规模猪场污水多级处理系统中重金属总量及其形态变化特征  

Total content of heavy metals and their chemical form changes in multilevel wastewater treatment system in intensive swine farm

作　　者：郭瑞华[1,2] 靳红梅 吴华山[1,2] 黄红英 叶小梅[1,2] 徐跃定 郑孟杰[3] Guo Ruihua;Jin Hongmei;Wu Huashan;Huang Hongying;Ye Xiaomei;Xu Yueding;Zheng Mengjie(Circular Agriculture Research Center,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;East China Scientific Observing and Experimental Station of Development and Utilization of Rural Renewable Energy,Ministry of Agriculture,Nanjing 210014,China;College of Environment,Hohai University,Nanjing 210098,China)

机构地区：[1]江苏省农业科学院循环农业研究中心,南京210014 [2]农业部农村可再生能源开发利用华东科学观测实验站,南京210014 [3]河海大学环境学院,南京210098

出　　处：《农业工程学报》2018年第6期210-216,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金面上基金项目(21577052);江苏省重点研发计划面上项目(BE2017363);江苏省农业科技自主创新资金项目(CX(16)1003-1;CX(17)1005-4)

摘　　要：为探明畜禽养殖场污水处理过程中重金属总量及其形态变化特征,以苏南地区一规模猪场的污水处理工程为研究对象,系统分析了夏、冬两季各处理环节(厌氧消化、多级沉淀、水生植物处理)出水中Cu,Zn,As,Pb,Cr浓度变化。结果表明:夏季污水中Cu,Zn,As,Pb,Cr总体积浓度分别为4 024.9,6 656.0,22.9,193.8,319.6μg/L,冬季分别为6 490.3,1 1687.9,89.3,152.0,351.7μg/L。除夏季总As外,其他均高于国家农田灌溉水质标准。经多级沉淀和水生植物处理后,出水中各重金属总量显著降低(P<0.05),均符合国家农田灌溉水质标准。夏季Cu,Zn,As,Pb,Cr的去除率分别达99.5%,99.2%,62.2%,88.7%,91.6%,冬季分别达99.8%,99.0%,91.0%,90.1%,87.9%。溶解态重金属含量变化复杂,总体上看,多级沉淀联合水生植物处理对污水中溶解态重金属有降低的作用,但夏季效果低于冬季。除夏季总As外,污水中其他重金属总量及其溶解态含量变化与p H值呈负相关,所有重金属总量与溶解态含量均与EC呈正相关。采用厌氧消化-多级沉淀-水生植物联合处理技术可有效降低猪场污水中重金属总量及其溶解态含量,提高养殖污水农田利用的安全性。Anaerobic digestion(AD)plant is an effective way to treat animal manures,which has been largely applied in China.As the main by-product of biogas,more than 1 billion tons of liquid digestate(i.e.,digested slurry)have been produced by AD plants.Applying digestate to land is the most attractive and effective option in terms of environmental issues,because it allows nutrients(such as nitrogen and phosphorus)to be recycled and,hence,increases the organic matter in soils.However,high levels of heavy metals,such as copper(Cu),zinc(Zn),arsenic(As),lead(Pb),chromium(Cr)in swine manure could result in high risk of land application.The AD plant is conservative for heavy metals,which results in high total concentrations of heavy metals in digested slurries.Furthermore,heavy metals may be highly leachable and soluble because of their inorganic forms during AD treatment;they can even shift from stable fractions to more bioavailability/toxic fractions after water addition and decomposition,especially for variable valence metalloid As.In addition,AD treatment effectively degrades the organic matter and causes obvious variations in physical and chemical properties,such as water content,pH value,oxidation reduction potential(ORP)and microbial activities.These changes may influence the chemical fraction of heavy metals,which is a critical factor in predicting their mobility and eco-toxicity(especially for As).However,there was no study dealing with the distribution of heavy metal contents and chemical fractions in digested slurries and follow-up processing steps,e.g.multilevel sedimentation pond,aquatic plant pond,etc.,from farm-based AD plant.In this study,we chose an intensive swine farm in southern part of Jiangsu Province as a model to study the changes of total and dissolved contents of Cu,Zn,As,Pb,Cr in primary digested slurry and follow-up processing effluent.The objective of this study was to provide scientific support for safety investigate concentrations of the main heavy metals and their morphologic changes characterist

关 键 词：污水 重金属 废水处理 规模猪场 多级处理 化学形态 

分 类 号：X713[环境科学与工程—环境工程]