Resumo

RADOVIć, Miljana D et al. Effects of system parameters and inorganic salts on the photodecolourisation of textile dye Reactive Blue 19 by UV/H₂O₂ process. Water SA [online]. 2014, vol.40, n.3, pp.571-578. ISSN 1816-7950.  http://dx.doi.org/10.4314/wsa.v40i3.21.

The photodecolourisation of textile dye Reactive Blue 19 (RB 19), an anionic anthraquinone dye of the reactive class, was investigated using UV radiation in the presence of H₂O₂ in a batch photo-reactor with low-pressure mercury lamps. The effects of the system parameters: initial pH, initial dye concentration, concentration of peroxide and radiation intensity, as well as the presence of salts, (NaCl, Na₂SO₄, NaNO₃, NaH₂PO₄) on dye decolourisation was examined. Increasing the initial pH resulted in an increase in decolourisation efficiency. Results showed that with an increase of dye concentration from 10 to 100 mg∙ℓ^-1, the efficiency of the process decreases. The highest decolourisation rates were noted at H₂O₂ concentrations of approximately 30 mmol∙ℓ^-1. The increase of radiation intensity from 730 to 1 950 µW∙cm^-2, linearly increases decolourisation efficiency. The inorganic ions investigated have inhibiting effects on RB 19 decolourisation by the UV/H₂O₂ process with inhibition intensities in the following order: H₂PO₄^- > NO₃^- > SO₄^2- > Cl^-. This study has shown that the UV/H₂O₂ process is a promising technology for degradation of RB 19 in water and wastewater.

Palavras-chave : UV/H₂O₂ process; Reactive Blue 19; decolourisation; inorganic salts.

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