A Clean Method for Vanadium (V) Reduction with Oxalic Acid

Water pollution deteriorates ecosystems and is a great threat to the environment. The environmental benefits of wastewater treatment are extremely important to minimize pollutants. Here, the oxalic acid used as reductant was used to treat the wastewater which contained high concentration of vanadium (V). Nearly 100% of vanadium was efficiently reduced at selected reaction conditions. The optimization results simulated by response surface methodology (RSM) analysis indicated the parameters all had significant effects on the reduction process, and followed the order: dosage of oxalic acid > reaction temperature > reaction time > initial pH of vanadium-containing wastewater. The reduction behavior analysis indicated that the pseudo first-order kinetics model could describe well the reduction process with Ea = 42.14 kJ/mol, and was described by the equation as followed: −LnC=K0·[pH]0.1016·[n(O)/n(V)]2.4569·[T]2.2588·exp(−42.14/T)·t.