Mojtaba Hadavifar - Department of Environmental Science, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran
Nader Bahramifara - Department of chemistry, Payam Noor University (PNU), Tehran, Iran
Habibollah Younesi - Department of Environmental Science, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran

Mercury is a toxic metal that causes the serious environmental problems. In present study, multi-walledcarbon nanotubes were functionalized in four stages to create thiolated multi-walled carbon nanotubes (MWCNTs-SH).The efficiency of all synthesized MWCNTs in mercury removal was investigated. MWCNTs-SH was more efficientrather than other synthetized adsorbents in mercury removal from aqueous solutions. Increasing in adsorbent dosageconcluded an enhanced mercury removal. Solution pH has a more effect on mercury removal. When the pH increasedfrom 2 to 8 the removal percentage ranged from 9.8 to 92%. The data fitted by Langmuir isotherm model (R2=0.966)better than Freundlich model (R2=0.935). The obtained maximum adsorption capacity (qm) by Langmuir model was206.64 mg/g while its experimental value was 160.90 mg/g and was higher than that reported in other literatures. Thusthe prepared synthetized adsorbent has high efficiency for mercury removal from aqueous solutions.

MWCNTs, Mercury, Functionalizing, thiol functional group, Isotherm models