We protect our water!
CLEAN WAT ER FROM YOU TO THE SEA
1 The next generation s water
2 CONTENTS
THIS IS SYVAB Our plant and its purpose...... 4
FROM DIRTY WATER TO CLEAN Here’s how...... 6
THE TUNNEL SYSTEM FAQs about the tunnels...... 10
VISIT SYVAB Syvab loves having visitors...... 12
UPGRADE Higher demands on the treatment plant.14
BIOGAS How we make fossil-free vehicle fuel...... 16
BIOSOLIDS An important end product...... 18
DID YOU KNOW? Fun facts...... 20
JOBS AT SYVAB A meaningful job...... 22
TIPS Little things that make a difference...... 24
RESEARCH AND DEVELOPMENT Research projects at Syvab...... 26
40+ YEARS OF TREATING WATER Read about Syvab’s history...... 28
FOR KIDS Simple guide to wastewater treatment....30 We protect our water!
Syvab Himmerfjärdsverket, SE 147 92 Grödinge | +46 8 410 776 00 | [email protected] | www.syvab.se
Production: Roxx Communication Group, www.roxx.se. Project Manager: Daniel Abenius. Text: Roxx and Syvab. Photo: iStockphoto, Jennifer Glans, Syvab’s own images. Graphic design & layout: Malin Svensson. Print: Åtta.45 2018 3 Sludge silo
Gas holder
Sludge thickener Sludge treatment
Bio reactors
Gas compressor station
This is Administration
Electrical & ventilation building Syvab M Primary The southwest Stockholm region's wastewater screening treatment company – SYVAB (known as Syvab) plant – owns and operates the Himmerfjärden waste water treatment plant, Sweden's fifth largest. The
plant is located in Grödinge, in the southern part Upgrading plant of Botkyrka municipality.
The wastewater treatment plants task External infrastructure is to receive and treat wastewater from The water reaches the plant through the more than 350,000 people in house- 55-kilometre tunnel system, which is holds, companies, schools, industries etc. owned by Syvab (see the tunnel system tanks, which means we are able to treat The water arrives at the plant through a illustration to the right). There are two any surface water mechanically in the 55-kilometre tunnel system that is con- pumping stations that pump water from event of power disruptions or abnormally nected to the municipalities of Botkyrka, the connected municipalities (previously high flows. Water is pumped from the Nykvarn, Salem, Södertälje, south Stock- mentioned) and in to the plant. There Pilkrog pumping station in Järna directly holm and parts of Huddinge. Every day it are measuring stations at the connection to the treatment plant via an underwater receives around 120,000 m3 of water for points so that each municipality is in- pressure line. All of Syvab's pumping treatment. It takes around 20 hours for voiced according to its share of the treat- stations are also equipped to handle com- the water to pass through all of the treat- ment plant's load. The Eolshäll pumping prehensive water ingress. When water is ment steps before it can be released into station in Hägersten transfers the water flushed away, it takes on average 8 to 10 the Baltic Sea. You can read more about from southwest Stockholm to the main hours before it reaches the wastewater how we do this on pages 6 to 9. tunnel. This station has sedimentation treatment plant. 4 The tunnel system
Eolshäll Skärholmen Mälarhöjden Segeltorp Slagsta
Östertälje Tullinge Södertälje Salem Rönninge Hamra Tumba Nykvarn Vårsta Tunnel Järna Pressure line Himmer ärden wastewater Pumping station Pilkrog treatment plant Skanssundet
The tunnel system and its two pumping stations move the water from the connected municipalities to the treatment plant. Read more about the tunnels on pages 10-11. Methanol tank
Sludge liquor treatment
Pre-sedimentation ILLUSTRATION: PETTER LÖNEGÅRD PETTER ILLUSTRATION:
M Fluidised bed B Aeration tanks
B F Intermediate sedimentation
Disc filter B
Post sedimentation
B Water outflow
Direction of the water
M Mechanical treatment
B Biological treatment
F Filtration
5 HERE’S HOW we treat the water
INLET AND MECHANICAL TREATMENT Inlet doms and rags that unfortunately arrive the phosphorus dissolved in the waste to Where the main tunnel discharges into the with the wastewater. Read more about become a solid that can be separated later. treatment plant 54 metres underground what may or may not be flushed away on there are sluice gates that protect the plant page 24. The solids are ground so that Main pumping station from extreme flows. The tunnel has such they do not plug up the treatment plant's With the aid of large pumps, the waste a large volume that it can store the water pumps; they are separated from the waste- water is then pumped up to the surface from five days' normal flow if a major power water at a later treatment stage. As a back- for further treatment. There are six pumps cut or similar should occur. up to the wastewater grinder there is a bar in all, and the number in operation de- screen with a 20 mm bar gap. The solids pends on the size of the flow to the treat- Wastewater grinder and coarse screen separated by the screen are compacted and ment plant. The average flow from the The first stage in the treatment process is a sent for incineration. A precipitant is added pumping station under normal conditions grinder for solids such as tampons, con- downstream of the grinder. This causes is 1,400 l/s.
