水分调控下生物炭施入对重金属污染农田土壤Pb、Zn形态的影响  

Effects of Biochar on Pb and Zn Forms in Farmland Soil Polluted by Heavy Metals Under Water Regulation

作　　者：何雨 罗云霞 樊仙 杨梓润 高鹏飞 王启 苏小娟 HE Yu;LUO Yunxia;FAN Xian;YANG Zirun;GAO Pengfei;WANG Qi;SU Xiaojuan(College of Ecology and Environment,Southwest Forestry University,Kunming 650224,China;Honghe Prefecture Agricultural Science,Honghe 661199,China)

机构地区：[1]西南林业大学生态与环境学院,云南昆明650224 [2]红河州农业科学院,云南红河661199

出　　处：《广东农业科学》2024年第8期104-114,共11页Guangdong Agricultural Sciences

基　　金：云南省农业基础研究联合专项(202101BD070001-031);云南省基础研究计划(202101AT070037);西南林业大学博士科研启动项目(01102/112114)。

摘　　要：【目的】探究水分调控和生物炭对矿区附近农田土壤的修复效果并提高耕地安全。【方法】以云南某铅锌矿附近农田土壤为研究对象,设置干湿交替(G)、淹水(Y)、自然含水量(Z)3种水分条件和0%(BC0,CK)、2.5%(BC1)、5.0%(BC2)、7.5%(BC3)4种生物炭添加量,通过土壤培养试验,研究不同水分调控措施下施加鸡粪生物炭对重金属污染土壤中Pb、Zn形态的影响。【结果】在3种水分条件下,施加生物炭均能提高土壤pH。生物炭处理土壤中水溶态和交换态Pb、Zn浓度均显著低于对照,降低了Pb、Zn生物有效性。生物炭处理土壤中可氧化态和残渣态Pb质量分数提高,其中ZBC2处理可氧化态和残渣态Pb质量分数最高,分别为64.58%、25.06%;各处理土壤残渣态Zn质量分数依次为干湿交替>淹水>自然含水量。不同水分条件下,施加生物炭显著降低TCLP提取态Pb、Zn质量浓度,且均远低于国际限制标准,其中GBC3处理土壤TCLP提取态Zn浓度最低,为3.45 mg/L。SGET法的Pb、Zn生物可给性平均质量分数小于PBET法和SBET法,其中ZBC3处理Pb、Zn生物可给性质量分数最低,为0.43%、0.27%。【结论】3种水分调控下施加不同量生物炭均可有效钝化土壤重金属Pb、Zn,降低其对土壤环境的危害。自然含水量条件下,施加较高量生物炭(5.0%、7.5%)对土壤重金属Pb钝化效果最佳;干湿交替条件下,施加7.5%生物炭对土壤重金属Zn钝化效果最佳。【Objective】The research was conducted to explore the remediation effect of water regulation and biochar on farmland soil near mining areas and improve the safe use of farmland.【Method】Taking farmland soil near a lead-zinc mine in Yunnan as the research object,three water conditions:dry-wet alternation(G),flooding(Y)and natural moisture content(Z),and four biochar addition amounts of 0%(BC0,CK),2.5%(BC1),5.0%(BC2),and 7.5%(BC3)were set up.Through soil culture experiments,the effects of applying chicken manure biochar under different water regulation measures on the forms of Pb and Zn in heavy metal contaminated soil were studied.【Result】Under the three water conditions,the application of biochar could increase soil pH.The concentrations of water-soluble and exchangeable Pb and Zn in soil treated with biochar were significantly lower than that of CK,reducing the bioavailability of Pb and Zn.The mass fractions of oxidizable and residual Pb in soil treated with biochar increased,with ZBC2 treatment having the highest mass fractions of oxidizable and residual Pb,which were 64.58%and 25.06%,respectively.The mass fractions of residual Zn in soils under various treatments ranked as:dry-wet alternation>flooding>natural moisture content.Under different water conditions,the application of biochar significantly reduced the mass concentrations of TCLP-extracted Pb and Zn,both of which were far below the international limitation standards.Among them,the soil treated with GBC3 had the lowest concentration of TCLP-extracted Zn,which was 3.45 mg/L.The average mass fraction of Pb and Zn bioavailability by SGET method was lower than that by PBET method and SBET method,while the ZBC3 treatment by SGET method had the lowest mass fractions of Pb and Zn bioavailability,which were 0.43%and 0.27%.【Conclusion】The application of different amounts of biochar under three types of water regulation effectively passivated soil heavy metals Pb and Zn,reducing their harm to the soil environment.Under natural moisture content condi

关 键 词：重金属污染 农田土壤 水分调控 生物炭 生物有效性 钝化 形态分级 生物可给性 

分 类 号：S282[农业科学—农业水土工程] X53[农业科学—农业工程]