In the presence of the Secretary General for the East African Community (EAC), Liberat Mfumukeko, the starting signal for an integrated water resources management programme in the Lake Victoria catchment area was given on 14 February 2020 in Kisumu, Kenya. The project, coordinated by the Lake Victoria Basin Commission (LVBC), is funded by the German Federal Ministry for Economic Cooperation and Development (BMZ) and the EU.
A joint venture of the companies Consulting Engineers Salzgitter (CES), AKUT Umweltschutz Ingenieure Burkard und Partner and MIBP Consulting Engineers as Project Implementation Consultant (PIC) was commissioned to implement Lot 2 of this programme. In this context, AKUT is responsible for the management of the High Priority Investment (HPI) “Kampala Nakivubo Channel”. The Kreditanstalt für Wiederaufbau (KfW) is responsible for the contract.
Expectations for the multisectoral project with a total volume of EUR 31.9 million (duration until February 2023) are high because the development of Lake Victoria, the second largest freshwater reservoir in the world, is highly alarming in terms of water quality, biodiversity and climate change impacts. Locating the project under the umbrella of the multilateral EAC supports regional cooperation in the region. By developing a “Water Framework Directive” – here following the European approach – the programme aims to reverse the recent negative trend and instead achieve “significant improvements” in water quality. More than 45 million people will benefit from this. To this end, new regulatory standards for discharge parameters are to be developed. In four “High Priority Investment Projects” in Kisumu (Kenya), Kampala (Uganda), Mwanza (Tanzania) and Kigali (Rwanda) concrete measures are planned which promise a considerable reduction of inflowing COD, nutrient and pollutant loads into the lake. One goal is also to develop new site-specific solutions/ technologies on a model basis, which can be implemented in the medium term at other locations in the Lake Victoria catchment area.
AKUT will focus on planning and implementing measures around the Nakivubo Channel, the largest discharger from the Kampala metropolitan region into the Inner Murchison Bay of Lake Victoria. In this context, a feasibility study for a constructed wetland for the treatment of 45,000 m³/day (both sewer water and sewage treatment plant effluent) will be examined and updated. Other variants and process combinations are also being examined in order to implement selected solutions in the next step.
In February 2020 AKUT opened a new branch office in Kampala, Uganda. Since 2005, AKUT has been continuously present with various projects in East and South Africa. With the office in Kampala, AKUT now has its first independent presence on the African continent. This is in connection with an expansion of the activities in the East African region. Our many years of experience in advising water and wastewater utilities are also in increasing demand in East Africa.
The expertise of AKUT lies in the development of locally adapted technological concepts (constructed wetlands, retention soil filters, small wastewater treatment plants, clarification ponds, SBR systems, novel sanitation systems ECOSAN, water loss reduction, measures for surface water remediation, renaturation, biogas plants, renewable energies, agricultural irrigation, multisectoral Nexus programmes) as well as in institutional consulting (development cooperation, SDG achievement, consulting on water tariff systems, capacity building, support in organisational development, social environment management, etc.). AKUT acts in a network with international and local partners.
At this year’s AfWA ICE 2020 (African Water Association International Congress and Exhibition) from 24th to 27th February in Kampala, AKUT can be found on the joint stand of the German Water Partnership (GWP) in Hall 1, B7-B8 & C14-C15. We are looking forward to your visit.
Contact: Romas Radtke
Press release: Programme-Launch.pdf
Development of a wastewater switch for the energy-efficient selective partial flow treatment of highly concentrated wastewater (ESTA) at municipal wastewater treatment plants
The research association ESTA is a merger of AKUT Umweltschutz Ingenieure Burkard und Partner, the Technical University of Berlin, FG Siedlungswasserwirtschaft and LAR Process Analysers AG. The aim was the development of an intelligent wastewater switch in the inflow of municipal sewage treatment plants for the separation of highly charged inflows and energy recovery by means of anaerobic treatment. The joint project “ESTA (FKZ 02WQ1382A-C)” was funded by the Federal Ministry of Education and Research (BMBF) within the framework of the SME-innovativ funding initiative.
