摘要
利用静态吸附实验研究了溶液p H值、反应时间、初始Cu^(2+)浓度等因素对凹凸棒石粘土矿中粘土质白云岩去除Cu^(2+)效果的影响,将准一级、准二级、Elovich动力学方程与反应动力学进行拟合,再利用Langmuir、Freundlich等温方程对实验数据进行等温式拟合,并与普通白云岩和凹凸棒石粘土进行了对比研究。结果表明,粘土质白云岩相对于其他两种材料受p H影响较小,且在p H 3~5范围内对Cu^(2+)去除率均大于85%,最佳p H为5;对Cu^(2+)的去除符合准二级动力学模型,粘土质白云岩对铜的去除速率和去除率均最高;等温数据符合Freundlich模型,对Cu^(2+)的最大去除量(p H=5,30℃)为186.2×10-3。粘土质白云岩去除水中Cu^(2+)的主要机制为矿物水化与溶解引起的表面沉淀及凹凸棒石与新生碱式碳酸铜[Cu_2CO_3(OH)_2]胶体的静电吸附。粘土质白云岩中纳米凹凸棒石与亚微米多孔白云石共生,具有较高的化学反应活性,除Cu^(2+)效果明显优于普通白云岩和凹凸棒石粘土,在处理含Cu2+废水方面具有潜在应用价值。
In comparison to common dolomite and palygorskite clay, the effects of parameters such as p H, contact time, initialconcentration of copper on removal of copper ions using clayey dolomite in palygorskite clay deposit was investigated using staticadsorption experiments. The kinetics of copper removal was discussed by the pseudo-first-order, the pseudo-second-order and theElovich model, and the sorption isotherm was analyzed by Langmuir and Freundlich isotherm equations. The results show that theeffect of p H on the removal of copper(II) ion by clayey dolomite was less than the other two. More than 85% of copper(II) ions wereremoved in the p H range of 3 to 5 and the optimum p H is 5. The kinetic data of the removal of copper by clayey dolomite fitted thepseudo-second-order kinetic model very well. The removal rate as well as the efficiency was the highest. The isotherm data can bedescribed by the Freundlich model and the removal capacity was 186.2 × 10^(-3). The removal mechanisms were mainly surfaceprecipitation induced by the mineral-water interactions and electrostatic attraction between palygorskite and the newly formed colloid[Cu_2CO_3(OH)_2]. The present study concludes that clayey dolomite is more effective because of the intergrowth of nanoscale palygorskiteand sub-micron porous dolomite, leading to the high-efficient removal of copper ions than the common dolomite and palygorskite clay,and it possesses the potential for treating copper wastewater.
出处
《高校地质学报》
CAS
CSCD
北大核心
2015年第4期616-622,共7页
Geological Journal of China Universities
基金
安徽省国土资源厅科技项目(2013-K-08)
博士后基金(2014M560504)
安徽省自然科学基金(1508085QD77)联合资助
关键词
粘土质白云岩
白云岩
凹凸棒石粘土
铜
去除
表面沉淀
clayey dolomite
dolomite
palygorskite clay
copper
removal
surface precipitation