Screen room Main pumping station
6 HERE’S HOW
Fine screens Grit washers Sand washer
Primary screening – consisting of fine burned to provide district heating. Follow- The particles that sink are scraped away screens, grit washers, sand traps and ing the fine screen, the water is cleaned in by means of scrapers along the bottom and sand washers a sand trap. In all, there are three parallel are then transferred to a sand washer. In Once up at ground level, the wastewater tanks, each 30 metres long, and this is the sand washer, the organic material is first passes a fine screen with 6 mm holes. where the heavier particles such as gravel washed away and returned to the waste- Here, the screenings that were crushed in and sand are separated from the water. water. The sand and the gravel are then so the inlet are separated. The separated sol- This is done by blowing precisely the right clean that they may be used again. After ids are transferred to a grit washer before amount of air through the water, so that primary screening, the water is led to the being led to a container that is transported the light particles stay in suspension while pre-sedimentation process. to a refuse incineration plant where it is the heavier particles sink to the bottom.
Primary screening was taken into operation at the end of 2016. The new, clean, working environment is much appreciated by the employees.
7 sludge consists of bacteria that "eat" the dissolved oxygen-consuming material and convert the nitrogen in the water. The bac- teria convert the nitrogen from ammonium (NH4) to nitrate (NO3), a process called nitrification. In other words, no nitrogen purification takes place in this step; in- stead, the nitrogen is merely converted into a new form. The micro-organisms are aero- bic, i.e. they need oxygen to breathe and for Pre-sedimentation tanks this reason air is added all day round from nozzles located on the bottom of the tanks. Pre-sedimentation To prevent the activated sludge from being Intermediate and post-sedimentation tanks » Pre-sedimentation is the final step in the flushed out of the system, the aeration mechanical purification process and com- tanks are followed by sedimentation tanks. prises the first section of the large tank Post sedimentation block. The tank block is located outdoors Intermediate sedimentation The micro-organisms that did not sink in and, between the various treatment steps, After aeration, the micro-organisms are the intermediate sedimentation process there are machine rooms for electricity, separated from the purified water by two sink in secondary sedimentation. Since it automatic control devices and pumping sedimentation steps, intermediate and is important to have bacteria with good equipment. post-sedimentation. The sludge is allowed sedimentation properties in the system, In all, pre-sedimentation consists of to sink to the bottom and is scraped into the bacteria that sink in the secondary 16 parallel tanks, each 50 metres long. a sludge hopper, from where it is pumped sedimentation are not wanted. The sludge Because the environment has little turbu- back to the aeration process. In this way, is scraped into a sludge hopper, from where lence here and the heavier particles have the micro-organisms are reused and can all the sludge is removed from the process the chance to sink to the bottom, they are do their job several more times. As the and pumped to the flotation plant. The separated from the water. The material micro-organisms reproduce and increase in water is led from secondary sedimentation that sinks to the bottom is called primary number, some of the biosludge is taken from to the fluidised bed, which is the last step sludge; it is removed by means of scrapers, the system and moved to the flotation plant. in the biological purification process. transferred to a sludge hopper and pumped away for sludge treatment. Fluidised bed, denitrification The fluidised bed is the final stage in the BIOLOGICAL PURIFICATION removal of biological nitrogen. This is Aeration, nitrification where micro-organisms transform the Following pre-sedimentation, the water is nitrate (NO3) formed in the aeration tank led to the biological purification process, into nitrogen (N2) in a process known as the main task of which is to remove the denitrification. The micro-organisms grow dissolved nitrogen and oxygen consuming as a biofilm on billions of small grains of material from the water. The water is distrib- sand (diameter approx 0.5 mm), that are uted into eight aeration tanks, where it is kept fluidised in the bed by the high velocity mixed with activated sludge. The activated Aeration tanks of the rising water pumped in through the
