Les émissions de méthane (CH[indice inférieur 4]), gaz à effet de serre provoquant le réchauffement climatique doivent être contrôlées. Les biofiltres peuvent être utilisés pour atteindre cet objectif. Les émissions de CH[indice inférieur 4] issues des industries agroalimentaires ou du traitement des eaux peuvent être accompagnées de vapeurs d’alcool. La présence simultanée de CH[indice inférieur 4], polluant à limitation par transfert de masse et d’alcool, polluant à limitation cinétique dans un mélange gazeux peut induire des limitations dans le biofiltre. L’objectif principal de cette recherche est l’évaluation des limitations dans un biofiltre traitant le CH[indice inférieur 4] en présence ou en absence de vapeur d’alcool en régime permanent ou transitoire. Dans un premier temps, une revue de littérature s’est penchée sur les limitations basées sur le transfert de masse et la cinétique lors de l’enlèvement de polluants organiques dans un biofiltre. Par la suite, l’élimination du CH[indice inférieur 4] a été effectuée dans un biofiltre afin d’évaluer l’influence de la concentration à l’entrée du biofiltre sur la performance du biofiltre. Une capacité d’élimination maximale de 45 g [indice supérieur -3] h[indice supérieur -1] a été obtenue pour une charge à l’entrée de 87 g [indice supérieur -3] h[indice supérieur -1] du biofiltre. Le biofiltre a toléré des charges par à-coups de CH[indice inférieur 4] de même que des privations de CH[indice inférieur 4] et de nutriments. Par conséquent, les comportements en régimes permanent et transitoire d’élimination du CH[indice inférieur 4] en présence de vapeurs d’éthanol ont été étudiés dans un biofiltre ayant un lit filtrant inorganique sous des temps de résidence en fût vide (EBRT) de 6, 3 et 1.5 minutes. L’ajout d’éthanol sur 3 cycles a été effectué en fonction des 3 EBRTs. Un EBRT de 6 min correspondant à des charges à l’entrée de CH4 et d’éthanol de 4.5 et de 132 g [indice supérieur -3] h[indice supérieur -1] a induit des limitations mineures en ce qui a trait à l’enlèvement du CH[indice inférieur 4] et de l’éthanol. En régime transitoire, la période de récupération après les 3 cycles a nécessité 10 à 25 jours. Ce délai est relié à la présence d’éthanol dans le lixiviat. Dans un dernier temps, deux biofiltres ayant un garnissage de pierres et un garnissage mixte ont été comparés pour l’enlèvement du CH[indice inférieur 4] et de l’éthanol présents dans un mélange gazeux en régime permanent. La section inférieure du biofiltre a permis l’élimination totale de l’éthanol. De plus, lors de l’élimination totale de l’éthanol dans la section inférieure du biofiltre, la production de dioxyde de carbone (CO[indice inférieur 2]) dépasse 16 g[indice supérieur -3] h[indice supérieur -1], pour des charges à l’entrée de CH[indice inférieur 4] et d’éthanol de 11 et 13 g m[indice supérieur -3] h[indice supérieur -1] respectivement. Par ailleurs, une concentration en éthanol dans le lixiviat excédant 2500 géthanol m[indice supérieur -3] lixiviat a été obtenue. Les biofiltres ont démontré une flexibilité pour des charges par à-coups d’éthanol suivies de périodes de carence. Le principal inconvénient du biofiltre à lit de pierres par rapport au biofiltre mixte est une perte de charge élevée dans la section inférieure du biofiltre. Une période de carence est un excellent moyen de contrer la perte de charge. / Abstract : Since methane (CH[subscript 4]) is a greenhouse gas with hazardous effects for global warming, every effort should be made to reduced methane emissions. Biofilters are potential candidates for CH[subscript 4] removal. In food and beverage industries as well as ethanol refineries, the feed of the biofilter might be a mixture of CH[subscript 4] emissions from wastewater treatment unit and ethanol emissions from other units. The presence of CH[subscript 4] as a mass transfer limited and ethanol vapor as a kinetic limited pollutant in a mixture can produce several limitations in a biofilter. The main objective of this research is to evaluate the limitations of CH[subscript 4] biofiltration or in the presence of ethanol vapors under steady and transient state conditions. First, a literature review was provided on mass transfer and kinetic limited organic pollutants removal in biofilters and the related