Dynamic Control of the Activated Sludge Process Utilizing Oxidation Reduction Potential

2001 ◽  
Author(s):  
Chu-Yang Chou ◽  
Ning Chang
Keyword(s):  
Activated Sludge ◽  
Reduction Potential ◽  
Dynamic Control ◽  
Activated Sludge Process ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

scholarly journals Dynamic control of nutrient-removal from industrial wastewater in a sequencing batch reactor, using common and low-cost online sensors

2015 ◽  
Vol 73 (4) ◽  
pp. 740-745 ◽  
Author(s):  
Jan Dries
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Industrial Wastewater ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Low Cost ◽  
Dynamic Control ◽  
Oxygen Demand ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

On-line control of the biological treatment process is an innovative tool to cope with variable concentrations of chemical oxygen demand and nutrients in industrial wastewater. In the present study we implemented a simple dynamic control strategy for nutrient-removal in a sequencing batch reactor (SBR) treating variable tank truck cleaning wastewater. The control system was based on derived signals from two low-cost and robust sensors that are very common in activated sludge plants, i.e. oxidation reduction potential (ORP) and dissolved oxygen. The amount of wastewater fed during anoxic filling phases, and the number of filling phases in the SBR cycle, were determined by the appearance of the ‘nitrate knee’ in the profile of the ORP. The phase length of the subsequent aerobic phases was controlled by the oxygen uptake rate measured online in the reactor. As a result, the sludge loading rate (F/M ratio), the volume exchange rate and the SBR cycle length adapted dynamically to the activity of the activated sludge and the actual characteristics of the wastewater, without affecting the final effluent quality.

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.

Oxidation-Reduction Potential (ORP) Regulation as a Way to Optimize Aeration and C, N and P Removal: Experimental Basis and Various Full-Scale Examples

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1209-1223 ◽  
Author(s):  
J. Charpentier ◽  
H. Godart ◽  
G. Martin ◽  
Y. Mogno
Keyword(s):  
Activated Sludge ◽  
Reduction Potential ◽  
Pilot Scale ◽  
Point Of View ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Winter Peak ◽  
Definition Of ◽  
Different Characteristics ◽  
P Removal

The control of aeration by measuring the oxidation reduction potential (ORP) of activated sludge, conducted at the YFFINIAC (West of France) sewage plant in 1983, showed this type of regulation to be attractive in that it can optimize energy costs and perfect the removal of carbonaceous and nitrogenous pollutants (CHARPENTIER et al, 1987). From a practical point of view, this new, inexpensive means of regulation has moreover proved easier to implement than the method based on measuring Dissolved Oxygen (D.O.). Before implementingthis process, we undertoook a pilot study that enabled us to make more accurate the ORP values for activated sludge that must be observed in order to achieve the satisfactory removal of carbonaceous and nitrogen pollutants. Furthermore, the ORP readings revealed points of inflection that can be used for regulation purposes. These have been related to the disappearance either of the ammonia or the nitrates with release of phosphates. The experience gained with 7 ORP regulating systems, most of them in operation now for several years, and installed in works with vastly different characteristics, shows that the range of ORP values used corresponds to the pilot-scale experiments. It also shows the attractive features of the ORP signal, compared with that of D.O., when used for the regulation and interpretation of the phenomena involved in the biological treatment. This type of regulation leads to improvements in the annual electricity balance, expressed in terms of kWh v. kg of treated BOD5, and has proved to be compatible with a programmed shutdown of the aerators during the winter peak hours when the tariff per kWh is particularly expensive. In conclusion, the diversity of experiments on site has largely contributed towards the definition of those practical methods upon which depends the success of the system.

Influence of dissolved oxygen and oxidation–reduction potential on the denitrification rate of activated sludge

1994 ◽  
Vol 30 (6) ◽  
pp. 91-100 ◽  
Author(s):  
Ewa Lie ◽  
Thomas Welander
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Reduction Potential ◽  
Inhibitory Effect ◽  
Denitrification Rate ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Low Concentrations ◽  
Denitrification Activity ◽  
Do Concentration

The influence of low concentrations of dissolved oxygen (DO) and the oxidation-reduction potential (ORP) on the denitrification activity of activated sludge has been studied in batchwise experiments. The ORP was maintained at different levels by automatic titration with air and the denitrification activity was determined by following the disappearance of nitrate. Oxygen was found to have a negative effect on denitrification even at lower concentrations than can be measured with conventional oxygen probes (<0.1 mg/L). The ORP was found to be a useful indicator of the DO concentration at this low level and the denitrification rate was found to decrease linearly with increasing ORP. However, the effect of the ORP on denitrification differed between sludges from different treatment plants. A linear relationship was also found between the ORP and the DO concentration in the region of measurable DO concentrations. Extrapolation of this straight line into the region where DO was under the detection limit indicated that oxygen exerts an inhibitory effect on denitrification at such low concentrations as a few μg/L.

Oxidation-Reduction Potential (ORP) Regulation: A Way to Optimize Pollution Removal and Energy Savings in the Low Load Activated Sludge Process

1987 ◽  
Vol 19 (3-4) ◽  
pp. 645-655 ◽  
Author(s):  
J. Charpentier ◽  
M. Florentz ◽  
G. David
Keyword(s):  
Activated Sludge ◽  
Energy Savings ◽  
Operating Conditions ◽  
Activated Sludge Process ◽  
Biological Phosphorus Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Low Load ◽  
Pollution Removal ◽  
Set Up

Aeration represents the main part of energy consumption in the low-load activated sludge process. Because of its ability to remove the various kinds of pollution (carbonaceous, nitrogenous) with a high dependability level, this process is the most widespread throughout France, particularly in its tropical overseas regions. A previous study led the authors to set up a graph which links energy savings and effluent quality (carbonaceous and nitrogenous pollution removal). This graph appears useful as well to monitor biological phosphorus removal in the low-load activated sludge process including an anaerobic basin. In order to optimize pollution removal and energy savings, ORP regulation has been carried out since January 1983 on the Yffiniac plant (West of France). It was preferred to dissolved oxygen (D.O.) regulation because of the low values of D.O. observed in this plant and the difficulties of operating D.O. regulation. A laboratory and full-scale study shows that ORP regulation is possible and particularly accurate as a contribution to optimizing pollution removal, energy savings and operating conditions. Since then other ORP Regulations have been installed. The observations we made specify which cases lend themselves to successful ORP regulation.

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