Manufacture of cellulose acetate membranes and chitosan nanoparticles for the retention of mercury in water

Abstract

In Colombia, an average of 75 tons of mercury is released annually due to the illegal mining activity of gold, causing natural water sources to be contaminated in regions that collect water through rivers and streams, generating mercury poisoning. Nanochitosan, a biopolymer synthesized at the nanoscale, has shown its ability to retain different heavy metals in wastewater due to its greater availability of amino groups at its surface. In this work, a set of preliminary parameters were identified and established for the development of cellulose acetate membranes with chitosan nanoparticles for mercury retention. Nanoparticles were synthesized by ionic gelation, varying the addition rate of sodium tripolyphosphate. The membranes were prepared by solvent exchange, varying the concentration of polyethylene glycol, the pore-forming agent. Finally, the samples were characterized by scanning electron microscopy and dynamic light scattering. The results showed that there is a proportional relationship between the rate of addition and the size of the particles obtained, while, for the membranes, 11% polyethylene glycol produced a porous network with cellulose acetate fibers inside the pores.