Head of research group: Jes Vollertsen

We are an internationally leading research group within the area of biological and chemical process engineering of sewer networks. Focus is on urban polluted waters, their treatment and interactions with the environment. Based on experimental investigations, the research aims at developing fundamental knowledge to solve pertinent environmental pollution issues.

The group has – based on its fundamental insight in sewer processes and technologies – been involved in a great number of international scientific programs and several R&D engineering projects in both Denmark and abroad. The group has an extensive publication record in terms of books, reports and papers published in international recognized journals and proceedings.

The scientific work within the group is aimed at engineering applications. At present, the main scientific topics in focus include:

Microplastic pollution of the environment
Microplastics represent a diverse group of emerging pollutants, which has received a great deal of media attention in recent years. A major part of the microplastic pollution enters the environment via urban polluted water. The ultimate goal of the research is to develop solutions to the microplastic problem.

The current research activities are focused on developing robust and reliable methods for microplastic analysis in all types of environmental samples (water, wastewater, biota, food, soil, sediments, biosolids, air, etc.). The methods are applied in projects aiming at quantifying the loads of microplastics into the natural environment; e.g., via wastewater and stormwater discharges, and via application of biosolids to agricultural land. As an integrated part of this work, the group also study the physical, chemical, and biological breakdown of microplastics in the environment.

Stormwater management
Urban and highway drainage makes up a problem for city and municipal engineers but is also a potential in terms of “water in the city”. Chemical and biological process engineering of both combined sewer overflows and stormwater runoff from urban areas and highways are central activities at the Urban Pollution research group.

Several research projects focusing on treatment of urban and highway runoff combined with the development of solutions that improve the recreational and ecological value of stormwater systems while achieving cost-effective solutions have been conducted over the years. We work on all levels of detail, focusing both on transport and transformation pathways for specific pollutants such as organic micro-pollutants and heavy metals as well as on full-scale implementation of best management practices.

In-sewer processes
The sewer systems are among the most important and valuable assets of a modern society. These systems are responsible for the safe management of urban wastewaters by providing a hygienic barrier against pathogenic microorganisms. However, sewers are typically designed exclusively for collection and conveyance of polluted water with little or no attention given to the microbiological and chemical processes taking place in biofilms, sediments and the wastewater itself. The consequence is in many cases severe problems in terms of odor, corrosion and health risks associated with build-up of toxic sewer gases.

A focal element of the research conducted by the Urban Pollution group is in-sewer processes with particular emphasis on hydrogen sulfide related problems, sulfide control technologies and integrated wastewater treatment design – taking into account the interactions between sewers and treatment plants. The group has pioneered this research area and is today world-leading experts. Based on more than 25 years of research, the group has established a conceptual understanding of the chemical and biological processes in sewers. A corresponding integrated sewer process model WATS (Wastewater Aerobic/anaerobic Transformations in Sewers) has been developed by the group.