Indicator organisms like coliforms, E. coli and enterococci are normally associated with the intestinal tract of warm-blooded animals, and can thus be used for indicating fecal contamination of water. This study investigated the removal efficiency of indicator organisms in a free water surface constructed wetland used for additional treatment of municipal wastewater. The species composition of enterococci and the prevalence of the tetracycline resistance gene tetM were also investigated. Samplings were done at five different sites: at the inlet, within and at the outlet of the wetland, as well as upstream and downstream of the wetland outlet into the adjoining river. A total of 86 enterococci isolates were characterized as E. faecalis, E. faecium or other Enterococcus spp., and the two former were also screened for the tetM gene. The investigated wetland showed a high removal rate of indicator organisms, with a removal of approximately 98%. E. faecium was identified as the predominant species in the wetland at a mean of 55.8%. In comparison, only 9.3% were E. faecalis, while other Enterococcus spp. were found to comprise 34.9%. Of the 56 isolates identified as E. feacalis or E. faecium 10.7% were positive for the tetM gene. The high removal of bacteria shown by this investigation provides further evidence of the benefits of constructed wetlands on wastewater treatment. It also offers a first indication of the Enterococcus spp. composition in Ekeby wetland, Eskilstuna, Sweden, and shows that the prevalence of the tetM gene is relatively low at this point in time.

Bacterial antibiotic resistance is an increasing global health problem, leaving few therapeutic options available for the treatment of pathogenic infections. The development of new antibiotics has been slow since their discovery more than 8 decades, therefore, monitoring the extent and distribution of antibiotic resistance is of great importance. The aim of this study was to determine the presence of antibiotic resistance genes in sludge samples obtained from three wastewater treatment plants (WWTPs) in Sweden. Samples were collected and analyzed for the presence of nalidixic acid (NA), chloramphenicol (CHL), and tetracycline (TC) resistance genes using polymerase chain reaction (PCR). The DNA extracted from Eskilstuna and MälarEnergi sludge showed the presence of NA and TC resistance genes, whereas Örebro sludge was found to have resistance for TC antibiotic genes. To validate the results, PCR detection for resistance genes was performed on Escherichia coli isolates from the sludge samples. Antibiotic susceptibility testing was used to confirm the genetic analysis for antibiotic resistance genes detection in these E. coli. The PCR results for TC resistance genes correlated between sludge PCR analysis and bacterial isolates for all 3 WWTPs. Based on the results obtained from the genotypic analysis of sludge and E coli, incomplete compatibility in regards to NA, and CHL were observed. However on the basis of antibiotic susceptibility testing, E coli isolates from MälarEnergi sludge samples unveiled the majority presence for antibiotic resistance genes. The results suggest that extra monitoring for the wastewater treatment facilities are vital to minimize the rising incidence of antibiotic resistant bacteria.

The modernized world is over-consuming low-cost energy sources that strongly contributes to environmental stress. As a consequence, the interest for environmentally friendly alternatives has increased immensely. One such alternative is utilizing the diazotrophic nature of the heterocystous filamentous cyanobacteria Nostoc sp. as feedstock for biodiesel and hydrogen production using pulp and paper wastewater – a phosphorous and nitrogen deficient medium. In this work, biodiesel and hydrogen production was studied with respect to three main aspects: biodiesel quality properties, lipid content and hydrogen production coupled with a preliminary study investigating the luminous effects on the biomass and biodiesel quality properties when exposed to low (50 μEm-2s-1), medium (150 μEm-2s-1) and high light (300 μEm-2s- 1). The preliminary study showed that an increase of light intensity was associated with parabolic results for biomass following the 10-day cultivation period, with the medium light intensity showing an average dried weight of at the most 203% greater than the two other light intensities. When analysing the FAME- composition, similar results were demonstrated for the fatty acid constituents preferred for biofuel applications, C18:1 and C18:2 fatty acids, where the low, medium and high light showed an accumulative 34.65, 43.1 and 31.6 dwt % respectively. The strain could be of interest as feedstock for biodiesel when cultivated in pulp and paper wastewater, due to the positive results pertaining to the lipid content and biodiesel quality properties. Following the 10-day cultivation period the lipid content obtained was 35.9 dwt %. The biodiesel quality properties were tested to assess the strains suitability for biodiesel and were tested to ensure its accordance to the standards on commercial biodiesel quality; European Standard for Biodiesel as heating oil (EN 14213) and European Biodiesel Standard (EN 14214). The critical parameters tested were the regulated (iodine value, cetane number, density, viscosity, pour point, cold filter plugging point, oxidative stability) and unregulated (FAME-composition) fuel properties. Results obtained showed values