Speciation of inorganic arsenic and selenium in contaminated ground water samples collected from two areas (Alkermiah and Al-Sawani) in Tripoli-Libya

Author(s): Abdunnaser Etorki, A. Elrgahii, M.El Rais

This work deals with the assessment of the arsenic and selenium concentration levels in ground water in two districts of Tripoli, Libya. The study conducted from March 2009 to January 2010 and 14 samples of ground water were collected and analyzed every two months using inductively coupled plasma optical emission spectroscopy (ICP-OES). A novel absorbent was prepared by 1,3-dimercapto propane sulphonic acid chemically modifying mesoporous titanium dioxide nanoparticles and was employed as micro column packing material for simultaneous speciation of inorganic arsenic and selenium species. As and Se species could be adsorbed quantitatively on 1,3-dimercapto propane sulphuric acid modified TiO2 nanoparticles within a pH range of 3-7 and only As(III) could be quantitatively retained on the column within a pH of 10 while As(V) and Se(IV) were passed through the column without the retention. The results show that arsenic levels in ground water varied from 1.05 to 31.08 ng/ml with a mean value of 4.5 ±0.34, which is high than the recommended World Health Organization (WHO) guidelines of 10 ng/ml for drinking water in some ground water samples. The data generated in this study will provide base line values for monitoring arsenic concentrations in ground water in surveyed area.

Speciation of arsenic, speciation of selenium, micro column packing, TiO2 nanoparticles, 1, 3-dimercapto propane sulphonic acid, ICP-OES

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