Shallow Shell SSTA63 resin: a rapid approach to remediation of hazardous nitrate

Abstract

This study examines the potential of Purolite Shallow Shell™ SSTA63 anion exchange resin for mitigating nitrate ion (NO₃⁻) contamination in aqueous environments. Through systematic experimentation, including dosage optimization, pH dependency, kinetic and desorption studies, we investigate the sorption behavior and practical applications of the resin. Results indicate that the resin effectively removes NO₃⁻ ions, with maximum efficiency achieved within 10 minutes. When 0.025 g of resin was used, 75% of NO₃⁻ was removed, whereas with 0.05 g, 89% was removed, and with 0.1 g of resin, 95% was removed. At pH 1, approximately 50% of NO₃⁻ ions were removed, with removal efficiency reaching 97% between pH 4 and 10. Sorption isotherms affirm the suitability of the Langmuir model for the current investigation. The monolayer maximum sorption capacity (q_max) value was found to be 53.65 mg g⁻¹. The resin demonstrates robust desorption capabilities using 0.1 M hydrochloric acid (HCl), effectively desorbing NO₃⁻ above 99%, indicating easy NO₃⁻ desorption and resin regeneration. The presence of coexisting ions such as chloride (Cl⁻), sulfate (SO₄²⁻), and phosphate (PO₄³⁻) showed a minimal impact on NO₃⁻ removal in individual binary mixtures, with efficiencies exceeding 93%, suggesting a strong selectivity of the resin towards NO₃⁻. Purolite SSTA63 anion exchange resin exhibited a high affinity for NO₃⁻ ions, even over other competing ions, despite the general trend of ion exchange resins to favor ions with a higher atomic number and valence. Overall, this resin presents a promising solution for NO₃⁻ removal, with implications for water treatment and environmental remediation.