Wastewater Aeration Control Using Filtered CO2 Gas Sensing

The patent introduces an intermediary substance (carbon dioxide) as a mediator between the organic matter in wastewater and the measurement system. Instead of directly measuring TOC which is prone to clogging, the system measures CO2 concentration in the gas phase, which serves as an intermediary indicator that reflects organic matter degradation without suffering from suspended solids and oil contents interference

The patent replaces the mechanical/physical TOC measurement system (which uses optical sensors susceptible to clogging) with a gas-phase CO2 measurement system. This substitution eliminates the direct contact between measurement sensors and contaminated wastewater, thereby preventing clogging while maintaining measurement capability through gas sampling from the reaction tank atmosphere

The patent converts the harmful effect of high BOD loading (which generates corrosive gases like hydrogen sulfide and ammonia) into a beneficial measurement opportunity. By measuring CO2 concentration in the gas phase, the system can detect and respond to high loading conditions, allowing for proactive adjustment of nutritive substance addition to prevent sensor damage while maintaining high treatment capacity

The patent implements a feedback control mechanism where CO2 concentration measurements from the gas phase are continuously monitored and fed back to the control system. This feedback allows real-time adjustment of nutritive substance addition based on actual treatment conditions, enabling the system to maintain high productivity while preventing the accumulation of corrosive gases that would otherwise damage sensors