This measure is not only intended to ensure compliance with legal requirements, but also to promote low-emission operating methods and improve sustainability in wastewater management. The member states must now transpose these requirements into national legislation and set deadlines for the implementation of emission measurement.
Implementation requires close cooperation between environmental authorities, wastewater treatment plant operators and measurement technology manufacturers. In particular, wastewater treatment plants must expand their infrastructure to capture not only N₂O, but also methane (CH₄) and CO₂ in order to minimize cross-sensitivities when measuring emissions.
A key challenge is the development of reliable, cost-efficient sensor technology for precise, continuous emission measurements. In the long term, consistent measurement can not only contribute to compliance with environmental regulations, but also enable operational optimization by controlling processes more efficiently and reducing emissions in a targeted manner.
The problem of N₂O emissions in wastewater treatment plants
N O₂ is produced in particular during biological nitrogen elimination, for example through nitrification and denitrification. In aerobic and anoxic process phases, it can be released as a by-product, especially if the process conditions are not optimally controlled. In addition to factors such as oxygen availability, pH value and carbon source, temperature and microbiological activity also influence the formation and emission of N₂O.
Precise emission measurement is essential in order to detect uncontrolled releases, as these not only represent a considerable environmental burden but also reduce the efficiency of wastewater treatment plants. Valuable nitrogen compounds are lost that could otherwise be converted into useful end products.
In order to generate reliable data, the EU has carried out extensive pilot studies. These not only quantified the actual quantities through precise emission measurement, but also investigated how various process parameters influence the formation of N O₂ . The resulting findings confirmed the need for standardized emission measurement in order to minimize the environmental impact in the long term and to control regulatory measures in a targeted manner. It also shows that optimization potential within the biological treatment stages can be uncovered.
By controlling the nitrification and denitrification processes more precisely, undesirable side reactions can be reduced and nitrogen elimination can be made more efficient overall.
Modern sensor technologies not only enable the continuous measurement of the N₂O concentration, but also the analysis of other critical parameters. This data allows targeted process adjustments to be made so that wastewater treatment plant operators can react to unfavorable operating conditions at an early stage and improve both the environmental balance and the operating costs of their plants in the long term.
To summarize:
- N₂O is formed during nitrification and denitrification under unfavorable process conditions.
- Factors such as oxygen, pH value and temperature influence the emissions.
- Uncontrolled release pollutes the environment and reduces wastewater treatment plant efficiency.
- EU studies confirm the need for standardized measurements.
- Optimized processes reduce emissions and improve nitrogen elimination.
- Modern sensors enable precise measurements and targeted adjustments.
- Better control reduces operating costs and improves the environmental balance.
Regulatory requirements and technical implications
The ordinance stipulates that all wastewater treatment plants must be equipped with suitable emission measurement systems within a period to be defined. In addition to the installation of appropriate sensors, there is also a comprehensive documentation obligation, meaning that the recorded emission values must be regularly transmitted to the responsible environmental authorities and stored in central databases.
The data collected from the emission measurements will serve as a basis for scientific analyses and political decisions in order to develop long-term strategies for reducing emissions. These measures are not only intended to ensure compliance with limit values, but also to enable data-based optimization of processes by allowing wastewater treatment plant operators to identify weak points in operation and take targeted countermeasures.
A key challenge for operators is the selection of a suitable emission measurement method. In addition to measurement accuracy, factors such as maintenance costs, long-term stability and integration capability into existing process control systems are of essential importance. Another important consideration is the scalability of the systems, as larger wastewater treatment plants have different requirements to smaller municipal plants.
In this context, non-dispersive infrared spectroscopy (NDIR) is becoming increasingly relevant, as it enables continuous, selective and cost-efficient emission measurement of the relevant gases. In addition, alternative methods such as electrochemical sensors or photoacoustic spectroscopy could play a role, especially if a higher sensitivity is required for specific applications.
