WWEM - Abstract

Abstract Information :

Resume In this presentation, we will convey the results from a major demonstration project, which shows how liquid phase measurements of hydrogen sulphide (H2S) provide a more accurate picture of a wastewater utility’s H2S challenge and why these sensors will have a crucial role in the ongoing digitization of the wastewater industry. We will present results from 2 case studies achieved in collaboration with major European wastewater utilities, demonstrating how continuous liquid phase measurements enable smarter and more proactive decision-making, contribute to reduce operational costs, and helps facilitate a more environmentally compliant approach to chemical dosing for H2S mitigation. Abstract Sensors are crucial for creating comprehensive overviews and enabling new process optimizations for wastewater utilities, making them an essential part for the ongoing smart water digitalization of the water sector. Despite the increased focus on intelligent wastewater monitoring systems for critical process parameters, utilities still lack sufficient knowledge about the volatile toxic gas hydrogen sulphide (H2S). Existing sensor technologies that measure H2S only in the air have not been able to provide a complete overview. This presentation will thus demonstrate how liquid phase measurements of H2S offer a more accurate depiction of a utility’s H2S challenges. These insights are crucial for adopting a data-driven approach H2S control and optimizing mitigation measures. H2S is bacterially produced under oxygen-free conditions, typically in pressure pipelines, and is released into the environment in pumping wells and further into the gravity network. H2S causes significant odour nuisances that immediately affect the surrounding environment and substantial long-term economic damage by accelerating the degradation of infrastructure assets such as sewer pipes, pumping station wells, and wastewater treatment plant inlets. In the first case study, we will highlight the fundamental advantage of measuring H₂S directly in the wastewater rather than in the air (gas phase). In collaboration with major European utilities, we have continuously measured H2S in pumping wells after pressure pipelines, comparing measurements taken directly in the untreated wastewater, just above the wastewater, and at the manhole cover. The results from these measurement campaigns clearly show that liquid phase measurements provide a more accurate insight into the full extent of the problem than gas phase measurements and are less dependent on external influences such as turbulence, ventilation, and oxidation. In the second case study, we will demonstrate how continuous liquid phase measurements can optimize processes for H2S control. Wastewater utilities often dose chemicals to combat H2S, but due to the lack of a complete overview, dosing is typically either excessive or insufficient. In collaboration with a European wastewater utility, we have shown how H₂S sensor-controlled dosing of iron sulphate can improve the efficiency of a chemical dosing station while reducing chemical usage. By dosing proportionally to the sensor’s real-time data, the dosing station used 50% less iron sulphate compared to a similar period with constant dosing. This demonstrates the potential for smart, data-driven approaches to significantly enhance the efficiency and sustainability of water industry operations.