8 FILTRATION Outlet Disc filters The treated water is coneyed 1,600 metres Following the biological treatment, the out into Himmerfjärden through two wooden water must be filtered before it can be pipes each 1600 mm in diameter to be released into the Baltic Sea. This is done released through 20 nozzles at a depth of using disc filters, where the last remaining 25 metres. It takes around 20 hours for the particles are separated from the water. The water to pass all the way through the treat- disc filters consist of cassettes with rotating ment plant, during which time the amount screens that have a pore size of 10 µm. of nitrogen is reduced by around 85%, Chemical treatment of the water may take phosphorus by just over 95% and organic place as necessary before the filter. This substances (BOD) by around 97%. If you Fluidised bed may mean the addition of a polymer to would like to read about treatment results, bind the small particles together or the you can do so in the environmental report bottom of the tank. Because the denitrifica- addition of poly aluminium chloride to published on our website www.syvab.se. tion bacteria are anaerobic, i.e. they do not precipitate phosphorus dissolved in the tolerate oxygen (O2) but instead use the water. After the chemical treatment, the Sludge treatment oxygen that is bound in the nitrate, no air water flows into the disc filter, where the The nutrients that are separated to form is added during this process. The bacteria water passes through the rotating cassettes sludge are digested in bioreactors. In this require organic material for nutrition, but covered with filter gauzes. The particles are process, the organic content is broken because most of the organic material was trapped on the inside of the filter mesh on down into carbon dioxide, methane and consumed in the aeration stage, a limited their way through the cassettes. When the water. Next, the water is led back to a amount of methanol is added upstream of gauzes are full of particles, they undergo special treatment stage where anammox the fluidised bed. what is known as backwashing, after which bacteria reduce the nitrogen content in the The retention time of the water in the they may be used again. The flush water water, which is then returned to the biolog- fluidised bed is approx 10 minutes, during used is led to the flotation plant for further ical treatment. which 95% of the incoming nitrate is treatment. After the disc filter, the water is The remaining sludge, which is very converted to harmless nitrogen. The nitro- led to the outlet. rich in nutrients, is recycled as fertiliser in gen formed is released to the atmosphere, the eternal cycle, and we use the methane which itself comprises 80% nitrogen. gas formed during sludge digestion, for There is a drum screen upstream of the heating buildings and fuelling vehicles. fluidised bed that makes sure larger par- This is described in more detail later in ticles that could damage the distribution the brochure; see pages 16-19 nozzles in the bed do not pass. If the flow is Psst! lower than the capacity of the distribution Read a simple guide pumps, a partial water flow is recirculated about the route water takes from back across the pumps. If the flow exceeds the toilet to the sea the plant component's capacity, the excess on page 30. is passed directly to the downstream disc filters. The denitrified water then contin- ues to the disc filter. Disc filter
9 FAQS about the tunnel system
10 Where does the wastewater How big are the tunnels? in the tunnels come from? At their narrowest points at the beginning It comes from the municipalities of of the system, they are 1.8 metres wide and Botkyrka, Nykvarn, parts of Huddinge, 2.0 metres high. They are biggest at the end Salem, Södertälje and southwest of the system, where they are 2.9 metres Stockholm. Most of the wastewater wide and 4.2 metres high. This is because is conveyed around 20 miles to the they must have room for more water at the Himmerfjärdsverket plant. end. If we have to shut down the plant, there is enough room for us to buffer water for FAQS How are they built? five days. They are blasted out of the bedrock, which comprises mostly granite and How do you get down to the gneiss. In some places, the tunnels have tunnels? been reinforced and sealed with concrete. There are special access tunnels that lead The tunnels are built with a slope of one down to the main tunnel. They are known meter per kilometre, so that the water as transport tunnels. flows downhill. However, in some places the water must be pumped, e.g. from How long does it take the water parts of Stockholm municipality. to run through the tunnels? From flushing away the water at home, How long are they? it takes 8 to 10 hours before it reaches In all, they are 55 kilometres long. the treatment plant.
How far below the surface are Is there a lot of poop floating around they? down there? At its lowest point, where it reaches No, it soon dissolves in the water just like the Himmerfjärdsverket, it is 54 metres toilet paper. The stuff that arrives at the plant below the ground. are things like cotton swabs, portion snuff, sanitary pads, paper towels etc.
11 Syvab loves having visitors. It gives us an opportunity to show how the treatment plant works and the exciting assignments employees have. By the time our visitors go home, they have also learned that they provide the best wastewater treatment themselves, by being careful about what they flush away.
