Soft sensors for control of nitrogen and phosphorus removal from wastewaters by neural networks

2002 ◽  
Vol 45 (4-5) ◽  
pp. 101-107 ◽  
Author(s):  
L. Luccarini ◽  
E. Porrà ◽  
A. Spagni ◽  
P. Ratini ◽  
S. Grilli ◽  
...  
Keyword(s):  
Phosphorus Removal ◽  
Biological Nutrient Removal ◽  
Batch Reactors ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Removal Processes ◽  
Pollutants Removal ◽  
Biological Nitrogen

In this paper, we describe the results of research aimed to evaluate the possibility of using a neural network (NN) model for predicting biological nitrogen and phosphorus removal processes in activated sludge, utilising oxidation reduction potential (ORP) and pH as NN inputs. Based on N and P concentrations predictions obtained via the NN, a strategy for controlling sequencing batch reactors (SBRs) phases duration, optimising pollutants removal and saving energy, is proposed. The NN model allowed us to reproduce the concentration trends (change in slope, or process end), with satisfactory accuracy. The NN results were generally in good agreement with the experimental data. These results demonstrated that NN models can be used as “soft on-line sensors” for controlling biological processes in SBRs. By monitoring ORP and pH, it is possible to recognise the N and P concentrations during different SBRs phases and, consequently, to identify the end of the biological nutrient removal processes. This information can then be used to design control systems.

Experimental considerations on monitoring ORP, pH, conductivity and dissolved oxygen in nitrogen and phosphorus biological removal processes

2001 ◽  
Vol 43 (11) ◽  
pp. 197-204 ◽  
Author(s):  
A. Spagni ◽  
J. Buday ◽  
P. Ratini ◽  
G. Bortone
Keyword(s):  
Dissolved Oxygen ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
Effective Control ◽  
Monitoring And Control ◽  
Nitrogen And Phosphorus ◽  
Ph Variation ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Removal Processes

An experimental study on monitoring Oxidation Reduction Potential (ORP), pH, Conductivity and Dissolved Oxygen (DO) in an Enhanced Biological Nutrient Removal process has been carried out. In the anaerobic phase, while ORP and conductivity were not reliable in monitoring simultaneously denitrification and P-release, pH showed the best performances. A significant relationship between P-released and pH variation was found. During the aerobic phase both ORP and pH were able to monitor successfully the nitrification, even though pH was much more reliable. pH can be also used for monitoring and control enhanced P-uptake. It has been concluded that, for a reliable and effective control of biological N and P removal processes a more sophisticated control system seems to be necessary.

Biological nitrogen and phosphorus removal in UCT-type MBR process

2009 ◽  
Vol 59 (11) ◽  
pp. 2093-2099 ◽  
Author(s):  
H. Lee ◽  
J. Han ◽  
Z. Yun
Keyword(s):  
Phosphorus Removal ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
Anoxic Zone ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Nitrate Inhibition ◽  
Biological Nitrogen ◽  
P Removal ◽  
Production Characteristics

A lab-scale UCT-type membrane bio-reactor (MBR) was operated for biological nitrogen (N) and phosphorus (P) removal simultaneously. In order to examine biological nutrient removal (BNR) characteristics of MBR, the lab unit was fed with a synthetic strong and weak wastewater. With strong wastewater, a simultaneous removal of N and P was achieved while application of weak wastewater resulted in a decrease of both N and P removal. Recycled nitrate due to the limited organic in weak wastewater operation probably caused a nitrate inhibition in anaerobic zone. In step feed modification with weak wastewater, both N and P removal capability recovered in the system, indicating that the allocation of COD for denitrification at anoxic zone was a key to increase the biological P removal. In addition, the analysis on the specific P uptake rate in anoxic zone demonstrated that denitrifying phosphorus accumulating organism (dPAO) played an important role to remove up to 40% of P along with N. The sludge production characteristics of UCT-type MBR were similar to ordinary activated sludge with BNR capability.

scholarly journals Removal of Nitrogen and Phosphorus from Wastewater by Modified Pyrite in a Sequencing Batch Reactor (SBR)

2019 ◽  
Vol 136 ◽  
pp. 06027
Author(s):  
Hou-Yun Yang ◽  
Pei Xu ◽  
Hua-Yuan Wang ◽  
Wei-Hua Li ◽  
Shu-Guang Zhu
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Removal Efficiencies ◽  
Removal Processes ◽  
Biological Nitrogen

The removal efficiency of nitrogen and phosphorus is challenging in the conventional biological nitrogen and phosphorus removal processes. In this study, the modified pyrite was used as the fillings of se-quencing batch reactor (SBR) in order to improve the efficiencies of nitrogen and phosphorus removal from wastewater. The results showed that SBR with the modified pyrite could significantly improve the removal efficiencies of nitrogen and phosphorus when compared with that in SBR without fillings (control SBR). The average influent ammonia nitrogen (NH4+-N) and total phosphorus (TP) were 6.96±0.17 mg L-1 and 6.94±0.01 mg L-1, respectively. The average NH4+-N and TP removals of modified pyrite constructed SBR were 49.65±19.49% with 3.54±1.31 mg L-1 of average effluent NH4+-N and 76.20±6.55% with 1.84±0.46 mg L-1 of average effluent TP, respectively. While the average NH4+-N and TP removal efficiencies of con-trol SBR were only 34.76±11.28% and 56.28±0.11%. The mechanisms of the SBR with enhanced simulta-neous nitrogen and phosphorus removals might be anaerobic and aerobic oxidations of modified pyrite, and phosphorus retained in the SBR of modified pyrite was mostly in the form of Fe-bound-P.

Improvment of nitrogen and phosphorus removal in the anaerobic-oxic-anoxic-OXIC (AOAO) process by stepwise feeding

2000 ◽  
Vol 42 (3-4) ◽  
pp. 89-94 ◽  
Author(s):  
H.Y. Chang ◽  
C.F. Ouyang
Keyword(s):  
Carbon Source ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Feeding Strategy ◽  
Synthetic Wastewater ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Kjeldahl Nitrogen ◽  
P Removal

This investigation incorporated a stepwise feeding strategy into the biological process containing anaerobic/oxide/anoxic/oxide (AOAO) stages to enhance nitrogen and phosphorus removal efficiencies. Synthetic wastewater was fed into the experimental reactors during the anaerobic and anoxic stages and the substrates/nutrients were successfully consumed without recycling either nitrified effluent or external carbon source. An intrinsic sufficient carbon source developed during the anoxic stage and caused the NOx (NO2-N+NO3-N) concentration to be reduced from 11.85mg/l to 5.65mg/l. The total Kjeldahl nitrogen (TKN) removal rate was between 81.81%∼93.96% and the PO4-P removal ratio ranged from 93%∼100%. The substrate fed into the anaerobic with a Q1 flow rate and a Q2 into the anoxic reactor. The three difference experiments contained within this study produced Q1/Q2 that varied from 7/3, 8/2, and 9/1. The AOAO process saved nearly one-third of the energy compared with typical biological nutrient removal (BNR) system A2O processes.

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