Active oxygen disinfection represents an emerging sanitation technology that has gained prominence in recent years, particularly within sectors such as drinking water treatment and medical wastewater management. A common misconception is that active oxygen monitoring is required solely for drinking water applications. However, this is not the case. In principle, any sewage or wastewater subjected to active oxygen disinfection requires subsequent monitoring of residual active oxygen concentrations to evaluate the efficacy of the disinfection process and ensure compliance with water quality standards.
Active oxygen disinfectants are predominantly available in the form of potassium peroxymonosulfate (KMPS) composite powder. Prior to application, the powder is dissolved in water to create a liquid solution, which is then introduced into the target water body for disinfection. The effectiveness of the sterilization process is subsequently determined by measuring the concentration of residual active oxygen remaining after a defined contact time.
Regarding regulatory limits, current national standards do not explicitly specify universal thresholds for active oxygen residuals. Nevertheless, empirical data from routine industry analyses suggest typical control ranges: for water supply facilities, residual active oxygen levels are generally maintained between 0.05 and 0.5 mg/L, whereas in wastewater treatment processes, the residual concentration is typically controlled at levels exceeding 0.5 mg/L.
The ROS900 Online Active Oxygen Analyzer, manufactured by Hangzhou Modi, utilizes either colorimetric methods or induced fluorescence techniques. This instrument is suitable for diverse applications, including both drinking water systems and medical wastewater treatment facilities.
The procedural framework for active oxygen monitoring involves three primary steps:
1.Preparation of Calibration Curve: A series of standard solutions with known active oxygen concentrations are prepared. Appropriate reagents are added, and absorbance measurements are obtained using a photometer to construct a standard calibration curve.
2.Calibration and Zero Adjustment:Instrumental zeroing and calibration are performed using sample blanks in the photometer to minimize baseline error and ensure the accuracy of subsequent measurements.
3.Sample Analysis:Representative water samples are collected according to protocol. Reagents are added to induce chromogenic reactions, followed by absorbance measurement. The active oxygen concentration is then calculated based on the previously established standard curve.
It is important to note that the parameters requiring monitoring vary depending on the specific operational context. While residual disinfectant concentration is a critical metric, it constitutes only one component of comprehensive water quality assessment. For instance, in medical wastewater monitoring, beyond routine physicochemical parameters, microbiological indicators—particularly coliform bacteria—are equally significant for evaluating sanitary safety.
