施污土壤重金属有效态分布及生物有效性  

The available forms and bioavailability of heavy metals in soil amended with sewage sludge

作　　者：铁梅[1] 宋琳琳[1] 惠秀娟[1] 张朝红[1] 薛爽[1] 陈忠林[1] 王杰[1] 张莹[1] 

机构地区：[1]辽宁大学环境学院,沈阳110036

出　　处：《生态学报》2013年第7期2173-2181,共9页Acta Ecologica Sinica

基　　金：辽宁省科技厅项目(20102086);辽宁大学"211"工程重点学科项目(HJ211010)

摘　　要：以城市污泥为研究对象,将城市污泥与土壤按照一定的质量比配成污泥混合土壤。采用6种不同性质提取剂(0.05mol/L EDTA、0.1 mol/L CH3COOH、0.01 mol/L CaC12、1 mol/L CH3COONH4,0.05 mol/L NaHCO3和0.05 mol/L Tris-HCl)分别对污泥混合土壤中重金属(Cd、Pb、Cu和Zn)的螯合态、酸溶态、中性交换态、中性结合态、碱性交换态和蛋白质结合态进行提取,考察污泥的添加对土壤中不同形态重金属的消长规律。通过黑麦草盆栽试验,探究污泥混合土壤中不同形态重金属的植物可利用性。结果表明:污泥混合土壤中重金属螯合态比例较大,占总量的20.3%—40.0%;其次为酸溶态和中性结合态,而中性交换态、碱性交换态和蛋白质结合态的含量较低。污泥的添加促进了黑麦草对Cd、Cu和Zn的吸收,在污泥添加率为44.4%时根部对其吸收量达最大,分别较CK处理增加了0.3、2.3和6.5倍。抑制了对Pb的吸收,在污泥添加率为37.5%时,根部对Pb的吸收较CK处理下降0.4倍。Pearson相关系数分析结果表明:污泥混合土壤中以螯合态、酸溶态和中性结合态存在重金属可被黑麦草吸收利用。This study, taking the soil amended with sewage sludge taken from the Northern Wastewater Treatment Plant （Shenyang, China ） as research object, investigated the dose-response effects of sewage sludge on chemical form distribution of Cd, Pb, Cu and Zn in soil. Moreover, the bioavailability of different forms of heavy metals in soil amended with sewage sludge was studied by means of Perennial Ryegrass pot experiment. The soil samples amended with sewage sludge with a sludge dosage rate of 0,9. 1%, 16.7% ,28.6% ,37.5% ,44.4% and 50% （dry weight basis） were designated as CK,S1 ,S2 ,S3 ,S4 ,S5 ,S6, respectively. The chelated form, acid-soluble form, exchangeable form and bound form in neutral condition, alkali-soluble form and protein-binding form of heavy metals in soil amended with sewage sludge were extracted with 0.05 mol/L EDTA, 0.1 moL/L CH3COOH, 0.01 mol/L CaC12, 1 mol/L CHsCOONH4, 0.05 mol/L NaHCOs and 0.05 mol/L Tris-HC1, respectively. Results showed that the relative content of the chelated form of heavy metals in soil amended with sewage was the highest, accounting for 20.3%--40.0% , followed by alkali-soluble form and bound form in neutral of heavy metals. The contents of the exchangeable form in neutral, alkali-soluble form and protein- binding form of heavy metals were relatively low. The accumulation of Cd, Cu and Zn in ryegrass was found to increase withincrease in sludge dosage rate. The highest content of Cd, Cu and Zn in ryegrass roots was observed with a sludge dosage rate of 44.4% , which was 0.3,2.3 and 6.5 times higher than those at control （CK）, respectively. In contrast, the accumulation of Pb in ryegrass decreased with the increase in sludge dosage rate. A decrease of 40% in Pb content in ryegrass roots was observed with a sludge dosage rate of 37.5% as compared to the control. In order to assess the bioavailability of metals, correlation analysis using SPSS statistical software was performed to investigate the relationship between the total accumulation of heavy metals in ryegra

关 键 词：城市污泥 重金属形态 黑麦草 生物有效性 

分 类 号：X53[环境科学与工程—环境工程]