As a result, peak inflow concentrations could be identified and evaluated with a time resolution of 6 minutes with regard to height and frequency in order to activate the wastewater diverter.
A successful operation of the wastewater switch and the anaerobic test reactor was possible despite the low peak concentrations and the low number of shock loads on the investigated wastewater treatment plant in combination with excess sludge. The simulation of the wastewater treatment plant showed that, despite the removal of the highly charged wastewater fraction and despite changes in the C:N ratio, the statutory monitoring values can be complied with under the underlying conditions (in particular the low ammonium inflow values). A maximum degree of electrical self-sufficiency of 75 % could be achieved.
A central component of the project was the construction and operation of a test plant at the Baruth (Brandenburg) sewage treatment plant, which was planned and installed in coordination with the project partners TU Berlin and AKUT. The project partner LAR was mainly responsible for the development of an adapted online analysis technology. Project start was 01.10.2016, project end was 31.03.2019.
With the help of the TOC-Online monitor a mechanism was controlled, which feeds inlet water of the sewage treatment plant to an anaerobic reactor from an adjustable threshold concentration. Both the analysed feed concentrations, the volume flows and loads fed into the reactor and the biogas produced in the reactor were evaluated.
Due to the implementation of the TOC online monitor on a trailer, the measuring equipment is now also available for mobile use. Measurement campaigns at other sewage treatment plants and at two industrial sites prove the operational capability. The basic load could be clearly determined and the concentration peaks could be evaluated with regard to height and frequency. It was possible to define threshold values in concentration and volume of an impact load which makes the investigation of a general conversion of the process with separate anaerobic sludge treatment useful.
“Although the Baruth wastewater treatment plant under investigation with the evaluated impact loads is below the threshold values determined and a further investigation does not appear to be appropriate here, the results of the other sites investigated certainly show potential”, explains project coordinator Dipl. Ing. Thilo Burkard (AKUT).
The participating project partners are accordingly optimistic that the new concept can be applied to new construction and conversion of wastewater treatment plants. A measurement campaign with the mobile measuring device is therefore planned for other wastewater treatment plants.
Further information: Thilo Burkard
Thousands of canals run through the cities in China. In the shallow estuaries of the major rivers, they have traditionally served as traffic routes navigable by barges. With rapid and extremely dense development, the drainage of water became increasingly important. However, this was accompanied by ever-increasing pollution. Hydraulically overloaded sewers and high material loads in rainwater runoff today lead to excessive pollution of surface waters. This has a bad effect on their oxygen balance, which leads to serious odour nuisance, especially in the warm season.
Since the government declared the remediation of these waters to be a central task for all municipalities, many technologies have been tested. In most cases, however, success has not been achieved. Obviously, the problem could not be solved by internal measures in the waters alone. In two cases, retention soil filters were now used, which are suitable for the short-term absorption of high hydraulic loads from the combined sewer and stormwater system and thus for treatment before overflowing into the sewer.
Within the framework of the BMBF-funded KEYS joint project entitled “Pioneering technologies for the sustainable management of urban watersheds as a key factor for the successful implementation of the “sponge city” concept”, the effect of these systems is to be demonstrated and investigated in parallel. Retention soil filters were developed in Germany and represent the key technology in this country for both centralised and decentralised treatment of rainwater and combined sewer overflows.
The engineers of AKUT, who have been working in China as consultants for 10 years, are aware that German technology cannot always be transferred one to one abroad. In particular, the data basis for optimal dimensioning is often missing there. In cooperation with the project partners, the prerequisites are now being created. During our visit in December 2019, the sampling locations for the planned measurement campaigns in 2020 were examined and operational data were obtained. The installation of online probes and rain recorders was prepared.
The two demonstration sites, each with 3 000 m² retention filter area, are located in Suzhou, Jiangsu Province. While the first retention soil filter at the Zhujing Channel has been in operation since 2018, the second filter at the Hongshuanglou Channel was not completed until winter 2019.
