Flooding from extreme rainfall is already taking place today in Sweden's urban areas. In order tocreate sustainable stormwater management that reduces the risk of flooding, various factorsshould be taken into account such as the choice of method for management. Bottlenecks in thestormwater system mean wells with undersized outlet pipes. A bottleneck area in Bollnäs urbanarea has already caused flooding. The aim of this study is to investigate if there are more similarareas and to contribute to sustainable stormwater management for Helsinge Vatten. Themethods chosen for the study were a literature study and a case study with simulation andcalculations. The literature study was conducted to see how stormwater is handled and what theclimate looks like. The case study was conducted to evaluate the flows that occur during heavyrains. In the case study, a terrain model was first made that showed drainage directions andwater dividers. The calculations in the case study were based on the rational method forcalculating design flow. The climate is changing and as the temperature rises, so does therainfall. The risk of extreme weather increases as the annual average temperature rises and aglobal increase in rainfall intensities has occurred. In Bollnäs, the annual average temperaturehas risen since the measurements began in 1969. In the future, the average temperature can beexpected to rise to 3-5 degrees until the end of the century in Gävleborg. In heavy rain, floodscan occur, they are called pluvial floods and can cause major damage to properties and roads,among other things. There are many methods for developing and making the stormwatersystem more sustainable. Among other things, there is something called blue-greeninfrastructure and this involves green surfaces in the management of stormwater. There, forexample, the water is allowed to infiltrate, evapotranspire or slowly pass on into the system.These solutions also have other benefits, they meet several social needs and can bring ecosystemservices. After the simulation that was carried out, 37 catchment areas could be observed andcalculations for design flow were made based on, among other things, the area in thesecatchment areas. Sustainable stormwater management can be introduced in Bollnäs urban area,when new guidelines and greater cooperation between Helsinge vatten and Bollnäs municipalityare needed. Sustainable stormwater management could reduce the risk of floods in bottlenecks.However, it is not possible to locate any bottlenecks in Bollnäs urban area due to missinginformation about the storm sewers in Bollnäs urban area. More studies would be needed tolocate bottlenecks. / Översvämningar från extrem nederbörd sker redan idag i Sveriges tätorter. För att skapa hållbardagvattenhantering som minskar översvämningsrisken bör olika faktorer tas i beaktning somexempelvis val av metod. Flaskhalsar i dagvattensystemet innebär brunnar medunderdimensionerade utloppsledningar. Ett flaskhalsområde i Bollnäs tätort har redan orsakatöversvämningar. Detta arbete går ut på att undersöka om det finns fler liknande områden ochbidra till hållbar dagvattenhantering för Helsinge Vatten. Metoderna som valdes för arbetet varen litteraturstudie och en fallstudie med simulering och beräkningar. Litteraturstudiengenomfördes för att se hur dagvatten hanteras och hur klimatet ser ut. Fallstudien genomfördesför att utvärdera vilka flöden som uppkommer vid kraftiga regn. I fallstudien gjordes först enterrängmodell som visade dräneringsriktningar och vattendelare. Beräkningarna i fallstudienutgick från rationella metoden för beräkning av dimensionerande flöde. Klimatet förändras ochnär temperaturen stiger så stiger också nederbörden. Risken för extremväder ökar till följd avatt årsmedeltemperaturen ökar och en global ökning av nederbördsintensiteter har skett. IBollnäs har årsmedeltemperaturen ökat sedan mätningarna började 1969. I framtiden kanmedeltemperaturen väntas öka upp mot 3-5 grader fram till slutet av seklet i Gävleborg. Vidkraftiga regn kan översvämningar uppstå, de kallas pluviala översvämningar och kan orsaka storaskador på bland annat fastigheter och vägar. Det finns många metoder för att utveckla och göradagvattensystemet mer hållbart. Bland annat finns det något som kallas blågrön infrastruktur (BGI) och detta involverar gröna ytor i hanteringen av dagvatten. Där får vattnet till exempelinfiltrera, evapotranspirera eller långsamt ledas vidare i systemet. Dessa lösningar har ocksåandra fördelar, de tillgodoser flera sociala behov och kan medföra ekosystemtjänster. Efter densimulering som utfördes kunde 37 avrinningsområden observeras och beräkningar fördimensionerande flöde gjordes utifrån bland annat arean på dessa områden. I Bollnäs tätort kanhållbar dagvattenhantering införas, då behövs nya riktlinjer och ett större samarbete mellanHelsinge Vatten och Bollnäs kommun. Hållbar dagvattenhantering skulle kunna minska riskenför översvämningar vid flaskhalsar. Däremot går det inte att lokalisera några flaskhalsar i Bollnästätort på grund av saknad information om dagvattenledningarna i Bollnäs tätort. Fler studierskulle behövas för att lokalisera flaskhalsar.

