污泥基生物炭重金属风险评价及对黑麦草生长的影响  

Risk Assessment of Heavy Metals in Sludge Biochar and Its Effects on Ryegrass Growth

作　　者：马若君 贾宏宇 杜一 于钧泷 赵晓东[1] 张秀霞[1] MA Ruo-jun;JIA Hong-yu;DU Yi;YU Jun-long;ZHAO Xiao-dong;ZHANG Xiu-xia(College of Chemical and Chemical Engineering,China University of Petroleum,Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)化学化工学院,山东青岛266580

出　　处：《生态与农村环境学报》2022年第6期802-809,共8页Journal of Ecology and Rural Environment

基　　金：石油石化污染物控制与处理国家重点实验室开放基金(PPC2019021);中国石油科技创新基金(2018D-5007-0605,2017D-5007-0601);中国石油集团安全环保关键技术研究项目(2017-4613)。

摘　　要：为探究污泥基生物炭的重金属潜在生态风险,考察污泥基生物炭对植株生长及土壤微生物多样性变化的影响,以城市污泥为原料热解制备污泥基生物炭,采用风险评估指数、米勒地质累积指数以及潜在生态风险指数对污泥及污泥基生物炭的潜在生态风险进行评估;通过盆栽试验探讨污泥基生物炭的施用对黑麦草(Lolium perenne)生长的影响;通过16S rRNA测序技术和生物信息学研究,分析黑麦草根系土壤微生物多样性的变化。结果表明,与对照相比,污泥基生物炭处理的风险评估指数和潜在生态风险指数均明显减小,生物有效态重金属含量降低,但米勒地质累积指数有所增高;污泥基生物炭施加比例为5%时,黑麦草的发芽率、单株叶片均重和平均叶长分别达到94%、0.1798 g、13.74 cm,相比于未施用时分别增加16百分点、62.12%和29.15%;添加污泥基生物炭对黑麦草根系土壤细菌群落丰度影响较小,群落多样性有所降低。研究表明,污泥基生物炭能够对重金属起到稳定化作用,其重金属含量低于GB 15618-2018《土壤环境质量农用地土壤污染风险管控标准(试行)》中的农田风险筛选值,潜在生态风险较低,在一定的施炭比例下可以促进黑麦草生长。To investigate both the potential ecological risks of heavy metals in sludge biochar and effects of sludge biochar on plant growth as well as microbial diversity in soil,sludge biochar was prepared by pyrolysis of municipal sludge.The potential ecological risks of sludge and its biochar were evaluated by the risk assessment code(RAC),Muller geo-accumulation index(I_(geo))and potential ecological risk index(RI).The effects of sludge biochar application on the growth of ryegrass were then discussed through pot experiments.The changes of microbial diversity in ryegrass root-soil were analyzed by 16S rRNA sequencing technology and bioinformatics.The results indicate that the RAC and RI indexes in the sludge decreased significantly after pyrolysis,and the bioavailability of heavy metals decreased,but the I_(geo) of each heavy metal increased,and the geological cumulative risk increased.According to the pot experiment,when adding 5%sludge biochar,the germination rate,average leaf weight per plant and average leaf length of ryegrass were promoted to reach 94%,0.1798 g and 13.74 cm,increased by 16.0%,62.12%and 29.15%,respectively in contrast with pots without adding biochar.There was no significant influence in the abundance of bacterial community of ryegrass root soil by adding biochar,but the bacterial community diversity of the soil slightly decreased.The results of this study show that sludge-based biochar has a significant stabilizing effect on heavy metals,and its heavy metal content is lower than the standard of farmland risk screening value in China(GB 15618-2018),and the level of potential ecological risk is relatively low.At the same time,by the application of carbon,the growth of ryegrass could be promoted at a certain ratio.

关 键 词：污泥基生物炭 重金属生态风险 黑麦草 污泥资源化 

分 类 号：X825[环境科学与工程—环境工程]