in ethanol-water cosolvents is a promising process for the preparation of bio-oil/biochar products.Effect of the combined use of ethanol and water on the distribution/transformation behaviors of heavy metals(HMs)contained in raw SS is a key issue on the safety and cleanness of above liquefaction process,which is explored in this study.The results show that pure ethanol facilitates the migration of HMs into biochar products.Pure water yields lower percentages of HMs in mobile/bioavailable speciation.Compared with sole solvent treatment,ethanol-water cosolvent causes a random/average effect on the distribution/transformation behaviors of HMs.After liquefaction of SS in pure water,the contamination degree of HMs is mitigated from high level(25.8(contamination factor))in raw SS to considerable grade(13.4)in biochar and the ecological risk is mitigated from moderate risk(164.5(risk index))to low risk(78.8).Liquefaction of SS in pure ethanol makes no difference to the pollution characteristics of HMs.The combined use of ethanol and water presents similar immobilization effects on HMs to pure water treatment.The contamination factor and risk index of HMs in biochars obtained in ethanol-water cosolvent treatment are 13.1-14.6(considerable grade)and 79.3-101.0(low risk),respectively.In order to further control the pollution of HMs,it is preferentially suggested to improve the liquefaction process of SS in ethanol-water mixed solvents by introducing conventional lignocellulosic/algal biomass,also known as co-liquefaction treatment.污水厂污泥在乙醇-水混合溶剂中液化是制备生物油/生物炭的一种有前景的方法。乙醇和水联合使用对污泥液化过程中重金属的迁移和转化行为的影响是有关上述液化技术的安全性和清洁性方面的重要课题。本论文针对这一课题展开了研究,结果表明:纯乙醇作为液化溶剂时,重金属向生物炭迁移的比例更高;纯水作为液化溶剂时,生物炭中活性态重金属的比例则更低;与单一溶剂液化相比,乙醇-水共溶剂对重金属的分布和转化行为的影响呈现随机效应或平均效应。污泥在纯水中液化后,重金属的污染程度由生原污泥的重度污染(污染指数25.8)降低到生物炭的中度-重度污染(污染指数13.4),生态风险则由中等风险(风险指数164.5)降低到低风险(风险指数78.8)。纯乙醇作为液化溶剂时对重金属的污染程度和生态风险影响甚微。乙醇和水的联合使用具有和纯水类似的重金属钝化效应。污泥在乙醇-水混合溶剂中液化所得的生物炭中重金属的污染指数和风险指数分别是13.1~14.6(中度-重度污染)和79.3~101.0(低风险)。为了进一步控制基于乙醇-水混合溶剂污泥液化过程中重金属的污染,可以通过在污泥液化过程中引入常规的木质纤维素或藻类生物质(也即采用共液化技术)。

关 键 词：sewage sludge LIQUEFACTION ethanol-water cosolvent heavy metals contamination degree ecological risk 

分 类 号：X70[环境科学与工程—环境工程]