FROM SIX-YEAR-OLDS TO PENSIONERS Our 4,000 annual visitors
On average, we get 20 visitors to the plant more interested in the technical solutions, of. Most of them are also surprised that it every day, or between 3,000 and 4,000 for others the environmental aspects are only takes around 50 people to treat what annually. Our youngest guests are six- more important. Syvab's visitor guides and 350,000 people flush away. year-old pre-school children, at an age experts have teaching skills and technolog- During the visits, Syvab gets the oppor- when they are very interested in what ical expertise to meet all of our guests on tunity to inform people and create key in- happens to the poop they flush away. And precisely the right level to make the visit fluencers – and most importantly ambassa- that is precisely what all our other visitors rewarding. Interpreters assist if necessary. dors – in their homes. Children and young would also like to know, although they Many of the visitors are surprised by people who teach the whole family how may have different approaches, previous the plant's advanced technology and how important it is not to flush away things that knowledge and special interests. Some are many different substances it must take care the treatment plant cannot take care of.
12 13 HIGHER STANDARDS
14 HIGHER STANDARDS Himmerfjärdsverket is facing its biggest challenge since the treatment plant was built in 1974. It results from the joint action plan agreed by the states surrounding the Baltic Sea and the European commission.
The countries surrounding the Baltic Sea graded. Underpinning the renovation nature in different ways.* It is also possible have agreed that each country must reduce works is an environmental permit from to include pharmaceuticals removal with its discharges of nutrients into the sea. It the Stockholm County administrative membrane technology, as this is certain mostly concerns nitrogen and phosphorus board issued in 2016. It regulates the to become a requirement in the not too from municipal wastewater treatment load Himmerfjärdsverket will be allowed distant future. Another advantage is the plants, the forestry industry and agricul- to receive in the future and the degree of ease with which the technology allows us ture. The goal is to reduce eutrophication purity the water must have when it leaves to scale up if we need to increase capacity to the same level as the 1950s. the plant. at the plant. A plan known as the Baltic Sea Action To achieve this, Syvab is looking for To save time, Syvab has carried out Plan (BSAP) also applies to the Kattegat technical and functional wastewater treat- two construction projects. The first was a and the sound between Sweden and ment technology offering the best econo- brand-new building for primary screening, Denmark. Other aspects included in the my. There is a lot of interest in membrane finished in 2016, and the conversion of the agreement are eco-friendly navigation, technology. The membranes also capture a plant to handle sludge liquor, which was biological diversity and that the sea may large share of the microplastics that today completed in 2017. Sludge liquor comes not be affected by hazardous substances. pass out into the sea. Microplastics are from the dewatering of the sludge remain- If Syvab is to meet these higher stand- plastic pieces smaller than 5 mm. They ing after biogas production. ards, the treatment plant must be up cause a great deal of damage to the sea and
*You can read more about research and news about e.g. micro plastics in our maritime environment at www.havet.nu. 15 ECO-FRIENDLY BIOGAS making fossil-free fuel
Once wastewater is treated, only sludge re- Syvab's buildings, to run large machines in the mains. It is rich in nutrients like phosphorus treatment plant and for use in the production and nitrogen and can be used as fertiliser in of vehicle fuel. Once carbon dioxide, sulphur, agriculture. But first, the organic material particles and moisture are removed from the must be broken down in airtight bioreactors. methane, it can be used as an eco-friendly fuel The sludge is mixed and digested together for cars, buses, trucks and machines. with other organic material such as food waste and waste fats from restaurants. Every year, Syvab has an upgrading plant for vehicle gas. Syvab receives around 50,000 tonnes of or- The plant produces 168,000 kg of vehicle gas ganic material for digestion. per month, which is sold through E.ON and AGA. Syvab has increased production with- During the digestion process, carbon dioxide out needing to expand the plant and we work and methane are given off at the same time. constantly at optimizing the process. Among other things, the gas is used to heat
HOW SYVAB makes vehicle fuel
Biogas is extracted from The sludge and the The biogas is processed The vehicle gas is compressed and trans- the sludge that remains waste is digested in a to form eco-friendly vehicle ported under high pressure in large tanks. after we treat wastewater biodegradation process to fuel. The process involves The tanks are then delivered directly to filling and from food waste and become biogas. removing the carbon diox- stations that sell vehicle gas. There are around other organic waste. ide, sulphur, particles and 150 of these in Sweden. moisture from the gas.
