Skogsindustriellt avloppsvatten behöver genomgå flertalet reningsprocesser innan det kan återföras till recipient. Vid Stora Ensos bruk i Skoghall används en luftad damm med slamåterföring som biologisk rening. Extraktivämnen i avloppsvatten försvårar luftning i dammen och problem med reningen kan uppstå då kommande skärpta utsläppskrav ska efterföljas från och med 2018. För att möjliggöra en kommande produktionsökning samtidigt som skärpta utsläppskrav följs driver nu Stora Enso ett investeringsprojekt för att effektivisera avloppsvattenreningen. En utredning ska genomföras med syfte att redovisa om ett försteg till den luftade dammen i form av en MBBR (Moving Bed Biofilm Reactor) skulle kunna underlätta rening i den luftade dammen. Om så är fallet kan en ökad produktion vara möjlig utan att ändra på dagens luftade damm samtidigt som utsläppsvillkor uppfylls. Detta är en fortsatt utredning av Karin Arvsells arbete som undersökte MBBR och luftad damm i labbskala. Stora skillnader mellan dessa arbeten är att vatten direkt från produktionen kontinuerligt går till försteget och att temperaturen i reaktorn inte regleras utan beror av vilka vattenflöden som skickas till luftad damm. En pilotanläggning byggdes upp på Stora Enso Skoghalls bruk där en Cipax-tank användes som reaktor och en bottenluftare byggdes på plats av en membranslang från luftad damm. Ett delflöde av det totala avloppsflödet till luftad damm leddes till reaktorn. Slang för inflöde gick in i botten av tanken för att bidra till omblandningen, resterande omblandning stod luftarsystemet för. Tanken var fylld med 800 liter vatten som reagerade med mikroorganismer växande som en biofilm på bärare. Uppehållstiden varierades med hjälp av en manuell ventil. För att utreda hur robust försteget är i förhållande till produktionsvariationer har TOC- och kloratreduktion analyserats samtidigt som tester har genomförts på ytaktiva ämnen, närsalter, SÄ, temperatur, VFA, SVI, EDTA, HRT och syrehalt. Luftningsförsök för att utreda hur effektiviteten på syresättningen påverkas av ett försteg samt kartläggning av mikroorganismer genomfördes. Pilotförsöken delades upp i tre olika försöksperioder. Under de 19 första dagarna genomfördes testperiod 1 där vattnet luftades i reaktorn utan bärare. Försöksperiod 2 var 45 dagar lång där avloppsvattnet reagerade med mikroorganismer växande som en biofilm på bärare. Försöksperiod 3 som var 16 dagar lång inleddes med att reaktorn isolerades. Utformningen av försöksperiod 3 är ett resultat av provsvar från försöksperiod 2 där det framkom att temperaturen sjönk nämnvärt under de timmar vattnet befann sig i reaktorn. Testperiod 2 visade reduktion av samtliga parametrar med en medelreduktion av TOC på 40 % och 86 % reduktion av klorat. Vid ytspänningsanalys visades en högre ytspänning på utgående vatten vilket tyder på att ytaktiva ämnen brutits ner. Detta underlättar luftningen vilket sågs tydligare efter luftningsförsök på ingående och utgående vatten där hastigheten för syretransporten dubblerades. Både frisimmande organismer och protozoer i form av klockdjur och toffeldjur hittades i vattnet. I samband med uppstart av testperiod 3 var CTMP-produktion och blekeri stoppat vilket ledde till att kvarvarande avloppsflöde hade en ingående temperatur på 51°C. Den höga temperaturen och det förändrade innehållet i avloppet samtidigt som reaktorn isolerades bidrog till att mikroorganismerna slogs ut. Klorat reducerades med 93 % och TOC reducerades med 19 %. Reduktionsgrader av övriga parametrar var lägre än tidigare och vid luftningsförsök visades ingen förbättring av syretransporten. Reduktionsgrader har varierat från dag till dag men då rimliga orsaker är kända kan resultaten anses trovärdiga, vilket innebär att ett biologiskt försteg i form av en MBBR som hanterar inkommande avloppsvatten med dess varierande temperatur kan underlätta rening för luftad damm. Ytaktiva ämnen bryts ner under den korta reaktionstiden i försteget och syretransporten dubbleras. Vid produktionsstörningar kan termofila förhållanden råda istället för mesofila som är fallet vid normalproduktion. Detta kan slå ut mikroorganismerna vilket påverkar avloppsvattenreningen negativt. För att lösa problemet kan eventuellt varma