生物炭对铜矿区排土场污染土壤理化性质和重金属形态的影响

Effects of Biochar on the Physical and Chemical Properties and Heavy Metal Forms of Polluted Soil in the Dump of Copper Mining Area

为了探讨在重金属胁迫下,不同用量(0,1%,2%,4%)生物炭对土壤pH、有机碳、全氮、全磷以及重金属形态的影响,以铜矿区排土场污染土壤为研究对象,开展室内盆钵试验。结果表明:与对照K相比,在不同剂量生物炭处理下,土壤pH、有机碳、全N和全P增幅分别为3.5%~23.0%,5.6%~13.2%,2.9%~6.8%和3.4%~9.5%,酸溶态Cd,Pb,Cu和Zn含量降幅分别为65.5%~71.2%,49.9%~71.5%,34.6%~50.6%和45.3%~52.1%,可还原态Cd,Pb,Cu和Zn含量降幅分别为71.5%~74.3%,44.4%~63.6%,38.5%~57.8%和29.1~39.1%,可氧化态Cd含量降幅为15.6%~36.9%,可氧化态Pb,Cu和Zn含量增幅分别为16.9%~20.5%、3.9%~26.0%和18.8%~55.9%,残渣态Cd,Pb,Cu和Zn含量增幅分别为42.4%~44.2%,11.0%~23.5%,15.0%~37.9%和20.0%~41.9%。添加生物炭可以提高土壤pH,增加土壤有机碳和全氮含量,对土壤全磷含量也略有增加,但无显著性影响,降低酸溶态和可还原态Cd,Pb,Cu和Zn含量,降低可氧化态Cd含量,增加可氧化态Pb,Cu和Zn含量及残渣态Cd,Pb,Cu和Zn含量。因此,生物炭可改善红壤矿区污染土壤的理化性质,并明显影响土壤重金属形态,是红壤矿区重金属污染土壤修复的一种理想调理剂。

In order to study the effects of different doses(0,1%,2%,4%)of biochar on soil pH,organic carbon,total nitrogen,total phosphorus and heavy metal morphology under heavy metal stress,an indoor pot experiment was conducted by using the polluted soil in the dump of copper mining area.The results showed that under different doses of biochar treatment,compared with the control K,soil pH,organic carbon,total N and total P increased by 3.5%~23.0%,5.6%~13.2%,2.9%~6.8%and 3.4%~9.5%,respectively,and acid soluble Cd,Pb,Cu and Zn contents decreased by 65.5%~71.2%,49.9%~71.5%,34.6%~50.6%and 45.3%~52.1%,respectively,the reducible Cd,Pb,Cu and Zn contents decreased by 71.5%~74.3%,44.4%~63.6%,38.5%~57.8%and 29.1%~39.1%,respectively,the oxidizable Cd content decreased by 15.6%~36.9%,and the oxidizable Pb,Cu and Zn contents increased by 16.9%~20.5%,3.9%~26.0%and 18.8%~55.9%,respectively,and the residual Cd,Pb,Cu and Zn contents increased of by 42.4%~44.2%,11.0%~23.5%,15.0%~37.9%and 20.0%~41.9%,respectively;the addition of biochar could increase soil pH,soil organic carbon and total nitrogen content,and also slightly increased but did not significantly affect soil total phosphorus content;it could also reduce acid-soluble and reducible Cd,Pb,Cu and Zn contents,decrease the oxidizable Cd content,increase the oxidizable Pb,Cu and Zn contents and the residue Cd,Pb,Cu and Zn contents.Addition of biochar can improve the physical and chemical properties of contaminated soil,significantly affect the forms of heavy metals in red soil mining areas.Biochar is an ideal conditioner for the remediation of heavy metal contaminated soil in red soil mining areas.