within the regulated values set by the different standards. However, due to a high saturated fatty acid content, the strain showed inadequate low temperature flow properties (cloud point, pour point and the cold filter plugging point). This study shows that this strain has a low potential for hydrogen production, with a hydrogen production of 0.13 nmol/mg dry wt/h following the 10-day cultivation period. This low hydrogen production could be attributed to the among other things the current growth phase of the cyanobacteria. Chemical analyses were conducted for revealing the total nitrogen, total phosphorus and chemical oxygen demand (COD) content. Following the 10-day cultivation period, the samples showed a 22% decrease in phosphorous concentration, 11% decrease in COD concentration and 51% increase of nitrogen concentration. The probable causes for this increase is the Nostoc’s diazotrophic nature and the ammonium excretion nitrogen fixation entails, as well as the nitrogen release following the final algal growth phase – the death phase. In conclusion, the results showed great potential, however, further studies are recommended investigating the changes that occurs during cultivation period to further assess the strains potential as well as assessing the continuity of the results with a greater initial cellular concentration. Nonetheless, due to the positive results obtained regarding the nutrient uptake, biodiesel and hydrogen production, this study shows potential for further optimization for the use of Nostoc grown in pulp and paper wastewater for wastewater treatment, biodiesel and/or hydrogen production.

This master thesis is about mathematical modelling of the anammox process with a moving bed biofilm reactor (MBBR) for a reject water application. Specifically, the aim of my research was to find out whether the model proposed by Erik Lindblom in (Lindblom et al. 2016) is a good model for this purpose and worth continuous research and optimization. The code for the model, implemented in Matlab/Simulink, was given; although not initially functioning in the given condition. Some modifications needed to be done to make it function properly. In order to confirm that the code was working and used in a correct way some results in (Lindblom et al. 2016) were reproduced. Before starting the evaluation of the model, some much-needed optimizations of the code were done, substantially reducing the run time. A sensitivity analysis was done, and the five most sensitive parameters were picked out to be used in the calibration. The calibration improved the total fit of the model to the available measurements, although one of the model outputs could not be calibrated satisfactorily. In short, I found that although there are still problems left to solve before the model can be stated to accurately model the anammox process with MBBR, it appears promising. Most importantly, more measurement data are needed in order to make a proper validation and to do a better calibration. / CONAN

The biological treatment of metalworking fluids (MWFs) is a cost effective alternative to conventional waste disposal processes. While research has proven that this process is capable of treating large volumes of wastes with high organic concentrations, there are uncertainties about the mechanisms by which the treatment occurs, and there are limitations that must be overcome. There is a need to understand the importance of the mechanisms by which carbon (and hence COD) is removed from the wastewater. This will allow for waste practitioners to make better decisions for optimizing the process, and for disposing of waste (i.e sludge) that is generated. The biological treatment process is also susceptible to biocides present within formulations. These compounds either need to be removed before the treatment process, or the bioreactors need to be made more resistant to them to ensure that their presence does not hinder the reactor functioning. This study aims to answer the uncertainties about the carbon removal mechanisms involved in the treatment of oil-containing MWFs. In the first experimental chapter, it is shown that the predominant mechanism of carbon removal is oil/water separation induced by emulsifier degradation, and hence the bioprocess treatment rate is significantly affected by the biodegradability of surfactants and by the presence of cations found naturally in the water that used to prepare the emulsions. The study then provides insights into the potential that coagulation and coalescence has for removing inhibitory components commonly found in MWFs. Coagulation and coalescence is shown to effectively remove biocides with low aqueous solubility (iodopropynyl butylcarbamate) and those that partition themselves into the oil phase (o-phenyl phenate and its sodium salt). Finally, to improve the resistance of reactors to inhibitory compounds, factors influencing the development of fixed-film reactors are investigated. A micro-cosmic system is used to study the both physico-chemical effects and nutritional factors on the development of biofilm reactors. It is shown that biofilm yields can be controlled through pH adjustment, and that these yields are maximized with phosphate stimulation and ammonium limitation. It is then shown that fixed-film reactors are able to treat metalworking fluids even under conditions deemed to be inhibitory. In summary, this project provides insights into further understanding and enhancing the biological treatment of MWFs.

