Bagasse hydrogels: water absorption and ions uptake

Purpose - The purpose of this paper is to prepare and optimize the preparation conditions of some new hydrogels and in addition, evaluate their water absorbance at different mediums and their ability to remove ions from aqueous solutions. Design/methodology/approach - Cellulose was extracted from depithed bagasse at two different pulping conditions; 3 and 6 hours cooking times, pulp (I) and (II), respectively. These pulps, in addition to cotton linter for comparison, were grafted with acrylamide followed by cross-linking with glutaraldehyde. The networks were partially hydrolyzed and the structures of products (before and after hydrolysis) were studied using FTIR, SEM, TGA and X-ray. The optimum preparation conditions were identified, before and after hydrolysis, to achieve maximum absorbance and the ability of prepared hydrogels to remove ions from solutions was investigated. Findings - Maximum level of absorption was recorded using hydrogels prepared with monomer concentration = 0.8 mol/l, cross-linker concentration = 0.01 mol/l, reaction time = 2 hours and temperature = 65 C. Hydrogels prepared using pulp (I) showed the best absorbance behavior and a tendency to remove ions from water. Research limitations/implications - The ability of the prepared gels to remove ions from water could be further investigated to evaluate the ability of their use in a multi-filtration system for water treatment. Practical implications - This piece of work has suggested a simple way to convert an agricultural waste to hydrogel able to remove metal ions from water. Social implications - Consuming this type of waste reduces the risks resulting from its burning in some countries, such as Egypt, that produce large amounts of it. Originality/value - In this paper, low cost hydrogels, with expected value in water treatment, were prepared using agricultural wastes. They have shown better reactivity than gels prepared using pure cellulosic materials (cotton linter).