flöden ledas direkt till luftad damm eller att genom kylning hålla ingående temperatur under 45°C. / Paper mill wastewater passes through several different purification steps before being reintroduced to the recipient. Stora Enso paper mill in Skoghall uses an aerated lagoon with sludge recirculation as biological treatment. Extractives in wastewater aggravates the aeration in the pond and problems with the purification can occur when stricter emission requirements needs to be followed from 2018. Stora Enso is now running an investment project to improve the efficiency of the wastewater treatment to enable future production growth while stricter emission standards are followed. A pre-treatment step before the aerated lagoon designed as a MBBR (Moving Bed Biofilm Reactor) will be analyzed to present whether it can ease the wastewater treatment in the aerated lagoon or not. If so, production growth could be possible without change the present aerated lagoon while emissions conditions are met. This is a further investigation from Karin Arvsells work that studied a MBBR and aerated lagoon in lab scale. Large differences between these studies are that the wastewater goes to the pre-treatment continuously and the temperature is not regulated. A pilot plant was built at Stora Enso Skoghall mill where a Cipax-tank was used as a reactor and an aerator was built with membrane from the aerated lagoon. A partial flow of the total wastewater flow to the aerated lagoon was passed to the reactor at the bottom of the tank. The incoming wastewater and the aerator mixed 800 liters of water with the microorganisms growing as a biofilm on the carriers. The hydraulic retention time was controlled with a manual valve. TOC- and chlorate reduction, extractives, nitrogen, phosphorus, suspended solids, temperature, VFA, SVI, EDTA, HRT and oxygen content are analyzed to find out how robust the pre-treatment is. Tests were made to analyze how effective the oxygen dissolves after a pre-treatment and to identify the microorganisms in the wastewater. The experiments were divided into three different periods. Under the first 19 days was trial 1 performed where the water reacted in the MBBR without carriers. Trial 2 was 45 days long and the wastewater was pre-treated with microorganisms growing on carriers. Trial 3 lasted for 16 days and then the wastewater was treated in an isolated tank with carriers. The design of trial 3 was a result of the test results from trial 2 where the temperature dropped significantly during the hours the wastewater was treated in the reactor. Trial 2 showed reduction of all parameters with an average reduction of 40 % of TOC and 86 % reduction of chlorate. Surface tension analysis demonstrated a higher surface tension after the pre-treatment step which indicates that extractives were decomposed. The higher surface tension will ease the aeration in the aerated lagoon which was shown in the aeration tests were the rate of oxygen transport was doubled. Both free-swimming organisms and protozoa were found in the water. At the start of trial 3 the production of CTMP and the bleaching process were stopped. As a result, the remaining wastewater had a temperature of 51°C. The high temperature and the changed content of the wastewater at the same time as the reactor was isolated resulted in an elimination of the microorganisms. Chlorate was reduced by 93 % and TOC by 19 %. The reductions of the other parameters were lower than before and the aeration trials showed no improvement in oxygen transport. The reduction varied from day to day but since reasonable causes are known, the results are considered reliable. This means that a biological pre-treatment step in form of a MBBR can ease the purification in the aerated lagoon. Extractives are decomposed during the short reaction time and the oxygen transport is duplicated. If the production is disrupted, thermophilic conditions may occur instead of mesophilic conditions which are the normal setting. This may eliminate the microorganisms which affect the wastewater treatment negatively. To solve the problem, the hot water could be led directly to the aerated lagoon or by cooling the water keep the incoming temperature under 45°C.

