A novel adsorptive ceramic membrane for efficient strontium removal

Abstract

In this paper activated carbon (AC) was doped with iron oxide (Fe2O3) nanoparticles and characterized and tested for its adsorptive efficiency towards strontium by varying the contact time, pH and strontium concentration in the feed solutions. The modified adsorbent (AC-Fe) proved to be far more effective than raw AC for strontium adsorption. Based on these results, novel hybrid ceramic membranes were prepared by incorporating AC and AC-Fe nanocomposites into an alumina (Al2O3) matrix via mixing-casting-sintering method. The pristine Al2O3, Al2O3/AC, and hybrid Al2O3/AC/Fe membranes were characterized and tested for strontium rejection. The incorporation of AC-Fe nanocomposites into the Al2O3 membrane matrix notably affected the average pore size, hydrophilicity and adsorption capabilities of the prepared membranes. The Al2O3/AC/Fe membrane was shown to be far superior relative to the pristine Al2O3 membrane and the Al2O3/AC membrane in terms of flux and strontium removal efficiencies at various pH values and strontium concentrations in the feed. Approximately 90 % of strontium was removed at a pH 7 and at a feed concentration of 2 mg/L. The Al2O3/AC/Fe membrane, when tested with real treated sewage effluent, exhibited more than 80 % removal of strontium from wastewater.