A laboratory study has been performed on the wastewater treatment (destruction of organic species in water) using a novel process called Integrated Adsorption-Oxidation (IAO) where activated carbon is being utilized as a catalyst-adsorbent, and ozone as oxidant. The results of ozonation alone on the pollutants in water are also reported to provide a comparison with the adsorption-oxidation scheme in semi-batch reactions. All experiments were conducted at room temperature in a semi-batch reactor using five (water soluble) representative chemicals as pollutants: Aniline, Acetamide, Pyridine, N,N-dimethyl formamide and O-cresol. We also studied two volatile compounds: Trichloroethylene and Chloroform. Phenol was studied in a continuous flow reactor.
Results indicate that this new integrated adsorption-oxidation technique provides substantially improved performance over either ozonation or adsorption operating as separate treatment processes. The presence of carbon appears to serve a catalytic effect, where the ozone and active radical species produced in the reaction process now act to regenerate charcoal during the process. This changes a separation technology to a destruction technology.
A detailed analysis of the reaction process supplies important information for understanding the reaction mechanism, and in developing a kinetic model for the future.
Improvements in destruction rate constants for this combined adsorption/oxidation process compared to rate constants for reaction with ozone alone are:
Compound |
Ratio |
Aniline |
1.21 |
Pyridine |
1.13 |
N,N-dimethyl Formamide |
1.59 |
O-cresol |
1.17 |
Acetamide |
1.68 |
Trichloroethylene |
1.14 |
Chloroform |
1.11 |
Ratio = kIAO / kozone alone
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