In contrast to the more water-rich regions, these soil filters will also be used in arid climates such as Beijing. A multifunctional use of the soil filters is being tested for this purpose. This means that in dry weather, the available filter area will be used for direct treatment of surface water. This protects the plant filters from drying out and simultaneously leads to an increased cleaning effect.
The joint project is led by the Institute for Sanitary Engineering of the Leibniz University of Hannover (ISAH) and funded by the Federal Ministry of Education and Research for 3 years within the framework of the funding measure “CLIENT II – International Partnerships for Sustainable Innovations”.
Photo: Till Ermisch (AKUT) interviews Ying ZHANG from Suzhou DeHua Eco Technology Ltd. about the discharge points at the restored Hongshuanglou Channel.
Mankind is facing “unprecedented suffering”, according to scientists from all over the world, if it does not seriously fight against global warming. 11,000 scientists warn against a “Continue like before”. Scientists warn that three quarters of the 184 pledges submitted to save greenhouse gases are not ambitious enough. Measured against the goal of reducing emissions by at least 40 percent by 2030, only the 28 EU states and seven other countries are on the right track (quote: ARD, Tagesschau 5.11.2019).
Already on 20 September the AKUT partners joined the call of commercial enterprises with Entrepreneurs For Future. It demands an ambitious climate protection law from the Federal Government of Germany.
However the federal government has passed a probably ineffective climate law, which will not reach the goals. We share the protest of the students of Fridays For Future.
Few days before the world’s governments meet in Madrid for the World Climate Conference, we need to reaffirm our commitment to effective climate legislation so that there are no more excuses for policy makers not to act effectively.
The Federal Government justifies its hesitant measures with the fact that it cannot impose consistent climate protection on people. However, climate protection and social policy must not be played off against each other.
For the first time, climate activists, environmental, development, social and welfare organisations are joining forces. We show: Climate protection and social justice belong together indivisibly. People in the Global South and future generations must have a climate-friendly future! A social-ecological turn is a huge chance for a fairer society – here and worldwide!
For more than 30 years AKUT has been working on technical solutions for environmental protection. We can no longer solve the global problem without a strong climate protection program also of the German government and a change of awareness among each individual.
Go out with us and with millions of people this Friday 29 November 2019 to the streets and demand effective climate protection now and for all.
From 16 to 20 June 2019, the International Water Association IWA hosted its “12th International Conference on Water Reclamation and Reuse” in Berlin: over 400 experts from more than 40 countries, more than 200 lectures, more than 120 posters, exhibitions, workshops and technical tours on the complex of “Overcoming Water Stress through Water Collection and Reuse”. In times of advancing climate change, water management is becoming increasingly important, as we experience in our daily work.
Part of the program was a tour of the former sewage farms in Berlin Hobrechtsfelde called “Hobrechtsfelder Rieselfelder”. AKUT has organized that tour.
In the information centre “Gut Hobrechtsfelde”, the former warehouse, there is a beautifully prepared exhibition on the history of Berlin’s wastewater treatment, in particular the sewage farms. The model of the agricultural use of the sewage farms around 1920 shown there is designed precisely. The Hobrechtsfelder Rieselfelder were taken out of operation after the commissioning of the sewage treatment plant north (today: WWTP Schönerlinde) in 1985. Both the drainage pipes, which continued to drain the area, and the heavy metals and phosphates, which had accumulated in the soil over the decades, remained in the soil. The reirrigation of the sewage farms was planned and implemented in 2004 by the AKUT / P2M / Spiekermann GmbH working group. A part of the existing drainage ditches including the drainage pipes were sealed, whereby a long retention time was aimed at. Re-irrigation of areas that had fallen dry became possible. This is done with already purified wastewater from WWTP Schönerlinde, which is further purified and hygienised at the request of the Lower Water Authority within the Hobrechtsfelder Rieselfelder. The treatment is carried out without electrical energy demand and with the lowest operating costs, as no operating resources are used. A system consisting of different zones, such as deep water zone, shallow water zone, overgrown zones and ground passages, has been created for the more extensive near-natural wastewater treatment within this so-called cleaning biotope. Since only limited data were available for the effect of the individual components, AKUT had planned pilot filtration plants / test basins for practical evaluation of the possible variants. Within the framework of a research project, not only nutrient degradation rates and hygienization were investigated, but also the removal of pharmaceutical residues and of other micropollutants. After completion of the test operation, the pilot plant has been adjusted for continuous operation. A good ten years after the re-irrigation had started, not only a large number of birds but also beavers have settled in the area. As planned, the sewage farms and the surrounding biotope are used as a silvopasture system where livestock and horses are moving independently with the side effect of low cost landscape conservation.
