SYNTHESIS AND CHARACTERIZATION OF MAGNETIC CMC-COFE2O4 ADSORBENTS IN REMOVING AND RECOVERING PHOSPHATE

摘要

Phosphate removal is important to control eutrophication; adsorption is a proven method for this removal. This research used improved co-precipitation method to prepare CoFe2O4-carboxymethyl cellulose (CMC) composite materials, which were then used as adsorbents for phosphate removal. The CMC-CoFe2O4 was characterized using SEM, XRD, and FT-IR. analyses. The research included an analysis of adsorbent desorption and regeneration, and determined that phosphate could be converted to Ca-5(OH)(PO4)(3) by recovering phosphate from a reusable desorption solution. Results showed that the most effective desorption solution was a 5% (w/v) NaOH solution; the optimum regeneration solution was a 15% (w/v) NaNO3 solution. The optimal phosphate removal rate was 95.24%, the saturated adsorption capacity was 3.81 mg/g, and the residual phosphate concentration was 0.48 mg/L in a 10 mg/L phosphate solution. This characterization showed that when using CMC-CoFe2O4, the adsorption was primarily physical adsorption. Using adsorption, desorption, and regeneration, the techniques effectively recovered phosphate from wastewater.