Efficient removal and recovery of vanadium (IV and V) from high acidic waste water with resins D851 and D201: A comparative study

Vanadium in acid waste water poses a potential environmental hazard due to its mobility and toxicity. A chelating resin D851 was used to remove and recover the vanadium from the acid solution system in contrast to resin D201. The adsorption efficiency of vanadium was >98 % with resin D851 at pH value of 1.5 for 60 min, while the adsorption efficiency of vanadium (IV and V) with resin D201 was <40 % and 60 %, respectively. Furthermore, the equilibrium adsorption capacity of vanadium (IV) was 162 mg/g with D851 and 104 mg/g with D201, respectively. The adsorption selectivity of vanadium with resin D851 was also better than that of resin D201 from titanium dioxide waste liquid (TDWL), in which the adsorption efficiency of V, Fe, Al, K, and Na was 88 %, 17 %, 14 %, 1 % & 2 % with D851, and 46 %, 33 %, 23 %, 5 % & 6 % with D201, respectively. The adsorption efficiency of vanadium remained >97 % within 10 times with the used resin D851 after regeneration. The adsorption process was accorded with the Freundlich model belonging to chemical adsorption. The vana-dium could be adsorbed with resin D201 by ion exchange between -OH of the -N(CH3)3OH and the anions of V (IV) and V(V). The -COOH of -CH2-N-(CH2COOH)2 in resin D851 played a key role, in which the -OH could be loosed to adsorb vanadium anions, and the H atom could also be loosed to form the stable conjugate structure of O-C-O adsorbing the cations of V(IV) and V(V).

Automated summary

The study found that resin D851 had higher vanadium adsorption efficiency in acidic wastewater compared to D201, and it had better selectivity. The equilibrium adsorption capacities for vanadium (IV) were 162mg/g and 104mg/g, respectively. Additionally, after regeneration, the adsorption efficiency of vanadium with resin D851 remained above 97%.