The conference participants from all over the world were impressed by the near-natural technology of the 19th century with sewage farms for the treatment and agricultural use of wastewater and nutrients. But even in the 21st century, when regional water scarcity is expected, there is great interest in near-natural solutions to strengthen the water balance through water recycling. At the same time, carbon sequestration in wetlands around the world represents an important contribution to climate protection.
We would like to take this opportunity to thank
- DECHEMA and Berliner Wasserbetriebe BWB for support in the organisational handling of the tour;
- the Pankow forestry office and
- the horse farm “Pferdekultur Gut Hobrechtsfelde” for opening the exhibition and the guided tour.
The conference “BLUE PLANET Berlin Water Dialogues meets AquaNES” will take place in Berlin on 09 April 2019 from 9 am to 5 pm. The conference meets every year to promote cooperation and knowledge exchange across industries. This spring, the research work and innovations of the Horizon 2020 project AquaNES will be specifically presented and debated through lectures, panel discussions and World Cafés.
AquaNES is a research network that investigates and promotes wastewater and drinking water treatment through a combination of near-natural and technical systems through 13 different demonstration projects in Europe, India and Israel. A wide range of climatic and hydrogeological factors will be covered and processes such as bank filtration, Managed Aquifer Recharge, Constructed Wetlands and technical pre- and post-treatment options will be tested and improved.
AKUT has been involved in the research project AquaNES since June 2016. Together with partner companies such as Berliner Wasserbetriebe (BWB), Kompetenzzentrum Wasser Berlin (KWB) and Erftverband, AKUT will present the results and hurdles of the combination of near-natural and technical systems for wastewater treatment and water treatment.
In cooperation with the BWB and the KWB, AKUT has developed a pilot plant at the Schönerlinde site to remove trace substances and pathogens from the effluent of the wastewater treatment plant. For this purpose, two different planted soil filters with upstream ozonation were built and their effect on improving water quality was investigated. Regina Gnirss (BWB) will present the results of the two-year pilot in her lecture “Ozonation combined with natural filtration processes – water quality gains”. In addition, Andrea Brunsch (Erftverband) will present the results of the pilot plant at the Rheinbach site in her lecture “Flexible use of modified retention soil filters to treat wastewater treatment plant effluent and combined sewer overflow”, in which a retention soil filter is used flexibly for the treatment of wastewater from wastewater treatment plants and mixed water overflows.
After the presentations AKUT and AUTARCON will lead the discussion group “Solutions for rural communities, remote locations and emerging countries” and will be available for questions and discussions on the topic.
The exact programme and further information on “BLUE PLANET Berlin Water Dialogues meets AquaNES” can be found at http://blueplanetberlin.de/next-event/ .
As part of the GIZ project “NEXUS – Water, Energy, Food Security”, a total of 36 participants were trained in a workshop on solar irrigation lasting several days in September 2018. The workshop took place in the Universidad Católica Boliviana (La Paz) and was attended by local and international experts, researchers and students as well as members of Bolivian institutions and authorities (e.g. Ministry of Environment and Water). The participants shall serve as multipliers by integrating the gained knowledge into their daily work.
The contents of the workshop included the topics renewable energies, description of typical photovoltaic applications with focus on agriculture, description and characterization of solar water pumps, irrigation needs and techniques, water needs, planning and design of solar irrigation systems, economic evaluation and financing of solar irrigation systems, description and practical application of the tool box “Solar powered irrigation systems” as well as practical applications and design of solar pump and irrigation systems.