16 The energy content in 1 Nm3 (normal cubic metre) vehicle gas corresponds to around 1.1 litre of petrol.
Vehicle gas is among the fuels with the ECO-FRIENDLY BIOGAS absolute lowest impact on the climate and environment. Compared to petrol and diesel, biogas CO2 emissions are up to 90% lower, and about 25% lower making fossil-free fuel than those of natural gas. Furthermore, gas-fuelled vehicles reduce the emission of NOx and particulates. Today, Sweden's waste and residual products could pro- duce biogas corresponding to the fuel for around 900,000 cars.
17 BIOSOLIDS REDUCE IMPORTS of fertiliser
The sludge separated in the treatment process is known as bio- REVAQ CERTIFICATION solids once it has been anaerobically digested in bioreactors and Syvab works hard to remove chemicals that are present centrifuged in the dewatering plant. Biosolids are an important in homes and industries such as flame retardants and product from the treatment plant. Because biosolids contain heavy metals that can arrive at the treatment plant nitrogen, phosphorus and mulching substances, they are an excel- with the wastewater. Syvab is also working intensively lent fertiliser for arable land and grassed areas. They are produced to encourage people to change their behaviour and by digesting the sludge that remains after wastewater treatment stop flushing away substances that cannot be removed in a biodegradation process together with organic material such in treatment plants. This is known as upstream work as food waste and fats from restaurants. This becomes biogas and and is one of two important parts of Revaq certifica- biosolids. Sweden imports large quantities of phosphorus in the tion by the Swedish Water & Wastewater Association. form of artificial fertiliser, which could be reduced by increasing The second part consists of the rigorous measures tak- the use of biosolids. Syvab produces about 25,000 tonnes of bio- en to ensure the quality of biosolids before they may be solids per year. spread on arable land and in forests. No fewer than 60 different substances are analysed in addition to various hygiene checks such as salmonella tests.
The Revaq certification system was developed by the Swedish Water & Wastewater Association together with the Federation of Swedish Farmers and the food retail sector. SP Technical Research Institute of Swe- den reviewed and approved Syvab's quality assurance and issued the certificate.
18 HOW SYVAB makes biosolids
The sludge is digested in The water is returned The biosolids are taken Approximately 75% of all the bioreactor. It is then cen- to the plant for further away and stored for six biosolids are spread on arable trifuged to remove the water. treatment. months before they may land. What is not reused on What remains is a substance be used. arable land is used for e.g. resembling soil – biosolids covering material in locations (see image to left). that are not cultivated such as noise barriers. 19 DID YOU KNOW?
The typical Swede uses around 160 litres of water per day. Syvab is next to beauti- ful Himmerfjärden. In our area it is even more. Imagine trying to carry that amount home in milk packaging. The wildlife around the It divides up roughly like this: plant is rich, and around persons/day 20 25 wild boar, four roe Many people take an interest in our deer, hares and the 10 LITRES FOR FOOD AND DRINK operation and clean water. Every day, around 20 people occasional visit our plant. moose can be
30 LITRES FOR found in the FLUSHING THE area inside TOILET our fence.
60 LITRES FOR PERSONAL 30 LITRES HYGIENE FOR WASHING EAT MORE GREENS! DISHES Meat increases the nitrogen load and meat production consumes 20 huge amounts of water. LITRES FOR WASHING It costs around SEK 10 LITRES FOR OTHER USES
Then we need water to produce our food, clothes and other goods. This is known as virtual water. So our true consumption is per person per year much higher. Almost all of the water we use 300 every day, or 97% of it, is virtual water, which to treat all the water con- is invisible to us. sumed when a person flush- es the toilet, showers, washes Producing the jeans you wear requires around 10,000 litres of virtual water. Cultivat- and washes up, in fact ing the coffee beans for one cup of coffee everything that goes down takes 140 litres of virtual water. the drain.
20 Every year, Syvab receives about 50,000 tonnes of organic waste from e.g. the food industry that is digested to produce gas. This means one Every year the plant treats truck per hour arrives with waste food and fat that is converted into eco-friendly vehicle gas. 43 BILLION Annual production equates to 850 trips around the earth if the car consumes LITRES OF WATER 0.07 Nm3 per kilometre. This is enough to fill 6,550 swimming pools every day. The average price for one litre of tap FRIDAY, THE PLANT’S PET TURTLE, water in Sweden is about SEK 0.04. In was flushed down a toilet around other words, you can drink 1000 litres of 30 years ago. She now lives in our pond at the reception. Friday is still doing tap water for the same price as a litre of well and has been joined by several bottled water. friends who have since arrived. Syvab has around 50 employees and 350,000 customers. This means that each employee on average × 1000 takes care of 7,000 customers. Annual ‘sales’ per employee are around SEK 3.4 million.
