马铃薯生物炭对土壤中Cd的钝化效果

【目的】 研究马铃薯生物炭对土壤中镉的钝化效果。【方法】 以马铃薯秸秆为原料,研究不同温度制备的3种生物炭(B300、B400、B600)对水中Cd²⁺的吸附效果;采用室内培养实验,研究不同添加量(0.5%、1.5%、3.0%)生物炭(B400℃)对2种宁南山区典型土壤(黑垆土和山地草甸土)的pH、有机碳及DTPA-Cd含量的影响;采用盆栽试验,分析生物炭对土壤中Cd的钝化效果。【结果】 3种生物炭对Cd²⁺吸附能力的大小顺序为:B400>B300>B600;生物炭显著降低2种土壤中DTPA-Cd含量,其中3.0%添加量效果最好,黑垆土DTPA-Cd含量降低幅度大于山地草甸土;2种土壤的pH值和有机碳含量均与各自DTPA-Cd含量变化呈现显著的负相关;3.0%添加量的马铃薯生物炭能促进玉米的生长,降低玉米对Cd的吸收,有效抑制Cd由土壤到玉米体内的转移。【结论】 马铃薯秸秆生物炭对2种土壤中Cd的钝化效应明显。

Immobilization of Cadmium in Soils by Potato Straw Biochar

【Objective】 To investigate the effect of biochar on the immobility of cadmium in soil. 【Methods】 Three biochars (B300℃, B400℃ and B600℃)derived from potato straw were prepared. Thereafter, the Cd²⁺ adsorption abilities of these biochars were compared to find the best biochar; the effects of biochar (B400℃) with different amount (0.5%, 1.5%, 3.0%) on the pH, organic carbon and DTPA-Cd content of two typical soils (dark loessial soil and mountain meadow soil) in southern mountainous area of Ningxia were studied by indoor experiment, and pot experiment was also carried out with 3.0% of biochar to study the effects of biochar on maize growth and its uptake of Cd from the dark loessial soil. 【Results】 The order of adsorption capacity of potato straw biochar to Cd²⁺ was: B400℃ > B300℃ > B600℃; the addition of biochar could reduce the content of DTPA-Cd in two typical soils significantly, of which 3.0% was the best, and the decrease of DTPA-Cd content in dark loessial soil was larger than that in mountain meadow soil; the pH value and organic carbon content of the two soils had significant negative correlations with the changes in their respective DTPA-Cd content; the pot experiment result showed that biochar could significantly increase the biomass of maize, and decrease the Cd accumulation in the shoot or root of maize, the 3.0% of biochar could also decrease the transportation of cadmium from root to shoot. 【Conclusion】 The potato straw biochar has obvious immobility effects on cadmium in two typical soils in the southern mountainous areas of Ningxia.