The significant rise in the number of micro-breweries in North America has increased the need for efficient on-site industrial wastewater facilities. Brewery wastewater is considered to be a high strength food industry wastewater with high variability in terms of both organic and hydraulic loading. Small breweries require cost-effective, reliable, and simple to operate treatment technologies to properly manage their brewery wastewaters. Moving bed biofilm reactor (MBBR) technology has shown promise at the lab-scale and full-scale with respect to brewery effluent treatment. MBBR systems have the capability for short hydraulic retention times (HRT), high organic loading rates, as well as increased treatment capacity and stability due to biofilm retention, all within a compact reactor size when compared to other aerobic and attached growth treatment options. Two MBBR systems utilizing two different carrier types (Kaldnes K5 and Kontakt), and a suspended growth (SG) control reactor, were used in this study to investigate the impacts of surface area loading rate (SALR) and HRT on attached growth (AG) and SG kinetics and carrier type for brewery wastewater at 2000 mg-sCOD/L. An increase in SALR from 10-55 g-sCOD/m2/d while at an HRT of 12 hr resulted in no significant impact in total volumetric removal rates between the MBBR systems and the SG control reactor; however, MLSS concentrations were lower for the MBBR systems at SALRs below 55 g-sCOD/m2/d, which indicated AG contribution. Over 92% soluble chemical oxygen demand (sCOD) removal was achieved at each SALR in each of the three reactors. These results indicated that the reactors were substrate limited and SG controlled. Due to the SG dependency, the difference between the two types of carriers was indeterminate. A decrease in HRT from 12-3 hr while maintaining an SALR of 40 g-sCOD/m2/d resulted in a shift from SG to AG dependency in the MBBR systems. The total volumetric removal rates for the MBBR systems were significantly higher at HRTs of 3 and 4 hr as compared to the SG control reactor. The AG volumetric removal rates from both MBBR systems were highest at an HRT of 3 and 4 hr. At an HRT of 12 hr all three reactors maintained over 92% sCOD removal; however, at an HRT of 4 hr the SG control reactor dropped to 88% and at 3 hr to 61%, whereas the MBBR systems maintained 95% removal at an HRT of 4 hr and only decreased to 73% at 3 hr. These results indicated that the MBBR systems were more effective at lower HRT than the SG control reactor, with no significant difference observed between the two carrier types tested. Biofilm morphology and viability from each of the two carriers utilized in the study of moving bed biofilm reactor (MBBR) treatment of brewery wastewater were investigated using stereoscopy and confocal laser scanning microscopy (CLSM) in combination with live/dead cell staining. Both carriers demonstrated thicker and more viable biofilms at high SALR and denser and less viable biofilms at low SALR. At lower HRT, the carriers reacted differently resulting in thicker, but less dense biofilms on the Kontakt carriers and thinner, but more dense biofilms on the K5 carriers. However, no trend in cell viability was observed with change in HRT. Although the systems were suspended growth (SG) dominated, based on the MBBR kinetics and carrier biofilm morphology and cell viability, either carrier would be a viable choice for an MBBR treating brewery wastewater at HRTs between 4 to 12 hr and SALRs between 10-55 g-sCOD/m2/d.

Lower production rate of solids in attached growth moving bed bioreactor (MBBR) systems as compared to conventional activated sludge (AS) systems makes them an attractive choice for municipal wastewater treatment (Ødergaard et al. 1994). However, the production of biologically-produced solids in MBBR systems is currently not well defined and requires additional investigation. Three identical MBBR reactors were operated under the same dissolved oxygen (DO) concentration, influent pH and volume of Anoxkalnes media in two different experimental phases. In the first phase, the hydraulic retention time (HRT) kept constant in three reactors and SALR increased and in the second phase, the SALR was the constant parameter while HRT increased. These two phases were implemented to investigate the effect of variations in HRT and SALR on biologically-produced solids in MBBR reactors. This study demonstrated that HRT and SALR play an important role in settling characteristics of the biologically-produced solids in MBBR systems.

Lower production rate of solids in attached growth moving bed bioreactor (MBBR) systems as compared to conventional activated sludge (AS) systems makes them an attractive choice for municipal wastewater treatment (Ødergaard et al. 1994). However, the production of biologically-produced solids in MBBR systems is currently not well defined and requires additional investigation. Three identical MBBR reactors were operated under the same dissolved oxygen (DO) concentration, influent pH and volume of Anoxkalnes media in two different experimental phases. In the first phase, the hydraulic retention time (HRT) kept constant in three reactors and SALR increased and in the second phase, the SALR was the constant parameter while HRT increased. These two phases were implemented to investigate the effect of variations in HRT and SALR on biologically-produced solids in MBBR reactors. This study demonstrated that HRT and SALR play an important role in settling characteristics of the biologically-produced solids in MBBR systems.

