Adsorption Study of Mercury Species from Aqueous Solution using Thiocarbamoyl Chitosan

Author(s): Wan Mohd Afiq Wan Mohd Khalik, Md Pauzi Abdullah, Fouad Fadhil Al-Qaim and Siti Yusliza Md Yasin

Thiocarbamoyl chitosan was succes sfully synthesized, characteriz ed and tested for mercury removal from aqueous solutions. The chemical structure of thiocarbamoyl chitosan was identified by using the Fourier-Transformed Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) for morphology surface analysis. EDX plot was further confirmed the presence of elemental sulfur on chitosan backbone with weight percentages calculate to be 14.58%. Elemental Analysis (CHNS) was demonstrated the value of 0.55 account to be substitution degree of thiocarbamoyl chitosan. Various parameters such as influence of pH, weight of sorbent, initial concentra tions, exposure time, stirring rate and presence of competitor ion was tested. In adsorption isotherm batch experiment, Langmuir model can be fitted well with correlation coefficient value, R 2 = 0.983-0.997 only for methyl and ethyl species. Maximum adsorption at monolayer for each species was obtained at 15.03 (MeHg), 11.59 (EtHg) and 27.17 mg/g (Hg (II)), respectively. For inorganic species, Freundlic h model was found can be fitted well with R 2 = 0.948. The experimental data was demonstrated to follow pseudo second-order kinetics with rate constant of 1.077 (methyl mercury), 1.12 (ethyl mercury) and 1.01 g/mg/min (inorganic mercury), respectively.

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