Abstract
Despite Acid Blue 113 (AB 113)'s extensive use and negative environmental impact, very few studies have focused on its efficient and environmentally friendly removal. This research aims the removal of AB 113 from environmental aqueous media and its consequent enzymatic biodegradation. A strongly basic anion exchange resin in Cl(-) form, Amberlite IRA 402 (IRA 402(Cl(-))) was used for AB 113 adsorption and a laccase was used to further biodegrade it. For the first time, two novel, efficient and environmentally friendly physical-chemical and biological assays for AB 113 wastewater removal and subsequent biodegradation were combined. The adsorption of AB 113 onto IRA 402(Cl(-)) was tested in batch and continuous flux modes. Influence of contact time, concentration and desorption in acidic media were evaluated. The kinetic data were best modulated by the Lagergren model with R(2) = 0.9275. The Langmuir isotherm model best fitted the experimental data, and the maximum adsorption capacity was 130 mg/g. Dye, resin and AB113 loaded resin were characterized by thermogravimetry and FTIR to evaluate their physical chemical properties modification. Based on the performed studies, a consecutive methodology is proposed, incorporating the ion exchange process in the first stage and the biodegradation process in the second. Thus, in the second stage the residual concentration of AB 113 is reduced by an efficient bio-degradation process produced by the laccase at pH = 4.