There is an increasing need for tertiary level wastewater treatment in Canada, driven in some cases by both provincial and federal regulation (Canada Gazette, 2012). Tertiary nitrification is the biologically mediated oxidation of nitrogen in the form of ammonia to nitrate following secondary treatment of carbonaceous material (Barnes & Bliss, 1983). The application of tertiary nitrification can prove challenging in the Canadian climate because of the temperature sensitive nature of nitrifiers (Hwang & Oleszkiewicz, 2007). Hence the greater than 1000 lagoon treatment plants currently in operation throughout country are susceptible to the full onslaught of weather effects and as such their nitrification processes become non-existent during the winter months (Delatolla et al., 2011,Hoang et al., 2014). The moving bed biofilm reactor (MBBR) system has been studied and shows promise for continuous nitrification with prolonged exposure to cold temperatures (Hoang et al., 2014). They are marketed as cost effective and low operation intensive upgrade options for existing treatment plants as well as effective stand-alone systems and are currently in operation in many countries worldwide (WEF, 2011). Despite the MBBRs initial development as a nitrification technology, recent research has been focused on COD removal systems. Studies showing that MBBR performance is directly related to surface area loading rates (SALRs) and not carrier type or shape have been performed exclusively on COD removal systems. The influence of MBBR carrier type on system solids production has also been solely studied for COD removal and the principles learnt have been transferred to tertiary nitrification systems without confirmation that they hold true. There is an absence of research on tertiary nitrifying kinetics; the effect of loading and carrier type, the nature of the solids produced and the carrier biofilm characteristics. This study investigated three MBBR carrier types, the K3, M and P Anoxkaldnes carriers in an effort to quantify the effects of carrier type on nitrifying kinetics, biologically – produced solids and the bacterial community at normal and high loading conditions. Four tertiary nitrifying laboratory scale MBBRs were fed with synthetic wastewater and operated at a high loading condition (HLC) with a SALR of 1.89 ± 0.10 g-N/m2•d and a normal loading condition (NLC) with SALR of 0.91 ± 0.1 g-N/m2•d. At both HLC and NLC, results show no difference in the ammonia removal rates obtained by the different carrier types. It was however noticed that stressed operational conditions developed for the P and M carrier at the HLC due to the clogging of carrier pore spaces with biofilm and subsequent reductions in removal efficiency were observed. Despite the fact that larger surface area to volume carriers (such as the M and P) may lead to MBBR designs with smaller footprints and lower operational cost, the study revealed their greater propensity to become clogged under high loading conditions than the smaller surface area carriers (such as the K3 ). In addition the larger surface area carriers demonstrated longer transitional periods from high loading conditions to lower loading conditions. A reduction in effluent total suspended solids (TSS) concentrations and improved solids settleability was observed with the shift from HLC to NLC. These results suggest the avoidance of high loading conditions in tertiary nitrifying MBBR operation. If low loading rates are not achievable then system design may have to consider the incorporation of coagulant use or an advanced solids separation technique to meet effluent solids regulation. Variable pressure scanning electron microscope (VPSEM) images at HLC showed the presence of water mites on the K3 carrier and nematodes and ciliates on the M and P carriers. While NLC images do not show these organisms. VPSEM also measured thicker biofilms during the HLC than the NLC for all carriers. The results demonstrate a difference in the meso-environments and suggest a difference in the micro-environments of the biofilm attached to each carrier. Microbial analysis showed no shifts in the dominant nitrifying species between the loading conditions, as well as no differences in the percent live /dead cell coverage. Nitrosomonas and Nitrospira were identified as the dominant AOB and NOB genera respectively at both the HLC and the NLC. Clear shifts in the microbial populations were observed for specific bacteria; with filamentous bacteria being observed at greater relative abundance at HLC than HLC. The increased relative abundance of filamentous organisms are also associated with the significantly poorer effluent settling characteristics observed at HLC.

Lower production rate of solids in attached growth moving bed bioreactor (MBBR) systems as compared to conventional activated sludge (AS) systems makes them an attractive choice for municipal wastewater treatment (Ødergaard et al. 1994). However, the production of biologically-produced solids in MBBR systems is currently not well defined and requires additional investigation. Three identical MBBR reactors were operated under the same dissolved oxygen (DO) concentration, influent pH and volume of Anoxkalnes media in two different experimental phases. In the first phase, the hydraulic retention time (HRT) kept constant in three reactors and SALR increased and in the second phase, the SALR was the constant parameter while HRT increased. These two phases were implemented to investigate the effect of variations in HRT and SALR on biologically-produced solids in MBBR reactors. This study demonstrated that HRT and SALR play an important role in settling characteristics of the biologically-produced solids in MBBR systems.