This research evaluates two different Biological Nitrogen Removal (BNR) systems for enhanced nitrogen removal in decentralized wastewater treatment. The first study evaluated the performance of Hybrid Adsorption and Biological Treatment Systems (HABiTS) at the pilot scale with and without stage 1 effluent recirculation. HABiTS is a system developed at the bench scale in our laboratory and was designed for enhanced BNR under transient loading conditions. It consists of two stages; an ion exchange (IX) onto clinoptilolite media coupled with biological nitrification in the aerobic nitrification stage 1 and a Tire-Sulfur Adsorption Denitrification (T-SHAD) system in the anoxic denitrification stage 2. The T-SHAD process incorporates NO3- adsorption onto tire chips and Sulfur Oxidizing Denitrification (SOD) using elemental sulfur as the electron donor for NO3- reduction. Previous bench scale studies evaluated HABiTS performance under transient loadings and found significantly higher removal of nitrogen with the incorporation of adsorptive media in stage 1 and 2 compared with controls (80% compared to 73%) under transient loading conditions. In this study, we hypothesize that a HABiTS system with effluent recirculation in nitrification stage 1 may enhance nitrogen removal performance compared to that without recirculation. The following were the expected advantages of Stage 1 effluent recirculation for enhanced nitrogen removal: 1) Pre-denitrification driven by the mixture of nitrified effluent from stage 1 with high concentrations of biochemical oxygen demand (BOD) septic tank effluent. 2) Moisture maintenance in stage 1 for enhanced biofilm growth. 3) Increased mass transfer of substrates to the biofilm in stage 1. 4) Decreased ratio of BOD to Total Kjeldahl Nitrogen (TKN) in the influent of stage 1. Two side-by-side systems were run with the same media composition and fed by the same septic tank. One had a nitrification stage 1 effluent recirculation component (R-system), which operated at a 7:1 stage 1 effluent recirculation ratio for the first 49 days of the study and at 3:1 beginning on day 50 and one was operated under forward flow only conditions (FF-system). The R system removed a higher percentage of TIN (35.4%) in nitrification stage 1 compared to FF (28.8%) and had an overall TIN removal efficiency of 88.8% compared to 54.6% in FF system. As complete denitrification was observed in stage 2 throughout the study, overall removal was dependent on nitrification efficiency, and R-1 had a significantly higher NH4+ removal (87%) compared to FF-1 (70%). Alkalinity concentrations remained constant from stage 1 to stage 2, indicating that some heterotrophic denitrification was occurring along with SOD, as high amounts of sCOD leached from the tire chips in the beginning of the study, reaching sCOD concentrations of 120-160 mg L-1 then decreasing after day 10 of operation of stage 2. Sulfate concentrations from stage 2 for each side were low until the last 10 days of the study, with an average of 16.43 ± 11.36 mg L-1 SO42--S from R-2 and an average of 16.80 ± 7.98 SO42--S for FF-2 for the duration of the study, however at the end of the study when forward flow rates increased, SO42--S concentrations increased to 32 mg L-1 for R-2 and 40 mg L-1 for FF-2. Similar performance was observed in the FF system as the bench scale reactor tests. The second part of the research focused on the findings from a study of a Particulate Pyrite Autotrophic Denitrification (PPAD) process that uses pyrite as the electron donor and nitrate as the terminal electron acceptor in upflow packed bed bioreactors. The advantages of using pyrite as an electron donor for denitrification include less sulfate production and lower alkalinity requirements compared with SOD. The low alkalinity consumption of the PPAD process led to comparison of PPAD performance with and without oyster shell addition. Two columns were operated side-by-side, one packed with pyrite and sand only (P+S), while another one was packed with pyrite, sand and oyster shell (P+S+OS). Sand was used as a nonreactive biofilm carrier in the columns. My contribution to this research was to carry out Scanning Electron Microscopy-Energy-Dispersive X-Ray Spectroscopy (SEM-EDS) analysis to support the hypothesis that oyster shell contributes to nitrogen removal because it has a high capacity for biofilm attachment. SEM analysis showed that oyster shell has a rough surface, supported by its high specific surface area, and that there was more biofilm attached to oyster shell than pyrite or sand in the influent to the column. EDS results showed a decrease in atomic percentages for pyrite sulfur in the effluent of both columns (59.91% ± 0.10% to 53.94% ± 0.37% in P+S+OS column and to 57.61% ± 4.21% in P+S column). This finding indicated that sulfur was oxidized more than iron and/or the accumulation of iron species on the pyrite surface and supports the coupling of NO3- reduction with pyrite oxidation.

