#: locale=sv
## Tour
### Description
### Title
tour.name = Sjöstadsverket Virtual Tour
## Skin
### Button
Button_586CDF23_7F0E_A972_41B5_99FBEDA43E22.label = QUIZ SCORE
Button_66CECC57_7BB1_95DB_41C1_71556463FF64.label = SHOW QUIZ RESULTS
Button_8254B73A_7881_1AA1_41D5_78533EAB5681.label = RESTART TOUR
Button_86977C30_7887_6EA1_41D4_BC646EFEB820.label = VISIT SMART CITY SWEDEN
Button_C7C0A902_DD1A_84D7_41DE_134BE19CD0D0.label = START THE TOUR
### Multiline Text
HTMLText_6C7E0662_7F0D_7BF2_41DC_2EC03835F426.html = COMPLETED
{{quiz.questions.answered}} / {{quiz.question.count}}
Combined membrane bioreactor and activated carbon for efficient treatment
Pharmaceuticals and PFAS that end up in the water need to be filtered away to not harm ecosystems, humans or animals. PFAS is a group of harmful hazards that are commonly used due to its water repellent quality. PFAS is not biodegradable and accumulates in the body, which can lead to diseases and negative health effects.
This pilot works as a membrane bioreactor, in which powdered activated carbon can be added to remove pharmaceutical residues. This is a project together with another wastewater treatment plant in the Stockholm area, Syvab Himmerfjärdsverket. The combination of PAC and MBR processes is providing a potential highly effective, less-space requiring and resource-efficient treatment system for sewage treatment, including removal of micropollutants such as pharmaceutical residues. The intensive work of starting up a pilot is ongoing, along with the installation of a highly automated process control system.
Green Hydrogen production from wastewater
The need for energy keeps increasing and today, about 80 % of the energy used worldwide comes from fossil fuels. To decrease CO2 emissions and reach the goals set up in Agenda 2030, the amount of fossil fuels used must decrease significantly.
Converting ammonium to hydrogen is an important part of the solution to create an energy system less dependent on fossil fuels. IVL develops the components to this electrolysis pilot, where ammonium is converted to hydrogen gas.
The electrode is made from coal fibre on thin layers of platinum and copper, making it more effective for sewage water applications. Compared to conventional active sludge treatment, this could potentially reduce the need for space and supervision for the sensitive microbiological process.
PFAS, also called the “forever chemical”, is a group of harmful hazards that are commonly used due to its water repellent quality. PFAS is not biodegradable and accumulates in the body, which can lead to diseases and negative health effects.
In this pilot, the electrolysis can remove PFAS by destroying its chains. By doing so, PFAS is reduced without the need for secondary treatment.
Production of bioenergy
The transport sector is a big polluter, responsible for about 1/5 of the world’s CO2 emissions. To reduce the emissions, several solutions are needed. The sludge created in the wastewater treatment process can be converted into biogas, a renewable fuel that can be used as vehicle gas.
This pilot uses anaerobic sludge digestion, which is one common way to recover the nutrients from the sludge and convert it to biogas. In Stockholm, busses run with the biogas produced at the wastewater treatment plant.
To prepare for the future Henriksdals construction period, tests were run to see how much stress the digester process can take. We conducted tests to see how much faster we can operate for digestion without compromising the biogas production volumes or crashing the process. It was also tested how many days it takes for the process to stabilize after changing the temperature from mesophilic to thermophilic. These tests provide an important reference for Stockholm Water, as the change of water treatment from the conventional active sludge process to the membrane bioreactor affects the sludge treatment.
Here, we have two identical digesters, so that we can run one digester for test and the other one for reference to improve the biogas productions or sludge treatment. It is also possible to test different temperatures.
The future technology for Stockholm’s wastewater treatment plant
This membrane reactor is one of the largest in Stockholm and will be used for the future treatment plant.
In these tanks, the aeration is controlled to remove organics and nitrogen. The tanks produce sludge, which is sent to the sludge pilot to digest in order to recover the nutrients for bioenergy. As you can see in the film, the pilot is equipped with sensors in all reactors. The sensors monitor oxygen levels, ammonium and nitrate. With this pilot, it is possible to optimize the aeration, energy consumption and chemical use.
Treatment technology for removal of micropollutants
Micropollutants such as pharmaceuticals, PFAS and pesticides that end up in our water pose a health risk to humans and animals. These cannot be taken care of in conventional wastewater treatment, which is why additional treatment may be necessary to reduce these emissions into the sea.
At Hammarby Sjöstadsverk, an advanced oxidation process pilot is used to clear the water from micropollutants by breaking them down with UV-light and hydrogen peroxide. The technology can remove certain micropollutants from the wastewater better than other technologies if applied in the right way. This technology allows us to target bacteria and viruses better than any other techniques.
Since 2008, Hammarby sjöstadsverk has conducted studies in a lab- and pilot-scale and our pilot test have led to Sweden’s first full-scale installations at wastewater treatment plants around Sweden. At Hammarby sjöstadsverk, we can take in any type of water with pollutants to tests, both municipal wastewater and industrial wastewater with certain characteristics.
Green chemicals from organic waste
A carbon source is essential for wastewater treatment plants, and the common source used in the conventional activated sludge process is often a fossil-based carbon source such as methanol.
