Adsorption of heavy metals on treated and untreated low grade bituminous coal

39-41<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Bituminous coal has been subjected to hydrothermal treatment to incorporate additional functional groups and to effect changes in the colloidal-chemical nature of the coal surface to enhance the adsorption of Cu (II), Ni(II), Zn(II) and Cr(VI) from aqueous system. The effectiveness of two such chemical pretreatments like hydrogen peroxide and manganese oxide impregnation has been investigated through adsorption of these metals, separately at the same condition of pH, temperature, adsorbent size and concentration. The rate of adsorption and capacity of bituminous coal is found to be enhanced significantly. Lagergren equation and Langmuir model have been used to determine rate constants of adsorption and capacity of treated and untreated bituminous coal.