Versatility of iron-rich steel waste for the removal of high arsenic and sulfate concentrations in water

Abstract

The aim of this work is to evaluate the application of a steel waste, basic oxygen furnace sludge (BOFS), rich in iron, to treat water contaminated with elevated arsenic and sulfate concentrations. In the first step, three doses (10, 60, and 80 g L⁻¹) of BOFS were tested to investigate the removal of As(III) and As(V) (67 mg L⁻¹) and sulfate (3700 mg L⁻¹) separately from an aqueous solution. In the second step, the efficacies of BOFS (10 g L⁻¹) and commercial ZVI (5 g L⁻¹) were compared to simultaneously remove arsenic and sulfate. The pH of the feed solution was adjusted to 2.5 and monitored during the experiment. The use of BOFS achieved arsenic removal up to 92% and sulfate removal of nearly 40% after 72 h of contact time. Use of BOFS also increased the solution pH to 12. Similar removal levels were achieved with both BOFS and ZVI. These results confirm the potential application of BOFS to remove high arsenic and sulfate concentrations from acidic solutions. The data obtained here should be used as a basis for further studies on the remediation of acid mine drainage with high concentrations of arsenic and sulfate using an abundant and low-cost steel waste.