【摘要】 在300、450、600℃下制备了玉米秸秆基生物炭,通过孔径与比表面积分析仪、傅里叶红外光谱仪以及Boehm滴定对生物炭理化性质进行了表征,研究了生物炭吸附水中诺氟沙星的动力学、等温线、热力学,最后探讨了吸附机理.结果表明:随热解温度升高,生物炭比表面积与孔容积明显增大,孔径趋于变小,表面羧基与酚羟基等酸性官能团数量减少;3种生物炭对诺氟沙星的吸附均符合准二级动力学方程;Langmuir方程对吸附等温结果拟合优于Freundlich方程,该吸附是吸热(ΔH>0)熵变增大(ΔS>0)的过程,吸附机理主要为物理吸附(ΔH<40kJ·mol-1);低温制备生物炭对诺氟沙星的饱合吸附量最大(114.20mg·g-1),主要是由于低热解生物炭中存在大量非炭化有机质的吸收-分配作用.更多还原

【Abstract】 The corn stalk biochar was produced at 300,450 and 600℃.The physicochemical properties of biochar were studied by pore size and specific surface area analyzer,FTIR and Boehm titration.Then,the adsorption dynamics,isothermals,thermodynamics as well as adsorption mechanism were investigated.The results showed that with the increase of pyrolysis temperature,the specific surface area and pore volume of biochar increased significantly,the pore size tended to decrease,and the number of acidic functional groups such as carboxyl groups and phenolic hydroxyl groups decreased.The adsorption of Norfloxacin by three kinds of biochars accorded with quasi-second-order kinetic equation（R2>0.9731）.Langmuir equation（R2>0.9173）fitted the adsorption isotherm better than Freundlich equation（R2>0.9099）.The adsorption was a process of endothermic（ΔH >0）entropy change（ΔS>0）.The adsorption mechanism was mainly physical adsorption(ΔH<40 kJ·mol^-1).The saturation adsorption of norfloxacin on biochars prepared at low temperature was the largest(114.20 mg·g^-1),mainly due to the absorption-distribution of non-carbonized organic matter in low pyrolysis biochars.更多还原