Wieland, Arne

Arne Wieland graduated with a degree in Chemical Engineering, specializing in Environmental Engineering, from the University of Applied Sciences in Osnabruck, Germany. Since 2004, he has been working with Xylem as a Process Engineer specializing in oxidation processes for municipal and industrial applications. His responsibilities include customer process consulting, system design, process-related research, and product improvements. Arne Wieland focuses on municipal and industrial wastewater treatment applications, particularly those dealing with micropollutants and advanced treatment methods. Since 2022, Arne Wieland is a member of Technical Committee "KA 8.5 Ozonation on WWTPs" of the German Water Association DWA.

Titles from this speaker

15 Years of Ozonation for Micropollutants Removal in Europe: A Review

Abstract

Ozone is well known as an effective disinfectant and oxidant and has been operated for drinking water treatment for more than 100 years, often in combination with biofiltration or biologically active carbon filtration. More recently, it is also applied on wastewater treatment plants (WWTPs) to mitigate the discharge of chemicals of emerging concern (CECs) into receiving surface waters. As a first European country Switzerland implemented a regulation to reduce the discharge of CECs from WWTPs in 2016. With the overarching goal to substantially reduce the load of CECs discharged into surface waters, requirements for advanced wastewater treatment were defined for the largest WWTPs and those plants which are discharging into sensitive water bodies in the country. In total more than 100 WWTPs of different sizes are affected. The discussion about the specification of the regulation was supported by pilot- and full-scale trials like at the WWTP in Regensdorf/Switzerland (Abegglen et al., 2009). Currently, there are ten WWTPs operating ozonation systems or combined ozonation + biologically activated carbon filters in Switzerland. The biggest installation is located at WWTP Werdholzli, which treats the wastewater of Zurich with a design flow of 6,000 l/s. No regulation for CEC mitigation on WWTPs is currently in place in the EU, but a draft of the Urban Wastewater Treatment Directive was proposed in October 2022, which for the first time includes requirements for advanced wastewater treatment. The approach is similar to regulations in Switzerland and defines an average removal of 80% for a list of indicator CECs, which will become mandatory for all large WWTPs (>100,000 PE) within the EU. In addition, requirements for CEC mitigation at medium sized WWTP will be assessed following a risk-based approach. Despite the lack of regulatory pressure, CEC mitigation has been applied at numerous WWTPs in different EU member states. In Germany, the installation of advanced treatment is funded by some federal state governments. Main treatment goal is the improvement of the chemical conditions of the receiving water bodies. Currently, sixteen ozonation systems are in operation on German WWTPs with the biggest at WWTP Aachen-Soers treating up to 3,000 l/s. In the Netherlands, Belgium, Sweden, and France first full-scale installations are close to start or in operation. Other EU member states such as Austria or Italy tested the process in pilot installation (e.g., KOMOZAK (Kreuzinger et al., 2015) and KOMOZAK II (Krampe et al., 2020)). It can be expected that the number of installations in the EU will increase rapidly once the revised UWWTD will become into place. Beside regulatory changes the design and control strategies have changed during the last years. The first installations were designed for ozone dosages up to 0.2 2 mgO3/mg DOC (Lyko et al., 2013), but recommended ozone doses decreased over time, these big ozone generators are nowadays operated a lower production level. Today, the recommended ozone dosages are ranging from 0.5 0.7mg O3/mg DOC (DWA, 2022) and can be even lower for combined processes of ozone and activated carbon. Ongoing research on related topics, e.g., testing of surrogate parameters for performance monitoring or dose control, leads to further optimization of the installed process. These optimizations significantly reduce the size of ozonation systems and the specific operational costs. In addition, different mixing concepts such as diffusors or injectors were installed and compared at pilot- and demonstration-scale. New tools such as computational fluid dynamics modelling (CFD) and kinetic model approaches support the optimization of ozone contact basins and support the layout of ozone mixing and effects on the water quality during the engineering of ozone installations. Additionally, the feedback from operators provides valuable input for improvement since some effects can only be seen during long-term operation. Based on experiences and optimization, new guidelines, for example in Germany (DWA, 2022) and Switzerland (VSA, 2021), support the design, installation, and operation of new systems. The current draft regulation in the EU includes medium to large WWTPs, which raises the question if comprehensive implementation of CEC removal is also expedient for small WWTPs. Although there is no active regulation in place, first projects were launched at smaller WWTPs that are discharging into small and sensitive waterbodies, which might even be used as drinking water sources. The adaptation of advanced treatment technology for small WWTPs bears new challenges because staff for operation and maintenance is often not available, influent flow and quality can have stronger variation, and specific operational and investment costs of smaller WWTPs are often higher. This presentation will provide an overview on current and planned installations of ozonation for CEC removal on WWTPs, highlight lessons learned from 15 years of full-scale operation, and outline expected trends for the future. Besides the discussion on small-scale WWTPs, we will emphasize potential synergies of CEC removal with the recently launched EU minimum requirements for water reuse in agriculture (EU Regulation 2020/741). Since reuse becomes more relevant for different EU member states, the considerations for CEC removal at WWTPs should include the option of future upgrades for water reuse purposes.

Ozonation for removal of CECs in municipal wastewater is an established and efficient process which can be integrated in WWTPs. Projects in various sizes demonstrate that an implementation on existing WWTPs is possible. Control concepts and tools for optimization of ozone transfer are implemented and can be easily transferred to new sites. The costs for operation and implementation vary in a range of 3-15 cents/m3 depending on the size of the treatment plant and existing infrastructure.

SpeakerWieland, Arne

Presentation time

10:30:00

10:50:00

Session time

10:30:00

12:00:00

SessionSynergizing Digital Solutions and Ozonation for Treatment of Micropollutants

Session number524

Session locationRoom 243

TopicAdvanced Level, Disinfection and Public Health, Microconstituents and Contaminants of Emerging Concern (Non-PFAS), Research and Innovation, Water Reuse and Reclamation

Author(s)