Traditional wastewater treatment is known not to be specifically designed to eliminate the new generation of chemical residues that ends up in the sewage system. Polluted wastewatereffluent therefore reaches the aquatic environment possibly causing adverse effects in aquatic wildlife. The effects of effluent water from five Swedish sewage treatment plants sampled on 6 occasions 2017, were studied in developing zebrafish (Danio rerio). The study included morphological, physiological and behavioural endpoints. Overall there were few effectswhere deviations from control animals could be seen in the exposed zebrafish. The overall outcome of this assessment was that the wastewater effluent had no consistent effects on the early development of zebrafish. The consequences of continuous low-level exposure duringthe whole life-cycle of wild fish are presently unknown and further studies are needed to evaluate potential risks.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the industrialization, the demographic growth and the consumption patterns of society there is an increase in the generation of solid waste, among which include polymeric waste. Thereby, the recycling emerges as a viable alternative, but for it to be effective is very important to carry out the cleaning of the waste, as well as the treatment of wastewater generated in the process. Thus, the main objective of this study was performed quantification, characterization and washing of polymer waste and treating the wastewater generated in the process. For the quantification of different polymeric waste was carried out a data collection in the Association of Selectors of Recyclable Materials (ASMAR). Where, also were collected the packages of HDPE, LDPE, PP, which were characterized by their degree of contamination and were subsequently used in the washing process. The washing process was carried out in three phases (pre-wash, washing and rinse), and using different cleaning products. Regarding the treatment of the effluent was adopted a physical-chemical process via the coagulation / flocculation, sedimentation, followed by filtration. The following coagulants were used: chitosan powder, chitosan diluted in acetic acid, tannin SG, tannin SL and aluminum sulfate. The results from the quantitation of different polymeric residues collected by ASRM demonstrated that the most representative resins in 2014 were the LDPE, with 33.87% and 21.74% with HDPE. Regarding the characterization of polymeric waste depending on their level of contaminants was possible to verify that packages of PP and HDPE, even though they come from selective collection still contained a high level of contaminants, unlike LDPE packaging. As the washing process, it was possible to ascertain that the three stages developed, consisting of an efficient sequence for obtaining clean polymeric residues and suitable for recycling. Furthermore, the combination of sulfonic acid with lauryl and sodium hydroxide showed be more efficient to the other conditions tested in the washing step. Regarding the treatment of the wastewater, the results indicated that the use of aluminum sulphate coagulating was the most efficient in the removal of turbidity. Also was noted the importance of completing the process of coagulation / flocculation before the filtration. From the results obtained in the characterization process of the raw and treated wastewater it was possible to verify that the chosen treatment is effective and appropriate, once the values removed for most of the analyzed parameters were higher than 90%, including turbidity, suspended solids, fixed and volatile amounted to