limitations. Subsequently, the CH[subscript 4] elimination was assessed in a biofilter in order to evaluate the effect of CH[subscript 4] inlet concentration in the range of 1000 to 13000 ppmv and a gas flow rate of 3 L min[supercript -1] on the biofilter performance. A maximum CH[subscript 4] elimination capacity (ECmax) of 45 g m[superscript -3] h[superscript -1] was obtained for a CH[subscript 4] inlet load (IL) of 87 g m[superscript -3] h[superscript -1]. The biofilter tolerated CH[subscript 4] shock loads as well as different types of CH[subscript 4] and nutrient starvations. Subsequently, the steady state and dynamic behaviors of CH[subscript 4] elimination in the presence of ethanol vapor was studied in an inorganic bed biofilter with empty bed residence times (EBRTs) of 6, 3 and 1.5 min. Ethanol addition was performed in 3 cycles based on the EBRTs. An EBRT of 6 min with corresponding CH[subscript 4] and ethanol inlet loads of 132 and 4.5 gpollutant m[superscript -3] h[superscript -1] respectively, caused the least limitations for the simultaneous removal of CH[subscript 4] and ethanol in the biofilter. According to dynamic behavior of the biofilter, the recovery time after the three cycles took from 10 to 25 days. The delayed biofilter recovery was linked to the presence of ethanol in the liquid effluent. Finally, a stone-based bed and a hybrid packing biofilter were compared for CH[subscript 4] and ethanol removal in a mixture under steady and transient state conditions. Ethanol was completely removed in the bottom sections of both biofilters. A large carbon dioxide (CO[subscript 2]) production rate exceeding 18 g m[superscript -3] h[superscript -1] occurred in the bottom sections for CH[subscript 4] and ethanol inlet loads of 11 and 13 g m[superscript -3] h[superscript -1] respectively. In addition, an ethanol concentration in the leachate exceeding 2500 gethanol m[superscript -3] leachate was obtained for both biofilters. The biofilters were flexible to an ethanol shock load followed by a starvation period. The main drawback of the stone based bed biofilter compared to the hybrid packing biofilter was an excess pressure drop in the bottom section. Starvation was found an effective strategy for reducing the pressure drop.

Ziel des Forschungsvorhabens war die Untersuchung von Möglichkeiten zur Intensivierung des mikrobiellen Abbaus des Geruchsstoffes Limonen unter Anwendung des Biofilter-verfahrens. Limonen stellt eine wesentliche Geruchskomponente bei der Intensivrotte der Bioabfallkompostierung dar und wird bisher in biologischen Abluftreinigungsanlagen oft nur unzureichend eliminiert. Dies führt zu einer Geruchsbelästigung des Personals und an-grenzender Wohngebiete. Die Verbesserung des hygienischen Status der Bioabfallkom-postierung und eine damit verbundene Steigerung ihrer gesellschaftlichen Akzeptanz erfordert daher ein Biofilterverfahren, das hinsichtlich des Limonenabbaus optimiert wird. Die Zuverlässigkeit von Biofiltern ist neben der Einstellung und Optimierung technischer Parameter auch von der biologischen Aktivität der im Strukturmaterial vorhandenen Mikro-organismenbiozönose abhängig. Viele zum mikrobiellen Abbau von Limonen befähigte Mikroorganismen sind zwar bekannt, doch handelt es sich bei den beschriebenen Abbau-mechanismen hauptsächlich um eine unvollständige Mineralisierung dieses Geruchsstoffes, die zu einer Anreicherung wiederum geruchsbelasteter Verbindungen führt. In dieser Arbeit wurden aus Umweltproben (Fichtenzapfen, -nadeln, -rinde; Waldboden; Schalen von Zitrusfrüchten; Bioabfall) vier bakterielle Mischpopulationen, die zur Ver-wertung von Limonen als einzige Energie- und Kohlenstoffquelle in der Lage sind und durch Wachstum auf diesem Substrat Biomasse bilden, in Schüttelkultur durch Metabolisierung von Limonen erfolgreich angereichert. Hinsichtlich ihrer Abbaukinetik für Limonen wiesen alle Batch-Kulturen eine starke Ähnlichkeit auf. Limonen wurde bei Anfangskonzentrationen von 536,5-889,5 mg/l nach 41-59 Stunden und mittleren Abbauraten von 48,1-51,0 mgl-1h-1 durch die Batch-Kulturen bis unter die Nachweisgrenze abgebaut. Nach erfolgter Degradation hinterließen die Proben einen neutralen Geruchseindruck. Eine Akkumulation von Metabo-liten oder Endprodukten konnte gaschromatographisch nicht