Tunnels have become increasingly important in the development of road networks to meet rising transportation demands. Washing of road tunnels must be performed regularly to ensure traffic safety. The washing procedure generates significant amount of polluted wash water. Before discharge to a receiving water body, treatment is necessary to avoid potential degradation of the water quality. In this study, 12 in situ sedimentation experiments were conducted to evaluate treatment efficiency of sedimentation, with and without the addition of chemical flocculent. The findings showed that untreated tunnel wash water was highly polluted with total suspended solids (804-9690 mg/l), PAHs (0.4–29 μg/l) and heavy metals. Most pollutants were associated with the particulate material. Significant correlations (r2 > 0.95) were found between suspended solids and metals. Efficient removal of pollutants was possible by sedimentation with addition of flocculent. Within 20 hours of sedimentation low concentrations were reached of suspended solids (<15mg/l), PAHs (<0.1 μg/l), Cd (<0.05 μg/l), Cr (< 8 μg/l), Hg (<0.02 μg/l), Pb (<0.5 μg/l) and Zn (< 60 μg/l). The results confirm the possibility to treat tunnel wash water with sedimentation and flocculation and to discharge treated wash water to a recipient, provided particular attention is given to very sensitive water bodies.

The desire for value addition to the organic waste management chain at Högbytorp using the Black Soldier Fly (BSF) process, as well as the problem of the escalating demand for protein in livestock feed motivated this study. Good quality crop land is devoted to growing feed for animals at the expense of human food, and ironically with a full understanding of the associated environmental footprints. Black Soldier Fly Larvae (BSFL) feed on organic waste voraciously while building their body composition of 40% protein and 30% fat. Their protein can be used in animal feedstock and pet food, replacing the more expensive but nutritionally comparable fishmeal, while their fat can be used for biodiesel production. They can also reduce a waste pile significantly, minimizing possible pollution. In this study, the process was tried on various waste streams (fruits, manure and ‘slurry reject’) at Högbytorp. Biomass conversion, larval fat and protein content, compost by-product characteristics and residence time requirements for each stream were assessed. The study involved literature review, chemical analyses and experimental design (rearing BSFL on waste through their lifecycle). The study yielded waste reduction up to 83% and fat and protein contents up to 42% and 41% respectively, depending on the waste stream. The residence time depended on the age at which the larvae started feeding, but ranged between 8-11 days. If applied in organic waste management chain, the process could contribute to greener energy provision (biodiesel) as well as sustainable protein provision to the animal, fish and pet industries. It could further reduce waste amounts significantly and generate income while contributing to the saving of Earth’s limited resources.

No description available.

The aim of this master’s thesis was to investigate if defattening of Parkinsonia aculeata (in swahili “mkeketa”) and Vigna unguiculata (in swahili “choroko”) would enhance the capacity of the seed’s properties in removing suspended particles from surface water. The seeds are used in local traditional treatment of drinking water in Tanzania. The aim was also to investigate the possibility to reduce high concentrations of fluoride with the seeds. The seeds contain proteins that act as coagulants. Coagulated particulate matter can be flocculated and separated from the water. A purification of the coagulants by defattening was expected to enhance the coagulating capacity. Experiments were conducted in jar-tests with dosages of coagulant solutions of undefattening and defattened seed solutions and alum (aluminium sulphate). The experiments showed that both Parkinsonia aculeata and Vigna unguiculata seeds can compete with alum in drinking water treatment of surface water, reaching the same or better final results in turbidity removal. Both seeds also produce less sludge volumes than alum and functions in turbidity removal together with alum. The seeds may be used as coagulant aids to reduce the usage of chemicals and sludge production. They were not able to clarify turbid waste water and did not reduce high concentrations of fluoride in groundwater. Further, the turbidity-removal capacity of the coagulants had reduced capacities in water with low pH-values.

