Fenton type processes for minimization of organic content in coloured wastewaters. Part II: Combination with zeolites

The addition of solid particles, namely synthetic zeolites NH4ZSM5 and HY, was investigated in order to enhance the efficiency of AOPs for dye wastewater treatment. Experiments were conducted at the optimal operating parameters for each Fenton type process and studied coloured pollutants established in Part I of this study in order to find the optimal dose of applied zeolites and understand their role in the new combined AOPs. Degradation of the studied dyes, C.I. Reactive Blue 49 and C.I. Reactive Blue 137, was monitored by means of the UV/VIS, TOC and AOX analysis, thus determining decolourization and mineralization extents of model solutions. Organic content adsorbed onto applied zeolites after the treatment was scanned and characterized using FT-IR spectrophotometer. Applied AOPs in combination with zeolites were shown to be very successful in colour removal, >98%, similarly like Fenton type processes reported in Part I of this study, while improvements in the mineralization of the studied dyes depended on the type and the dose of zeolite, as well as on dye structure and the type of applied AOP.