Anoxic Selector Single Stage Nitrification Process Waste Water Plant Theory and Practise

1,216 views
818 views

Published on

Texas Commission on Environmental Quality (TCEQ) Annual Water Quality Training Conference. Practical application of Nitrification and Denitrification at a new or existing wastewater treatment plant (WWTP). Principles and Theory.

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,216
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
27
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Anoxic Selector Single Stage Nitrification Process Waste Water Plant Theory and Practise

  1. 1. Anoxic selector, single stage nitrification process TCEQ Annual Water Quality Training Conference October 18, 2006 Daniel Christodoss PhD, PE and Mike Jupe City of Waco Water Utility Services
  2. 2. Presentation  Review of Theory  Nitrification  Denitrification Characteristics of bioreactors  Aerated or Oxic  Un-aerated or Anoxic Nitrification Optimization Denitrification Optimization  PRACTICAL APPLICATIONS @ WMARSS   
  3. 3. Nitrification  Oxidation of ammonia to nitrite in oxic conditions by nitrosamonas group (Optimum pH 8.0):  2NH3+ + 3O2 2H+ + 2H2O + 2NO2-  Oxidation of nitrite by nitrobactor group:  2NO2- + O2 2NO3- (nitrates)  Oxygen mechanically provided by blowers  Oxygen Consumption: 4.6 lbs of oxygen per lb of ammonia oxidized to nitrates (energy intensive!)  Recover Nitrification Cost: De-nitrification  Nitrobes that Nitrify are facultative (oxic or anoxic). In anoxic they can use NO3 in lieu of direct O2 for cellular respiration and denitrify
  4. 4. Aerated (Oxic) Bioreactor O2 + Pollutants + Microorganisms Primary Effluent RAS (microorganisms) WAS
  5. 5. Denitrification Using biomass in wastewater as carbon source for bacteria: C5H7NO2 + 4.6 NO32.8 N2 + 5 CO2 (biomass) (nitrates) + 1.2 H2O + 4.6 OH Because within the anoxic reactor no dissolved oxygen is supplied bacteria strip the oxygen molecule from the nitrates and consume the BOD present. ADVANTAGES OF DENITRIFICATION    N2 Nitrate is reduced to nitrogen: NO3 BOD is consumed Alkalinity is replenished saving the buffer for subsequent pH sensitive biological reactions
  6. 6. Un-aerated Bioreactor (Anoxic Zone) Nitrate Recycle Primary Effluent Anoxic Aerobic RAS WAS
  7. 7. Nitrification Optimization Summary  Test nitrification rate occasionally  Select appropriate SRT  Keep DO at min 2 mg/l @ peak conditions  Keep pH about neutral (optimal 7.5 to 8.5)  Provide sufficient alkalinity  Replenish a portion of the alkalinity consumed during the nitrification process by denitrification
  8. 8. Denitrification Optimization Summary  Minimize DO in anoxic zone (< 0.2 mg/l)  Maximize recycle capabilities  Provide sufficient carbon source
  9. 9. Ludzak - Ettinger Process
  10. 10. Brazos River Effluent Influent 4 Digestors Chlorination & Dechlor DAF TF cogen WMARSS Aerial Admin ary rim 4p 5 aeration tanks Sludge Lagoons 4 final clarifiers Filters ks tan Pelletization Facility

×