Removal of mercury ion from aqueous solution by activated carbons obtained from biomass and coals
Introduction
The problems for the protection of the environment from various pollutants are not new, but still are considered worldwide as fundamental for mankind. Some regions in Bulgaria and Turkey have serious problems with water contaminated with metal ions and other pollutants.
The heavy metals (Hg, As, Cd, etc.) have a harmful effect on human physiology and other biological systems when they are found above the tolerance level [1].
Mercury is considered to be one of the most toxic metals found in the environment [2].
The aim of present work is to study the possibility of the removal of mercury Hg(II) ion by activated carbons from turkish coals and different sources of biomass (apricot stones and furfural) obtained by simple single stage method—pyrolysis in the presence of water vapour.
Section snippets
Experimental
Six activated carbons from four turkish coals, apricot stones and furfural were used in this study. The coals and biomass samples are carbonized and activated in a one-step pyrolysis method in the presence of water vapour at 750 °C with a heating rate of 10 °C, soak time at the final temperature 2 h [3]. The amount of oxygen functional groups with increasing acidity was determined by Boehm's method [4]. The basic group content is determined with 0.05 N HCl [5]. The adsorption capacity towards
Results and discussion
Some of the characteristics of the investigated carbons are displayed in Table 1, Table 2. The BET surface area is respectively 400–725 m2/g for coals and 1000 and 1110 m2/g for apricot stones and furfural adsorbent. The experimental data show that various oxygen-containing groups of acidic character (carboxyl groups, carboxyl groups in lactone-like binding, phenolic hydroxyl and carbonyl groups) with different chemical properties and basic groups are present on the carbon surface. Carbonyl
Conclusions
Based on this study, activated carbons obtained from different turkish coals and biomass materials by one-step method—pyrolysis of water vapour, were identified as effective adsorbents for removal of Hg(II) from aqueous solution. Adsorption followed Langmuir isotherm.
References (11)
- et al.
Carbon
(1987) - et al.
Water Res.
(1970) - et al.
Carbon
(2000) - et al.
Water Res.
(1981) Standards for Drinking Water
(1971)