Degradation of Para-Phenylenediamine in Aqueous Solution by Photo-Fenton Oxidation Processes

In this research Photo-Fenton Oxidation of Para-Phenylenediamine (PPD) in aqueous solution by UV/Fenton’s reagent (Fe2+ and H2O2) was investigated. Experiments were conducted in a batch reactor, at pH 3.5 and at 25°C with a source of UV-C light. The effects of different reaction parameters such as initial PPD concentration, pH of the solution, ferrous concentration, Hydrogen peroxide concentration, on the oxidative degradation of PPD were measured. Final concentration of PPD and COD of the solution after treatment were determined to know degree of degradation of the compound. Iron source used for photo-Fenton’s oxidation were Ferrous Sulphate (FeSO4.7H2O).The optimum conditions established by Fenton’s oxidation without UV, were considered for this investigation. Only the maximum removal conditions were tried with the UV for reaction time of 3 hours. The results showed that under optimum experimental conditions, the pH 3.5, 50 mg/L H2O2, 3 mg/L Fe2+and UV reaction time of 3 hours, the initial concentration 10 mg/L of PPD was reduced by 71.20% with 65.89% COD removal. Likewise the removal efficiencies for PPD concentration of 20, 30, 40 and 50 mg/L keeping the same proportion of H2O2and Fe2+dosage (with ratios of PPD:Fe2+:H2O2::10:1:16.7) were investigated and the results showed, PPD removal were 65.10, 61.23, 58.34 and 54.26% and COD removal was 61, 54, 52 and 50.32% respectively. From the results obtained it can be concluded that Fenton’s reagent favours the lower concentration of Phenylenediamines and UV-C assisted photo-Fenton showed that the photo-Fenton process was very effective than the normal Fenton process.Keywords: Para-Phenylenediamine; COD; UV-C light; Fenton’s reagent; Oxidatio

Degradation of Para-Phenylenediamine in Aqueous Solution by Photo-Fenton Oxidation Processes

In this research Photo-Fenton Oxidation of Para-Phenylenediamine (PPD) in aqueous solution by UV/Fenton’s reagent (Fe2+ and H2O2) was investigated. Experiments were conducted in a batch reactor, at pH 3.5 and at 25°C with a source of UV-C light. The effects of different reaction parameters such as initial PPD concentration, pH of the solution, ferrous concentration, Hydrogen peroxide concentration, on the oxidative degradation of PPD were measured. Final concentration of PPD and COD of the solution after treatment were determined to know degree of degradation of the compound. Iron source used for photo-Fenton’s oxidation were Ferrous Sulphate (FeSO4.7H2O).The optimum conditions established by Fenton’s oxidation without UV, were considered for this investigation. Only the maximum removal conditions were tried with the UV for reaction time of 3 hours. The results showed that under optimum experimental conditions, the pH 3.5, 50 mg/L H2O2, 3 mg/L Fe2+and UV reaction time of 3 hours, the initial concentration 10 mg/L of PPD was reduced by 71.20% with 65.89% COD removal. Likewise the removal efficiencies for PPD concentration of 20, 30, 40 and 50 mg/L keeping the same proportion of H2O2and Fe2+dosage (with ratios of PPD:Fe2+:H2O2::10:1:16.7) were investigated and the results showed, PPD removal were 65.10, 61.23, 58.34 and 54.26% and COD removal was 61, 54, 52 and 50.32% respectively. From the results obtained it can be concluded that Fenton’s reagent favours the lower concentration of Phenylenediamines and UV-C assisted photo-Fenton showed that the photo-Fenton process was very effective than the normal Fenton process.Keywords: Para-Phenylenediamine; COD; UV-C light; Fenton’s reagent; Oxidatio

Structural studies on nitroimidazooxazoles with antitubercular and antileishmanial activities

145-1512,3-Dihydro-2-ethyl-6-nitroimidazo[2,1-b]oxazole and 2,3-dihydro-3-phenyl-6- nitroimidazo[2,1-b]oxazole are found to exhibit good in vitro and in vivo activity against Leishmania donovani. These molecules had been reported earlier to have potent antitubercular properties. Since the synthetic route to these involves opening mono substituted oxiranes by 2,4-dinitroimidazole, many structural possibilities exist for the products, particularly regarding location of the substituent (ethyl, phenyl) in the oxazole ring. The structures given earlier by us needed confirmation. Single crystal X-ray studies have confirmed the structure of the product from butylene oxide and has led to revision of structure of the product from styrene oxide. NMR spectra, HMBC spectrum and proton coupled 13C NMR spectrum of the monocyclic precursor alcohols have established their structures convincingly

Structural studies on nitroimidazooxazoles with antitubercular and antileishmanial activities

2,3-Dihydro-2-ethyl-6-nitroimidazo[2,1-b]oxazole and 2,3-dihydro-3-phenyl-6- nitroimidazo[2,1-b]oxazole are found to exhibit good in vitro and in vivo activity against Leishmania donovani. These molecules had been reported earlier to have potent antitubercular properties. Since the synthetic route to these involves opening mono substituted oxiranes by 2,4-dinitroimidazole, many structural possibilities exist for the products, particularly regarding location of the substituent (ethyl, phenyl) in the oxazole ring. The structures given earlier by us needed confirmation. Single crystal X-ray studies have confirmed the structure of the product from butylene oxide and has led to revision of structure of the product from styrene oxide. NMR spectra, HMBC spectrum and proton coupled C-13 NMR spectrum of the monocyclic precursor alcohols have established their structures convincingly