Treatment Wetlands
Natural water treatment at the highest level
A lot has happened since plant- and soil-based wastewater treatment systems were rediscovered in Germany in the 1980s. Whereas wastewater treatment used to require an area of 10 m² per inhabitant, compact filters using less than 1 m² per inhabitant are now possible.
The modern systems are state of the art. Most systems already meet the higher requirements of German wastewater regulations for treatment facility size classes 2 or 3 (meaning 5 000 PE or 10 000 PE respectively). This means very good degradation of organic substances and extensive nitrogen oxidation without the supply of external energy. The mostly vertically perfused soil filters are therefore an excellent and ecological alternative when energy efficiency is particularly important.
AKUT has been testing nature-based solutions since the 1990s and has further developed them in numerous research projects. Starting with two-stage “hybrid” constructed wetlands consisting of vertical filters and downstream horizontal filters, through to actively aerated soil filters and combinations. AKUT is a founding member of Global Wetland Technology (GWT). This association enables the worldwide use and dissemination of leading technologies in this sector.
No matter where and what kind of water you want to treat: let us develop a customized, nature-based solution for your application.
Municipal Wastewater Management
The robust two-stage soil filters with integrated sludge treatment are the “workhorses” among constructed wetlands. This combination is also known as the “French system.” In France, they account for a large proportion of rural wastewater management in municipalities with up to 2,000 inhabitants or more. These are the only vegetated soil filters that are also suitable for treating combined sewage. They are an ideal replacement for old pond treatment plants. The municipality of Theres, Bavaria received the Bavarian Wastewater Management Innovation Award 2016 for a such a solution developed by us.
Stormwater Management
Rainwater runoff from contaminated areas such as roads or industrial sites must be treated before being discharged into a receiving water. Due to the high flow dynamics, only large-scale, nature based systems have become established here. In Germany, special retention and filtration wetlands have been developed for this purpose. They temporarily store the water on the surface and then treat it in a vertical soil passage. AKUT has exported this soil filter technology to China as part of the KEYS project funded by the BMBF (Federal Ministry of Education and Research) supporting the concept of sponge cities.
Diffuse Pollution
Nutrient accumulation in standing waters is a widespread problem. Agricultural drainage systems play a major role in this. Upstream wetlands can be used to effectively reduce nitrogen and phosphorus inputs. In various studies, we have developed concepts for the use of special soil filters and reed polders to protect lakes. In China, for example, our partner DeHua has constructed a retention strip with 3 hectares of vertical flow filtration wetlands and 12 hectares of surface flow wetlands to protect the famous Tai Lake.
Surface Water Treatment
There is growing demand for the direct treatment of small water bodies. This involves the removal of nutrients and algae or, in the case of bathing water, hygienization. Vertical flow plant filters are also used here. Combinations with technical filters is also conceivable. Reactive substrates can be used for the elimination of phosphorus. Several years of experience are available for such a combination.
Bathing Water Treatment
For many years, soil filters have been used to sanitize and purify the water in swimming ponds. In these closed-loop systems, the pathogens introduced by bathers must be effectively reduced. In combination with reactive media, phosphate and thus algae formation can also be largely suppressed. Our oldest filter has been in use in a public facility for over 20 years. In a research project, we have also determined its effectiveness for surface waters and bathing areas in open systems.
Water re-use
One very important application is the treatment of sewage or gray water for reuse. This is particularly interesting in decentralized systems, where the risk is minimal or very easy to assess and there is no need for an extensive service water network. Simple vertical filters that can be operated with minimal effort are ideal for this purpose. We have installed such a system, for example, in a social institution with a laundry and a high volume of gray water.
Phragmilfiltre® constructed wetlands
Establishment of decentralized sewage treatment plants for integrated sludge treatment of more than 2 000 inhabitants in three mountainous sites with a special focus on avoiding odors and process intensification. In Portugal horizontal flow constructed wetlands with a higher land usage and only moderate treatment efficiencies had been the exclusive technology up to this point of time. In order to fulfill the latest requirements concerning environmental standards and increasing wastewater volumes two older existing plants had to be refurbished here. more >
