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sonicatin presentation

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sonicatin presentation

  3. 3.  OUTLINE OF THE PROBLEM  Water pollution is a serious problem throughout the world. According to the UN’s latest figures, approximately 40% of the world’s population of more than two billion people faces water shortage.  Chemical industry, especially pharmaceutical industry is at the forefront of the water management challenge, due to increasing government pressure on effluent discharge, raw water usage, increasing process water costs and in many locations, general lack of available water.
  4. 4.  pharmaceuticals have been reported to be present in surface water and sewage effluent treatment plants (STPs) due to their poor biodegradability. Because of their toxicity to various microorganisms, poor microbial elimination efficiencies are particularly expected for antibiotics and various countries regulate the level of antibacterial residues in agricultural, veterinary, dairy, and meat-based food products.  Antibiotics and other domestic chemicals are normally released to the environment after going through treatment in wastewater treatment plants, or domestic septic systems, which often are not designed to remove antibiotics
  5. 5.  Various chemical oxidation techniques have emerged in the last decades for the treatment of industrial wastewaters.  On the other hand, the emerging wastewater treatment methods are gaining popularity since they are more efficient in converting harmful organic pollutants into innocuous compounds such as carbon dioxide and water.  Among the emerging technologies, advanced oxidation processes have emerged as potentially powerful methods that are capable of transforming the pollutants into harmless substances.
  6. 6. •Ultrasonication (US) •Ultrasonication / Hydrogen Peroxide (US/H2O2) •Fenton reaction •Ultrasonication / Fenton’s reaction (US/Fenton)
  7. 7.  The world’s highest drug levels entering Indian stream are from a treatment plant in an Industrial area (Patancheru) of Telangana, where about 90 Indian drug manufacturing industries dump their residues/wastes.  There has been an increasing concern about the impact of antibiotic waste water on public health and on the environment not only due to their toxicity to human and aquatic microorganisms.
  8. 8.  Gemifloxacin is known to cause severe pollution problems in aquatic environments. Gemifloxacin is an oral broad- spectrum quinoline antibacterial agent used in the treatment of acute bacterial exacerbation of chronic bronchitis and mild to moderate pneumonia. Gemifloxacin being chosen as a model compound for the degradation using advanced oxidation process. Hence, the objective of the present study is focused on the comparative degradation and assessment of this compound by different AOPs processes (US, US/H2O2, fenton reaction Sono/Fenton,).
  9. 9. •Degradation of gemiflaxocin with Ultrasonicator •Peroxide mediated sonodegradation of Gemifloxacin. •Sono Fenton assisted mineralization of the model compound •TiO2 mediated sonodegradation of the model compound •To study a wide range of experimental conditions such as frequency, power, pH, H2O2 and Fe+2 for the degradation of this compound. •Evaluation of the degradation of the compound in terms of COD reduction •Finally, a comparative assessment of all the processes studied will be done in the present study to evaluate the efficacy of the treatment
  10. 10.  Sample  The model compound selected for this study is Gemifloxacin procured from pharma lab. Aqueous stock solutions of Gemifloxacin were prepared by dissolving Gemifloxacin in ultra pure Milli-Q water.
  11. 11. s.no Name of the Chemical Molecular Formula 1 H2O2 2 Ferrous Sulphate FeSO4 3 Titanium Dioxide TiO2 4 Sodium thio Sulphate Na2S2O3 5 Ferrous Ammonium Sulphate (FeNH4 )2 (SO4)2 6 Potassium dichromate K2Cr2O7 7 Mercuric Sulphate HgSO4 8 Silver Sulphate AgSO4 9 Sulfuric Acid H2SO4
  12. 12. 2.3Equipment/Instruments The following Instruments/Equipment were used for analytical work 2.3.1. UV –Visible Spectrophotometer (analytic jena SPEKOL 1200)
  13. 13. Fig 2.3.2 A Schematic representation of ultrasonicator
  14. 14.  Desired quantities of substituted gemifloxacin is weighed and dissolved in distilled water to prepare stock solution. The shelf life of the stock solutions was maintained for 1 week. Further dilutions are made from stock solution. All the stock solutions, standards and pure compounds are stored in dark below room temperature. Experimental Methodology
  15. 15. Analytical procedure Gemifloxacin concentration is measured by shimazdu -2450 UV-Vis Spectrophotometer at a wave length of 265nm. Reduction in COD is calculated as per the standard method No. 5220 C, from STANDARD METHODS for the examination of Water and Wastewater 20th addition 1998, APHA and pH is measured using pH meter (ELICO LI-120, India).
