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Study on Controlling Strategy and Mechanism of Autotrophic Nitrogen Removal in One Reactor

Author: WeiYing
Tutor: GuoJinSong；FangFang
School: Chongqing University
Course: Environmental Engineering
Keywords: Single-stage autotrophic nitrogen Process control parameters Denitrification mechanism
CLC: X703
Type: Master's thesis
Year: 2008
Downloads: 119
Quote: 0
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Abstract

Single-stage autotrophic denitrification system has the advantages of simple, efficient, low energy consumption significantly attracted widespread attention in the field of biological nitrogen removal. The present study was carried out on the basis of pre-established single-stage autotrophic nitrogen removal system. This stage utilizes a set of pre been continuous aeration reactor under conditions of continuous aeration system ORP and DO concentration variation; another set of reactor destroyed by the intense disturbance promote recovery control strategy research; recovery of the system after its carried out a preliminary study of the mechanism of the single-stage autotrophic denitrification system denitrification. Draw the following conclusions: single-stage autotrophic denitrification system biofilm and activated sludge floc nitrite massive accumulation of reactor effluent nitrite concentration of 70mg / L, with a total nitrogen removal rate decreased from 78.6% to 13.1%; DO concentration of short-term adjustment of denitrification system performance without significant improvement; to quickly hang the film can be taken to control higher DO concentration, nitrogenous substances transformed according to the system adjust the concentration of DO to gradually improve the system performance of denitrification for recovery. Experiment, the DO concentration of 1.6 ^{2 .2 mg / L under the conditions of about 20d achieve rapid hanging film, after adjustment for the conversion of nitrogen-containing substances DO concentration, nitrogen removal performance continued recovery, but also by the 98d total nitrogen removal rate of 80%. Single-stage autotrophic nitrogen removal system for continuous aeration, in a reaction cycle, ORP curve faster pace growth the basic ammonia conversion completed later time points, the the ORP curve growth rate is slowing down. ORP curve is gentler slope break point with the ammonia conversion corresponding basic completion point in time; the DO curve begins slight fluctuations in the control DO values ??near the basic ammonia conversion complete, DO concentration started to rise beyond the normal The fluctuation range. Therefore, ORP, DO can be used as the control parameters of the system, it is recommended that the collaborative control of continuous aeration of the single-stage autotrophic denitrification system combined with ORP and DO parameters. Batch test results show that the single-stage autotrophic denitrification system does not exist the nitrosated bacteria denitrification in this metabolic pathway, the two anaerobic ammonia oxidation metabolic pathways may exist in the system, but the angle from the gas analysis need further confirmed; system, although there is a very small number of conventional denitrification nitrogen removal pathway of ammonia nitrogen removal, but through this pathway. Biofilm growth on single-stage self-raising Removal System suspended activated sludge, biofilm growth on the filler, the inner wall of the reactor Autotrophic denitrification activity were: 0.0034gN · g ^{-1 VSS ^{-1 d ^{-1 , 0.0087gN · g ^{-1 VSS ^{-1 d ^{-1 , 0.016gN · g ^{-1 VSS ^{-1 d ^{-1 ; nitrosated activity were: 0.015 gN · g ^{-1 VSS ^{-1 d ^{-1 , 0.026 gN · g ^{-1 VSS ^{- 1 d ^{-1 , 0.035 gN · g ^{-1 VSS ^{-1 d ^{-1 ; The maximum anaerobic ammonia oxidation activity were: 0.011 gN g ^{-1 the VSS ^{-1 d ^{-1 0.021 gN · g ^{-1 VSS ^{-1 d ^{-1 , 0.027 gN · g ^{-1 VSS ^{-1 d ^{-1 . Biofilm activity than the activated sludge. The research results have certain reference value for further in-depth study of the single-stage autotrophic denitrification system, and help to improve the practical application of the single-stage autotrophic denitrification system.}}}}}}}}}}}}}}}}}}}}}}}}}}}}

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