There is a significant need to remove ammonia from municipal wastewater to meet increasingly stringent regulations set by Canada, US, and Europe. Although existing conventional biological wastewater treatment technologies are shown to achieve effective ammonia treatment, they are substantially limited by increased operational intensity and cost. Due to these limitations, other cost-effective biological treatment technologies, such as partial nitritation/anammox (PN/A), have become a more attractive solution for nitrogen removal at wastewater resource recovery facilities (WRRF). A moving bed biofilm reactor system (MBBR) operating under a novel design strategy using elevated total ammonia nitrogen (TAN) loading rate has shown promise to achieve robust partial nitritation and the oxidation of TAN with limited oxidation of nitrite without the need for intense operational measures. However, the novel and promising design strategy using elevated TAN loading rate was applied at higher influent TAN concentrations that are typically greater than concentrations in mainstream municipal wastewater. Therefore, the objective of this dissertation is to investigate and optimize the design and performance of a promising elevated loaded partial nitritation MBBR technology for mainstream, municipal wastewater treatment followed by downstream anammox to complete the design of a robust, stable, energy-efficient, and low operational cost total nitrogen removal PN/A system for mainstream wastewaters. The first specific objective of the dissertation is to isolate the optimal design parameter of a mainstream elevated loaded partial nitritation MBBR system. The results identifies optimal distinct elevated surface area loading rate (SALR), hydraulic retention time (HRT), and airflow rate that achieve stable partial nitritation performance (i.e., optimum total ammonia nitrogen (TAN) removal kinetics and percent NOₓ as nitrite) in a mainstream elevated loaded partial nitritation MBBR system. The study shows that TAN SALR, HRT, and airflow rate significantly affect TAN surface area removal rates (SARR) and percent NOₓ as nitrite and, as such, identifies the optimal design parameters (TAN SALR, HRT and airflow rate) of a mainstream elevated loaded partial nitritation MBBR system. A TAN SALR of 5 g TAN/m²∙d, HRT of 2h and airflow rate of 1.5 L/min are identified to provide stable partial nitritation performance with a TAN SARR of 2.3 ± 0.3 g TAN/m²∙d and a percent of NOx as nitrite of 84.8 ± 1.2% in the mainstream elevated loaded partial nitritation MBBR system. The second specific objective further identifies a new design configuration and the mechanism of nitrite oxidation suppression of the mainstream elevated loaded partial nitritation MBBR technology. The results identifies a unique design strategy using an elevated TAN SALR of 5 g TAN/m²∙d to achieve cost-effective, stable, and elevated rates of partial nitritation in an MBBR system under mainstream conditions. The elevated loaded partial nitritation MBBR system achieves a TAN SARR of 2.01 ± 0.1 g TAN/m²∙d and NO₂⁻-N:NH₄⁺-N stoichiometric ratio of 1.15:1, which is appropriate for downstream anammox treatment. The elevated TAN SALR design strategy promotes nitrite-oxidizing bacteria (NOB) activity suppression rather than a reduction in NOB population as the reason for the suppression of nitrite oxidation in the mainstream elevated loaded partial nitritation MBBR system. NOB activity is limited at an elevated TAN SALR, likely due to thick biofilm embedding the NOB population and competition for dissolved oxygen (DO) with ammonia-oxidizing bacteria for TAN oxidation to nitrite within the biofilm structure, which ultimately limits the uptake of DO by NOB in the system. The third specific objective of this research characterizes the effects of distinct mixing and aeration strategies on the performance of the mainstream elevated loaded partial nitritation MBBR technology. This is addressed through a study investigating and comparing the kinetics, biofilm characteristics, and embedded biomass of three distinct mixing and aeration strategies employed to operate the mainstream elevated loaded partial nitritation MBBR system. The study compares the conventional mixing and aeration condition, continuous aeration with mechanical paddle & aeration, and recirculation pump & aeration utilized to optimize the partial nitritation MBBR system to achieve low DO effluent concentrations for optimal downstream anammox treatment. The results show that maintaining mixing and aeration in the elevated loaded partial nitritation MBBR system with recirculation pump & reduced aeration achieves lower effluent DO concentration and stable partial nitritation with appropriate NO₂⁻-N:NH₄⁺-N stoichiometry ratio of 1.09:1 for subsequent