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

Abstract

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.

Impacts of operating parameters on oxidation–reduction potential and pretreatment efficacy in the pretreatment of printing and dyeing wastewater by Fenton process

“…Oxidation-reduction potential (ORP) has been used as a tool for monitoring, control and optimization of biological treatment systems since 1980s [29][30][31], and has been proven to be economical and an effective technique for process control in many wastewater treatment systems, such as alternating aerobic-anoxic system [32], sequencing batch reactor [33], extended aeration treatment system [34] and sulfide oxidizing bioreactor [35]. For Fenton process, the hydroxyl radical is the major oxidizing species, however, on-line monitoring the hydroxyl radical is difficult.…”

Using Oxidation–Reduction Potential as Septicity Control Parameter During Reclaimed Wastewater Transportation

“…Using oxidation-reduction potential (ORP) as a control parameter for wastewater treatment systems has been proposed in recent years (Charpentier et al, 1987 andDelgado et al, 1999;Elmaleh et al, 1998;Thévenot, 1989 andHéduit et al, 1993 and1996;and Lie and Welander, 1994). Because many aerobic processes take place at concentrations of DO that are impossible to measure using commercial DO probes, it is important to have a tool that can provide information about the degree of oxygen limitation.…”

“…Because many aerobic processes take place at concentrations of DO that are impossible to measure using commercial DO probes, it is important to have a tool that can provide information about the degree of oxygen limitation. The ORP has often been used to indicate the reaction progress of activated-sludge processes when operating at low DO concentrations (Charpentier et al, 1987 and. The ORP has often been used to indicate the reaction progress of activated-sludge processes when operating at low DO concentrations (Charpentier et al, 1987 and.…”

Optimizing the in-line ozone injection and delivery strategy in a multistage pilot-scale greywater treatment system: System validation and cost-benefit analysis

“…Negative ORP values indicate that the amount of ozone in the system is insufficient to effectively disinfect the microorganisms present in greywater [16]. Therefore, the pilot-scale greywater treatment system should be operated at the lowest flowrate of 10 L/min and the ozone concentration injected into the system should be optimized in order to obtain the most suitable and cost-effective ozone dosage that can effectively disinfect the microorganisms present in the system.…”