LOW-COST AND UP-SCALABLE ADSORBENT HYDROGELS FOR ANIONIC DYES REMEDIATION AND INDUSTRIAL WASTEWATER DECONTAMINATION BY ELECTROSTATIC INTERACTIONS

1. Introduction Water pollution from dyes, deriving from the textile industry, food colorants, printing, and cosmetic manufacturing is harmful to the environment, plants, animals, and humans. Dyes removal from contaminated water is a daily challenge for experts in the field, often addressed using adsorption methods. 2. Results and Discussion New low-cost and up-scalable adsorbent materials for anionic dye remediation and water decontamination by electrostatic interactions were developed. To this end, two cationic resins (R1 and R2) were synthesized by reverse suspension copolymerization of styrene-based monomers (M1 and M2) and dimethylacrylamide (DMAA). Upon their dispersion in an excess of water, R1 and R2 provided hydrogels (R1HG and R2HG) with equilibrium degrees of swelling (EDS) of 900% and 1000% and equilibrium water contents (EWC) of 90 and 91%, respectively. They were characterized by ATR-FTIR analyses, rheological experiments, evaluation of content of cationic groups, crucial for the electrostatic-based absorbent activity, and by potentiometric titrations. In absorption experiments in batch, using methyl orange (MO), fluorescein (F), and their mixture (MOF) as dyes models, R1HG and R2HG showed high removal efficiency (RE) (97–100%), while R1HG and R2HG-based columns, mimicking decontaminating systems by filtration, were capable to totally remove from water (100%) all dyes and their mixture in different conditions of use. 3. Conclusions R1HG and R2HG represent low-cost and up-scalable column packing materials that are promising for application in industrial wastewater treatment.