University, Diss., 2006--Hannover.

Zugl.: Berlin, Techn. Universiẗat, Diss., 1998. / Zugl.: Berlin, Techn. Univ., Diss., 1997. - Zsfassung in engl. Sprache.

Zugl.: Berlin, Techn. Univ., Diss., 2008

Techn. Universiẗat, Diss., 2001--Darmstadt. / Zsfassung in engl. Sprache.

Paderborn, University-GHS, Fachb. Chemie u. Chemietechnik, Diss. 1990.

Bayreuth, Univ., Diss., 2008.

One major environmental challenge is to manage agricultural soil in asustainable way. Since nutrients in the soil are taken away every harvest, there is a need to recycle nutrients back to the soil. One solution is to use sewage sludge as a fertilizer. However, sludge can also contain substances that could potentially be harmful to crops or humans. This study examined the long-term effect of sewage sludge amendment in agricultural soil. The aim of this study was to analyse the general effects on the microbial community by sequencing the 16SrRNA gene, as well as studying the response to the amendments of nitrifying and denitrifying microorganisms. This was done by qPCR quantification of marker genes and activity tests of potential denitrification and N2O production in the soil. The main conclusion is that long-term effects of sewage sludge amendments on the microbial community, as well as on microorganisms involved in nitrogen cycling,are relatively small compared to effects caused by differences in soils. Moreover, the effects on the microbial community differed between soils, implying that attention needs to be paid to the characteristics of the soil when evaluating effects of sludge amendments. It was clear that the ratio of ammonia oxidising bacteria and archaea differed between treatments, however further studies are needed to conclude the reason for this. Finally, positive correlations between both measured activities and denitrifying marker genes were found, which suggests that quantification of marker genes can be used for studying reactions in the soil.

Kväverening är en viktig process som utförs i många av de större reningsverken i Sverige föratt eliminera farliga ämnen som i stor utsträckning påverkar miljön och den globalauppvärmningen. En effektiv metod för att bli av med det kemiskt bundna kvävet är att användasig utav en denitrifikationsprocess med en kolkälla vars huvuduppgift är att med hjälp av kolreducera kvävet till mer stabila och mindre reaktionsbenägna molekyler. Att välja rätt kolkällakräver att många olika parametrar tas i akt eftersom olika kolkällor arbetar olika bra i olikamiljöer. SÖRAB använder idag Brenntaplus som kolkälla i deras denitrifikationsprocess för att få enönskad kväverening. De har undersökt alternativa kolkällor som helt eller delvis skulle kunnaersätta den befintliga kolkällan. Initiativtagare och uppdragsgivare för examensarbetet ärJohanna Leback på SÖRAB. Det primära målet med examensarbetet var att undersöka om denglykol som SÖRAB får in som farligt avfall skulle kunna användas som kolkälla eller om deninnehåller för mycket av farliga ämnen. Utöver denna potentiella kolkälla låg även fokus på attundersöka några externa kolkällor ur ett ekonomiskt samt ett miljömässigt perspektiv. För att bestämma om den inkommande glykolen skulle vara lämplig att använda som kolkällagjordes flera provtagningar på olika batcher för att avgöra om sammansättningen av deninkommande glykolen skiljde sig avsevärt mellan olika prover. För att veta om ämnena iglykolen skulle påverka lakvattnet och göra så att det utgående lakvattnet innehåller halter somöverstiger det uppsatta riktvärdena så gjordes beräkningar på hur glykolen skulle påverkalakvattnet. Vid kväverening med närvaro av kolkälla är det även viktigt att ta i akt mängden COD ikolkällan och hur lätt bakterierna i vattnet har att komma åt dessa. Eftersom det inte fannstillgång till praktiska försök på detta så gjordes en uppskattning baserad på tidigare studier frånandra reningsverk samt en teoretisk beräkning. De kolkällor som undersöktes utöver glykol var etanol, metanol, glycerol, ättiksyra samt dennuvarande kolkällan. Mängden för dessa kolkällor skiljer sig dock avsevärt eftersom de är olikaeffektiva vid kväverening men priserna för dessa jämnade ut och gav ett likvärdigt pris. Denkolkällan som stack ut var metanol som var ungefär hälften så dyr som resterande kolkällor.Kolkällorna arbetar under olika betingelser och kräver olika kriterier för att fungera. Vissa avkolkällorna är explosionsklassade och kräver särskilda rör medan andra har en hög fryspunktvilket måste tas i akt när förvaringen av kolkällan ska göras. Slutsatsen som kan dras av detta examensarbete är att varje enskild reningsanläggning reagerarolika på olika kolkällor och det är svårt att teoretiskt beräkna en mängd som ska doseras vidbestämda betingelser. Teoretiskt kan ett referensvärde räknas ut som används vid förstadoseringen men efter det behövs en justering för att hitta den mängd som ger den bästa reningensamtidigt som inget överskott utav kolkälla tillförs. Den deponerade glykolen som SÖRAB fårin via privatpersoner anses inte lämplig att dosera då innehåller från sats till sats skiljer sig mycket. / Nitrogen reduction is an important process that many of the larger treatment plants in Swedenuse since nitrogen affects the environment and the global warming. An efficient method to getrid of nitrogen is to use a process called denitrification. In this process a carbon source is usuallyused and has a main purpose to reduce the nitrogen to more stable and less reactive molecules.There are many parameters to take into consideration when choosing the most suitable carbonsource for the specific treatment plant. The reason for this is that the carbon sources that areavailable are more or less effective in different environments which depends on parameters suchas pH levels and temperatures. SÖRAB use Brenntaplus as carbon source in their denitrification process to achieve a reductionof nitrogren. They have recently looked at alternative carbon sources that could replace parts ortheir current one. The primary aim with this project was to investigate if the glycol that SÖRABreceive as waste from the public could be used as carbon source for the leachate, or if it containstoo much dangerous chemicals and heavy metals that will affect the wastewater. In addition tothe glycol, there was some focus was on comparing some other carbon sources to each other inan economic and environmental perspective. To determine wheter the incoming glycol is suitable to use as a carbon source or not, severalsamplings were made on different batches of the incoming glycol. The purpose of this was tosee if there was a variety in the composition of the glycol from batch to batch. To determine ifthe content of the glycol would affect the wastewater by raising the concentration of dangerouschemicals to such a high values that the wastewater would not meet the emission requirementsthat SÖRAB has set, a calculation were made to see how much the glycol would affect theleachate. When reducing nitrogen in the presence of a carbon source it is important to acknowledge thatthe amount of COD in the carbon source determines how much nitrogen that can be reduced.The problem that occurred is the lack of practical testing in the process makes it hard to give aprecise number of how much carbon source that is needed to give the desired nitrogen reduction. The carbon sources that were investigated were ethanol, methanol, glycerol, acetic acid and thecurrent one, Brenntaplus. From an economical perspective the price for respective carbon sourcewere the same if looking one the amount needed in consideration to the price per kilo for eachone. The carbon sources work in different conditions and need different requirements to workfunctionally. Some of the carbon sources are an explosive risk and need special handling andsome sources have a very high freezing temperature which requires special storage. The conclusion that can be drawn from this master thesis is that every individual treatment plantreacts different to different carbon sources and it is really hard to theoretically estimate whatamount that needs to be dosed. Theoretical a reference value can be determined and in regard tothis the dosage can be adjusted with several tests until an amount of carbon source that give thewanted nitrogen reduction is found. The deposited glycol that SÖRAB receives from theirrecyclingstations is considered to not be suitable for dosage because the composition differsfrom batch to batch.

