The presence of heavy metals in aqueous streams arising from the discharge of industrialrneffluents into water bodies is one of the most important environmental issues because of theirrntoxic nature and its removal is highly essential. This paper deals with the adsorption studies forrnthe removal of hexavalent chromium ions from aqueous solutions using acid treated lignite coalrnas adsorbent. The collected samples were stage crushed and sieved to a wide particle size rangernof (250-500Î¼m) and washed using hydrochloric acidic solution to remove any inorganic ashrnmaterial for production of adsorbent. Preliminary investigation of proximate analyses for rawrnlignite coal and acid treated was done. The adsorption study was evaluated as the function ofrninitial chromium(VI) concentration, adsorbent dosage and pH. Batch experiments werernconducted using artificial wastewater containing Cr(VI). The effects of independent variables onrnvarious initial Cr(VI) concentrations between 20 mg/l and 100 mg/l were evaluated. A Cr(VI)rnremoval efficiency of 98 % was achieved at pH 1 with 3.5 g of acid treated lignite in 200mL ofrnsolution at 4 hours contact time using initial Cr(VI) concentration of 20 mg/l. Adsorption ofrnCr(VI) ions was highly pH-dependent and the results showed that the optimum pH for thernremoval was found to be pH 1. The equilibrium adsorption isotherm (Langmuir and Frendlich)rnand adsorption kinetic models (first and second order) were evaluated using experimental data.rnFrendlich isotherm model and second order kinetic model were better for the description of acidrntreated lignite coal for the adsorption of Cr(VI).rnKeywords: Cr(VI) Adsorption, Acid treated Lignite Coal, Equilibrium Isotherms, Kinetics.