Dissertation > Excellent graduate degree dissertation topics show

Performance and Mechanism of Strengthening Nigrogen Removal by Up-flow Microaerobic-oxic Process

Author: ZhaoShuang
Tutor: ZhangHuanZuo
School: Chinese Geology University (Beijing)
Course: Environmental Engineering
Keywords: Up-flow microaerobic column Strengthen nitrogen removal microaerobic gradients of MLSS particle diameter
CLC: X703
Type: Master's thesis
Year: 2013
Downloads: 22
Quote: 0
Read: Download Dissertation

Abstract


The national12thFive-Year Plan on urban sewage treatment and recyclinginfrastructure construction clearly stated that we should further increase the capacity ofwastewater treatment plants （WWTPs）, speed up the sewage treatment plant upgradingand reconstruction, and improve the function of nitrogen and phosphorus removal. As aconsequence, nitrogen and phosphorus removal is still the challenge to be urgently solvedin the WWTPs. The innovation of new process and techonogies for strengthening nitrogenand phosphorus removal is becoming the focus of research.A novel process, up-flow microaerobic-oxic （M/O） process, for strengtheningbiological nitrogen removal on a laboratory scale was proposed which is consisted of anup-flow microearobic column reactor and an oxic reactor to treat the real domesticwastewater. The up-flow microaerobic reactor is the key unit and integrated theadvantages of micro-aerobic environment and upflow condition. Micro-aerobiccircumstantce is benefit to microorganism diversity which is helpful to many nitrogenremoval pathways such as simultaneous nitrification and denitrification （SND）, shortcutNitrification-denitrification. Upflow condition could form the dissolved oxygen （DO）concentration and mixture liquor suspended solid （MLSS） gradients which contribute toresistance of loading shock. As a result, this new process created necessary conditions forstrengthening biological nitrogen removal.In this thesis, the performance of M/O process under different sludge age, hydraulicretention time （HRT） and Internal return ratio （r） was investigated with demesticwastewater. The optimal operating condition was obtained that sludge age was25d, HRTwas12h, and interal return ratio was200%. Under these conditions, the average removalefficiencies of chemical oxygen demand (CODCr), ammonium nitrogen （NH4+-N）and totalnitrogen （TN-N） were88.3,66.5, and91.8%with effluent concentrations of CODCr,TN-N and NH4+-N of22.8,2.7and16.9mg/L, respectively. The process ran stably and theactivated sludge performed well even when the influent loading varied greatly.Comparision of performance and mechanims between M/O and A/O processes in terms of pollutant removal and the stabllity of reactor was conducted by controlling thesame operation conditions.The result showed that the M/O process was higher15.5%thanA/O process in terms of average removal efficiency of total nitrogen. This phenomenonexisted in up-flow microearobic column reactor and oxic reactor. M/O process has theadvantages of more stable performance and better resistance to the load shock than theconventional A/O process.Investigated the characteristics of microearobic column reactor, we found that therewas sludge concentration gradients along the column reactor height, the MLSS is10g/Lat bottom of microearobic column. Micro-earobic column could change the constituent ofCODCr, improve F/M of influent, and promote using efficiency of carbon. The distributionof sludge particles diameter was measured, the particle diameter ranged in0μm to500μm,mean diameter was about230μm at the same time. So there was dissolved oxygen （DO）gradients within activated sludge flocs, it was good for occurring many novel biologicalreactions of nitrogen removal in this circumstances.

Related Dissertations

  1. An Experimental Study on the Burnout Characteristic of Coal Affected by Ratio and Particle Size,TK227.1
  2. Effect of Structure Differences in Surfactant on the Retention of Phenol During Micellar-Enhanced Ultrafiltration,X703
  3. Research on the Diameter and Shape Control of Silver Nano-particle,TB383.1
  4. Study on an Anaerobic-microaerobic Baffled Reactor for High-sulfate Organic Wastewater Treatment,X703
  5. Underground Drainage with Gas Atomization Process Research,TE377
  6. Enhancement of Phosphate Removal from Anaerobic Anoxic-oxic Process by Hydrolysis and Acidification,X703
  7. Start-up of EGSB Reactor Treating Coking Wastewater,X703
  8. The Study on Charging and Agglomeration of Micro-particles in ESP Flue,X701.2
  9. Preparation and Application of CPF Emulsion as Flocculation by Dispersion Ploymerization,X703
  10. Experimental Study on the Technologies of Wastewater Treatment by a Hybrid Biological Reactor,X703
  11. The Preparation,Characterization and Application of inorganic Ultrafine Powders,TQ110
  12. Synthesis and Applied Research of Polyacrylamide-styrene Soap-free Emulsion,TQ316.334
  13. PB latex agglomeration agglomeration latex graft trial,TQ331
  14. Enhancement of Aqueous Alcohol Mass Transfer by 4A Molecular Sieve in Three-phase Bubble Column,TQ021
  15. Study on the Preparation and Properties of Water-Based Acrylic Pressure-Sensitive Adhesives,TQ436.3
  16. Research on the Screw-pneumatic Reclaimer’s Separation Principle,TH24
  17. Study on Technology of Wine Aging in Stainless Steel Tank with Innerstaves,TS262.6
  18. Preparation of micro-aerobic fermentation of 1,3 - propanediol and metabolic flux analysis,TQ923
  19. Performance of Pollutant Removal by EGSB Reactor Under Microaerobic Condition,X703
  20. Study of Synthesize Large Particle Size Latex with One-step Emulsion Polymerization,TQ316.334
  21. The Synthesis and Application of Agglomeration Agent to Latex,TQ320.1

CLC: > Environmental science, safety science > Processing and comprehensive utilization of waste > General issues > Wastewater treatment and utilization
© 2012 www.DissertationTopic.Net  Mobile