Avloppsreningsverket i Hallsberg kommun är beläget i direkt anslutning till Hallsberg, med Ralaån som recipient. Tekniken på reningsverket bygger på principerna för en klassisk aktivslamanläggning med mekanisk rening, kemisk rening, biologisk rening och en slambehandling där rötning av primär- och sekundärslam används för utvinning av biogas. Hallsberg ARV har under en längre tid haft problem med kvävereningen. Under senaste åren har man överskridit riktvärdet för kväveutsläpp vid ett flertal tillfällen och under 2009 överskreds även gränsvärdet. Riktvärdet för Hallsberg ARV är i dagsläget satt till 10mg NH4-N/l som medelvärde per månad, gränsvärdet är satt till 10 mg NH4-N/l som medelvärde per kalenderår. Då Hallsberg ARV inte drivs vid full kapacitet antas en minskning av kväveutsläppen vara möjlig att genomföra genom trimning av befintligutrustning och processer på verket. Detta antagande låg till grund för det här examensarbetet som syftar till att optimera kvävereningen på Hallsberg ARV. I optimeringen ingick en teknisk, ekonomisk och miljömässig utvärdering av olika alternativa lösningarna för att förbättra funktionen hos anläggningen. Extra hänsyn togs till energi- och kemikalieåtgång i syfte att få en så effektiv drift av verket som möjligt. Arbetet genomfördes genom en initial litteraturstudie på området, vartefter en provtagningsserie om fyra veckor realiserades på verket. Data som ligger till grund för slutsatserna i projektet har också inhämtats från onlinemätare på verket samt från äldre externt analyserade prover. Efter analys av insamlad data antas orsakerna till Hallsberg ARV:s höga utsläpp av kväve bero på en kombination av flera faktorer: -Vid vår och höst kan brunnsslamintaget vara så stort att bräddning sker ut till verket. Detta leder till att kvävebelastningen höjs så kraftigt att nitrifierarna inte hinner acklimatisera sig och får förhöjda kväveutsläpp till följd. -Mycket kväve följer med slammet från simultanfällningen till rötningen. Detta kan påverka halten kväve i rejektet från rötkamrarna som i sin tur kan leda till störningar i kvävereningen. -Centrifugens rejekt innehåller mycket kväve och körs idag endast under ett par dagar i veckan vilket leder till stora variationer i inkommande kvävehalt. -En hög förfällning av fosfor och organiskt material har bidragit till en låg halt av organiskt material i denitrifikationen. Sammantaget föreslås att vidare studier bör genomföras av ovan nämnda områden för att driften på Hallsberg ARV ska kunna drivas med så låga miljömässiga och ekonomiska kostnader som möjligt. / The waste water treatment plant in Hallsberg municipal is situated adjacent to Hallsberg, with Ralaån as a recipient. The technique at the waste water treatment plant is based on the principles for a classical activated sludge treatment plant and includes mechanical treatment, chemical treatment, biological treatment, and a sludge treatment where the digestion of primary and secondary sludge is used for extraction of biogas. Hallsberg waste water treatment plant has during some time had problems with the nitrogen removal with high nitrogen emissions as a consequence. The target value has been exceeded a couple of times during the last years and in 2009 the limit value was exceeded as well. The target value for Hallsberg waste water treatment plant is 10 mgNH4-N/l as an average value per month, the limit value is set to 10 mg NH4-N/l, as an average value per year. Since the waste water treatment plant in Hallsberg not is operating at full capacity, a lowering of the nitrogen emissions is assumed to be possible though a trimming of the existing equipment and of the processes on the site. This assumption formed the basis for this thesis, designed to optimize the nitrogen removal at the waste water treatment plant in Hallsberg. A technical, economical and environmental evaluation was included in the optimization to improve the function of the plant. Extra evaluations were made in the energy- and chemical consumption in order to streamline the operations at the plant as much as possible. The project was carried out through an initial literature-investigation followed by a four week period of sampling and analyzing at the site. The data that form the conclusion in this project has also been collected through online measurements at the plant as well as through analyses of older samples. After analyzing the collected data, the reasons for the high emissions of nitrogen is thought to be due to a combination of reasons: -During the spring and the autumn the external intake of well sludge can lead to a direct release of sludge in to the plant. The change of nitrogen content will not give enough time for the nitrifying bacteria to acclimatize, with elevated emissions of nitrogen as a consequence. -The usage of simultaneous precipitation could lead to an irregular concentration of nitrogen released to the treatment plant from the digesters. This in turn could contribute to higher nitrogen emissions. -The irregularities of the usage of the centrifuge contribute to nitrogen irregularities and contribute to the difficulties of acclimatization of the nitrifying bacteria. -A high pre-precipitation of phosphorus and organic matter has contributed to a level of organic material in the denitrifikation below what is recommended. To sum up, further investigations are suggested in the above mentioned areas to make the operations at the plant carried trough at the lowest possible environmental and economically cost.