anammox treatment compared to operation with continuous aeration or mechanical paddle & aeration. The fourth specific objective of this research investigates the promising elevated loaded PN/A configured system for nitrogen removal under mainstream conditions. This is achieved through the operation of the elevated loaded partial nitritation MBBR system following the anammox unit as a combined two-stage system for nitrogen removal at mainstream municipal concentration. The elevated loaded partial nitritation MBBR system provides optimal NH₄⁺-N:NO₂⁻-N stoichiometric effluent ratio of 1:1.17, resulting in the successful operation of a downstream anammox unit with a total nitrogen removal rate at 0.22 ± 0.2 g N/m²/d and total nitrogen removal efficiency at 74.1 ± 0.7%. The average NO₂⁻-N to NH₄⁺-N molar removal ratio is 1.05 ± 0.1 from the anammox unit. Also, the anammox bacteria (AnAOB) gene copies are at 3.28 ± 0.7 × 10⁸, a value significantly higher than the AOB and NOB gene copies at 9.17 ± 1.1 × 10⁴ and 6.23 ± 1.0, respectively. This confirms that anammox activity is established and nitrogen removal is primarily through the anammox process. The results and overall system performance demonstrate that the combined two-stage mainstream elevated loaded partial nitritation/anammox MBBR system has shown promise and offers great insights for further advancement of the anammox process at mainstream municipal wastewaters. Finally, the economic evaluation and cost comparative analyses conducted show that compared to the conventional biological nitrification/denitrification process for nitrogen removal, the two-stage elevated loaded PN/A system offers a 57.6% savings on energy cost, 100% savings on chemical cost, and 68.7% savings on the cost of sludge disposal. Therefore, the two-stage elevated loaded PN/A system, in addition to high nitrogen removal efficiency, reduced footprint, and ease of operation, is also economically favorable and reduces the overall operational cost of wastewater treatment system by 61.6%, thus saving up to an average of 3.7 million CAD every year.

Kläder och textilier produceras och konsumeras i allt högre grad med stor påverkan på miljö, klimat och jordens resurser som följd. En attraktiv lösning på det är återvinning av kläder, vilket företaget re:newcell gör. Detta är en förstudie med syfte att undersöka vilka reningsmetoder re:newcell skulle kunna implementera för att förbättra sin vattenreningsprocess i framtiden. Tre ämnen vars halter i nuläget inte reduceras i reningen valdes ut till studien: nonylfenol, bromerade flamskyddsmedel och sulfat. En litteraturstudie kring dessa ämnen och möjliga reningsmetoder resulterade i att tre lämpliga reningsmetoder valdes ut till studien: ozonering, biologisk rening och jonbyte. En försöksplan utformades med målen att ta reda på (1) hur tidigare rapporterade ozondoser påverkade nonylfenolhalten i re:newcells vatten, (2) hur stor andel TOC (Total Organic Carbon) en MBBR (moving body bioreactor) kunde reducera och (3) ifall PBDE (bromerade flamskyddsmedel) och sulfat var möjliga att bryta ner med i en MBBR, (4) hur stort jonbytarfilter som skulle krävas i re:newcells process för att reducera sulfathalten samt (5) i vilken ordning reningsstegen bör implementeras i framtida reningsprocesser. Ozoneringsförsök utfördes på re:newcells laboratorium i Kristinehamn med totalt fem olika ozondoser. En biologisk MBBR utformades i laboratorium på Karlstad Universitet, där två olika uppehållstider testades för reducering av flamskyddsmedel, sulfat och TOC. Beräkningar på jonbytarfilter utfördes teoretiskt. En ozondos på 0,45 mgO3/mgCOD gav en reducering på ca 31 % och 0,75 mgO3/mgCOD gav 78 % reducering vid en nonylfenolhalt på 1100 mg/L. Resultaten från MBBR visar att bakterier trivs i re:newcells vatten och att de kunde reducera TOC med ca 50 %. Däremot kunde ingen reducering av sulfat uppmätas, vilket tyder på att ingen anaerob zon har uppstått. Halten av PBDE reducerades med ca 90 % med en uppehållstid på 45 h i MBBR, men om det beror på nedbrytning eller adsorption till slammet är inte fastställt. Resultaten från beräkningen på jonbytarfiltret visade att filtret behöver vara 5,7-15 m3 vid regenerering en gång per dygn i re:newcells nuvarande pilotskaliga process. Denna metod anses därmed inte vara en lämplig för sulfatreducering. Den framtida reningsprocessen föreslås starta med MBBR och efterföljande sedimentering, följt av kemfällning, sedimentering/flotation, sandfilter, ozonering och sist aktivkolfilter, men vidare studier rekommenderas rörande vilken ordning reningsstegen bör implementeras för optimal effekt. Vidare studier kring vilken ozondos som krävs och vilken uppehållstid som är optimal i MBBR föreslås också. / Clothes and textiles are increasingly produced and consumed