Real-time biomonitoring of oxygen uptake rate and biochemical oxygen demand using a novel optical biogas respirometric system

• Published in: Journal of environmental management 2021-01, Vol.277, p.111467-111467, Article 111467
• Main Authors: Hussain, Fida, Yu, Hye-Weon, Chon, Kangmin, Lee, Yong-Gu, Eom, Heonseop, Chae, Kyu-Jung, Oh, Sang-Eun
• Format: Article
• Language: English
• Subjects: Biochemical oxygen demand (BOD); Oxygen uptake rate (OUR); Real-time monitoring; Respirometer
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.111467

In response to the ever-increasing need for monitoring-based process control of wastewater treatment plants, an online applicable respirometer shows great promise for real-time measurement of oxygen uptake rate (OUR) and biochemical oxygen demand (BOD) measurements as a surrogate of the biodegradability of wastewater. Here, we have developed a photosensor-assisted real-time respirometric system equipped with bubble counting sensors for accurate measurement of microbial oxygen consumption in a bottle. This system can measure OUR and BOD in a bottle equipped with a tube containing NaOH solution to absorb carbon dioxide and supplied with continuous atmospheric oxygen to the bottle, which reliably supplies non-limiting dissolved oxygen (DO) for aerobic biodegradation even at high organic loads. These technical improvements allow a sensitive and rapid analytical tool offering real-time profiles of oxygen uptake rate as well as BOD measurements with an extended measurable range (0–420 mg O2/L), enabling significant reduction or elimination of dilution steps. The respirometric system was used to elucidate the biodegradable kinetics of domestic and swine wastewaters as a function of the type and concentration of organic matters, depending on source characteristics including rapidly or slowly oxidizable organic substances by bacteria. Compared with conventional and manometric BOD methods, our method is reliable and accurate. [Display omitted] •A novel respirometric system has been developed to measure oxygen consumption.•This system offers real-time profiles of OUR as well as BOD measurements.•This method enables significant reduction of dilution steps for measuring BOD.•Compared with conventional BOD methods, this method is reliable and accurate.