玉米秸秆生物炭对五氯苯酚吸附行为及吸附动力学研究

[目的]研究玉米秸秆生物炭对五氯苯酚的静态吸附特性。[方法]探讨吸附剂量、溶液p H、吸附时间等参数对吸附的影响,用Langmuir和Freundlich等温式研究吸附平衡过程。[结果]酸性条件有利于玉米秸秆生物炭吸附剂对五氯苯酚的吸附,吸附过程在30 min即可达到平衡,玉米秸秆生物炭对五氯苯酚的吸附更符合Freundlich等温式。吸附动力学研究表明,吸附过程更符合准二级动力学模型,吸附速率常数为0.015 9 g/(mg·min)。吸附过程是吸热的,升高温度有利于吸附。[结论]玉米秸秆生物炭可用于吸附五氯苯酚。

Adsorption Kinetics and Equilibrium of Pentachlorophenol onto Corn Stalk Biochar

[Objective] To study the adsorption removal of pentachlorophenol from aqueous solution by corn stalk biochar.[Method] Experiments were carried out as function of adsorbent dosage,pH and contact time.The adsorption isotherms were modeled with Langmuir and Freundlich.[Result]The results showed that it was favorable for the adsorption of pentachlorophenol from aqueous solution by corn stalk biochar under acid conditions.The adsorption process was fast,and it reached equilibrium in 30 min contact time.The date fitted well with the Freundlich isotherms.The kinetic data were analyzed using pseudo-first-order and pseudo-second-order models.The pseudo-second-order model was the best for the adsorption pentachlorophenol by corn stalk biochar and the adsorption rate constant is 0.015 9 g/(mg · min).The sorption process was endothermic and raising temperature is favourable for it.[Conclusion] Biochar corn straw can be used for the adsorption of pentachlorophenol.