偶联剂改性凹凸棒土处理含汞(Ⅱ)废水的研究
Removal of mercury ion from aqueous solutions by chemical modified attapulgite
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摘要: 利用一种含氮硅烷偶联剂γ-氨丙基三乙氧基硅烷改性凹凸棒土,对凹凸棒土改性前后的表面性质进行了分析,并通过静态吸附实验研究了材料对水中汞离子的吸附性能。研究结果表明,酸活化增加了凹凸棒土吸附材料的孔道直径,使吸附速度加快,30 min即达到吸附平衡。通过硅烷偶联剂对凹凸棒土的改性,在材料表面引入了大量氨基,提高了材料对汞离子的去除效果,最大吸附量从改性前的3.8 mg/g提高到92.6 mg/g。该吸附过程符合Langmuir单层吸附模型,其动力学行为符合准二级动力学方程。同时离子强度、pH值以及各种共存离子对其吸附效果的影响均较小。Abstract: Attapulgite (ATP) was modified with an amino-terminated organosilicon (γ-aminopropyltriethoxysilane,APTES). Surface properties of the APTES-modified ATP(M-ATP) were characterized,and the adsorption properties of mercury ion onto M-ATP were studied. The results show that the pore diameter of the adsorbent was enlarged by acid treatment, which accelerated the adsorption process, and the adsorption equilibrium of mercury on M-ATP was achieved within 30 minutes. M-ATP has excellent adsorption ability for mercury ion than original attapulgite, the Qmax increases from 3.8 mg/g to 92.6 mg/g. The adsorption process follows Langmuir isotherm,and kinetics follows the mechanism of the pseudo-second-order equation. It also shows less effects of pH,ionic strength and water constituents on Hg(Ⅱ) uptake by chemical modification of attapulgite.
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Key words:
- attapulgite /
- silane coup ling agent /
- amine-modified /
- mercury ion
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