Removal of lead ions from wastewater using novel Schiff-base functionalized solid-phase adsorbent

Abstract

ABSTRACTThis article discusses the synthesis, characterization and lead ions sorption capability of a novel recyclable Schiff-base anchored cross-linked polyacrylamide. The synthesized polymeric adsorbent was characterized by FT-IR technique, XRD and SEM analysis. Sorption parameters, such as solution’s pH, contact time, polymer dose, lead ions initial concentration, etc., were studied and optimized. Experimentally, the optimum sorption pH was around 5.0 and the sorption equilibrium was attained after 30 min. Under the optimal conditions, the maximum sorption capacity was found to be 355 mg/g, which is considered high when compared with different adsorbents. Effect of interfering ions on the sorption capacity was explored. Sorption isotherms, kinetic and thermodynamic studies were considered to identify the sorption behavior of the new polymeric adsorbent. Sorption isotherm studies showed that the maximum sorption capacity was attended as a result of homogeneous monolayer sorption of lead ions on the surface of the synthesized polymeric adsorbent. The mechanism of lead ions sorption by the synthesized polymeric adsorbent was found to be chemisorption complexation mechanism. Moreover, kinetic studies revealed that the sorption process followed a pseudo second order kinetic model. Thermodynamic data depicted that the sorption process is spontaneous, reversible and exothermic in nature. Experiments on elution and reusability of the synthesized polymeric adsorbent were executed and the results showed its validity for reuse for at least four cycles with 11% loss in its original capacity. Finally, the applicability of the synthesized Schiff-base anchored solid phase adsorbent for the removal of lead ions from industrial wastewater was explored and the results indicated its good removal efficiency.