nearly 100% removal. Therefore, the washing process applied was efficient for obtaining clean polymeric materials and favorable to recycling and the method employed for treatment of wastewater also played a great role, since it allows the obtention of a treated wastewater with appropriate quality standards, which gives safety and reliability for its reuse in the washing process of polymeric residues. / Com a industrialização, o crescimento demográfico e os padrões de consumo da sociedade há o aumento da geração de resíduos sólidos, entre os quais destacam-se os resíduos poliméricos. Assim, a reciclagem surge como uma alternativa viável, porém para que esta seja efetiva é de suma importância a realização da lavagem desses resíduos, assim como, do tratamento do efluente gerado nesse processo. Diante disso, o principal objetivo deste estudo foi realizar a quantificação, a caracterização e lavagem dos resíduos poliméricos, bem como, tratar o efluente gerado no processo. Para a quantificação dos diferentes resíduos poliméricos foi realizada uma coleta de dados na Associação de Selecionadores de Materiais Recicláveis (ASMAR). Onde, também foram coletadas as embalagens de PEAD, PEBD e PP, que foram caracterizadas quanto ao seu grau de contaminantes e posteriormente foram utilizadas no processo de lavagem. O processo de lavagem foi desenvolvido em três etapas (pré-lavagem, lavagem e enxague), sendo utilizados diferentes produtos de limpeza. Quanto ao tratamento do efluente foi adotado um processo físico-químico, via coagulação/floculação, sedimentação, seguida ainda por filtração. Os seguintes coagulantes foram utilizados: quitosana em pó, quitosana diluída em ácido acético, tanino SG, tanino SL e sulfato de alumínio. Os resultados obtidos a partir da quantificação dos diferentes resíduos poliméricos coletados pela ASMAR demonstraram que as resinas mais representativas no ano de 2014 foram a de PEBD, com 33,87% e a de PEAD com 21,74%. Referente à caracterização dos resíduos poliméricos em função do seu grau de contaminantes foi possível verificar que as embalagens de PP e PEAD, apesar de serem provenientes de coleta seletiva ainda continham um elevado grau de contaminantes, diferentemente das embalagens de PEBD. Quanto ao processo de lavagem, foi possível averiguar que as três etapas desenvolvidas, consistem em uma sequência eficiente para obtenção de resíduos poliméricos limpos e próprios para posterior reciclagem. Além disso, a combinação de ácido sulfônico com lauril e hidróxido de sódio se mostrou mais eficiente que as demais condições testadas na etapa de lavagem. Quanto ao tratamento do efluente, os resultados indicaram que o uso do coagulante a base de sulfato de alumínio foi o mais eficiente na remoção da turbidez. Também se observou a importância da realização do processo de coagulação/floculação anteriormente à filtração. A partir dos resultados obtidos no processo de caracterização dos efluentes bruto e tratado foi possível verificar que o tratamento adotado é eficiente e adequado, uma vez que os valores de remoção para a maior parte dos parâmetros analisados foram superiores a 90%, inclusive a turbidez, os sólidos suspensos, fixos e voláteis chegaram a quase 100% de remoção. Portanto, o processo de lavagem adotado foi eficiente para obtenção de materiais poliméricos limpos e propícios à reciclagem e o método empregue para o tratamento do efluente também desempenhou uma excelente função, visto que possibilitou a obtenção de um efluente tratado com padrões de qualidade adequados, o que lhe confere segurança e confiabilidade para o seu reúso no processo de lavagem dos resíduos poliméricos.