Transporting one litre of bottled water gives rise to carbon dioxide emissions that are greater by a factor of 1000 than the same quantity of tap water. MEANINGFUL WORK
22 Are you passionate about a clean- er environment and want to enjoy meaningful work in a vital sunrise industry?
If so, there is a good opportunity to find your dream job at Syvab. You will be part of a knowledge-based or- ganisation that conducts ongoing R&D into technology and processes that can protect the environment from hazardous discharges. Collaboration with various universities, colleges and other countries around the Baltic Sea is well-developed. Syvab's assignment also includes informing and disseminating knowledge of water and wastewater treatment to politicians, organ- isations, companies, schools and private individuals. Syvab's work concerns everyone.
Around 50 people work at Syvab and have one of the following assignments:
• Business developer • IT manager • Foreman • Process manager • Controller • Process engineer • Operations and maintenance • Process technician technician • Production manager • Operations manager • Production technician • Financial manager • Project coordinator • Electrical engineer • Receptionist • Information and communica- • Service hostess tions manager • System administrator • Information officer • System specialist • Investment manager • CEO GREAT TIPS!
You are important! Maybe you think that what you do – just one solitary individual – does not really make a difference. Oh, but it does. What you do is really important for the environment. If we all just stop and think before we act, we each can Do not buy goods and clothes with make a great difference. bactericides And best of all – it is easy to do things right. They are found in such things as clothes, shampoo, refrigera- tors, dishwashers and washing machines and they destroy the good bacteria that work in the treatment of wastewater. Triclosan is one such substance you should avoid. It is found VACUUM THOROUGHLY in certain toothpastes and deodorants, among other things. This reduces the amount of brominated flame retardants, phthalates, per- and polyfluoroalkyl pollutants you inhale. This way, they are sucked into the vacuum cleaner bag instead of sticking to the mop when you wipe off your floor, whence they end up in our treatment plant. Burning the vacuum cleaner bag is much better for our Hand in old medications at the pharmacy. environment than these substances ending Never flush them down the toilet. up in the water. Can you reduce your use of over-the-counter medicines? Medications are secreted in urine and faeces, and wastewater treatment plants today lack the technology to remove them.
24 Do not use Read more good tips on our website at the toilet as www.syvab.se or on your municipality's a trash can website.
You may flush pee, poop Choose and toiletpaper down the eco-labelled toilet – NOTHING ELSE! goods! Use the waste paper basket for Look for the Swan mark, rubbish such as cotton buds, Good Environmental dental floss, panty liners, portion Choice or the EU eco DO NOT WASH label in the store. snuff, cigarette ends, cotton make-up removers or condoms. THE CAR AT HOME! Take the car to a car wash – never wash it on the street or on a paved garage driveway. This will cause hazardous pollutants to drain Would you like more great directly into watercourses, lakes or tips about how you can the sea through the surface water help the environment? drains. If you do not have access to a Collection points and car wash, it is less harmful to wash READ MORE HERE: recycling stations the car on grass or gravel. www.naturskyddsforeningen.se take care of rubbish that www.pandaplanet.se contains eco-toxins www.hallakonsument.se Here is where you deposit household www.kappalaforbundet.se fats from food preparation, nail varnish bottles, oils, leftover paint, items that contain electronics, and a load of other stuff. Read more at www.srv.se and www.telge.se. RESEARCH FOR development
Research has always been, and continues to be, a natural part of Syvab's operation. Our research began even before the treatment plant was built in the 1970s. For more than 40 years, Stockholm University has taken continuous samples of the water in Himmer fjärden outside Syvab's plant. But this is far from the only research that has taken place and which continues at or in collaboration with Syvab. New know-how, technology and analytical methods mean that research and treatment standards are constantly evolving.
Syvab collaborates with universities and colleges and participates as a co-financer in a number of research projects under which many tests are conducted at the Himmer fjärden wastewater treatment plant. In other projects, Syvab's employees take part as experts in reference groups and/or as end-users of the findings.
