Synthesis, Characterization and Performance Validation of Hybrid Cation Exchanger Containing Hydrated Ferric Oxide Nanoparticles (HCIX-Fe) for Lead Removal from Battery Manufacturing Wastewater

摘要

This study is aimed to synthesize, characterize and validate the performance of a novel hybrid nano-adsorbent for selective removal of lead from a battery manufacturing wastewater. The hybrid nano-sorbent, named as HCIX-Fe, was prepared by impregnating hydrated Fe (III) oxide (HFO) nanoparticles inside polymeric cation exchange resin containing negatively charged sulfonic acid (-SO_3~-) fixed functional groups. HCIX-Fe was characterized by SEM-EDX and XRD to confirm the distribution and determination of phase of HFO dispersed inside the hybrid nano-sorbent. Fixed-bed column runs with HCIX-Fe beads were carried out using wastewater from a battery manufacturing plant. The wastewater had a pH of 1.8 and contained of 3.5 mg/L of Pb~(2+) coexisted with 250 mg/L Ca~(2+) ions. The results have shown that HCIX-Fe column could treat lead-contaminated water up to 6,500 bed volumes (BVs) before the occurrence of breakthrough concentration of 0.2 mg/L Pb~(2+) resulting in a removal capacity of 6.85 mg Pb~(2+)/ml of the HCIX-Fe bed. Under similar condition, adsorbent columns with cation exchange resin (C100), granulated activated carbon (GAC) and granulated activated carbon impregnated with HFO (GAC-Fe), could treat the same wastewater only until 400, 900 and 1,500 BVs, respectively. When compared with the parent adsorbents, impregnation by HFO greatly enhanced the Pb~(2+) removal capacity of C100 and GAC by 1,625% and 167%, respectively. Both HFO and high density of sulfonic acid (-SO_3~-) in the host cation exchanger are individually capable of selective removal of Pb~(2+) ions; however the hybrid material demonstrated a synergistic effect for Pb~(2+) removal through the Donnan Membrane effect. Due to amphoteric behavior of HFO, the HCIX-Fe could be regenerated and reused with 10 BVs of 2% HNO_3 and 1% FeCl_3-6H_2O solution.