Effect of pyrolysis temperature of biochar on Cd, Pb and As bioavailability and bacterial community composition in contaminated paddy soil.
Effect of pyrolysis temperature of biochar on Cd, Pb and As bioavailability and bacterial community composition in contaminated paddy soil.
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DOI：
10.1016/j.ecoenv.2022.114237
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发表时间：
2022-10
影响因子：
6.8
通讯作者：
Yan Wang;Xinyue Shen-;R. Bian;Xiaoyu Liu;Jufeng Zheng;K. Cheng;Zhang Xuhui;Lianqing Li;G. Pan
中科院分区：
文献类型：
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作者：
Yan Wang;Xinyue Shen-;R. Bian;Xiaoyu Liu;Jufeng Zheng;K. Cheng;Zhang Xuhui;Lianqing Li;G. Pan
为进一步研究热解温度对Cd、Pb、As多金属污染水稻土中生物有效性和细菌群落结构的影响，以木屑和花生壳为原料，制备了6种生物炭，在300 °C、500 °C和700 °C条件下培养45 d。结果表明，添加生物炭使土壤中生物有效态Cd减少了31.3%-42.9%，Pb减少了0.61- 56.1%，而生物有效态As从9.68 mg kg-1变为9.55-10.84 mg kg-1。结果表明，热解温度对生物炭中Cd的生物有效性没有显著影响，而Pb的生物有效性随热解温度的升高而明显降低。与对照相比，生物质炭使土壤中可溶态和交换态Cd的比例从45.0%降低到11.2-15.4%，而对Pb和As的形态没有显著影响。木屑生物炭比花生壳生物炭具有更好的降低Cd、Pb生物有效性的潜力。虽然高温生物炭比中低温生物炭导致了更大的细菌种类增加，但原料在改变土壤细菌多样性和群落组成方面发挥了比热解温度更重要的作用。光合细菌通过增加土壤溶解碳（DOC）而增加土壤细菌的多样性。生物质炭主要通过改变土壤电导率、DOC和Cd的生物有效性来改变土壤细菌群落结构。此外，高温光合细菌的施用增加了与氮循环相关的细菌属，如Nitrospira、Nitrosotaleaceae和Nitrosotalea。
To further investigate the effect of pyrolysis temperature on bioavailable Cd, Pb and As, as well as the bacterial community structure in multi-metal(loid) contaminated paddy soil, six types of biochar derived from wood sawdust and peanut shell at 300 °C, 500 °C and 700 °C were prepared and incubated with Cd, Pb and As contaminated paddy soil for 45 days. The results showed that adding biochar decreased bioavailable Cd by 31.3%− 42.9%, Pb by 0.61–56.1%, while bioavailable As changed from 9.68 mg kg−1to 9.55–10.84 mg kg−1. We found that pyrolysis temperature of biochar had no significant effect on Cd bioavailability while Pb bioavailability decreased obviously with pyrolysis temperature raising. Biochar reduced the proportion of soluble and exchangeable Cd from 45.0% to 11.2–15.4% in comparison with the control, while no significant effect on the speciation of Pb and As. Wood sawdust biochar (WSBs) had more potential in decreasing bioavailable Cd and Pb than peanut shell biochar (PSBs). Although high-temperature biochar resulted a larger increase in bacterial species than low-and mid- temperature biochar, feedstock played a more important role in altering soil bacterial diversity and community composition than pyrolysis temperature. PSBs increased the diversity of soil bacteria through elevating soil dissolved carbon (DOC). Biochar altered soil bacterial community structure mainly by altering the level of soil electricity conductivity, DOC and bioavailable Cd. In addition, applying high-temperature PSBs increased the genus of bacteria that relevant to nitrogen cycling, such asNitrospira,NitrosotaleaceaeandCandidatus_Nitrosotalea.