Removal of inorganic mercury from aqueous solutions by carbonized waste newsprint fiber

The ability of carbonized waste newsprint fiber to remove Hg(II) from aqueous solutions by physicochemical adsorption was investigated. Defiberized waste newsprint was carbonized in a nitrogen atmosphere at temperatures ranging 600 to 900 degreesC for 3 h. Research parameters included carbonization temperature, initial solution pH. contact time, solution temperature, and initial concentration of Hg(II). The studies showed the adsorbents to be an efficient adsorbent for removing Hg(II) from aqueous solutions. Of the parameters studied, carbonization temperature and initial solution pH were considered to be the most crucial. The amount of Hg(II) adsorbed onto the adsorbent increased with increasing carbonization temperature in the pH range 3 to 9, while it decreased as the temperature increased at pH 11. The extent of the adsorption was also dependent upon the contact time, solution temperature, and initial concentration of Hg(II). The adsorption data were well fitted to both the Freundlich and Langmuir isotherms, Desorption studies imply the occurrence of strong interaction of the Hg(II) species with the active sites on the surface of the adsorbent.