In connection with the admittance of the EC-directive (99/31/EC) in Swedish politic, through the constitution of waste depositing (2001:512) at year 2001, the rules about management the landfills and leachates tightened. At the landfill Vissberga in the municipality of Hallsberg, a leachate treatment plant was constructed just a year thereafter. This treatment plant consisted of an aerated pond with a following land treatment and a willow cultivation to replace the land treatment during the summer. In this case the parameters, which were estimated as the most important to reduce, were iron and nitrogen. The iron would react with the oxygen-rich water in the aerated pond and precipitate to ferric-hydroxide and than settle in a calm zone of the pond. The rest of it would be reduced by filtration in the land treatment. The elimination of nitrogen would happened by two biological processes. The first one was intended to be in the aerated pond, where ammonium ions would oxidise to nitrate by the process called nitrification. The established nitrate would then be transformed to nitrogen gas by a denitrification in the land treatment and be emitted to the air. Unfortunately the reduction has not been desirable, why the main objective of this thesis is to quantify the problem and identify the limitations of the plant by describing the processes involved and find out which factors that affects them, in particular the impact of the temperature. This was executed by a literature study about the processes and by studying results from analysis that were obtained both from earlier samples and from samples which were done during this thesis. At the end it appears that the plant was overloaded and that this probably depends on incorrect estimates of the leachate water flow, done during the dimensioning of the plant. Due to the high flow the ferric-hydroxide can’t be settled and the nitrifyers don’t have enough time to reduce the nitrate. One part of the objective was to found out in which degradation phase the landfill are for the moment, to see what changes is to expect in the combination of the leachate water in the future. However, it was difficult to say with certainty, due to the circumstances that the landfill currently is in the methane phase and the knowledge of the next phase, the humic phase, is very limited because very few landfills has now days reached this phase. The phase determination was made by comparisons between composition of the leachate water of Vissberga and leachate water from the literature. An interview study was also done during this thesis, where people from the Counties Agency in the county of Örebro and Västmanland, the municipality of Uppsala and the Environmental Protection Agency were attended. The question was: Which new requirements that might be claimed at leachate water treatment in a foreseeable future?