Adsorption Performance of Ball-Milling Wheat Straw Biochar to Lead and Its Influencing Factors

Abstract

本文制备了球磨秸秆生物炭，并进行了红外光谱和孔隙结构表征，研究了球磨生物炭对重金属Pb2+的吸附动力学、吸附等温线，考察了pH值、离子浓度、种类等因素对生物炭吸附Pb2+的影响。结果表明，球磨生物炭有着丰富的表面官能团，有利于吸附重金属，对铅的最大吸附量达93.0 mg/g。准二级动力学模型和Langmuir方程能较好地拟合球磨生物炭吸附重金属Pb2+。在pH = 6时球磨生物炭吸附Pb2+的吸附量最高，而Na+和Ca2+对球磨生物炭吸附Pb2+均呈现抑制作用。 Ball-milling straw biochar was prepared and characterized by infrared spectroscopy and pore structure. The adsorption kinetics and isotherm of ball-milling biochar for heavy metal Pb2+ were studied. The effects of pH value, ion concentration, and ion species on Pb2+ adsorption were inves-tigated. The results showed that the ball-milling biochar had abundant surface functional groups, which were favorable for the adsorption of heavy metals, and the maximum adsorption capacity of lead reached 93.0 mg/g. The quasi-second-order kinetic model and Langmuir equation can fit the adsorption of heavy metal Pb2+ by ball-milling biochar well. The adsorption capacity of ball-milling biochar for Pb2+ reached maximum at pH = 6, while both Na+ and Ca2+ had adverse effect on the Pb2+ adsorption.