Bioavailability of Cd and Zn in soils treated with biochars derived from tobacco stalk and dead pigs
Bioavailability of Cd and Zn in soils treated with biochars derived from tobacco stalk and dead pigs
复制标题
用来自烟秆和死猪的生物炭处理的土壤中镉和锌的生物有效性
DOI：
10.1007/s11368-015-1326-9
复制
发表时间：
2017-03-01
影响因子：
3.6
通讯作者：
Wang, Hailong
中科院分区：
文献类型：
--
作者：
Yang, Xing;Lu, Kouping;Wang, Hailong
目的以往的研究表明，生物炭的应用会降低土壤中重金属的生物有效性。通过植物生长试验，研究了烟草秸秆和死猪来源的生物炭对污染土壤中镉(Cd)和锌(Zn)的浸提性和再分配的影响及其对烟草的影响。植物生长。材料和方法本研究使用了Cd和Zn污染的土壤表层20 cm。将烟草秸秆和死猪提取的生物炭按0、1、2.5、5%四种施用量(0、1、2.5、5%)施于土壤中，种植烟草植株。结果与讨论植物生长试验表明，烟秆生物炭和死猪生物炭(P<； 0.0 5)显著提高了土壤pH值，但对土壤电导率(EC)无显著影响。CaCl2浸提态Cd、Zn含量随施肥量增加而降低。当施用量为5%时，烟秆生物炭处理的可提取态Cd和Zn含量分别下降了64.2%和94.9%，死猪生物炭处理分别下降了45.8%和61.8%。添加生物炭后，交换态Cd主要转化为碳酸盐和铁锰氧化物结合态，而锌主要固定在铁锰氧化物结合态。当施用量为5%时，烟秆生物炭使烟株地上部生物量增加30.3%，根部生物量增加36.2%。在2.5%施用量下，死猪生物炭使烟株地上部生物量增加43.5%，根部生物量增加40.9%。两种生物炭均显著降低了烟草植株对Cd和Zn的积累(P<； 0.0 5)。结论作为土壤改良剂，烟秆生物炭对Cd的去除效果更好，而死猪生物炭对锌的去除效果更好，且施用量越高效果越好。总体而言，从烟草秸秆中提取的生物炭在修复受Cd和锌污染的土壤以及促进烟草生长方面比死猪生物炭更有效。
PurposePrevious studies show that application of biochar can reduce the bioavailability of heavy metals in soil. A plant growth experiment was carried out to evaluate the effect of tobacco stalk- and dead pig-derived biochars on the extractability and redistribution of cadmium (Cd) and zinc (Zn) in contaminated soil, and the impact on tobacco (Nicotiana tabacumL.) plant growth.Materials and methodsThe top 20 cm of a soil contaminated with Cd and Zn was used in this study. Biochars derived from tobacco stalk and dead pig were applied to the soil at four application rates (0, 1, 2.5, and 5 %), and tobacco plants were grown. After 80-days growth, the pH, electrical conductivity (EC), CaCl2-extractable heavy metals and fractions of heavy metals in soil samples, as well as the plant biomass and the concentrations of heavy metals in the plant were determined.Results and discussionThe plant growth experiment demonstrated that tobacco stalk biochar and dead pig biochar significantly (P< 0.05) increased the pH, but had no significant effect on the electrical conductivity (EC) of the soil. The CaCl2-extractable Cd and Zn content decreased as the application rates increased. The concentration of extractable Cd and Zn decreased by 64.2 and 94.9 %, respectively, for the tobacco stalk biochar treatment, and 45.8 and 61.8 %, respectively, for the dead pig biochar treatment at 5 % application rate. After biochar addition, the exchangeable Cd was mainly transformed to fractions bound to carbonates and Fe-Mn oxides, while the Zn was immobilized mainly in the fraction bound to Fe-Mn oxides. Tobacco stalk biochar increased the tobacco plant biomass by 30.3 and 36.2 % for shoot and root, respectively at the 5 % application rate. Dead pig biochar increased the tobacco plant biomass by 43.5 and 40.9 % for shoot and root, respectively, at the 2.5 % application rate. Both biochars significantly (P< 0.05) decreased the Cd and Zn accumulation by tobacco plant.ConclusionsAs a soil amendment, tobacco stalk biochar was more effective at removing Cd, whereas dead pig biochar was more effective at removing Zn, and a higher application rate was more effective than a lower application rate. Overall, biochar derived from tobacco stalk was more effective, than dead pig biochar, at remediating soil contaminated with Cd and Zn, as well as promoting tobacco growth.