竹笋壳对碱性染料的吸附行为及吸附机制研究  

Adsorption behavior and mechanism of basic dyes on bamboo shoot shell

作　　者：赵丹华[1] 彭伟聪 张少丽 詹李明 王柯 Zhao Danhua;Peng Weicong;Zhang Shaoli;Zhan Liming;Wang Ke(College of Chemistry and Materials Science,Guangdong Second Normal University,Guangzhou 510303)

机构地区：[1]广东第二师范学院化学与材料科学学院,广州510303

出　　处：《化工新型材料》2021年第10期179-185,共7页New Chemical Materials

基　　金：广东省普通高校特色创新项目(2019KTSCX118);广东省大学生创新实验项目(S201914278027,S202014278021);广东省普通高校先进材料与节能减排工程技术开发中心项目(2016GCZX007)资助。

摘　　要：以竹笋壳为吸附剂,碱性湖蓝BB(MBB)及碱性艳蓝R(BBR)为吸附质,考察了竹笋壳对碱性染料吸附过程的动力学和热力学行为,以及吸附剂投加量、吸附剂粒径、染料初始浓度、吸附时间、温度、离子强度和水体pH等多种因素对吸附性能的影响,并结合SEM和FT-IR光谱分析,初步探讨了竹笋壳对染料的吸附机制。结果表明,25℃下,2.0g/L 140目竹笋壳在中性条件下处理350mg/L碱性染料溶液时,吸附平衡时间为60min,MBB和BBR的吸附量分别为174.4mg/g和148.9mg/g。竹笋壳对碱性染料的吸附行为符合Langmuir等温吸附方程,热力学参数ΔH、ΔG和ΔS均为负值,说明该吸附过程可自发进行,低温利于吸附。动力学数据分别用准一级吸附动力学方程、准二级吸附动力学方程和颗粒内扩散方程进行拟合,表明该吸附过程符合拟二级动力学模型(R^(2)=0.999),吸附过程主要由化学吸附控制,主要分为表面吸附和内扩散吸附两个阶段。The removal of hazardous dyes of methylene blue BB and basic brilliant blue R in aqueous media were studied with agricultural bamboo shoot shell as adsorbent.The effects of adsorbent on the basic dye adsorption process were investigated in detail,such as the adsorption kinetics and thermodynamics,particle size of adsorbent,the initial concentration of dyes,adsorption time,the temperature,ionic strength and pH of system.At 25℃,the adsorption equilibrium time of 60 min,2.0 g·L;140 mesh bamboo shoot shells in the neutral of 350 mg·L;basic dye solution,the results showed the adsorption capacity of MBB and BBR were 174.4 mg·g;and 148.9 mg·g;,respectively.The Langmuir adsorption isotherm model fitted the adsorption process well.The enthalpy (ΔH ),free energy (ΔG)and entropy(ΔS)changes of adsorption were all negative.The adsorption of MBB and BBR was spontaneous and exothermic process,and therefore,low temperature was advantageous to the adsorption.The kinetic data were fitted by the firstorder adsorption kinetic equation,the second-order adsorption kinetic equation and the diffusion equation in the particle.The results of kinetic showed that the adsorption of MBB and BBR could be described by the pseudo-second order kinetic model,and controlled by the chemical reaction(R^(2)=0.999).The MBB and BBR adsorption process comprised two steps:surface adsorption and intraparticle diffusion adsorption.

关 键 词：竹笋壳 阳离子染料 吸附行为 动力学 热力学 

分 类 号：X703[环境科学与工程—环境工程]