In addition, automated control based on the collected data could be implemented in the future to minimize emissions in real time. Advanced control systems could, for example, be based on artificial intelligence to recognize patterns in the emission measurement data through machine learning and make adjustments to the operating parameters. However, these approaches require close integration with existing process automation and the development of powerful algorithms for pattern recognition and emission prediction.
In addition, such systems could be connected to cloud-based platforms to enable data exchange between different wastewater treatment plants and facilitate cross-regional analysis of emission measurement.
Further potential lies in the development of autonomous sensors that can calibrate themselves and adapt to changing environmental conditions in order to ensure precise emission measurements and lower maintenance costs in the long term.
To summarize:
- All wastewater treatment plants must install emission measurement systems and regularly transmit data to environmental authorities.
- Collected data is used to reduce emissions and optimize processes.
- Challenge: Selection of a suitable measurement method with high accuracy, low maintenance and good integration.
- NDIR technology is gaining in importance, supplemented by electrochemical sensors or photoacoustic spectroscopy.
- AI-supported systems could minimize emissions in real time and automatically adjust operating parameters.
- Cloud-based platforms facilitate data exchange and enable cross-regional analyses.
- Autonomous sensors with self-calibration could enable more precise measurements with less maintenance in the long term.
Significance for measurement technology manufacturers
The new regulation opens up a growing market for companies that specialize in the development and production of gas sensors. In addition to measuring N₂O, wastewater treatment plant operators are increasingly interested in the simultaneous detection of methane (CH₄) and CO₂, as CO₂ serves as a reference gas for correcting potential cross-sensitivities. This enables a more precise determination of the individual gas components and significantly improves the overall data quality.
Our company has already developed three Silarex sensor solutions that cover different measuring ranges. We are currently working on a fourth product generation that takes moisture into account in addition to gas concentration to enable even more precise measurement. The integration of humidity measurements is particularly important for N₂O detection, as water vapor can influence spectral absorption and correction factors are therefore necessary. This represents a technological advance that significantly improves the precision of measurements under changing environmental conditions.
- New Silarex generation with moisture measurement for more precise N₂O detection.
- Water vapor correction improves measurement accuracy under variable conditions.
- Technological progress optimizes accuracy and reliability.
We are also working on expanding the sensor technology in order to further optimize measurement accuracy and facilitate integration into existing control systems. A central development focus is on reducing cross-sensitivities and improving the long-term stability of the sensors. By using advanced algorithms for real-time compensation of disturbance variables, we can deliver more accurate measured values and increase the reliability of our sensors.
In addition, advanced sensor technologies with AI-supported data processing and adaptive algorithms could be developed. These would analyze emission values in advance and enable targeted control measures in real time. Intelligent adaptation of processes based on this data could not only minimize emissions, but also reduce operating costs.
In addition, cloud-based solutions for data storage and analysis could be used to enable cross-regional networking of measuring stations. This would improve the comparability of emission values between different wastewater treatment plants and enable more comprehensive regulatory control.
To summarize:
- New regulation creates growth market for gas sensors.
- Combined measurement of N₂O, CH₄ and CO₂ improves data quality.
- Silarex sensors with moisture measurement optimize N₂O detection.
- AI-supported algorithms enable more precise analyses and control.
- Cloud solutions improve networking and regulatory control.
Advantages of NDIR technology
NDIR spectroscopy is an established method for gas analysis, which is characterized in particular by the following advantages in emission measurement:
- High specificity and accuracy: Differentiation between different gas components using characteristic absorption bands. This enables precise emission measurement of N₂O, CH₄ and CO₂, even in complex gas mixtures.
- Long-term stability: No consumables required, which reduces operating costs. In addition, the sensors are robust against environmental influences and rarely require recalibration, which makes emission measurement reliable over long periods of time.
- Low maintenance: These are long-lasting sensors with minimal calibration requirements. Self-diagnostic functions allow potential faults to be detected and rectified at an early stage.
- Flexibility in application: They are adaptable to different process conditions and system integrations. The sensors can be integrated into existing control systems and offer modular expansion options for scalable measurement.
