Metals in aqueous solutions and real effluents: Biosorption behavior onto a hemp-based felt

International audienceIn this study, a hemp-based material in the form of a felt is used to adsorb metals in individual aqueous solutions and in polycontaminated effluents using the batch method. The factors affecting the biosorption process were initial metal concentration,biosorbent dosage, contact time and pH. In controlled conditions, results showed that: (i) the felt exhibited high adsorptioncapacities towards metals in the following order: Pb &gt Cd &gt Cu &gt Zn &gt Co ∼ Fe ∼ Ni ∼ Cr ∼ Al ∼ Mn; (ii) no significant differences were observed for the three salts used (sulfate, chloride and nitrate); (iii) the process was rapid: 10 min were sufficient to attain equilibrium ; iv) the biosorption efficiency increased considerably with the increase of the biosorbent dosage; and (v) the adsorption capacities were independent of pH between 4 - 6. The maximum adsorption capacities for Cd, Cu, Zn, Co, Fe, Ni, Cr, Al and Mn were 27.47, 14.64, 10.59, 7.99, 7.85, 7.87, 6.53, 6.38 and 4.55 mg/g, respectively. Interesting results were also obtained for real polymetallic effluents. Ecotoxicological tests also confirmed the efficiency of the biosorption to radically decrease the effluent toxicity.CONCLUSIONS: Based on these results, hemp-based felt could serve as a novel and efficient biosorbent material for pollutant removal from industrial effluents