No description available.

As populations continue to grow, the demand for fresh drinking water is increasing. This puts a lot of pressure on drinking water producers to strive for more efficient solutions and techniques. Many producers worldwide use surface water as a raw water source, which they often treat through coagulation and flocculation techniques. This is done by adding coagulant (e.g. metal coagulants), creating instability in the suspension, causing flocculation. In this work, PIX-311 (a FeCl3 coagulant produced by Kemira) and Al2(SO4)3 (Kemwater ALG) were used as primary coagulants and CaCl2 (produced by TETRA Chemicals) as an adjunct in a coagulation and flocculation study. The goal of this work was to study the effects of CaCl2 additions to Fe(III) and Al(III) flocculation. The experiments were conducted at Ringsjöverket (a water treatment facility), using jar tests to simulate the treatment process on a laboratory scale. The raw water samples used in this study, were taken from Bolmen, a lake in southern Sweden. A spectrophotometer was used to monitor the efficiency of flocculation by UV-VIS absorption. In the first experiments, various CaCl2 additions were added to Fe(III) flocculation, with FeCl3 as a primary coagulant. To see if FeCl3 could be substituted with CaCl2, the amount of primary coagulant was reduced to about 80% of the optimal dosage (the dose used daily by the water treatment plant). In the next series of experiments, various amounts of CaCl2 were added with an optimal dose of FeCl3. After that, the effects of CaCl2 additions to Al(III) flocculation were conducted, using Al2(SO4)3 as a primary coagulant. The experiments followed the previous scheme used in Fe(III) flocculation. The UV-VIS results showed that no CaCl2 additions were effective enough to replace the primary coagulant. However, reduced amount of primary coagulant benefited slightly from small CaCl2 additions. A likely explanation for this is the ability of Ca2+ to aid in charge neutralization and reduce the repulsive forces between particles in suspension, aiding coagulation. Furthermore, CaCl2 additions, with reasonable certainty, did not increase the efficiency of Fe(III) flocculation. When the CaCl2 dose was increased (from about 13µl to 820 µl per liter raw water), the effect became negative. In other words, high doses of CaCl2 inhibited flocculation by, most likely, occupying adsorption sites for the primary coagulant. This was observed for an optimal FeCl3 dose, reduced FeCl3 dose and an optimal dose of Al2(SO4)3. In the more brief study on Al(III) flocculation, low CaCl2 doses did not appear to have any effect on flocculation at first.  However, when a reduced amount of Al2(SO4)3 was used, the samples with CaCl2 gave better UV-VIS results once the pH was increased from 6 to about 6.15. One explanation for this could be that the shift in flocculation mechanism at higher pH, causes CaCl2 to have an increased positive effect.

Industries are becoming more aware of how they use water in their production process. In many cases, they release wastewater back into the water supply untreated, which can cause adverse side effects to the ecosystem. A sustainable environment requires efficient water purification. One approach to purify wastewater uses rotating bed reactors. An impeller filled with catalyst pellets that absorb the pollutants spins in the contaminated fluid. The inertial forces from the spinning impeller propel the contaminated water through the packed bed and purify it. In this study, we used one of these rotating bed reactors. However, the motors that drive these impellers can be bulky and may not be compatible with some tanks or environments. To solve this problem, we designed, constructed, and tested a container around the impeller that provides maximal outflow, using only the impellers pumping capability. We also developed a CFD simulation of the container to analyze the internal flows and forces. Because the flow generated by the rotating impeller displaces the fluid in a radial direction, the design works as a custom-made centrifugal pump. We constructed the container using plastic and wood with an outlet nozzle made of metal. The container's pump capability was around 2.5 liters per second when the impeller spun at 300 RPM. The developed CFD simulations gave a higher flow rate at 3.1 liters/second but overall helped shed light on the internal forces happening inside the container during high RPM testing. The design could generate a sufficient outflow of fluids, converting kinetic fluid energy to fluid pressure energy at the outlet, causing a pump effect. Overall, the design proved sturdy and could handle the forces occurring inside the container. The implementation of this design could allow industries to more efficiently and ergonomically utilize the purifying capabilities of the RBR in otherwise complex scenarios. By purifying wastewater before releasing it back into the water supply, we can take immediate action in achieving a sustainable environment.

