Cupric ion removal by dyed cellulosic materials

Four different cellulosic materials namely cotton fibers, bamboo pulp, jute fibers, and saw dust were dyed with monochlorotriazine type reactive dyes. The cupric salts, viz., copper nitrate, copper sulphate, copper chloride, and copper acetate were adsorbed from their aqueous solutions of about 250 ppm strength by both undyed and dyed substrates. It was observed that although the undyed substrates do adsorb the metal salts significantly, their capacity increases greatly on dyeing with reactive dyes. Thus, in many cases, the different dyed substrates show an adsorption level of above 90%. Since the substrates chosen differ from each other in a number of ways, the actual adsorption values show wide variation.