Real-Time Control of Wastewater Treatment Systems Using ORP

Abstract

Oxidation-Reduction Potential (ORP) can be used as a process control parameter for real-time automated control of batch sewage treatment systems. Results suggest that ORP has great potential for the control of anoxic sequences, since the distinct breakpoint in the ORP-time curve correlates to the disappearance of nitrates.

Removal of nutrients and micropollutants treating low loaded wastewaters in a membrane bioreactor operating the automatic alternate-cycles process

“…Paul et al [11] have showed as the ORP bending points are detected only if the oxygen level is suited to the feed load and, more precisely, to the oxygen demand, emphasizing that the best working range is <2 mgO2/l. Because of the high influent dilution, the system was not always able to maintain the DO under 2 mg/l; in the aerobic phase the DO bending points appeared (Fig.…”

“…The length of the cycles is automatically determined on the basis of the oxidationreduction potential (ORP) and dissolved oxygen (DO) signals. These reveal the end of the nitrification and denitrification processes [9][10][11][12][13]. In particular, the ammonia disappearing during the aerobic cycle, identified by a flex-point in the DO profile with time, at the end of ammonia nitrification, and the nitrates disappearing (breakpoint) in the anoxic cycle, identified by a flex-point in the ORP profile with time, at the end of nitrate denitrification process, are the main evident observations [14,15].…”

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.…”

Nitrogen removal optimization in a sequencing batch reactor treating sanitary landfill leachate

“…[19] Reports have been made with regard applications providing for the use of dissolved oxygen (DO), pH and oxidation-reduction potential (ORP) on monitoring and control wastewater treatment plants, both in continuous and batch processes. [20−22] The majority of studies applying the above signals have been performed on urban wastewaters [23,24] although a few have also been carried out on industrial (for example pharmaceutical [25] ) or agricultural wastewaters. [26,27] In batch reactors, DO, pH and ORP have been frequently used in phase-length optimization.…”