【摘要】 以农业废弃物柚子皮为原料,在300和600°C下制备得到2种柚皮生物炭(BC300和BC600)。运用元素分析仪、扫描电镜和比表面积仪对生物炭的理化性质进行表征,同时从吸附动力学以及吸附热力学角度探讨生物炭对土壤磷的吸附能力。结果表明,随制备温度升高,柚皮生物炭芳香性增强,极性减弱。土壤对磷的吸附量随生物炭施加量增加而降低,且添加BC300的土壤对磷的吸附量高于添加BC600的土壤。准二级动力学方程和Freundlich等温方程可较好描述添加生物炭土壤对磷的吸附动力学和吸附等温行为。热力学计算结果表明,添加生物炭土壤对磷的吸附是吸热和熵增加的自发过程。柚皮生物炭可减少土壤对磷的固定,提高土壤磷的有效性,对于改良土壤具有一定的潜力。更多还原

【Abstract】 Two pomelo peel biochars(BC300and BC600)were prepared at different pyrolysis temperatures(300and 600 ℃)by oxygen-limited environment,respectively.The physical and chemical characteristics of pomelo peel biochars were characterized by Elemental analysis,BET-N2 surface area,scanning electron microscopy and FTIR spectra.The adsorption kinetics and thermodynamics were used to evaluate the adsorption capacity of phosphorus onto soil amended with pomelo peel biochars.The results showed that the aromaticity of biochars gradually increased and the polarity decreased with the increasing pyrolysis temperature.The adsorption capactity of phosphorus onto soil was inhibited with the increasing biochar dosages.In addition,the adsorption amount of phosphorus in soil amended with pomelo peel biochars obeyed the sequence of BC300>BC600.The time-resolved curves of phosphorus adsorption on pomelo peel biochars amended soil followed the pseudo second-order kinetic equation,and the adsorption isotherms was well described by the Freundlich model.The thermodynamic parameters indicated that phosphorus adsorption onto soil was spontaneous,endothermic,and entropy increasing process.In all,Pomelo peel biochars can reduce soil phosphorus fixation and enhance soil phosphorus availability,revealing that pomelo peel biochars have the potential for soil improvement.更多还原