The increasing awareness towards PFAS pollution makes it increasingly important to treat. Many agencies over the globe, including the Swedish Food Agency, are introducing ever so strict control over PFASs in drinking water. One of Norrvatten’s back-up drinking water plants, the Hammarby plant, is a groundwater plant that saw elevated concentrations of PFASs (sum of 32 PFASs~80 ng/L) and total uranium (~109 µg/L). The aim of this work is to investigate the possible remediation for PFAS and uranium pollution in the groundwater. The main objective is to examine the possibility of SorbixTM, a strong-base anion exchange resins provided by ETC2, adsorbing PFAS and uraniumfrom the groundwater. Furthermore, the optimal solution of groundwater and sodium chloride that prevents microbial growth is to be investigated. This is of interest considering the intermittent operation of the Hammarby plant, where water would be allowed to stagnant for longer periods thus being prone to microbial growth. The effect of microorganisms on the resins is of concern. Biogrowth experiments were conducted using four different brines: 0%, 5%, 15%, and 25%. Identical masses of AIX resins were soaked in these solutions for 19-29 days in order to investigate whether the brine is effective at inhibiting biogrowth. The tests were analyzed mainly using plate count method, and secondly using flow cytometry. For uranium and PFAS removal, batch experiments using (1) resins that were previously soaked in brine were performed, (2) resins that were exposed to microorganisms as well as (3) new unused resins. Results showed that brines with 15% salinity or higher are capable of completely stopping microbial growth. The SorbixTM was capable of removing PFAS to below detection levels, as well as 99% removal of total uranium. To further develop on this study, column experiments with continuous water flow should be investigated. Continuous flow is a more accurate representation of the real case and will give knowledge on additional information regarding the breakthrough volume of the individual PFASs, the required water flow relative to available resin area that ensures acceptable removals, and how the competitiveness of uranium affects PFAS adsorption. It is also recommended to investigate the potential for regenerating the AIX resins. The Swedish Food Agency restricts the chemicals that are allowed to come in contact with any drinking water equipment. This means that some of the regenerative substances used in other studies are prohibited in Sweden. / Den växande uppmärksamheten kring PFAS gör det allt viktigare att avlägsna dessa från dricksvatten. Flera myndigheter över hela världen, inklusive Livsmedelsverket, inför gränsvärden och kontroller på PFAS i dricksvatten som blir allt striktare. En av Norrvattens reservvattenverk, Hammarby, är en grundvattenanläggning som visade förhöjda koncentrationer av PFAS och uran, där summan av de 32 mest förekommande PFASs är 80 ng/L och den totala uranhalten är 109 µg/L. Syftet med detta arbete är att undersöka möjligheten till PFAS och uran borttagning från grundvattnet. Huvudmålet är att undersöka möjligheten för SorbixTM, en starkbasisk anjonbytesharts som är framtagen av ETC2 Sverige (ETC2, n.d.), att adsorbera PFAS och uran från grundvattnet. Dessutom ska den optimala lösningen av grundvatten och natriumklorid, som förhindrar mikrobiell tillväxt, undersökas. Detta är av intresse med tanke på den intermittenta driften av Hammarby-anläggningen, där vattnet i ledningarna är stillastående under längre perioder och därmed blir utsatt för mikrobiell tillväxt. Effekten av mikroorganismer på jonbytesharts är, enligt andrastudier, bekymmersam. Tillväxtexperimenten utfördes genom användning av fyra olika saltlösningar: 0%, 5%, 15%och 25%. Identiska massor av anjonbytesharts blötlades i dessa lösningar i 19-29 dagar för att undersöka biologisk tillväxt. Testerna analyserades huvudsakligen med tre-dagars-tillväxt och imindre utsträckning med flödescytometri.För uran- och PFAS-avlägsnande så användes standardiserad skaktester med (1) jonbytesharts somtidigare blötlagts i saltvatten, (2) jonbytesharts som exponerats för mikroorganismer samt (3) nytt och oanvänt jonbytesharts. Resultatet visade att lösningar med 15% salthalt eller högre kan bromsa den mikrobiella tillväxten helt. SorbixTM lyckades ta bort PFAS till under detektionsnivåer, samt avlägsnade över 99% av den uppmätta uranen i grundvattnet. För vidare studier så rekommenderas kolonnförsök med kontinuerligt vattenflöde. Kontinuerligt flöde är en mer exakt representation av det verkliga fallet och kommer att ge ytterligare information såsom: breakthrough volymen för de enskilda PFASs, optimala vattenflödet i förhållande till tillgänglig yta av jonbytesharts som säkerställer acceptabel avlägsnande samt hur stark konkurrensen mellan uran och PFAS blir och vilken av de som adsorberas/desorberas först. Dessutom rekommenderas undersökningar på regenereringen av jonbytesharts, med tanke till de begränsade regenereringsämnen som är tillåtna enligt Livsmedelsverket. Många regenerativa ämnensom används i andra studier är förbjudna att använda i Sverige.

