鸡蛋壳废料对水体中Cr(Ⅵ)的吸附特征与机理  

Characteristics and mechanism of egg shell waste for Cr(Ⅵ) adsorption from aqueous solution

作　　者：谢越[1,2] 孔维芳 韩传红[1,2] 马万征[1] 周毅[1] 孙晟[1] 汪建飞[1,2] 

机构地区：[1]安徽科技学院城建与环境学院,凤阳233100 [2]农业部生物有机肥创制重点实验室,蚌埠233000 [3]昆山蓝德环保科技有限公司,昆山215331

出　　处：《环境工程学报》2015年第4期1585-1592,共8页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金青年基金项目(31101598);安徽省自然科学基金项目(1508085QD74);安徽省高校省级自然科学研究重点项目(KJ2012A067);安徽省高校自然基金资助项目(KJ2013Z056)

摘　　要：利用鸡蛋壳废料对水中的Cr(Ⅵ)进行吸附处理,研究溶液p H、振荡时间、投加量和温度对鸡蛋壳废料吸附水体中Cr(Ⅵ)的特征和吸附机理。结果表明,在含有1 mg/L的Cr(Ⅵ)溶液的100 m L吸附体系中,鸡蛋壳废料可在30 min内完成吸附过程。溶液p H=2.5时,吸附量最大。鸡蛋壳投加量为1.0 g时,平衡吸附容量为0.0917 mg/g。利用鸡蛋壳去除水中Cr(Ⅵ)的最佳工艺参数为振荡时间30 min,初始p H为3.0,投加量2.0 g,体系温度35℃。鸡蛋壳对Cr(Ⅵ)的吸附过程用Langmiur和Freundlich方程能较好拟合,其中理论饱和吸附量在20℃、30℃和40℃时分别为0.1944、0.2034和0.2096 mg/g。吸附的焓变为8.76×10-3k J/mol,熵变为-45.96 J/(mol·K),吉布斯自由能变均为正值,变化范围是4.357~9.693 k J/mol。鸡蛋壳对Cr(Ⅵ)的吸附过程主要为物理性的单分子层和多分子层吸附。The egg shell was used for Cr( Ⅵ) adsorption from aqueous solution. The p H,shake time,dosage and temperature were investigated to explore the characteristics and mechanism of the adsorption process. The results showed that in the 100 m L solution system contained 1 mg / L Cr( Ⅵ),the adsorption process could be completed by egg shell within 30 min. The maximum adsorption capacity was observed at p H 2. 5. The equilibrium adsorption capacity was 0. 0917 mg / g when the dosage of egg shell was 1. 0 g. The optimal conditions of egg shell Cr( Ⅵ) adsorption were original p H 3. 0,egg shell dosage of 2. 0 g,shake time of 30 min with temperature at35℃. Both of Langmiur and Fruendlich equations were fitted the sorption data very well,and the theoretical saturated adsorption capacityies at 20℃,30℃,40℃ were 0. 1944,0. 2034 and 0. 2096 mg / g,respectively. The adsorption enthalpy was 8. 76 × 10- 3k J / mol and the entropy was- 45. 96 J / mol. K,and all the Gibbs free energy change were positive with the range of 4. 357- 9. 693 k J / mol. The adsorption of Cr( Ⅵ) by egg shell mainly was a physical monolayer and multi-layer process.

关 键 词：鸡蛋壳 吸附Cr(Ⅵ) 动力学 热力学 机理 

分 类 号：X52[环境科学与工程—环境工程]