26 Examples of completed Examples of research research projects. projects in progress.
EXRT experiment, 2013–2015, doctoral project in collaboration Fault detection by online sensors. Doctoral project in collabo- with IVL Swedish Environmental Research Institute, KTH Royal ration with IVL, Uppsala University, Käppala Association and Stock- Institute of Technology, SLU and the Käppala Association. An experi- holm Vatten. ment to operation of the bioreactors more efficient. Evaluation of alpha meters (a special kind of oxygen meter) in Digestion experiment at different temperatures in the bio biological wastewater treatment and how air consumption can be reactors. Doctoral project conducted in 2010. reduced without negative impact on the treatment results. Optimizing the addition of air to biological treatment through Removal of pharmaceutical residues with the aid of enzymes, in control using ammonium feedback; conducted 2010-2013. Doctoral collaboration with IVL and ABC and financed by Vinnova. project in collaboration with IVL Swedish Environmental Research Advanced removal of pharmaceuticals. A project run by IVL with Institute, UU, SLU, Stockholm Vatten and the Käppala Association. support from the Swedish Agency for Marine and Water Manage- Monitoring water quality in Himmerfjärden with the aid of satel- ment. Carried out in collaboration with Syvab and Stockholm Water. lite monitoring, 2009–2011 in collaboration with Vattenfall. Strategy for future sludge handling at Syvab. Carried out together Pilot tests with disc filters for final filtration to achieve 0.2 mg P/l with the IVL Swedish Environmental Research Institute. and 5 mg BOD7/l in discharge water. Carried out in 2012 in collabo- Modeling Syvab’s environmental impact in today's existing plant ration with Nordic Water. and the plant after the planned expansion. Carried out in collabora- Experiment with 2-stage operation of the anammox plant aimed tion with the IVL Swedish Environmental Research Institute. at increasing capacity. Carried out in 2012 in collaboration with Purac. Study of Syvab’s carbon footprint and possible measures to Pilot tests with MBR to achieve 6 mg N/l, 0.2 mg P/l and 5 mg reduce climate impact. Carried out in collaboration with the IVL BOD7/l in discharge water. Carried out in 2013 in collaboration with Swedish Environmental Research Institute. Alfa Laval. Various possibilities for the extraction of phosphorus from Experiment with removal of residual pharmaceuticals from dis- sludge. The work is led by SP Technical Research Institute of Swe- charge water with the aid of ozone and activated charcoal. Carried den in cooperation with many wastewater treatment plants in out in 2013 in collaboration with the IVL Swedish Environmental Sweden. Research Institute. Increased biogas production through control with the aid of the Experiment to increase the capacity of the sand filters by killing bacterial flora. The work is led by Lund University and run in collab- microorganisms with a disinfectant. Carried out in 2013 in collabora- oration with several other wastewater treatment plants. tion with Kemira. Experiment in digesting sludge from an MBR plant. Run in col- Experiment with disc filters for high-flow treatment. Carried out laboration with Stockholm Vatten and IVL Swedish Environmental in 2014 in collaboration with Nordic Water. Research Institute. Development of a digital tool for evaluating sludge quality and the quality of organic substrates received for digestion. Begun in 2014 in collaboration with the IVL Swedish Environmental Research Institute. Evaluation of mercury-free COD analysis. Carried out in 2015 in collaboration with many Swedish wastewater treatment plants and SP Urban Water Management.
27 MORE THAN 40 YEARS OF WASTEWATER TREATMENT
2008 1969 1980 1991 1997 Further refinements to Construction of the Water that previously A plant is built to dry Syvab adds a stage for the process are readied tunnels and Syvab's went to the treatment the sludge and thus nitrogen separation, including a so-called Himmerfjärd waste- plant in Järna is now reduce the number of which removes no deammonification water treatment plant pumped instead to sludge transports from less than 95% of the plant, an ozone plant begins. Syvab. the plant. nitrogen. and a gas engine.
1963 1974 1984 1993 2007 Company formed by January 16, municipal- Also the water that was Construction of a new Three large disc filters the municipalities of ities start the flow of handled by Eolshäll's wastewater treatment are installed to help Grödinge, Botkyrka, their wastewater to treatment plant in stage with sand filters in treatment work in the Salem, Södertälje and Syvab. Hägersten is now led tanks is completed. best possible manner. the City of Stockholm. south to Syvab. 1971 addition of Hud- dinge municipality.
28 2013 Four disc filters are installed in the sand filter building. As a further step to enable increased production of biogas, one of the thickening 2016 devices is upgraded in order The old sand trap is renovated to receive external liquid and the fine screen for the new materials that do not need plant component – primary 2010 to be processed through the The NKH project planning screening. This was necessary hygienisation treatment. stage kicks off for the new to enable compliance with redevelopment. Discharge standards get future requirements for better total phosphorus purification. The renovated sand A degassing tower is built tougher for trap was built into the new plant to collect the methane gas of 0.4 mg/l and total nitrogen component together with the given off by sludge in the of 8 mg/l. new strainers (which remove sludge store instead of Syvab submits an application solids) and sand washers releasing the gas to atmos- for a new environmental (that remove sand and coffee phere. A project is begun to permit to the county admin- grounds etc.). replace parts of the tanks in istrative board in Stockholm the existing sand filter with County. A reception station Syvab receives a new environ- two new disc filters to achieve is built to handle external mental permit with tougher better emission results. material that cannot be limit values. Because of the pumped. The material is new requirement, upgrading mixed with sludge and used the existing treatment process for biogas production. became a necessity.