The workshop can be classified as a success. More than half of the participants stated in an evaluation that they could apply the acquired knowledge in their field of work and all participants stated to be satisfied or very satisfied with the results of the workshop. As a result of the discussion between members of various stake holders the potential for solar irrigation in Bolivia could be classified as very high.
The workshop is one of several training cycles within the GIZ project “NEXUS – Water, Energy, Food Security”. This project, which runs from August 2017 to October 2019, includes workshops of this kind as well as the development of management models and financing concepts for two selected pilot projects with Nexus character and Integrated Water Resources Management (IWRM).
AKUT has been commissioned to provide advice for a multi-purpose dam project (Misicuni). A water distribution plan is to be elaborated in order to balance out the water use between agricultural use (irrigation), drinking water supply and secure energy production.
The adaptation to climate change (e.g. reduction of the available quantity of water, increased need for irrigation) shall be achieved through the development of proposals for the management of the limited resource of water with the various user groups.
A GIS-based open-source information system is to be set up in order to present and design the water supply and distribution in a transparent manner.
Another important objective of the project is poverty reduction. Solar irrigation should contribute to this by reducing water and energy consumption. In addition, poverty is to be reduced by reforestation and the introduction of agroforestry systems to sustainably improve land use in the upper reaches of catchment areas.
Picture: Group photo at the end of the workshop
Companies that discharge production waste water into the sewage system (indirect dischargers) must comply with the discharge limit values of the respective wastewater utilities. If limit values are tightened the challenge is to develop particularly economical solutions that avoid the installation of a complete new wastewater treatment plant. AKUT was assigned to develop a solution for a similar situation regarding the wastewater discharge of the phosphating plant at Robert Bosch Automotive Steering GmbH in Berlin-Wittenau.
Current studies show that the implementation of technical adaptation and optimization measures at the chemical-physical waste water treatment plant has been successful in regards to tightened limit values. The measured total phosphate values in the discharge of the cleaning plant after the conversion have dropped to 90 percent less than the new limit values for discharge into the sewer system of Berliner-Wasserbetriebe (BWB).
The effluent limits for total phosphate were reduced to 50 mg/l by BWB beforehand.
Robert Bosch Automotive Steering GmbH had then decided to technically convert the existing plant for the removal of metal ions from wastewater to ensure compliance with the reduced phosphate discharge limit value.
AKUT Partner designed the cost-effective adaptation solution after an intensive assessment.
By converting, technically supplementing and optimizing the existing treatment plant, the phosphate is (now in addition to the previously precipitated metal ions) precipitated with automatically dosed lime and separated from the wastewater in an existing chamber filter press.
The contract included that the selected plant concept has been supervised and monitored until final acceptance and commissioning.
As requested by the customer the TÜV approval of the now semi-automatically operated chemical-physical wastewater treatment plant passed the plant without imposing any additional requirements.
Other relevant effects of the extensive automation of the wastewater treatment process are time savings for the operating personal and a reduction of the electric energy demand.
The low investment costs (compared to the installation of a new wastewater treatment plant) and the positive effects on operating costs increase the overall profitability of the phosphating plant in Berlin-Wittenau.
Photo: Robert Bosch Automotive Steering GmbH, Berlin – Wittenau. Buffer tank for the phosphate-containing wastewater, in the background the chamber filter press for separating the lime sludge.
Overall, the framework conditions in South Africa for the generation of electricity from sewage gas are rather difficult. The remuneration for feed-in from renewable energies is fixed at auctions, this procedure prefers scalable technologies such as photovoltaics. Biogas, on the other hand, is limited by the availability of raw materials. This restriction applies in particular to the conversion of sewage and landfill gases into electricity. The unique selling point of biogas, simple storage and power generation at peak times, is also not affected by this process of auctioning.
Thus, the only economically decisive factor on the South African energy market is the savings in own electricity consumption. The current electricity prices of around 1.20 rand/kWh (around 0.08 €/kWh) are low by German standards. However, the electricity price has multiplied since 2007: at that time, it was 0.013 €/kWh. In addition, annual price increases of 10% have been announced.
