Vanadium(V) reduction by using a by-product of the yellow phosphorus industry

Abstract

Release of vanadium(V) from industry has threatened the environment and human health. In this paper, a removal method of vanadium(V) is proposed using a by-product of the yellow phosphorus industry (phosphorus-iron) as a reducing agent. The thermodynamics analysis shows that the Gibbs free energy is always negative from 0 to 100 °C, indicating a spontaneous process. Effect of the phosphorus-iron slag/sulfuric acid dosage and temperature on the removal efficiency is comprehensively studied, and the kinetics parameters are calculated based on a quasi-first order reaction kinetics model. Results indicate that vanadium(V) can be entirely reduced by using phosphorus-iron slag, the frequency factor and apparent activation energy are 3.23 × 109 min−1 and 64.50 kJ·mol−1 for vanadium(V) reduction. Based on above results, a lab-scale reactor is constructed and achieves a removal efficiency of ∼100% and a treatment capacity of 200 ml vanadium(V) solution (2 g·L–1) within 3 h. This work demonstrates the feasibility of vanadium(V) reduction using phosphorus-iron slag as a reducing agent in applications.