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Ground Water Denitrification by Packed Bed Bioreactor With KMT Packing

Hemmati, Azadeh | 2009

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 39833 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Borghei, Mehdi
  7. Abstract:
  8. In this study biological denitrification method by moving bed biofilm reactor is investigated. The main advantage of MBBR reactor is due to their capacity for high removal rates and low operational problems such as clogging. Two MBBRs in series with 3 liter volume each, were designed in experimental set up and used in this research. Nitrification reactor worked under aerobic conditions and denitrification reactor operated under anaerobic conditions. Methanol was used as carbon source in the reactors throughout the study. Fifty percent of each reactor volume was occupied with KMT1 packing. To finding the optimum nitrate loading rate, the concentration of ammonium and nitrate were changed from 100 to 400 mgN/l. effluent of each reactor was monitored in 24,16,8 and 4 hr HRT and steady state conditions, and nitrate, nitrite and residual methanol concentrations was measured. It was concluded that, first the ammonium present in feed diffuses to the biofilm layer on the packings and by autotrophic microorganisms layers, ammonia is used to produce nitrate. At second stage heterotrophic denitrifier bacteria convert nitrate to nitrogen. According to results, the removal kinetic and optimum loading rate was estimated during the experiments in different concentrations and different HRTs for this type of reactor. According to experiences by ammonium chloride as feed, the optimum hydraulic retention time for aerobic reactor was more than the one for anaerobic reactor. So by diminishing the nitrification reactor sodium nitrate was fed to the anaerobic reactor directly. Maximum nitrate removal observed in 3-4 g NO3-N/m2 packing d loading rate, and it was 2.9 g NO3-N/m2 packing d. So the optimum nitrate loading rate is equal to 3.5 g NO3-N/m2 packing d. Also, the optimum COD is 6.5 g COD/g N or 1.625 g C/g N. Considering the kinetic k and KS was estimated 0.1 to 0.5 d-1 and 0.2 to 8.0 mg/l.

  9. Keywords:
  10. Groundwater ; Modeling ; Moving Bed Biofilm Reactor (MBBR) ; Stable Modes ; Polyphenylene Oxide (PPO)Hollow Fiber Membrane ; Carbon Source

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