The researchers compared both biologically produced manganese oxides and chemically produced manganese oxides for the oxidation of diclofenac. Because biologically produced manganese oxides are known to have high specific surface areas and high catalytic reactivity, this substance offers higher rates of oxidation for diclofenac when compared to chemically produced manganese oxides.² If biologically produced manganese oxides prove to completely eliminate diclofenac from the water supply, the researchers will have found a solution to rid diclofenac from the water supply.
Materials. Biological manganese oxides were synthesized using an axenic culture of Pseudomonas putida MnB6 in a growth medium, which was supplemented with 〖MnCl〗_2.² A diclofenac …show more content…
The following tests were performed using Erlenmeyer flasks containing NaCl.² The BioMnOx batch experiments were initiated by adding 150 mL of the buffered test solution to BioMnOx pellets and to the diclofenac stock. The chemical 〖MnO〗_2 batch experiments were initiated by adding the chemical 〖MnO〗_2 and diclofenac to 150 mL of the buffered test solution. The controls of this experiment consisted of distilled water and Pseudomonas putida cultures, which were grown in manganese free medium. Lastly, the behavior of 5-hydroxydiclofenac, which is a human metabolite of diclofenac, was examined in distilled water in both an Mn free Pseudomonas culture and in the presence of BioMnOx. In order to distinguish between the removal by sorption onto and the reaction by the manganese oxides, ascorbic acid was added to solubilize the Mn oxides and the sorbed amounts of diclofenac. Inhibition tests with azide were performed to inhibit biological processes. The pH was measured at the beginning and at the end of all of the tests. Samples were taken frequently throughout the experiment to identify diclofenac and other oxidation products, and for …show more content…
Ozonation, photocatalytic oxidation, and catalytic and photocatalytic ozonation experiments were carried out in cylindrical reactors.^4 Each reactor was equipped with mechanical agitation and inlets used for measuring temperature and gas intake, sampling, and one outlet for the gas that was not absorbed. The reactor was located in the center of a wooden box, where four 15 W black light lamps were placed in each of the corners inside the box. The internal walls of the box were also covered with aluminum foil in order to increase the flux of absorbed radiation due to reflection. The evolution of the reaction was followed through the production of formaldehyde, which was formed upon reaction of methanol with hydroxyl radicals. An aqueous solution containing the diclofenac, sulfamethoxazole, and 〖TiO〗_2 were charged at the reactor. In the photocatalytic experiments, the black light was turned on to start the run. In the ozonation experiments, an ozone-oxygen mixture was led into the reactor. In all of the runs at regular intervals, samples were withdrawn from the reactor, centrifuged, and filtered through PET Chromafil filters to retain 〖TiO〗_2 particles and concentrations of pharmaceutical compounds. Throughout this process, dissolved ozone, hydrogen peroxide, and TOC were determined. Ozone concentration in the gas leaving the reactor was also
Materials. Biological manganese oxides were synthesized using an axenic culture of Pseudomonas putida MnB6 in a growth medium, which was supplemented with 〖MnCl〗_2.² A diclofenac …show more content…
The following tests were performed using Erlenmeyer flasks containing NaCl.² The BioMnOx batch experiments were initiated by adding 150 mL of the buffered test solution to BioMnOx pellets and to the diclofenac stock. The chemical 〖MnO〗_2 batch experiments were initiated by adding the chemical 〖MnO〗_2 and diclofenac to 150 mL of the buffered test solution. The controls of this experiment consisted of distilled water and Pseudomonas putida cultures, which were grown in manganese free medium. Lastly, the behavior of 5-hydroxydiclofenac, which is a human metabolite of diclofenac, was examined in distilled water in both an Mn free Pseudomonas culture and in the presence of BioMnOx. In order to distinguish between the removal by sorption onto and the reaction by the manganese oxides, ascorbic acid was added to solubilize the Mn oxides and the sorbed amounts of diclofenac. Inhibition tests with azide were performed to inhibit biological processes. The pH was measured at the beginning and at the end of all of the tests. Samples were taken frequently throughout the experiment to identify diclofenac and other oxidation products, and for …show more content…
Ozonation, photocatalytic oxidation, and catalytic and photocatalytic ozonation experiments were carried out in cylindrical reactors.^4 Each reactor was equipped with mechanical agitation and inlets used for measuring temperature and gas intake, sampling, and one outlet for the gas that was not absorbed. The reactor was located in the center of a wooden box, where four 15 W black light lamps were placed in each of the corners inside the box. The internal walls of the box were also covered with aluminum foil in order to increase the flux of absorbed radiation due to reflection. The evolution of the reaction was followed through the production of formaldehyde, which was formed upon reaction of methanol with hydroxyl radicals. An aqueous solution containing the diclofenac, sulfamethoxazole, and 〖TiO〗_2 were charged at the reactor. In the photocatalytic experiments, the black light was turned on to start the run. In the ozonation experiments, an ozone-oxygen mixture was led into the reactor. In all of the runs at regular intervals, samples were withdrawn from the reactor, centrifuged, and filtered through PET Chromafil filters to retain 〖TiO〗_2 particles and concentrations of pharmaceutical compounds. Throughout this process, dissolved ozone, hydrogen peroxide, and TOC were determined. Ozone concentration in the gas leaving the reactor was also