Recycling the steel pickling waste liquor to produce a low-cost material for immobilization of heavy metal(loid)s

Abstract

This work aims to demonstrate the practicability of employing Iron (Fe)-manganese (Mn) binary oxide (FMBO) synthesized from pickling wastewater to immobilize arsenic (As(V)) and antimony (Sb(V)). Visual MINTEQ software was used to simulate the speciation of As(V) and Sb(V) under different pH values. The adsorption performance of FMBO for Sb(V) and As(V) were examined by batch experiments, the pH impact, sorption kinetics, sorption isotherms and the reuse of the adsorbent were investigated. The pH impact results demonstrated that the absorption capacity decreased dramatically as the pH value increased, the maximum adsorption capacities As(V) and Sb(V) were obtained at pH value of 4 as 95.24 and 147.1 mg/g, respectively. The kinetic results indicated that the pseudo-second order model could fit the kinetic data of Sb(V) and As(V) well. Equilibrium studies displayed that the adsorption of Sb(V) and As(V) on FMBO could be appropriately described by Freundlich model. Results of the binary adsorption indicated that Sb(V) exhibited ∼ 5% improvement for As(V) when the initial Sb(V) content raised from 0 to 500 mg/L, while As(V) showed a significant hindrance for Sb(V) adsorption. Moreover, utilization of FMBO could also effectively reduce the TCLP extractable and easy mobile As and Sb in contaminated soil, thus reducing their bioavailability. In view of the advantages of cost-effective, eco-friendly and excellent sorption performance, the steel pickling waste liquor-derived FMBO could be regarded as a promising amendment for remediating As and Sb contamination in environment. • A new low-cost adsorbent (FMBO) was prepared from steel pickling waste liquor. • FMBO exhibited an excellent performance for sorption of As(V) and Sb(V). • The existence of Sb(V) favor As(V) sorption, while As(V) showed opposite effect on Sb(V). • The FMBO could also effectively reduce the bioavailability of soil As and Sb.