CONICET | Buscador de Institutos y Recursos Humanos

Among the most common water pollutants, heavy metals are highly disturbing due to their non-biodegradability and their high toxicity. For instance, lead (Pb) is a potent neurotoxin which may cause critical diseases in human beings, including cancer. Thus, many researches invest their efforts in the development of systems that allow the elimination of lead from water to safe levels1. In this context, many cellulose-containing materials and cellulose derivatives have been reported as useful for the adsorption of heavy metals2. Both, the natural abundance of cellulose, and the possibility of obtaining it not only from pulps derived from wood but also from a number of alternative abundant and underutilized cheaper cellulose sources, make this polysaccharide very attractive as raw material. On the other hand, the separation processes of cellulose from plant sources require the use of reagents that can have a negative environmental impact3. Conversely, bacterial cellulose (BC) has the same molecular formula as plant cellulose, but it has the advantage of being produced free of lignin, hemicelluloses and pectin, thus avoiding the need for chemical treatments devoted to the removal of these compounds prior to cellulose derivatization.Taking into account the above discussion and considering that Pb (II) exists as a positive ion, the use of insoluble carboxymethyl cellulose (CMC) as cation exchanger could be a good alternative for lead removal from water. Water solubility of CMC is determined by the degree of substitution4 (DS). Previously, some of us reported a systematic study of reaction variables to tailor the DS of carboxymethylated BC (CMBC)3. Based on our previous experience, in this work, insoluble carboxymethyl cellulose was synthetized and lead adsorption studies were carried out.