Production of cellulosic biosorbents, used for removing heavy metals from aqueous solution

摘要

Before reaction the reaction mixture or one of the components has elemental sulphur added to it. Production of biosorbents, especially for removing heavy metals from aqueous solutions, comprises heating and phosphorylating cellulose containing materials with phosphoric acid or ammonium phosphate in presence of urea, followed by cooling and washing out impurities. Before reaction the reaction mixture or one of the components has elemental sulphur added to it. Independent claims are also included for the following: (i) products with a P content of 5-10% and N content 1-4%, the N being in the form of carbamide groups; and (ii) products as per (i) above but with the synthesis mixture treated with elemental sulphur prior to reaction.