Abstract A heterogeneous Fenton-like process was explored for oxidation of phenazine dye using ceria polishing material (CP-2). XRD, SEM, FTIR, UV-vis DRS, and pHPZC techniques were applied to characterize the catalyst features. The performance of the heterogeneous Fenton-like process was investigated under various parameters (reaction time, pH, H2O2 concentration, catalyst dosage, initial dye concentration, temperature of the medium, and inorganic salt content). Results indicated that the main content of CP-2 catalyst was CeO2 (60-70%) with lower contents of La2O3 (30-40%), Pr6O11 (≤6%), Nd2O3, and CaF2 (≤5%). CP-2 possessed a typical CeO2 cubic fluorite structure with high content of rare earth oxides (REO) and α-Fe2O3. The average crystallite size and band gap energy of CP-2 were found to be 37.2 nm and 3.0 eV, respectively. Over 81.3% of neutral red (NR) oxidation efficiency was achieved in 60 min. Pseudo-first-order kinetic model gave the best fit with an acceptable coefficient of determination R2. The activation energy (Ea) was 16.4 kJ/mol suggesting that the degradation reaction proceeded with a low energy barrier and the removal process was feasible, spontaneous, and endothermic. The synergistic effect of Fe- and/or REO-CP-2 and H2O2 greatly enhanced the reactive oxygen species (ROS) such as •OH, O2 •-, 1O2, and HO2 • for effective oxidation of NR via a heterogeneous Fenton-like process.

Abstract Bismuth ferrite, BiFeO3 (BFO) prepared via a coprecipitation method, was used as an effective photocatalyst for the degradation of methylene blue (MB) using a white light-emitting diode (LED-50 W) lamp. The as-prepared material was characterized by TGA, XRD, SEM-EDX, FTIR, and UV-vis-DRS techniques. The effects of experimental key parameters such as pH, catalyst dosage, initial dye concentration, and calcination temperature were investigated. Results showed that BFO-600 (calcined at 600 °C/3 h) was a rhombohedrally-distorted perovskite oxide with the R3c space group. The average crystal size and band gap energy for BFO-600 were found to be 24.8 nm and 2.1 eV, respectively. Under optimal operating conditions ([MB]=20 mg.L-1, BFO-600/dye mass ratio=0.5 g.L-1, pH=11, and 25 °C), MB/BFO-600/LED process exhibited an efficient photodegradation (up to 94.4%) within 120 min, much higher than the MB sorption process (MB/BFO-600/dark system, 69.4%) and the MB self-photolysis system (MB/LED, 33.9%). The photocatalytic degradation of MB was found to fit well with the pseudo-first-order kinetic model. Thus, the MB photodegradation was attributed to the generation of reactive radicals such as •OH, h+, H2O2, and MB•+ via direct heterogeneous photocatalysis and mediated by MB through a self-photosensitization process of MB over BFO-600 NPs.

Abstract: Background: Varicose veins and the complications of venous disease are common disorders in humans. Objective: To study the effects of bleomycin as a potential new sclerosing agent and its adverse events in treating varicose veins. Methods: Bleomycin-loaded liposomes 0.1ml was injected in the dorsal ear veins of white New Zealand rabbits. Sodium tetradecyl sulfate was used as a positive control. Normal saline was used as negative control. The blood vessels of the treated ears were photographed before and at one hour and two, eight and 45 days after treatment. Biopsies from the treated areas were obtained for histological examination. Blood samples were collected to determine any possible toxicity. Results: Bleomycin by itself was ineffective; therefore, liposomes were used as a vector to deliver bleomycin to the vein lumen. Subsequently, bleomycin started showing its sclerosing effects. Toxicity monitoring showed no apparent hematologic, pulmonary, hepatic or renal toxicities. This study revealed that bleomycin induced vasculitis, which led to vascular occlusion, which was observed on day 1 and day 8. No bleomycin-related injury was noted by histopathological examination of lung sections. The calculation of the lung/body weight coefficient indicated that edema was present in the experimental groups compared with the negative and positive controls. Study limitations: Relatively small number of experimental animals used. Conclusions: This study showed that bleomycin-loaded liposomes were able to induce vasculitis and vascular occlusion without any toxicity or complications. It might be useful, hence, to treat patients suffering from Varicose veins and other ectatic vascular diseases with this agent.