Studies On The Chemical Oxidation Of Recalcitrant Organic Wastewater

Many organic pollutants in the wastewater exhibit high toxicity, and are difficult to be treated with conventional biological processes. Advanced Oxidation Processes (AOPs), are emerging as powerful and efficient techniques to destroy such pollutants in recent year.In this work, phenol, aniline, nitrobenzene were chosen as the model pollutants for wet air oxidation treatment. The relationship between the reactivity and the molecular structure of these three compounds was studied. Simultaneous phenol and nitrobenzene wet air oxidation, one of the co-oxidation systems, was thoroughly investigated. The promoted effect of phenol on the nitrobenzene degradation was discussed in detail. Nitrobenzene got 35% removal efficiency in the co-oxidation system at 210 oC after 3 hour degradation, while it was only 9% degradation in the single oxidation system at 260 oC after 3 hours. Catalytic wet air co-oxidation of nitrobenzene and phenol with metal salt was also examined. Co-oxidation system is an alternative method for the recalcitrant organic waste water treatment.Based on the traditional wet air oxidation process, a new efficient and easy wet oxidation system with NaNO₂ as catalyst was developed for wastewater treatment. Trichlorophenol (TCP), a model pollutant, completely degraded in the new catalytic system. With 100 mol % of NaNO₂, more than 99% of TCP was destroyed and 96% of chlorine was mineralized, together with 72% of COD reduction under 0.5 MPa of oxygen at 150 oC for 8 hours. The intermediate(s) produced during...