CSZ: centrate TSS sensor system
Introduction: from pioneering to proven value
The first SOLiSENZ CSZ measurement systems were installed in 2022. Based on our prototype experience, we expected it to be a suitable solution for sludge treatment. Since then, together with our customers, we have learned a great deal about the complexity of centrate measurement in real-world applications. As of 2024, sixteen SOLiSENZ CSZ systems are in operation both in the Netherlands and abroad. Over this time, the SOLiSENZ CSZ has proven to be robust and reliable. Along the way, we have also encountered challenges, linked to external factors such as sludge quality, extreme contamination, or fluctuating inlet and outlet conditions. Thanks to an innovative and flexible team, these challenges were not only overcome but led to an even stronger product.
The SOLiSENZ CSZ has also evolved alongside real-world operations. Both software functionality and cleaning options have been further developed, resulting in a more user-friendly and powerful system that better meets the needs of operators.
In practice, we notice that the introduction of real-time centrate measurement can be a significant shift for operators. Where they once had to rely on weekly lab results or visual assessment, the SOLiSENZ CSZ suddenly provides continuous insight into process dynamics. This can lead to surprising discoveries with variations in concentration, the influence of sludge feed systems, or unusual equipment behaviour that previously went unnoticed.
It is precisely in this transition, between familiar practice and new insights, that the SOLiSENZ CSZ shows its true value. Because measuring means knowing. And knowing leads to better processes.
Why measuring centrate matters
When optimizing sludge dewatering, understanding centrate quality is essential not only for process optimization and polymer savings but also for preventing overload of the secondary clarifier or effluent treatment system. Yet, many plants still rely on occasional laboratory measurements, which only provide snapshots in time. With the introduction of the SOLiSENZ CSZ, that is a thing of the past.
The SOLiSENZ CSZ is an innovative TSS sensor specifically designed for real-time measurement of suspended solids in the most challenging part of the sludge process: the centrate. Over the past few years, the sensor has been extensively validated at multiple sites under a wide range of operating conditions. The results show that the SOLiSENZ CSZ is not only robust and low-maintenance but also delivers excellent agreement with laboratory analyses.
Validation results: comparison with lab measurements
To substantiate the performance of the SOLiSENZ CSZ, extensive validation campaigns were carried out at several locations. Across a wide measurement range, laboratory samples were collected simultaneously and compared to the SOLiSENZ readings.
The average correlation of 0.909 across all locations with a total of 133 laboratory samples confirms that the sensor provides reliable results even under highly variable process conditions.
The Technology
Developed specifically to meet the needs of decanter sludge treatment plants, the CSZ offers a unique composition that ensures long-term, reliable TSS measurements in centrate. With its robust peristaltic pump, CSZ ensures a continuous flow of wastewater through the device, while the double automatic cleaning system keeps the device clean and functional at all times.
In addition, the CSZ features ultrasonic sample conditioning to ensure that there is no air in the centrate, which helps the optical solids sensor measure TSS in a stable manner within 30 to 90 seconds from the supply. The device is can be easily operated by the user through a user-friendly touchscreen interface. This interface allows you to adapt the system to your own installation conditions, making it a customizable solution that fits your unique needs.
Maintenance and robustness
The SOLiSENZ CSZ is designed for practical, long-term use. The sensor is equipped with an automatic cleaning system, which in most cases is sufficient to keep the measurement optics clean for extended periods. In practice, a simple visual check and manual cleaning once every two weeks is often enough. Even at sites with centrate concentrations above 5000 mg/L, the SOLiSENZ CSZ continues to perform reliably. For such heavy-duty installations, we recommend more frequent visual inspection, but structural failures have not been observed.
Thanks to ongoing development in recent years, the cleaning options of the SOLiSENZ CSZ have been expanded, enabling improved self-cleaning performance even under severe fouling conditions. This ensures dependable measurement, even in the most challenging environments.
