Renovation of an Extended Aeration Plant for Simultaneous Biological Removal of Nitrogen and Phosphorus Using Oxic-Anaerobic-Oxic Process

1990 ◽  
Vol 22 (7-8) ◽  
pp. 61-68 ◽  
Author(s):  
Katsumi Moriyama ◽  
Kazuaki Sato ◽  
Yoshinobu Harada ◽  
Kazuo Washiyama ◽  
Koich Okamoto
Keyword(s):  
Control System ◽  
Treatment Plant ◽  
Optimum Level ◽  
Simultaneous Removal ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Biological Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Aeration Process

The effect of the oxidation reduction potential (i.e., ORP) control system on the simultaneous removal of nitrogen and phosphorus, utilizing the oxic-anaerobic-oxic process, was investigated. A full-scale wastewater treatment plant which was designed as an extended aeration process was modified for this process to study. The optimum ORP at the first basin for the simultaneous removal was 125 mV in this experiment. In the first oxic basin the nitrification reaction and the denitrification reaction occurred simultaneously to maintain the optimum level of the ORP value. The averaged values of the effluent of this process were 1 mg/l of total nitrogen (T-N), 0.5 mg/l of total phosphorus (T-P) and 5 mg/l of BOD respectively. It was also clearly shown by the statistic analysis that the ORP control was more effective in comparison with the control of dissolved oxygen (DO) concentration for the operating method of this process. Additionally, it was supposed that the simultaneous nitrification and denitrification using the ORP control system was a reliable nitrogen removal system for renovating the conventional activated sludge process because the hydraulic retention time of the first basin used in this study was equal to that of the conventional process.

High rate and compact single sludge pre-denitrification process for retrofit

1994 ◽  
Vol 30 (6) ◽  
pp. 31-40 ◽  
Author(s):  
Hiroyshi Emori ◽  
Hiroki Nakamura ◽  
Tatsuo Sumino ◽  
Tadashi Takeshima ◽  
Katsuzo Motegi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
High Rate ◽  
Activated Sludge Process ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Treatment Techniques ◽  
Conventional Activated Sludge Process ◽  
Denitrification Process

For the sewage treatment plants near rivers and closed water bodies in urbanized areas in Japan and European countries, there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus from the viewpoints of water quality conservation and environmental protection. In order to remove nitrogen by the conventional biological treatment techniques, it is necessary to make a substantial expansion of the facility as compared with the conventional activated sludge process. In such urbanized districts, it is difficult to secure a site and much capital is required to expand the existing treatment plant. To solve these problems, a compact single sludge pre-denitrification process using immobilized nitrifiers was developed. Dosing the pellets, which are suitable for nitrifiers growth and physically durable, into the nitrification tank of single sludge pre-denitrification process made it possible to perform simultaneous removal of BOD and nitrogen in a retention time equal to that in the conventional activated sludge process even at the low water temperature of about 10 °C. The 3,000 m3/d full-scale conventional activated sludge plant was retrofitted and has been successfully operated.

Microbial Biomass and Enzyme Activities in Chromium and Lead-Contaminated Sediments

2013 ◽  
Vol 798-799 ◽  
pp. 1139-1143
Author(s):  
Chao Wang ◽  
Shuai Cheng ◽  
Pei Fang Wang ◽  
Yan Yan Ma
Keyword(s):  
Heavy Metals ◽  
Microbial Biomass ◽  
Enzyme Activities ◽  
Chemical Properties ◽  
Nitrogen And Phosphorus ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Organic Carbon Oxidation ◽  
The Relationship ◽  
Cr Contamination

The relationship between microbial biomass and enzyme activities under heavy metal pollution had attracted much attention in ecology. The experimental sediment samples were supplemented with Pb and Cr and incubated at room temperature for a month. Microbial properties such as microbial biomass, urease, catalase and cellulase activities, together with several chemical properties such as pH, total organic carbon , oxidation-reduction potential, total nitrogen and phosphorus were measured to evaluate changes in sediment qualities. Our results demonstrate that heavy metals would inhibit sediment microbe biomass and enzyme activities. Such decreases in sediments microbial biomass and enzyme activities by Pb and Cr contamination may help to evaluate heavy metals contaminated soil ecologies.

scholarly journals Biological Removal NOx from Simulated Flue gas in aerobic biofilter, by Jiang R., Huang S.B. and Yang J.

