天然蛭石吸附废水中Cr(Ⅵ)的动力学试验研究  

Experiment Research on the Cr(Ⅵ) Adsorption by Natural Vermiculite

作　　者：高鑫[1,2] 蒲一凡 朱静平[1,2] 周丽 

机构地区：[1]西南科技大学资源与环境学院,四川绵阳621010 [2]西南科技大学低成本废水处理技术国际科技合作基地,四川绵阳621010 [3]四川省绵阳市江油市环境监测站,四川绵阳621700

出　　处：《非金属矿》2015年第4期63-66,共4页Non-Metallic Mines

摘　　要：以新疆尉犁天然蛭石为吸附材料,初步研究其对Cr（Ⅵ）的吸附性能。采用静态实验方法,通过对p H值、投加量、初始Cr（Ⅵ）质量浓度、温度的考察,讨论蛭石吸附Cr（Ⅵ）的适宜条件,并研究了蛭石对Cr（Ⅵ）的吸附动力学和热力学特性。实验表明,蛭石对Cr（Ⅵ）的吸附效果较好,其适宜吸附条件为：蛭石投加量为2.5 g/L,吸附温度为室温,p H值为4,吸附时间为20~30 min。此条件下在10 mg/L的Cr（Ⅵ）溶液中最大吸附量为2.27 mg/g。吸附过程可用准二阶方程较好地进行描述;以Langmuir方程拟合得到理论最大吸附量为15.29 mg/g;ΔGθ〈0,ΔHθ=11.93 k J/mol,表明蛭石对Cr（Ⅵ）的吸附是自发的吸热过程,吸附以物理吸附为主,并伴随化学吸附。This article has made a systematic study on the adsorption performance of natural vermiculite when it is used to adsorb hexavalent chromium ion. With the static experimental method, the optimum adsorption condition can be obtained and the characteristics on sorption kinetics and thermodynamics can be understood further by investigating p H value, the dosage of natural vermiculite, initial concentration of hexavalent chromium ion and temperature. As the results shown, natural vermiculite has a good effect on adsorbing hexavalent chromium ion and the average adsorption amount is 2.27 mg/g at the optimum adsorption condition： 2.5 g/L dosage of natural vermiculite, room temperature, p H value of 4, and adsorption time of 30 min. The adsorption process can be demonstrated by pseudo-second order kinetics equation vividly. The theoretical maximum adsorption amount fitted by Langmuir isothermal is 15.29 mg/g. ΔGθ0, Δ Hθ= 11.93 k J/mol, so the adsorption process is spontaneous and endothermic with predominant physisorption and auxiliary chemisorption.

关 键 词：吸附 蛭石 Cr(Ⅵ) 动力学 

分 类 号：X703[环境科学与工程—环境工程] TQ424.24[化学工程]