Decolorizing dye wastewater from the agate industry with Fenton oxidation process

The aim of this work was to investigate the efficiency of Fenton’s reaction in the treatment of the effluents generated by the agate industry. Experiments with different dosages of Fenton’s reagents (H2O2 and FeSO4) were carried out and the treated wastewater quality was analysed in terms of colour, turbidity, suspended solids, COD, surface tension, and sludge generation. Results showed that 2 mL L−1 of H2O2 (32–36.5%) and 0.16 g L−1 of FeSO4 dosages are enough to completely decolourise the effluent, remove suspended solids, reduce the organic content and increase the surface tension. Optimised Fenton’s conditions were used to investigate by GC–MS the organic products remaining in the degradation process. The analysis of the mass spectrum of the compounds present in the wastewater after degradation by the Fenton’s process showed the presence of xylene, linear and branched hydrocarbons, phenolic compounds, and nitrogenated phenol as residual compounds. Thus Fenton’s reaction may be used as a potential chemical oxidant for the treatment of dye organic effluents.