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污染控制技术及原理

摘要：为了将玉米秸秆资源化,成为一种能够有效去除水及废水中硝酸根的吸附剂,将玉米秸秆进行化学改性制备了阴离子交换剂.重点研究了改性玉米秸秆对硝酸根的吸附热力学及动力学特性.结果表明,改性玉米秸秆对硝酸根的吸附均符合Langmuir等温模式和Freundlich等温模式.在20℃和40℃条件下的最大吸附量分别为80.8407mg·g^-1和72.7273mg·g^-1.吸附过程放热,降低温度有利于吸附的进行.改性玉米秸秆对硝酸根的吸附为快速吸附过程,30min内即可达到吸附平衡.改性玉米秸秆对不同初始浓度硝酸根的吸附过程均为一级反应,吸附过程受液膜扩散和颗粒内扩散同时控制.研究结果表明,改性玉米秸秆是一种良好的硝酸根吸附剂.

Abstract：To remove nitrate from wastewater,corn residues were modified into anion exchangers.The nitrate adsorption ability of the material was systematically examined through batch experiments which indicate that the modified corn residues adsorbee nitrate effectively.The adsorption data fit the Freundlich adsorption isotherm and the Langmuir adsorption isotherm.The maximum adsorption capacities were 80.84 mg·g^-1 and 72.73 mg·g^-1 at 20℃ and 40℃.The modified corn residues adsorbed nitrate quickly,reaching equilibrium within₃₀ minutes.The kinetics of nitrate adsorption at different initial concentrations(30 mg·L^-1 ,50 mg·L^-1 ,100 mg·L^-1 ) all fit a first order reaction.The adsorption rates were controlled by both membrane diffusion and intra-particle diffusion.