Preparation Of Salt-tolerant Superabsorbent Resin And Its Adsorption Behavior To High-salt Wastewater

Salt tolerance of superabsorbent resin is an important factor limiting its use.Cellulose-based superabsorbent resin is a new type of material with cellulose or cellulose derivatives as the main skeleton,which has the advantages of biodegradability and biocompatibility.In this study,sodium carboxymethyl cellulose(CMC-Na)as macromolecular framework,potassium persulfate(KPS)as initiator,N,N-methylene bis-acrylamide(MBA)as crosslinking agent,using reverse suspension polymerization,a new type of salt tolerant cellulose-based superabsorbent resins with biodegradability were prepared.In this paper,the preparation technology of a new completely biodegradable salt-tolerant cellulose-based superabsorbent resin was studied by grafting different concentration of CMC-Na with petroleum-based monomers,and its water absorbency,salt tolerance,adsorption performance,and water holding ratio,as well as water-retention capacity of soil were studied.The main contents and results of this paper are as follows:1.CMC-Na,carboxymethyl chitosan and sodium carboxymethyl starch were used to produce high salt tolerance superabsorbent resins by grafting with petroleum monomers.The water absorption properties were compared and analyzed.The results showed that the cellulose-based superabsorbent resin with 8 wt%CMC-Na had highest water absorbency,and its water absorbency in distilled water and high concentration salt solution were 594.5%and 60.3%,respectively.In addition,it also had good water-retention capacity which was up to 67.5%at 55?for 8 h and up to 25.6%after continuous water loss for 16 h.2.CMC-Na was used to completely replace AMPS to prepare a new biodegradable salt-tolerant cellulose-based superabsorbent resin,and its water absorption,salt tolerance,water retention and adsorption properties were studied.The results showed that,the biodegradable salt-tolerant cellulose-based superabsorbent resin was prepared successfully by using CMC-Na completely replace AMPS,and its swelling ratio in distilled water increased by 164.5%,as well as its salt tolerance increased by 32.2%.Besides,the maximum adsorption capacity of cellulose-based superabsorbent resin for ammonium nitrogen,nitrate nitrogen and phosphate were 30.24 mg·g^-1,20.47mg·g^-1 and29.2 mg·g^-1,respectively.3.The effect of cellulose-based superabsorbent resin in soil was studied via soil leaching and soil water-holding ratio experiments.The results showed that the water-holding ratio of soil treated with cellulose-based superabsorbent resin was 10%?20%higher than that of pure soil.The cumulative leaching loss of NH₄⁺-N was reduced by28.44%and the cumulative loss of NO₃^--N was reduced by 10%.