title: Inorganic particulates in removal of heavy metal toxic ions IX. Rapid and efficient removal of Hg(II) by hydrous manganese and tin oxides.
abstract: Batch studies have been carried out in the removal of Hg(II) from aqueous solutions by using well-synthesized and -characterized hydrous manganese oxide (HMO) and hydrous tin oxide (HTO) employing a radiotracer technique. Results obtained reveal that increased sorptive concentration (10(-8)-10(-2) mol dm(-3)), temperature (298-328 K), and pH (ca. 2.0-10.5) enhance the removal efficiency of these solids. First-order uptake of Hg(II) on HMO and HTO follows the Freundlich adsorption isotherm for entire concentration range. Positive values of DeltaH0 for the uptake process on both solids indicate endothermic uptake and desorption experiments point to irreversible uptake. Radiation stability of the adsorbents has also been assessed using a 300-mCi (Ra-Be) neutron source having an integral neutron flux of 3.85 x 10(6) N cm(-2) s(-1) and associated with a nominal gamma-dose of ca. 1.72 Gy/h.
authors.affiliation: Nuclear and Radiochemistry Laboratory, Department of Chemistry, Banaras Hindu University, Varanasi 221005, India.
authors.forename: Shuddhodan P
authors.initials: SP
authors.lastname: Mishra
authors.forename: Som Shankar
authors.initials: SS
authors.lastname: Dubey
authors.forename: Diwakar
authors.initials: D
authors.lastname: Tiwari
mesh_terms: D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D008631:Mercury Radioisotopes / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D017971:Tin Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014877:Water Pollution, Chemical / Q000517:prevention & control
chemical_list: D007477:Ions; D017895:Manganese Compounds; D008631:Mercury Radioisotopes; D019216:Metals, Heavy; D010087:Oxides; D017971:Tin Compounds; D014867:Water; C027424:manganese oxide; D008628:Mercury; C045358:stannic oxide