causing a major impact on the environment, the climate and the earth's resources. One solution to the problem is to recycle clothes that are no longer used, which is what the company re:newcell does. This is a feasibility study aimed at investigating what purification methods re:newcell could implement to improve their water purification process in the future. Three substances not currently purified sufficiently were selected for the study: nonylphenol, brominated flame retardants and sulfate. A literature review on these substances and possible purification methods for them resulted in that the following methods were selected for the study: ozonation, biological purification and ion exchange. An experimental plan was developed with the aim of finding out (1) how previously reported ozone doses affected the nonylphenol content in re:newcell's water, (2) how much TOC an MBBR (moving body bioreactor) could reduce, (3) and whether the levels of brominated flame retardants and sulphate were possible to reduce in it,  (4) the required size of the ion exchange filter in re:newcells process to reduce sulfateand (5) the order in which the purification steps should be implemented in future purification processes. Ozonation experiments were carried out at re:newcell's laboratory in Kristinehamn with a total of five different ozone doses tested. A biological MBBR was designed in a laboratory at Karlstad University, where two different hydraulic retention times were tested for reducing flame retardants, sulfate and TOC. Calculations on ion exchange filters were performed theoretically. An ozone dose of 0.45 mgO3/mgCOD produced a reduction of about 31% and 0.75 mgO3/mgCOD produced a 78% reduction at a nonylphenol content of 1100 µg / L The results from MBBR showed that bacteria thrived in re:newcell´s water and that they can reduce TOC by about 50 %. However, reduction of sulfate could be measured, suggesting that no anaerobic zone has occured. The content of PBDE was reduced by about 90% with a hydraulic retention time of 45 hours in MBBR, but whether it is due to degradation or adsorbation to the sludge is not determined. The calculation regarding the ion exchange filter show that the filter needs to be 5,7-15 m3 when regenerated once a day in re:newcell's current pilot scale process this method is therefore not considered appropriate  for sulfate reduction for re:newcell. The future purification process is proposed to start with MBBR and subsequent sedimentation, followed by chemical precipitation, sedimentation / flotation, sand filter, ozonation and last activated carbon filter, but further studies are recommended regarding which order the purification steps should be implemented for optimal effect. Further studies on which ozone dose is required and which residence time is optimal in MBBR are also suggested.

The pulp and paper mill requires a lot of water during the production. Stora Enso Skoghall requires about 33m3 of water for 2204 lb produced carbon or paper. Before the wastewater returns to the recipient, the water must be purified from organic material. Organic material is naturally found in wood, and if a high level of organic material is added to the recipient it will lead to deficiency of oxygen in lakes. In order to avoid deficiencies of oxygen in lakes, the wastewater must go through a biological treatment, Stora Ensos biological treatment is consisting a long-term aerated active sludge, LAS, which is similar to a large pond. During a period, Stora Enso Skoghall constructed a pre-treatment step fort their LAS which is a Moving Bed Biofilm Reactor, MBBR. Stora Enso has been struggling to aerate the wastewater in the LAS, which has affected the production of the industry badly. The purpose of building the MBBR is to facilitate the LAS, in order to deliver full production. The biological treatment requires a lot of energy to operate the aeration system, about 50 percent of the total energy demand for a treatment plant goes to the biological treatment.   The purpose of this study is to examine the impact on the LAS if a MBBR-process is connected as a pre-treatment step. The aim of this study is to examine how the new biological treatment effects the energy demand considering aeration, compared to before the MBBR was connected. Wastewater samples were collected at Stora Enso Skoghall and taken to a laboratory at Karlstads University for analysis and tests. The wastewater samples have been studied regarding its content of TOC and how it affects the possibility of aerating the water. The a- and b-values, and as well the theoretical oxygen demand, were experimentally determined in cylinder aerators that contains 30 liters. The energy use for aeration of the MBBR and the LAS has been estimated. In order to compare if the new biological treatment effects the ability of purification in the existing LAS and if the energy demand changes, wastewater samples were taken before and after the MBBR was connected.   