| A study of the Decomposition and metal recovery of metal-porphyrinic compounds with ultrasonic irradiation process in the presence of radical-induced reactions is presented in this dissertation. Metalloporphyrins existed in petroleum are known as poisonous compounds to catalysts in the catalytic cracking processes of heavy oil. The other structural synthetic analogues of metalloporphyrins, metallophthalocyanines, have been widely used in industries as pigments. Treatment of spent pigments for color and metal removal is of great significance recently.; In the initial investigation, decomposition of metal-porphyrinic compounds dissolved in different solvents with water mixture was performed under ultrasonication. Among these solvents, the chlorinated-type solvents achieved a higher decomposition efficiency due to more oxidizing species generated during sonication process. The other factors such as surfactant, temperature, and hydrogen peroxide that affect the reaction efficiency also were discussed. Under optimal condition, the decomposition efficiency of four target compounds reached over 90% in about one hour.; The proposed mechanism, including several radicals as the major oxidizing species and one important intermediate can explain the reaction pathways. The metal released from the sample decomposition almost can be recovered into an aqueous phase by chelating agent after sonication. The decomposition of target compound under sonication appears to be a pseudo-first-order reaction and inhibited by initial feed concentration. The dependence of the rate constant on the initial concentration can be fitted to the Langmuir-Hinshelwood equation. A kinetic model based on the consecutive first-order reactions can better fit the experimental data.; From an economic perspective, a higher intensity of ultrasound can provide a higher sonochemical effect. Also, the continuous ultrasonication is not necessary to achieve significant enhancement in the decomposition efficiency. The optimal pulse ratio of ultrasound is 60% in the decomposition of NiTPP.; From the results of this dissertation, it can be seen that ultrasonic process is an effective option to treat metal-porphyrinic contaminants or wastes in order to turn them into environment-friendly materials and avoid the release of metals into the environment. |
