Adsorption of Crystal Violet on Montmorillonite (or iron modified Montmorillonite) followed by degradation through Fenton or photo-Fenton type reactions

GUZ, LUCAS; TORRES, ROSA; CURUTCHET, GUSTAVO; CANDAL. ROBERTO

Journal of Environmental Chemical Engineering

Elsevier

Año: 2014

2213-3437

The feasibility to adsorb and biodegrade crystal violet, a model triarylmethane dye, by bacterial strains isolated from the Reconquista River, a heavy polluted river from Argentina, was explored. Four bacteria strains were isolated and three were identified via 16-S rRNA: Enterobacter sp., Actinobacterium sp., and Rahnella sp. The forth strain (strain III) is a Gram negative rod with positive catalase and oxidase activity. Crystal violet adsorption kinetics and isotherms were determined and the physicochemical parameters were calculated. Adsorption kinetics follows a second order behavior, being faster the adsorption on Actinobacterium sp.. The isotherms were fitted by Langmuir (Actinobacterium sp., Rahnella sp., strain III) and Hill (Enterobacter sp.) model. The adsorption behavior was consistent with the electrophoretic mobility and surface charge of the different bacteria strains. Actinobacterium sp. displayed biodegradation activity of crystal violet in liquid phase; complete discoloration of a solution containing 25 mg L-1 of crystal violet was accomplished in less than 48 hours. The inoculation of the biosorbents loaded with crystal violet with Actinobacterium sp. lead to the complete discoloration of the adsorbed dye in 8 days (90% in 2 days). These results show a possible solution to the final disposition of contaminated adsorbents, which is one of the main problems of biosorption processes.