The result of this study shows that the MBBR has a positive impact on the existing LAS at Stora Enso Skoghall. There is a higher reduction of COD and the oxygen uptake capacity is better in the LAS, compared to before the MBBR was connected as a pre-treatment step. The total energy demand has increased with 58 percent, compared to the results before the MBBR were connected. The wastewater from the CTMP production contains high levels of TOC. It contains high levels of surfactants and high ionic strength, which usually worsen the ability of aeration. The flow into the MBBR contains mainly wastewater from the CTMP and the aeration tests showed that only 1-6 percent of the oxygen dissolved in it. As a result, the estimated energy demand remains very high. In conclusion, with the new biological treatment system the industry can now deliver full production of pulp and cardboard, while the LAS gets enough oxygen to effectively purify the wastewater. The MBBR relives the LAS through reduce the right amount of COD so the LAS can aerate the wastewater more easily. Moreover, the total energy demand of the biological treatment has increased when it comes to aerate the wastewater due to the fact that the production of pulp and cardboard has increased with 46 percent.

Discharging cheese production wastewater with high concentrations of organics and nutrients is detrimental to receiving aquatic systems, as the release of these deleterious substances cause oxygen depletion, and eutrophication respectively. On-site treatment of cheese production wastewater requires the removal of high concentrations of organics and nutrients with a small land footprint to meet regulations. There is therefore a critical need for compact, high-rate, cost-effective wastewater technologies such a as the moving bed biofilm reactor (MBBR). Although MBBR systems have been well established for carbon and nitrogen removal, to date only a limited number of studies have achieved enhanced biological phosphorous removal in sequencing batch moving bed biofilm reactor (SB-MBBR) systems, and only for municipal-strength wastewater. Operating SB-MBBR systems under sequencing batch mode enables the reactor operation to be well synced to the fluctuating influent concentrations and flow characteristics of cheese production wastewaters. Furthermore, cycling between anaerobic and aerobic conditions can be achieved in a single sequencing batch reactor, which can promote the proliferation of poly-phosphate accumulating organisms. The SB-MBBR is studied in this research for the removal of carbon, nitrogen, and phosphorous from cheese production wastewaters. Specifically, the effects of anaerobic staging time, aeration rate, enhanced aerobic operation, and adding a second reactor in series was studied by analyzing the kinetics, biofilm characteristics, and microbiome. Extending the anaerobic staging time was shown to achieve aerobic soluble chemical oxygen demand removal rates of 92.5±2.8 g·m⁻²d⁻¹, by selecting for a thinner biofilm with, with a lower biofilm dry-density and a more rough biofilm surface, and therefore likely a biofilm with an enhanced mass transport. A significant shift in the microbiome was observed with longer anaerobic staging times and lower aeration, whereby possible putative poly-phosphate accumulating organisms including Brachymonas, and Dechloromonas were selected for in greater relative abundances compared to anaerobic bacteria. The total phosphorous removal in the possibly resulted from enhanced biological phosphorous removal, supported by the high abundance of putative poly-phosphate accumulating organisms (43.1±8.4%), which dominated the biofilms in the SB-MBBRs with 120 and 168 minute anaerobic staging times. Finally, total ammonia nitrogen oxidation was achieved through partial nitritation with a two reactor in series configuration with a removal rate of 1.07±0.05 g-N·m⁻²d⁻¹. Two SB-MBBRs operated in series was shown to be the superior strategy for achieving TAN compared to a single SB-MBBR with extended aerobic operation. By operating two SB-MBBRs in series, competition between autotrophic nitrifiers and heterotrophs is averted, and AOB proliferate in the biofilm, achieving TAN oxidation. Since TAN oxidation is likely achieved through partial nitrification, the SB-MBBR technology may be incorporated in a deammonification treatment train. The overall study presents novel information for the SB-MBBR design and operation, along with biofilm and microbiome fundamental findings that will guide future pilot- and full-scale applications of the SB-MBBR to treat cheese production wastewater.