Sveriges avloppsreningsverk står inför ett antal utmaningar, där en av utmaningarna är minskning av växthusgaser. Lustgas är en av dessa växthusgaser, som bildas vid rening av avloppsvatten. Lustgas är 300 gånger skadligare för klimatet i jämförelse med koldioxid. Dessutom påverkar den nedbrytningen av ozonskiktet. I dagsläget är det svårt att mäta och uppskatta lustgasutsläpp, på grund av att det pågår flera samtidiga processer på stora ytor. För att driften av avloppsreningsverk ska ske på ett effektivt sätt och med en ytterst liten miljöpåverkan måste man kunna förstå hur lustgas uppstår och hur bildningsprocesserna samverkar med de andra reningsprocesserna och driftparametrarna. Utsläpp av lustgas har studerats vid avloppsreningsverket i Göteborg. Syftet har varit att tillhandahålla resultat och mätningar från Gryaab AB reningsverk och fastställa vilka processer som ger upphov till störst eller minst lustgasemissioner. Utsläpp av lustgasemissioner har mätts från rejektrening med nitrifikation och denitrifikation process. Analyser på resultaten ska förhoppningsvist kunna hjälpa Gryaab AB med fortsatt studier om lustgas. Som mätningsmetod användes EPA-huvmätning som man mätte med ovanför vattenytan på bassängerna och mobilt extraktiv FTIR som åkte runt anläggningen. Den dominerande källan för lustgas visade sig bildas allra mest i nitrifikationsprocessen. Där mätningarna med huv-mätning och stickprov visade totala utsläpp motsvarande 1,8 ton N2O/år. Den totala lustgasemissionen från biologiska reningsprocessen visade totala utsläpp motsvarande 3,5 ton N2O/ år. Som en slutsats bör fler mätningar med olika mätningsmetoder och mer studier göras för att få en bättre överblick till varför och hur lustgas bildas. Samt vilka åtgärder som kan minska lustgasemission. Det finns ett behov av fortsatta studier med mätningar med olika mätningsmetoder på Gryaab AB. / Sweden's wastewater treatment plant faces several challenges, one of them is the reduction of greenhouse gases. Nitrous oxide is one of these greenhouse gases, which is formed during the purification of wastewater. Nitrous oxide is 300 times more harmful to the climate compared to carbon dioxide. In addition, it affects the depletion of the ozone layer. At present, it is difficult to measure and estimate nitrous oxide emissions, since several simultaneous processes are taking place on large areas. For the operation of sewage treatment plants to take place in an efficient manner and with an extremely small environmental impact, it is important to understand how nitrous oxide is formed and how the formation processes interact with the other treatment processes and operating parameters. Emissions of nitrous oxide have been studied at the wastewater treatment plant in Gothenburg. The purpose has been to provide results and measurements from Gryaab AB wastewater treatment plant and to determine which processes give rise to the highest nitrous oxide emissions. Emissions of nitrous oxide emissions have been measured from reject cleaning with the nitrification and denitrification process. Analysis of the results will hopefully be able to help Gryaab AB with further research. As a measurement method, EPA hood measurement was used, which was measured above the water surface in the basins and mobile extractive FTIR was driven around the facility. The dominant source of nitrous oxide was found to be formed most in the nitrification process. Where the measurements with hood measurement and sampling showed total emissions corresponding to 1.8 tons of N2O / year. The total nitrous oxide emissions from the biological treatment process showed total emissions corresponding to 3.5 tons of N2O /year. As a conclusion, more measurements with different measurement methods and more research should be done to get a better overview of why and how nitrous oxide is formed. And what measures can reduce nitrous oxide emissions. There is a need for further studies with measurements with different measurement methods on Gryaab AB.