In this field of tension AKUT was commissioned by the Deutschen Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH to prepare two studies on the use of sewage gas for the two sewage treatment plants Kingstonvalle and Zeekoegat.
Economic plus ecological advantages
Against the current background of water scarcity in Cape Town, the relevance and explosive nature of the topic becomes very clear. The lack of rainfall is primarily attributed to climate change. The studies therefore identify emission reductions, in this case reductions in methane emissions, as a significant advantage in addition to economic advantages. At present, the gas produced by sewage sludge digestion is released into the atmosphere without further measures. This is now to be changed so that the gas is collected, processed and used for power generation.
The studies present detailed comparisons of various technical components, operating models and organisational forms. In both sewage treatment plants, the economic benefit can be maximised by optimising the utilisation of the existing digestion towers. Capacity utilisation is to be increased by adding so-called co-substrates, either digested sludge from neighbouring sewage treatment plants or waste from the agricultural industry. The latter could be identified by local AKUT employees so that specific modelling could be carried out, taking into account both the biogas potential and transport costs.
Economically reasonable are also the variants with an exclusive treatment of the sewage sludge of the sewage treatment plant. However, the then lower investments will lead to a slight reduction in profitability.
In addition to the technical components and the various operational management, operator models from in-house operation to BOT models were also examined. Two preference variants were determined from six different operator models.
The decision now lies in the field of politics. Should the measures be implemented? Which of the preferred variants is preferred? GIZ and AKUT are ready to continue to support the City of Tshwane and Mbombela municipalities – both in decision-making and in technical implementation.
The international IWA conference on sustainable solutions for small water and wastewater treatment systems (s2small2017) was held October 22-26 in Nantes, France. Florent Chazarenc (IMT Atlantique) chairman of the conference emphasized that small systems play a significant role in solving problems of humanity: „Small is beautiful, efficient and affordable – small is the future“ he said. More than 200 participants responded to the call and discussed their proposals for solutions in the areas of resource-oriented sewage systems, wastewater treatment and recycling.
As a German contribution to the improvement of small sewage treatment plants Heribert Rustige, AKUT partner from Berlin, presented the new DWA worksheet A 262 on the topic of constructed wetlands. This guideline is expected to be published in November 2017 and replaces the previous A 262 from 2006, whereas many new solutions and system variants have been added to the new worksheet. This includes the so-called French system, which consists of a combination with raw wastewater pre-treatment in a planted gravel filter and post-treatment in a planted sand filter (e.g. Phragmifiltre). Another newly described method using active aeration is particularly innovative. It was developed by Scott Wallace in the USA and extensively tested on site for several years in Germany by the UFZ research institute in Leipzig.
International Interest in the German Constructed Wetland Guideline
In the past, the A 262 had already attracted interest from other countries. It was last translated into Russian. Many users are now waiting for the release of the current version. An English version will also be available soon from the DWA in Hennef.
The advantage of such a detailed set of rules is the increased safety for planners and operators. The worksheet specifies minimum requirements for the dimensioning of soil filters and refers to values derived from practical experience. The user must check in each case whether the boundary conditions are correct in his application. In doing so, the regulations focus on the treatment of domestic and municipal wastewater, including combined sewerage systems. In addition, the treatment of grey water in soil filters is also taken into account.
The tables, which describe, for example, the different wastewater compositions or specific design values, are helpful. Various useful combinations of processes are shown. However, Rustige emphasized in his speech that the guideline is not a simple construction manual, as it requires specialist knowledge. No design formulas or modeling approaches are shown because they have not yet proven themselves in practice.
What is more interesting is the presentation of minimum requirements with which certain effluent values or performance degrees can be achieved. In the theoretical modeling of treatment efficiency, it is often not taken into account that hydraulics or oxygen transfer rates can be decisive limiting factors, which in the worst case can lead to a total clogging of the soil filter. It is better to orientate oneself on the statistically relevant results derived from practice, as they are used in the A 262.