水稻秸秆生物质炭对土壤磷吸附影响的研究

Effect of Rice Straw Biochar on Phosphorus Adsorption in Paddy Soil

以水稻秸秆为原料,分析了不同热解温度下所制备的生物质炭的性质,并采用批处理法,分析了生物质炭添加量和不同热解温度制备的生物质炭对土壤磷吸附特性的影响。结果表明:随着热解温度的升高,生物质炭的碳化程度、比表面积和磷含量增加。添加生物质炭显著减少了土壤对磷的吸附量,而且随着生物质炭热解温度的增加,土壤对磷的吸附量显著增加。Langmuir方程和Freundlich方程都能够较好地拟合添加生物质炭土壤的磷等温吸附曲线。准一级动力学方程和准二级动力学方程可较好地描述添加生物质炭土壤的磷吸附动力学行为。通过以上研究结果可知,水稻秸秆生物质炭可以减少土壤对磷的吸附并增加土壤有效磷的含量,因此在土壤磷肥肥效改良方面具有一定的应用潜力。

Properties of rice straw biochars made under different temperatures were analysed and effects of biochars addition amount on Phosphorus （P） adsorption in a paddy soil were investigated by batch method. The results showed that carbonization degree, specific surface area and P concentration of biochar increased with the increase of pyrolysis temperature. Compared with the control （without biochar）, biochar addition reduced P adsorption by inhibiting P adsorption to soil. Moreover, P adsorption of rice straw biochar was affected significantly by the pyrolysis temperature, which increased with the increase of pyrolysis temperature. Langmuir and Freundlich isotherm equations well described P adsorption isotherm behavior, and Pseudo first-and second-order kinetics well described the behavior of P adsorption kinetics in soils amended with rice straw biochar. Overall, rice straw biochar could improve phosphorus availability in soil through reducing P adsorption in soil and introducing additional P to soil, therefore, it has a great potential in improving phosphorus fertility in soils.