SUMMARY
The objective of this work is to utilize a coal beneficiation tailing from Moatize (Mozambique) for the adsorption of hexavalent chromium from water in batch model and fixed bed column. Coal waste was used in particle size between 0.7 and 1.5 mm. The effects of pH, contact time and solid adsorbent concentration were analyzed by batch experiments. The results indicated that it was possible to obtain 98.6% of removal under the experimental conditions of pH 2, 10 h of process and 8 g.L-1 of solid adsorbent. From these experimental results, equilibrium isotherms were build and Langmuir and Sips models presented a better fit to the experimental data. The adsorption of chromium hexavalent from aqueous solution onto coal waste was investigated in a fixed bed column at 298 K. The effects of the inlet concentration, feed flow rate, bed depth on adsorption were investigated. In general, the evaluated parameters improved as a results increase in a Z (bed deep) and decreases in Q (feed flow rate). These performance metrics also improved as C0 (inlet concentration) was increased.