Study On Treatment Technique Of Uv/o₃/fe³⁺ Applied In Printing And Dyeing Wastewater

This study uses O₃,UV,and Fe³⁺ technology ,which was applied in the advanced treatment to the secondary biological effluent treated by A/O process from XinDa Printing and Dyeing factory. Study examined treatment effect of Fe³⁺ dosage,ozone dosage,pH,reaction time and intensity of ultraviolet irradiation. And on this basis, it analyses the interaction between them and a majority of organic matter in printing and dyeing wastewater was directly degradated to CO₂ and H₂O. In addition, O₃/UV/Fe³⁺ technical used to the advanced treatment the printing and dyeing wastewater treatment and reuse to production that have not been reported at home and abroad. Therefore, this study has a strong innovative and more far-reaching in economic and practical value.Through a series of experiments, the following conclusions:1. The degree of the factors impacting on the removal of COD is: [Fe³⁺]>[O₃]> pH > HRT; The best reaction conditions is: [Fe³⁺] 3mg/L , [O₃] 9.22mg/L, pH value10, hydraulic retention time 60min.In optimum reaction conditions , The removal rate of COD reached 90%, the chroma 2, The removal rate of TOC reached 98%.2. In the initial stage, the synergy between UV and O₃ is obvious, as the reaction continues it is not obvious; the synergy between UV and Fe³⁺ is not as obvious as the synergy between the UV and O₃, and even in acidic conditions, it did not show the synergy between them, but UV/O₃/Fe³⁺ reaction system compared to others have a better effect for the total removal of organic matter.3. Fe³⁺ played a certain role in adsorption in the reaction, and with the pH value increases. However, the role of Fe³⁺ as flocculants is less than its own in the reaction solution as oxidation catalyst. When Fe³⁺ was used alone in treatment, it showed smaller as the adsorption and partial catalytic oxidation than in UV/ Fe³⁺,O₃/ Fe³⁺and O₃/UV/Fe³⁺.4. It illustrates that organic pollutants is degradated into CO₂ and H₂O directly by UV/O₃/Fe³⁺ reaction system. Through the determination of TOC and UV-visible spectrophotometers spectra.