INVENT has introduced the ALPHAMETER 2.0, the next generation of its measurement and control system for biological wastewater treatment. The system records key process parameters in real time, providing a basis for direct, quantitative control of the oxygen supply. It also continuously monitors and documents nitrous oxide emissions.
Understanding biological activity and controlling aeration
Conventional aeration control in biological wastewater treatment is primarily based on dissolved oxygen (DO) readings. While these readings indicate the current oxygen content in the aeration tank, they provide only indirect information about the biological process’s actual oxygen demand and the efficiency of oxygen transfer.
The ALPHAMETER 2.0 addresses this limitation by continuously measuring parameters from the gas and liquid phases. It combines these measurements with operating data and the known pure-water performance of the aeration system.
From this information, the system determines key process parameters in real time. These include the oxygen uptake rate (OUR), oxygen transfer efficiency under operating conditions (αOTE) and the α-value.
The measurements reveal what is happening within the biological process, including how active the biological system is, its current oxygen demand and how efficiently the aeration system transfers oxygen under the prevailing process conditions.
The required airflow rate can then be calculated directly from the current oxygen demand and actual oxygen-transfer conditions. Instead of adjusting aeration only after the DO value changes, the ALPHAMETER 2.0 enables direct, quantitative and demand-based oxygen control.
This reduces reliance on purely reactive control logic and provides a more precise basis for aeration. Changes in biological activity and influent load can be accommodated more quickly, helping operators avoid over-aeration. It also makes opportunities for energy savings visible so that they can be targeted more effectively.
The ALPHAMETER’s continuous measurement of OUR and oxygen transfer provides the basis for demand-based aeration and energy optimisation
Monitoring oxygen demand and transfer efficiency
The continuous measurement of OUR, αOTE and the α-value provides valuable information for plant operation and optimisation. Load profiles and changes in biological activity become visible, as do variations in oxygen transfer caused by factors such as fouling, scaling or the ageing of aerators.
The ALPHAMETER 2.0 therefore combines process monitoring and aeration optimisation on a shared data platform. This provides a foundation for predictive operations management and condition-based maintenance.
Measuring nitrous oxide emissions
The ALPHAMETER 2.0 expands the system’s capabilities to include the measurement and documentation of nitrous oxide (N₂O) emissions from biological wastewater treatment.
Nitrous oxide is a potent greenhouse gas that can be produced during biological nitrogen-conversion processes. By combining gas analysis with the measured exhaust-air volume, the system can quantify and document Nâ‚‚O emissions throughout the process.
Operators can view the development of biological activity, oxygen demand, oxygen transfer and Nâ‚‚O emissions together. This makes the relationships between process control, energy consumption and emissions more apparent.
Supporting the Urban Waste Water Treatment Directive
Under the new Urban Waste Water Treatment Directive (UWWTD), energy efficiency, greenhouse gas emissions and data-driven operation at municipal wastewater treatment plants are receiving greater attention. These requirements increase the importance of accurate data in biological wastewater treatment.
The ALPHAMETER 2.0 supports this development by providing a unified database covering process performance, energy consumption and emissions. Continuous measurement of the oxygen uptake rate and oxygen transfer provides a foundation for demand-based aeration and energy optimisation. At the same time, Nâ‚‚O monitoring enables the quantitative documentation of nitrous oxide emissions.
The next generation of biological process control
With the ALPHAMETER 2.0, INVENT combines biological process intelligence, direct aeration control and emissions monitoring in a single system. It converts continuous measurement data into information that operators can use immediately for process control.
By bringing these capabilities together, the system provides a more precise and data-led approach to biological wastewater treatment.
