Investigation of the Efficiency of the UV/H2O2 Process on the Removal of Dye Acid Green 16 from Aqueous Solutions: Process Optimization and Toxicity Assessment

摘要

The effects of the removal of Acid Green 16 (100 mg AG-16/dm(3), COD = 111 mg O-2/dm(3)) from aqueous solutions by the UV/H2O2 process in UV reactors: low pressure lamp (LP, 15 W) and medium pressure lamps (MP, 150 W) are presented. The best results of AG-16 removal were obtained for H2O2 250 mg/dm(3) (99.85%, AG-16 = 0.15 mg/dm(3)) and 200 mg/dm(3) (99.80%, AG-16 = 0.20 mg/dm(3)) for LP and MP lamps, respectively, with the same parameters, i.e. 30 min reaction time and pH 6. Under these conditions, the AG-16 solution was completely discolored and the COD removal efficiency was 57.3% (LP lamp) and 63,4% (MP lamp). However, at optimum conditions of decolorisation, no decrease in the toxicity of solutions (Microtox test) was observed. For the MP lamp, the toxicity of solutions remained at the same level as in the initial solutions (Toxicity Unit, TU = 3), whereas in the case of the LP lamp, the TU value after the process increased to 6. In conclusion, the AOPs for toxic pollutants should also be optimised from the point of view of toxicity.