Volatile Fatty Acids (VFAs) are short-chain fatty acids that are the primary compounds produced during anaerobic digestion of sludge and other organic waste, such as food waste. The VFAs are a renewable carbon source and can therefore be used for different applications, including bioplastics and biodiesel production.
This pilot at Hammarby sjöstadsverk is created to test different digestion processes, and VFA testing is one of many possible applications. The VFAs are produced and then tested in the biological treatment line to see if the VFAs can replace other carbon sources to make the process greener. The pilot is built in a mobile container, which means that it can be moved and adapted to the needs of different conditions. Previously, it has been used for tests of ways to increase the capacity of biogas production.
Anaerobic wastewater treatment: Sustainable technology for water treatment
Treating wastewater requires a lot of energy and leads to production of sludge. The common biogas production requires the process temperature of 37 or 55 degrees, and heating the system requires much energy.
In this pilot, the anaerobic digestion is at a lower temperature, therefore the energy consumption is lower than in the conventional anaerobic digester. The energy produced during the process is in the form of methane. Removing organic matter from wastewater anaerobically will save energy and produce biogas.
Membrane separation
Wastewater contains micropollutants such as microplastics, PFAS and pharmaceuticals, but also bacteria and viruses. These need to be filtered away when cleaning the wastewater to ensure good water quality.
With this final step of the membrane reactor process, we can extract any particles over the size of 0.04 micrometre, including bacteria and viruses. These will be left in the sludge. As the tiny pores tend to clog over time, the membranes need regular cleaning with aeration and chemicals. Here, apart from optimising the process for the future full scale, we also test how much we can reduce chemical and energy consumption without compromising the water quality.
We also use membrane-treated water for water reuse applications, both for direct potable use (drinking water) and indirect water uses (e.g. irrigation, industrial use or groundwater recharge). We use different additions technologies like activated carbon, additional membranes, ozonation and innovative technologies under development to remove micropollutants.
In the project Pu:rest, we made a beer from wastewater with this pilot, showing it is possible to clean the water so much it is even drinkable.
Resource-efficient nitrogen removal
In the common wastewater treatment CAS (Conventional Activated Sludge) process, a high amount of energy is needed, as well as chemicals. Ammonium in wastewater can damage human health and ecosystems when it ends up in the sea and causes eutrophication.
At Hammarby Sjöstadsverk, we are extracting the ammonium by using ammonia-oxidising bacteria and anammox bacteria. These types of bacteria do not need help by added chemicals to complete the nitrogen removal from the water. This means we can reduce ammonium in water without chemicals. This technology also consumes less energy and does not produce any sludge.
The process is suitable for reject water (the water that is removed from the sludge) as it has favourable living conditions for these bacteria. At Hammarby Sjöstadsverk, we are also testing if the process can be adapted to clean the wastewater.
For many years, the research group at KTH Royal Institute of Technology has been world-leading in their research of the anammox process. The first full-scale installation in Scandinavia of the process was based on these pilot tests. Today, the anammox process is used at many wastewater treatment plants around the world.
Resource-efficient sludge treatment
The population in Stockholm is increasing and with the increased capacity of wastewater treatment, there will be more sludge to be handled as a by-product of the wastewater that is treated. This sludge needs to be transported, leading to CO2 emissions.
In this sludge pilot, we have a sludge thickener that concentrates the sludge to be fed into the digester. This allows increasing the volume of sludge to be treated without increasing the volume of the digester. To reduce the emissions from transport, the sludge will be dewatered to take out the volume.
The sludge also contains nutrients such as nitrogen and phosphorous, which are limited resources that are crucial for all living things. However, the sludge also contains pollutants such as microplastics and pharmaceuticals, which need to be removed before the sludge can be recycled.
The sludge that has been used to produce biogas in this pilot will also be used for nitrogen and phosphorous recovery. After it is tested so that it does not contain harmful contents such as hazardous substances or heavy metals, the sludge can be used for i.e. fertilisers.
Quantification of greenhouse gas emissions
Human-driven emissions of greenhouse gases are the primary driver of climate change and are one of the biggest challenges in our time. Globally, greenhouse gas emissions have increased significantly in the last decades, leading to an increase in temperature on earth. Greenhouse gases are released into the atmosphere during the combustion of fossil fuels, such as coal, oil, and natural gas.
In this pilot, we measure the greenhouses gases (nitrous oxide, methane and carbon dioxide) so that we can evaluate the operation process and reduce the emissions from the treatment processes. This is done by using a gas sampler, where we collect the gas from the water surface. The pilot is mobile and can be used at different wastewater treatment plants.
Contactless image and data analysis the future monitoring technology
Sensors are used in waterpipes to measure water flows, water quality and more. When these sensors need maintenance, it disturbs the traffic flow. Old water pipes might have leakage problems that are left unnoticed, leading to high costs for cities.
Researchers at IVL have developed a touch-free sensor. This means that the sensor is not touching the water, but instead, image and data analysis is used to measure turbidity and liquid levels. Since the sensors do not touch water, the need for cleaning the sensors is not as big. This means less maintenance of the sensors, which leads to fewer traffic disturbances. Using sensors instead of manually measuring also means that the data collected is in real-time, which could lead to fewer emissions and quicker action to avoid flooding.
In the EU project SCOREwater, we are currently looking into building resilience against high water flows by monitoring sensors at building sites in the city of Gothenburg.