- Real-time data acquisition: This enables immediate reactions to changes in the operating process. Combined with AI-supported data analysis, anomalies in emissions measurement can be detected at an early stage, allowing precise process control.
- Extended connectivity: Modern NDIR sensors can be connected to cloud-based platforms via digital interfaces, enabling cross-regional processes and optimized data evaluation.
The combination of these advantages makes NDIR technology one of the most efficient methods for continuous emission measurement in wastewater treatment plants. Its application not only enables compliance with regulatory requirements, but also provides valuable insights into process optimization and operational efficiency improvements.
To summarize:
- High precision thanks to differentiation of N₂O, CH₄ and CO₂.
- Long-term stability without consumables and infrequent recalibration.
- Low maintenance thanks to durable, self-diagnosing sensors.
- Flexible use in various process systems and scalable.
- Real-time data acquisition for fast reactions and optimized control.
- Cloud connectivity enables cross-regional analysis and data evaluation
- Efficient method for emission control, process optimization and cost reduction.
Challenges in sensor development
Despite the advantages of NDIR technology, the development of practical sensors requires continuous optimization in terms of sensitivity, interference compensation and signal processing. Precise emission measurement requires accurate detection of low N₂O concentrations, while at the same time cross-sensitivities due to water vapour or other accompanying gases must be minimized. This requires the development of advanced signal processing algorithms that filter out unwanted interference and enable improved selectivity.
The sensors must also be designed in such a way that they can be easily integrated into existing process control systems. Smooth emission measurement requires digital interfaces, modular designs and robust signal processing - essential development aspects that determine the acceptance and spread of the technology.
Another challenge is to minimize the energy consumption of the sensors. Increasingly, energy-efficient microcontrollers and low-power sensor technologies are being used to enable autonomous operation.
Another important aspect is long-term monitoring and the development of intelligent self-diagnostic functions that minimize maintenance costs and ensure high data quality. Modern sensor concepts already integrate predictive maintenance functions that detect potential malfunctions at an early stage and enable predictive maintenance.
In addition, the integration of wireless sensor networks could make installation and maintenance even easier. Central monitoring systems in the cloud could continuously analyze the data and report operating anomalies. These developments open up new possibilities for more efficient and cost-effective emission measurement in wastewater treatment plants.
To summarize:
- Optimization of sensitivity and signal processing for accurate N₂O detection.
- Minimization of cross-sensitivities through advanced algorithms.
- Simple integration into existing process control systems with digital interfaces.
- Reduction of energy consumption through low-power technologies.
- Long-term monitoring and self-diagnostic functions for less maintenance.
- Predictive maintenance detects malfunctions at an early stage.
- Wireless sensor networks and cloud connection facilitate maintenance and analysis.
Conclusion and outlook
The new EU regulation on the measurement of N₂O emissions in wastewater treatment plants marks a significant step towards precise, scientifically based environmental regulation. The challenge now lies in the practical implementation and harmonization of national requirements, particularly in the area of continuous emission measurement.
For wastewater treatment plant operators, this means a regulatory adjustment that also holds potential for increasing efficiency. Precise measurement not only enables compliance with legal requirements, but also data-based optimization of process management. By continuously measuring emissions, fluctuations can be detected at an early stage and targeted countermeasures can be taken to minimize emissions and reduce operating costs.
Manufacturers of measurement technology have the opportunity to develop innovative, cost-efficient and highly precise sensor solutions that meet both regulatory requirements and the practical needs of operators. With the further development of Silarex technology, our company strives to make a decisive contribution to the sustainable design of wastewater treatment technology and to continuous emission measurement.
The coming years will show to what extent technological advances and regulatory adjustments can further improve emission measurement in wastewater treatment plants and reduce emissions in a targeted manner.
However, it is clear that continuous emission measurement and analysis of N₂O emissions will play a central role in environmental protection and process optimization. The combination of predictive analyses, intelligent control systems and innovative sensor technology could lead to a sustainable reduction in climate-damaging emissions in the long term.