  16. 16. Degradation of the selected Gemifloxacin Degradation of the selected gemifloxacin using various AOPs is examined at different operational parameters. A series of experiments are carried out to evaluate the degradation trends and further rate kinetics is determined.
  17. 17.  A comparative assessment of Gemifloxacin degradation by different AOPs (US, US/ H2O2, Fenton and US/Fenton is performed in terms of compound and COD reduction after optimization of all the parameters. Finally, cost evaluation studies are carried to determine the degradation efficacy of the treatment system.
  18. 18.  In this chapter investigations are carried out for the degradation of gemifloxacin. The rate of degradation of gemifloxaci is investigated operational parameters such as ultrasonic power and ultrasonic frequency, insitu sonoperoxidation, Fenton, Sonofenton. The results obtained during the degradation studies are presented in this chapter and discussed in detail.
  19. 19.  Effect of Frequency  The sonochemical degradation of gemifloxacin is studied under two different frequencies (25 kHz and 33 kHz). Fig 3.1 shows the percentage degradation of gemifloxacin at two frequencies. It can be illustrated from the figure that the % degradation of Gemifloxacin was increased with increasing the applied frequency. That is of 16 and 12% at 33 kHz and 25 kHz.
  20. 20. 0 2 4 6 8 10 12 14 16 18 0 min 30 min 60 min 90 min 120 min 150min %Degradtionofgemifoxacin Time (min) 25khz 33khz S.No. Frequency Degradation of Gemifloxacin(%) 1 25kHz 12 2 33kHz 16 Effect of frequency on sonochemical degradation of gemifloxacin
  21. 21. Effect of Power Sonochemical degradation of gemifloxacin is studied at different powers of 500W, 880W and 1255W (Fig.3.2). From the graph it is clearly seen, that %degradation of gemifloxacin increased with increasing applied power. It is observed that at power of 500W only 12% of the gemifloxacin concentration is degraded. As the power is increased to 1255W, increase in degradation (20%) is observed.
  22. 22. 0 5 10 15 20 25 0 min 30 min 60 min 90 min 120 min 150min %degradationof gemifloxacinAxis Time(min) 500w 885w 1255w Effect of power on sonochemical degradation of gemifloxacin S.No. Power Degradation of gemifloxacin (%) 1 500w 12 2 880w 15 3 1255w 20 Effect of power on sonochemical degradation of gemifloxacin
  23. 23. Effect of pH on sonochemical degradation of gemifloxacin: Solution pH is an important factor in determining the physical and chemical properties of the solution which in turn affects the bubble dynamics. The effect of pH on percentage degradation of gcomound in sonication process was investigated by varying the pH from 3-11 (fig 3.3). The results indicated that the ultrasonic degradation in neutral solutions (pH -3) are higher (30%) than those obtained in acidic and basic medium. These results may be caused by the physical and chemical properties of the gemifloxacin.
  24. 24. 0 5 10 15 20 25 30 35 0 min 30 min 60 min 90 min 120 min 150min %Degradationofgemifloxacin Time(min) pH-3 pH -5 pH -7 pH -9 pH- 11 S.No. pH Degradation of gemifloxacin (%) 1 3 30 2 5 28 3 7 26 4 9 27 5 11 22 Effect of pH on degradation of gemifloxacin
  25. 25. Effect of Concentration The effect of initial concentration on the sonochemical degradation of gemifloxacin is investigated at 33 kHz with ultrasonic power of 1255W. The initial concentration of gemifloxacin is varied from 10mg/L to 100mg/L. The initial degradation of gemifloxacin increased linearly from 10mg/L up to a concentration of 25mg/L after which the degradability diminished. At higher concentrations [>25mg/L of initial concentration], the hydroxyl and hydroperoxyl radicals formed in the cavitation bubbles may be completely scavenged by gemifloxacin at the interface and are consequently not released in to the liquid Further .OH and HOO. Radicals recombine with each other to form H2O2.
