Coir pith of the green coconut in the decontamination of radioactive aqueous effluent

Industrial segments as plant of mining, hospitals and university generate considerable volumes of radioactive wastewater containing uranium. The increasing development of the use of the nuclear energy to lead away to an expansion of the sectors of the nuclear fuel cycle, but it leads to security problems and it appears the necessity of control of the removing of uranium and radioactive effluent treatments. Researches evaluate if the technique of the biosorption would promote an alternative process with attractive characteristics of cost-benefit. The residual biomass from agricultural activities has been studied and used as adsorbent of metals and organic composts by low cost, abundance and for being biodegradable. In this work, it is presented the efficiency of the coir pith for the adsorption of ions UO22+. The coir pith is a by-product of the harvest of the coconut, a renewable natural source. The study was accomplished using the batch techniques. The influence from pH 2 to 5, the dose of the coir pith, equilibrium time and the models of kinetic reaction were investigated. It was verified that the adsorption increased with the increase of pH and of the dose. The equilibrium time was of 30 min and the best correspondence with the model of pseudo second-order was observed. The results obtained has been promising, so use as adsorbent of metallic ions represents an economic alternative in relation to the conventional treatment of effluent. (author)