1.Institute of agricultural resources and agricultural regionalization, Chinese Academy of Agricultural Sciences;2.Institute of Agricultural Environment and Resources, Yunnan Academy of Agricultural Sciences;3.Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences
the National Key Research and Development Program of China (No. 2021YFD1700200), the National Modern Agricultural Industrial Technology System of the Ministry of Finance and Ministry of Agriculture and Rural Areas (No. CARS-22) and the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences
研究不同植物源生物质炭的性质，评价其对云南东川地区镉（Cd）污染应用效果。开展了稻秆炭（RBC）、麦秆炭（WBC）、玉米秆炭（MBC）、麻秆炭（HBC）、田菁炭（TBC）、花生壳炭（PBC）的Cd吸附特征研究和FTIR（傅里叶变换红外光谱）分析、XRD（X射线衍射）分析；通过盆栽试验分析了上述生物质炭对东川镉污染土壤的Cd赋存形态和油麦菜Cd吸收的影响。结果表明，Langmuir吸附等温线及准二级动力学曲线能较好模拟生物质炭对Cd的吸附， TBC饱和吸附量最大分别为37.1和27.9 mg·g-1；WBC、RBC、TBC解吸率较低，各浓度梯度下均不超过10%；FTIR分析表明田菁炭含有较多的含氧官能团；XRD分析表明各生物质炭元素种类存在差异。与不添加生物质炭处理（CK）比较，TBC土壤有效Cd降幅最大为24.3%，且达显著水平（P<0.05）；同时土壤Cd形态由酸溶态向稳定态转化。与CK相比， HBC处理油麦菜地上Cd含量降幅最大为26.4%，且达显著水平；WBC、HBC处理显著降低油麦菜体内Cd的转运系数，转运系数分别为0.6620、0.6928。聚合增强树分析（ABT）分析结果表明，土壤可溶性有机碳（DOC）与土壤pH是土壤有效Cd的主要影响因素，呈极显著负相关，贡献率分别为33.0%和21.9%。综上，供试各植物源生物质炭能降低东川Cd污染土壤中Cd的有效性，减少植物对Cd的吸收及转运，不同生物质炭间存在差异。综合材料性质及试验结果，TBC是东川地区修复Cd污染土壤的较优材料选择。
【Objective】Cadmium(Cd) is a harmful element to the human body and can cause many serious diseases. At present, many soils are faced with serious Cd contamination. For example, the soil in Yunnan Province highly polluted by Cd, and necessary steps need to be taken to remedy this situation. The application of biochar to soils is a common way to remedy soil Cd contamination, therefore, this research is designed to study the properties of biochar from different plant sources and evaluate their application effect on Cd pollution in the Dongchuan area, Yunnan Province. 【Method】The isothermal adsorption-desorption and adsorption kinetic characteristics of rice straw biochar (RBC), wheat straw biochar (WBC), corn straw biochar (MBC), hemp straw biochar (HBC), sesbania biochar (TBC) and peanut shell biochar (PBC) were studied; Through pot experiments, the effects of the above biochar on Cd fraction in Cd-contaminated soil and Cd uptake by Lactuca sativa L. in Dongchuan were analyzed. 【Result】Fitting results of adsorption models showed that Langmuir adsorption isotherm and the pseudo-second-order model could better simulate the adsorption process of Cd by biochar. TBC’s maximum saturated adsorption capacity was the highest, 37.1 mg·g-1 in the isothermal adsorption model and 27.9 mg·g-1 in the adsorption kinetic model, respectively. The desorption rates of WBC, RBC and TBC were lower than those of MBC, HBC and PBC, and no more than 10% under each concentration gradient. Fourier transform infrared spectroscopy (FTIR) analysis showed that TBC contained more oxygen-containing functional groups (OH-, C=O etc.). Also, the XRD analysis showed the biochars were mainly composed of C and Si elements, while different biochars also had some different elements (e.g. Fe, Mn etc.). Compared with the treatment without biochar (CK), WBC, MBC, HBC, TBC and PBC treatments significantly reduced the content of soil available Cd. Among them, the maximum decrease was observed for TBC (24.32%). At the same time, the Cd fraction changed from an acid soluble state to a reducible state, oxidizable state and residual state. Compared with the treatment without biochar, WBC, MBC, HBC and TBC treatments significantly reduced the Cd content in the aboveground parts of Lactuca sativa L. (P<0.05), and the maximum decrease occurred in HBC (26.40%). In addition, WBC and HBC treatments significantly reduced the translocation factors of Cd in Lactuca sativa L., which were 0.6620 and 0.6928 respectively. The results of ABT(aggregated promoted tree) analysis showed that soil soluble organic carbon(DOC)and soil pH were the main influencing factors of soil available Cd, with a significant negative correlation, and the contribution rates were 33.0% and 21.9% respectively. 【Conclusion】In conclusion, all the biochars from different plant sources can reduce the availability of Cd in Cd-contaminated soil in Dongchuan, change the Cd fraction in soil, and reduce the absorption and transport of Cd by plants. There are differences between different biochars. Moreover, TBC can be selected to remedy Cd-contaminated soil in the Dongchuan area through the results of the isothermal adsorption test, adsorption kinetics test and pot experiment.
Wang Yikun, Liang Ting, Zhou Guopeng, Chang Danna, Gao Songjuan, Fu Libo, Fan Hongli, Cao Weidong. Cadmium Adsorption Characteristics of Different Biochar and Their Regulatory Effects on Soil Cd Pollution, in Yunnan[J]. Acta Pedologica Sinica,,[In Press]