  26. 26. 0 5 10 15 20 25 30 35 0 min 30 min 60 min 90 min 120 min 150min %Degradationofgemifloxacin Time(min) 10ppm 25pp 50ppm 75ppm 100ppm S.No. Concentration of gemifloxacin (ppm) Degradation of gemifloxacin (%) 1 10 16 2 25 32 3 50 28 4 75 25 5 100 23 Effect of Initial Concentration of gemifloxacin in ultrasonication using ultrasonic frequency of 33 kHz, power output intensity: 1255W; pH: 7.
  27. 27. Degradation of gemifloxacin by US/Fenton (Fe2+/H2O2) The degradation of gemifloxacin compound using sonooxidation is investigated in the presence of Fenton (Fe2+/H2O2) with varying concentration ratios of 1:1 (20mg of Fe2+/20mg of H2O2), 1:5 (20mg of Fe2+/100mg of H2O2), 1:10 (30mg of Fe2+/200mg of H2O2)and 1:15 (20mg of Fe2+/300mg of H2O2). The results are given in( fig 3.7) and the %degradation of the gemifloxacin is observed to only 84% at a fenton ration of 1:1. However, the degradation increased to almost 94% at the fenton ratio of 1:10.
  28. 28. Ultrasound coupled with Fe2+/H2O2, hydrogen peroxide reacts with ferrous ions to generate active hydroxyl radicals, which further accelerate the degradation via the usual Fenton chemistry (8). The resulting Fe3+ can react with H2O2 to generate an intermediate complex (Fe- O2H2 +), which is effectively dissociated into Fe2+ and HO2 . under ultrasonic irradiation. The isolated Fe2+ further reacts with H2O2 and generates a higher concentration of hydroxyl radicals as shown in the equations below.
  29. 29. Fe2+ + H2O2 → Fe3+ + OH- + HO- Fe3+ + H2O2 → Fe - O2H2+ + H+ Fe - O2H2+ + ))) → Fe2+ + HO2 . Fe2+ + H2O2 → Fe3+ + OH- + HO-
  30. 30. 0 10 20 30 40 50 60 70 80 90 100 0 min 30 min 60 min 90 min 120 min 150min %Degradationofgemifloxacin Time(min) 20ppm 100ppm 200ppm 300ppm Effect of sono Fenton on the degradation of gemifloxacin
  31. 31. S. No. Fenton (Fe2++ H2O2 ) ratio’s Degradation of gemifloxacin (%) 1 1:1 84 2 1:5 94 3 1:10 90 4 1:15 78 Effect of Fenton on the degradation of gemifloxacin (25 ppm) at pH: 3 using ultrasonic frequency of 33 kHz, power output intensity: 1255W
  32. 32. COD Reduction (%): To further determine the % degradation of COD (Initial COD is 300mg/l) on sonodegradation of gemifloxacin in US, US/H2O2,fenton process and US/Fenton systems are given in fig.3.9. The maximum COD reduction of gemifloxacin i.e.92% was observed in US/Fenton system where as 50% cod reduction was observed in Fenton reaction (after 2hrs reaction time) and 55% was observed in US/H2O2 after 2hrs of ultrasonic irradiation. The highest removal was observed in US/fenton system compared to US, Fenton reaction and US/H2O2.
  33. 33. 0 10 20 30 40 50 60 70 80 90 100 0 min 30 min 60 min 90 min 120 min 150min %CODReductionofgemifloxacin Time (min) US US/H2O2 Fenton US/ Fenton
  34. 34. S.No. Reactive Systems COD Reduction (%) 1 US 28 2 US/H2O2 65 3 Fenton reaction 58 4 US/Fenton 92 COD Reduction of gemifloxacin with different reactive systems
  35. 35. CONCLUSIONS •The results of this study showed that the degradation of gemifloxacin is strongly accelerated by the sonochemical oxidation process. •The rate of degradation of gemifloxacin by US/Fenton is greater than that which can be achieved by either ultrasound alone or in combination with any other chemical or reagent used in the present study. •H2O2 played an important role in degradation efficiency which could be well described via its varied concentration effect on response. •Thus, sonochemicaloxidation process could be used as an effective treatment system for the maximum mineralization of gemifloxacin.