The sustainability of water resources is an international and national concern. With increased human activity, water distribution on a global, regional, and local scale has been negatively impacted. Managing water resources also includes managing wastewater. A promising solution to the issues of water scarcity and distribution in the environment is the reuse of wastewater. Wastewater is produced from various sources (domestic, industrial, and commercial); however, if this water is able to be reused closer to the source of generation it could positively impact water distribution. In the United States, approximately 25% of domestic wastewater is treated in onsite wastewater treatment systems OWTS (mainly septic tanks and drainfields). However, septic systems are not efficient at removing nitrogen and pathogens, making them a risk to public health and the environment. In recent years, advanced onsite wastewater treatment systems have been developed to reduce contaminants into the environment. These systems are effective at removing contaminants but often require many mechanical parts and have high energy requirements. These additional components require homeowners to perform more maintenance on advanced OWTS than conventional systems or pay for maintenance to be performed. Passive Nitrogen Reduction Systems (PNRS) are being developed that provide high levels of nutrient removal while keeping maintenance requirements and costs low for the homeowner. (PNRS) use two-stage packed bed bioreactors to remove nitrogen from wastewater via nitrification (Stage I) and denitrification (Stage II). Our laboratory has developed a two-stage bench scale PNRS that uses ion exchange (IX) materials, clinoptilolite and scrap tire chips, to enhance the removal of nitrogen from wastewater by buffering transient loads to the biological processes. Pathogens can be present in domestic wastewater and if untreated can be released to groundwater and open water bodies endangering the health of the public. PNRS have the potential to reduce pathogenic microorganism released into the environment, however; the reduction of pathogens in PNRS that include IX media had not previously been studied. In this research, E. coli was used as a fecal indicator bacteria (FIB) because of its simplicity and national and worldwide acceptance. In our study, the performance of a PNRS with and without IX media was evaluated. Hourly studies were performed to determine the removal efficiency of E. coli from the system under varying hydraulic loading rates. Biofilm detachment experiments were conducted to measure E. coli adsorption and growth patterns within the column reactors. Batch adsorption experiments were completed to determine the effect of different types of media with and without IX material on E. coli growth over extended time periods. E. coli enumeration data from the hourly experiments demonstrated that there was a 0.84 log reduction of E. coli throughout the PNRS from the septic tank effluent to the final effluent released from the system. The evening and afternoon periods showed a higher reduction of E. coli compared with the morning period. Removal efficiencies were greater in the first stage of treatment (nitrification) as compared to the second stage treatment (denitrification). However, these variances did not result in significant differences in overall E. coli removal efficiency. Adsorbed E. coli were evenly distributed in the column containing IX media, while a decrease in adsorbed E. coli with depth was observed in the column without IX media. Batch adsorption studies revealed that when E. coli are present in wastewater solution with media, E. coli are initially adsorbed but can grow in the system after 6-12 hours. This growth indicates that other FIB should also be used to determine the fate of pathogens in PNRS. Based on all E. coli enumeration experiments, the PNRS developed reduce E. coli by almost 85%; however, this reduction is not adequate to meet onsite water reclamation regulations. Further studies are needed to develop tertiary treatment for pathogen reduction and wastewater reuse.

Změny kvality vody v malých tocích, vyvolané vybudováním čistírny odpadních vod, představují doposud málo studované a přitom velmi aktuální téma současné hydrologie. Tato studie se zabývá popsáním těchto změn a faktorů, které je ovlivňují. Pro účely výzkumu bylo vybráno pět malých, zemědělsky využívaných povodí prvního řádu (čtyři povodí průměrně 6 km2 , jedno 16 km2 ). V každém zájmovém území byla vždy jedna vesnice od 640 do 2 500 obyvatel. Během 7 - 16 let trvajícího měsíčního monitoringu základních indikátorů kvality vody (O2, BSK5, CHSKCr, TOC, konduktivita, N-NH4, N-NO2, N-NO3, PC, P-PO4) byla zachycena stavba čistíren v obcích. Spolu s daty o účinnosti čistíren byly vyhodnoceny změny kvality vody v toku. Identifikované typy změn ukazují na problematické aspekty vývoje kvality vody v malých povodích. Kromě očekávaného rychlého a razantního snížení hodnot zátěže po výstavbě čistírny odpadních vod se vyskytují i odlišné projevy změn - pouze mírné snížení zátěže, stagnace, dokonce i zvýšení koncentrací sledovaných indikátorů. Mezi další typické změny patří navýšení hodnot 1-2 roky před uvedením čistírny do provozu a opožděná nitrifikace v toku způsobená nevhodným provozem čistírny. Mezi nejdůležitější faktory ovlivňující změny patří provoz čistírny, velikost průtoku recipientu, zemědělské...