2009 2011 2015 2017 Syvab begins produc- Two new plant components The greenhouse facility The new sludge liquor plant ing vehicle gas, which are built to expand the re- in the neighbouring comes on stream during 2017. is sold to filling stations ception of external material property is run down in The plant has greater capacity for gas-fueled vehicles. and enable increase produc- order to release land for than its predecessor. The primary At the same time, some tion of eco-friendly biogas future renovations of the sedimentation tanks used for old sections of the plant vehicle fuel. One installation existing plant. sludge liquor treatment can now are upgraded to enable is a receiving station for ABP be restored to boost sedimenta- them to receive more material (animal byproducts) tion capacity. liquid organic materials in a hygienisation plant, and In 2017, a policy decision was from e.g. restaurants the other is a station that adopted by Syvab’s board for and institutional receives packaged organic the implementation of the NKH kitchens for use in material. The packaging project. gas production. is crushed apart and the contents are used for biogas In the same year, a liability guaran- production. The packaging is tee was requested from Syvab’s cleaned and recycled. owner.
29 FOR KIDS From you to the sea How it works – let's follow it all the way!
Poo, pee and toilet paper go down the Once it reaches the treatment plant, the loo at home when you flush. So does the water runs through a bar screen located water when you wash the dishes, prepare 54 metres underground. It's exactly what it food, take a shower and wash clothes. It sounds like – a screen with bars. This is where goes down in long tunnels underground. the biggest things are caught that would The tunnels are so big you can row boats otherwise block our pumps and pipes. down there. But we only do that if there seems to be something wrong in the tunnel. The tunnel slope a little bit so the water runs downhill all the way to the treatment plant. Knowledge booster: These cassettes are called disc filters.
Now we can release the water into the Baltic Sea again. It was cloudy and dirty when it reached the treatment plant but once the water has gone through all the processes it can be released into the sea again. This is how we make sure you can swim there and that fish and other animals that Nearly done! The last part of the treatment takes live there feel good. place in the disc filters. The disc filters are cassettes with rotating screens that catch the final particles Think about what you flush – it affects the sea! before the water can be released into the Baltic Sea.
30 Knowledge booster: This Knowledge stage is called booster: This primary sedi- is called an mentation aeration tank.
Next, the water is pumped up to ground In the next stage we take away something When the water continues on level and passes through primary screen- called phosphorus because it’s harmful to the its way it comes to a tank that ing. Here it goes through fine screens that sea. We catch it by adding a substance that bubbles like crazy! We blow in air catch rubbish like cotton buds, panty liners 'grabs hold' of the phosphorus. A bit like the way so that all the nice bacteria there and portion snuff that weren't caught by the a magnet grabs hold of sewing needles. They can get some oxygen. They need bar screen. Then the water is led to the form clumps that are so heavy they sink to the it to keep busy changing the sand trap tanks. This is where we catch bottom. So when the water moves on to the nice substances that remain into stuff everything such as sand and coffee grinds calm primary sedimentation tanks, the particles that isn't dangerous. that are too small to get caught by the bar can sink to the bottom in peace and quiet where screen and the fine screens. They are heavy they are scraped off and carried away. and sink to the bottom. Knowledge booster: These are called fluidised beds. Fluid means there is something floating freely in the water. Here it is sand.
We don't throw the bacteria away, but use them again. Their job is to Our friends the bacteria who remove harmful work in the various treatment substances. Knowledge stages are really important for booster: The bacteria stay in the water, What you're looking treating the water. They do a really good (the fluidised but in the next two stages (inter- In the next tank at is two rows of job and we can use them again. We have to bed) there are other bacteria that tanks. The first is mediate and secondary sedimen- take very good care of them. They don't like are busy removing nitrogen. Too called intermediate tation) things are quiet, so the household fats, thinners, leftover paint etc., much nitrogen is also harmful to sedimentation and bacteria sink to the bottom where so think about what you flush away! life in the sea. the one furthest we can scrape them up. away is secondary sedimentation. 31 We protect our water!
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