Manganese-doped ferrihydrite/cellulose/polyvinyl alcohol composite membrane: Easily recyclable adsorbent for simultaneous removal of arsenic and cadmium from soil

Simultaneous removal of arsenic (As) and cadmium (Cd) from soil has been a matter of great concern. In this study, manganese-doped ferrihydrite/cellulose/polyvinyl alcohol composite membranes were prepared via loading manganese-doped ferrihydrite on cellulose mesh and then wrapping with polyvinyl alcohol. The obtained composite membranes exhibited excellent mechanical properties and could be easily separated from soil. The adsorption capacities of Cd(II) and As(III) on the composite membrane were 11.11 mg/g and 72.08 mg/g respectively. After mixing the composite membrane with polluted soil at dosage of 0.3% (w/w), the removal efficiency of the toxicity characteristic leaching procedure leachable As and Cd reached 65% and 69% respectively with one cycle. The stability and reusability of composite membrane were demonstrated by no decrease in tensile strength and the retention of 94% and 96% of As(III) and Cd(II) removal efficiency respectively after four adsorption cycles. The prepared composite membrane had application prospect in the remediation of As and Cd co-polluted soil.