2013 ◽  
Vol 10 (2) ◽  
pp. 241-248
Keyword(s):  
Gas Phase ◽  
Flue Gas ◽  
Removal Rate ◽  
Nox Removal ◽  
Biological Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
O2 Concentration ◽  
Blank Experiment ◽  
Nitrate And Nitrite

A bench-scale biofiltration system was developed to evaluate the NOx removal efficiency under high oxygen concentration. The system had been running for 120 days and kept on a steady NOx removal rate above 80%. A stable NOx removal with an efficiency of more than 80% from the gas phase can be obtained by the bioreactor concept, when flue gas containing NO (400-600 ppmv) and a certain O2 concentration (0-20%). In the blank experiment, less than 35% NO was removed as oxygen increased. The tendency of the three curves about NO removal rate with various O2 concentrations was mainly similar but some differences in the highest and lowest removal rate happened in the definite O2 concentration range. Oxygen was shown to have a significant effect on NOx removal at the first two or three days when oxygen concentration increased sharply. The higher concentration NO influent gas contained, the longer time the microflora need to regain activities. Compared with humidifier, microbial regenerator which was incorporated in biofilter can improve aerobic denitrifying bacteria activity by applying alternating oxic–anoxic conditions in the presence of nitrate and nitrite. Oxidation-Reduction Potential (ORP) and Dissolved Oxygen (DO) were used to control the dose of carbon source.

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.

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.

Improving the sensitivity of the activated sludge respiration inhibition test and verifying the results using an oxidation-reduction potential electrode

2016 ◽  
Vol 75 (2) ◽  
pp. 247-254 ◽  
Author(s):  
F. Friedrichs ◽  
K. U. Rudolph ◽  
Bich Hanh Nguyen ◽  
D. Meinardi ◽  
W. Genthe ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Oxygen Sensor ◽  
Reduction Potential ◽  
Treatment Plant ◽  
Inhibition Test ◽  
Synthetic Wastewater ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Potential Electrode ◽  
Nutrient Solutions

The inhibition of activated sludge respiration is one of the most important parameters for monitoring wastewater toxicity. The main objective of this study was to improve respiration inhibition testing in order to protect the biological degradation within the aerobic process in a wastewater treatment plant more efficiently. In order to influence the sensitivity of the testing bacteria, two different nutrient solutions were selected for biological testing, synthetic wastewater according to ISO 8192 and NaAc (sodium acetate). The effects of the nutrient solutions on heavy metal speciation and their respiration inhibition were investigated. The toxicants Zn(II), Cu(II), Cr(VI) and 3,5 DCP (3,5-dichlorophenol) were used as standards to determine toxicities and to study the influence of nutrient solutions. Results have shown that NaAc as a nutrient solution sensitized the respiration inhibition test up to a factor of 7.7. Furthermore, an oxidation reduction potential electrode can be used as an alternative tool to verify the results obtained with an oxygen sensor.

scholarly journals Aeration Process in Bioreactors as the Main Energy Consumer in a Wastewater Treatment Plant. Review of Solutions and Methods of Process Optimization

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 311 ◽  
Author(s):  
Jakub Drewnowski ◽  
Anna Remiszewska-Skwarek ◽  
Sylwia Duda ◽  
Grzegorz Łagód
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
High Efficiency ◽  
Good Condition ◽  
Treatment Plant ◽  
Treatment Technology ◽  
Conventional Activated Sludge ◽  
Smart Control ◽  
Biological Decomposition ◽  
Aeration Process

Due to the key role of the biological decomposition process of organic compounds in wastewater treatment, a very important thing is appropriate aeration of activated sludge, because microorganisms have to be supplied with an appropriate amount of oxygen. Aeration is one of the most energy-consuming processes in the conventional activated sludge systems of wastewater treatment technology (may consume from 50% to 90% of electricity used by a plant), which makes it the most cost-generating process incurred by treatment plants. The paper presents the construction of aeration systems, their classification as well as parameters and factors that significantly affect the aeration process e.g., oxygen transfer efficiency, diffuser fouling, methods of dealing with diffuser fouling, diffuser selection. Additionally, there are briefly presented “smart control” systems in wastewater treatment and effect of application control strategy based on Supervisory Control and Data Acquisition system connected with the decrease in the energy consumption for aeration of bioreactors with activated sludge. It is noted that before the process is optimized, the system should be equipped with suitable metering devices. Only when relevant data is available, the improvements can be carried out. However, it’s important, that the operator should regularly maintain good condition and high efficiency of diffusers.

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