Method for collaborative control of organic nitrogen and inorganic nitrogen in denitrification process

Patent metadata

Field	Value
Publication number	US-11905192-B2
Application number	US-202217588274-A
Country	US
Kind code	B2
Filing date	Jan 29, 2022
Priority date	Dec 30, 2021
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

A method for collaborative optimization control method for organic nitrogen and inorganic nitrogen in a denitrification process is provided. The method includes: establishing ASM-mDON-DIN models for simultaneous simulation of microbial dissolved organic nitrogen (mDON) and inorganic nitrogen (DIN) in denitrification processes; and selecting a corresponding ASM-mDON-DIN model according to a set carbon/nitrogen ratio to collaboratively optimize the concentration values of mDON and DIN in the effluent in the denitrification process, to obtain best process operation parameter values.

First claim

The invention claimed is:

1. A method, comprising:
S1: establishing a model 1 and a model 2 for simultaneous simulation of microbial dissolved organic nitrogen (mDON) and inorganic nitrogen (DIN) in denitrification processes; and
S2: selecting the model 1 or the model 2 according to a set carbon/nitrogen ratio to collaboratively optimize concentration values of mDON and DIN in an effluent of a denitrification process, to obtain best process operation parameter values;

wherein:
in S1, operations for establishing the models 1 and 2 comprise:
S1-1: data collection: measuring chemical oxygen demand (COD), total nitrogen (TN), inorganic nitrogen (iDIN), dissolved organic nitrogen (rDON) and pH in an influent of a target sewage plant in the denitrification process, inorganic nitrogen (eDIN) and dissolved organic nitrogen (eDON) in the effluent, dissolved oxygen (DO), a hydraulic retention time (t) of a denitrification stage, and a mixed liquor suspended solid (MLSS) of activated sludge;
S1-2: model construction: according to a kinetic process of production, transformation and consumption of mDON during a complete denitrification process, adding mDON as a new component and a carbon/nitrogen ratio as a new parameter into an activated sludge model (ASM), and constructing the models 1 and 2 at different carbon/nitrogen ratios by using mDON and DIN as objects;
S1-3: model initialization: initializing the models 1 and 2 based on data collected in S1-1, calculated values of model parameters and the models 1 and 2 constructed in S1-2;
S1-4: model calibration: calibrating a parameter estimation function based on simulated mDON and DIN kinetics and a result of sensitivity analysis; and
S1-5: model establishment: replacing initial parameter values in the models 1 and 2 with parameter calibration values to obtain calibrated models 1 and 2;

values of 10 components and 9 processes are modeled in the model 1 by using 22 parameters and a kinetic parameter of an inhibition constant (K IAS ) of the anoxic substrate of heterotrophic bacteria; and the values of the 10 components and the 9 processes are modeled in the model 2 by using the 22 parameters; wherein:
the 10 components comprise: heterotrophic bacteria X H , particulate inert substance X I , dissolved biodegradable organic matter S S , microbial organic nitrogen S mDON , ammonia nitrogen S NH , nitrate nitrogen S NO 3 , nitrite nitrogen S NO 2 , nitric oxide S NO , nitrous oxide S N2O and alkalinity S ALK ;
the 9 processes comprise: four-step anoxic growth of heterotrophic bacteria based on the dissolved biodegradable organic matter, comprising conversion of nitrate nitrogen into nitrite nitrogen, conversion of nitrite nitrogen into nitric oxide, conversion of nitric oxide into nitrous oxide and conversion of nitrous oxide into nitrogen, and decay of heterotrophic bacteria, ammonification of microbial dissolved organic nitrogen, assimilative reduction of nitrate nitrogen into nitrite nitrogen and assimilative reduction of nitrite nitrogen into ammonia nitrogen; and
the 22 parameters comprise: a yield coefficient Y H of anoxic S S -based growth of heterotrophic bacteria, an oxygen containing proportion i XB of organism, a proportion f H,DON of mDON formed by heterotrophic bacteria based on organism growth, a proportion f 1 of inert substances produced by organism, a maximum specific growth rate μ H of anoxic growth of heterotrophic bacteria, a half-saturation utilization constant K S of a substrate of heterotrophic bacteria, an ammonia half-saturation constant K H,NH of heterotrophic bacteria, an anoxic growth factor η 2 of heterotrophic bacteria in a process 2, the anoxic growth factor η 3 of heterotrophic bacteria in a process 3, the anoxic growth factor η 4 of heterotrophic bacteria in a process 4, the nitrate nitrogen half-saturation constant K NO 3 , a nitrite nitrogen half-saturation constant K NO 2 , a nitric oxide half-saturation constant K NO , a nitrous oxide half-saturation constant K N 2 O , a decay coefficient b H of heterotrophic bacteria, an ammoniated mDON half-saturation constant K H,DON of heterotrophic bacteria, an ammonification rate κ a of microbial dissolved organic nitrogen, a NO 3 − -N half-saturation constant K 7,NO3 of ANRA, an inhibition constant K 17NH of ammonia nitrogen in the ANRA process, an inhibition constant K 18NO2 of nitrite nitrogen in the ANRA process, a half-saturation constant K 8,NO2 of nitrite nitrogen in the ANRA process and an oxygen half-saturation constant K H,O of heterotrophic bacteria;

the models 1 and 2 are divided according to the carbon/nitrogen ratio in the influent:
(1) when the carbon/nitrogen ratio is less than or equal to 4, the model 1 is selected, and the kinetic equations for the model 1 are as follows:

DIN
⁡
(

S
DIN

)

:

dS
DIN

dt

=

(

-

i
XB

-

f

H
,
DON

Y
H

)

⁢

(

V
1

+

V
2

+

V
3

+

V
4

)

+

V
6

+

(

-

1
+

2.86

f

H
,
DON

0.571

Y
H

+

Assignees

• Nanjing University

Inventors

• Hu Haidong
• Cui Xian
• Liao Kewei
• Ding Lili
• Wu Bing
• Ren Hongqiang

Classifications

• C02F3/006 Primary

  Regulation methods for biological treatment · CPC title

• C02F3/305

  characterised by the denitrification · CPC title

• C02F2209/06

  pH · CPC title

• C02F2209/08

  Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD] · CPC title

• C02F2209/10

  Solids, e.g. total solids [TS], total suspended solids [TSS] or volatile solids [VS] · CPC title