nachgewiesen werden, was auf einen vollständigen Limonenabbau hindeutet. Substratkonzentrationen von > 4042 mg/l führten dagegen zu einer Inhibierung des Limonenabbaus und zu einer Stagnation des Wachstums bzw. zum Absterben der Bakterien in den Schüttelkulturen. Die mikrobiologische Grobcharakterisierung führte zur Isolierung von insgesamt 44 Reinkulturen, die einzeln auf Limonenabbau getestet wurden. Es gelang, sechs Bakterien-stämme zu isolieren, die in der Lage waren, Limonen ohne Akkumulation geruchsintensiver Intermediärverbindungen abzubauen. Mittels physiologisch-biochemischer sowie chemotaxo-nomischer Untersuchungen wurden die Bakterienisolate vorbehaltlich der Nachfolgeunter-suchungen der Gattung Pseudomonas zugeordnet. Die molekularbiologische Untersuchung mittels Proteingel-Elektrophorese ergab durch Vergleich einzelner Proteinbanden im Gesamt-zellproteinmuster der Isolate untereinander sowie mit Referenzstämmen die Identität der Isolate L1,2, L2,4 und L4,10. Isolat L2,6 wies deutliche Unterschiede im Proteinbandenprofil gegenüber den übrigen Isolaten und Referenzstämmen auf und wurde zum Vergleich der Isolate L3,6 und L3,8 zu einer 16S rRNA Teilsequenzanalyse herangezogen. Die vollständige Sequenzanalyse des Isolates L3,6 führte zu einer Identität von 97 % mit P. alcaligenes. Hier muß davon ausgegangen werden, daß es sich um eine neue bisher nicht beschriebene Spezies der Gattung Pseudomonas handelt. Isolat L2,6 zeigte in der Teilsequenzanalyse eine Über-einstimmung von 96 % mit P. mendocina, was für die Zugehörigkeit zu einem neuen Genus spricht. Der Vergleich der Teilsequenzen von Isolat L3,8 mit denen bekannter Spezies ergab eine Identität von 98 % mit Pseudomonas sp. B13. Die endgültige taxonomische Einordnung ist allerdings erst nach einem Sequenzvergleich durch DNA-DNA-Hybridisierungen mit bisher sequenzierten Spezies möglich. Die Limonen-abbauenden Bakterienstämme L2,6, L3,6 und L3,8 repräsentieren daher eindeutig verschiedene Spezies, die vorläufig dem Genus Pseudomonas zugeordnet wurden. Die Wirksamkeit der Strategie, den Limonenabbau im Biofilter durch den Einsatz einer leistungsfähigen Anreicherungskultur (Mix der vier Anreicherungskulturen) zu verbessern, wurde im Überführungsversuch in zwei parallel laufenden Modellbiofiltern gaschromato-graphisch untersucht. Aus dem inokulierten Biofilter wurden Wirkungsgrade bis zu 100 % nach 67 Tagen Laufzeit bei kaum geänderter Gesamtkeimzahl ermittelt. Auch nach Einstellung der Beimpfung betrug die Konzentrationsminderung für Limonen bis zu 89 %. Die Einlaufphase des inokulierten Biofilters konnte gegenüber einem konventionellen Biofilter um 46 Tage auf 35 Tage wirksam verkürzt werden. Eine mikrobiologische Charakterisierung der aus zwei Biofiltern isolierten Bakterienkulturen ergab nicht die erwar-teten Unterschiede hinsichtlich der mikrobiologischen Besiedelung des Filtermaterials beider Biofilter. Die Wirksamkeit der Inokulationskulturen im Biofilter ließ sich gaschroma-tographisch und olfaktometrisch anhand der eliminierten Limonen- oder Geruchsstoffkon-zentrationen eindeutig nachweisen. Die Unterschiede in den Abbauleistungen beider Biofilter widerspiegeln sich folglich nicht deutlich in den taxonomischen Merkmalen der Bakterien-biozönosen. Vielmehr ist die mit der Ausbildung spezieller Enzymsysteme verbundene physiologische Adaptation verschiedenster Bakterienspezies entscheidend, um eine Opti-mierung des mikrobiellen Abbaus von Limonen in Biofiltern zu erreichen. / This study aimed to investigate the opportunities for the intensification of the microbial biodegradation of the odourous compound limonene by biofiltration as a biological waste gas treatment technology. Limonen represents a considerable odourous component during the intensive composting process of organic waste materials and its elemination capacity by using the biological waste gas treatment facilities is so far insufficient. This results to a molestation of the staff of composting facilities and adjacent residential areas by odours. The improvement of the hygienic status of the composting process connected with the increase of their social acceptance requires a biofilter system which is to be optimized regarding the biodegradation of limonene. The reliability of such biological deodorizing methods depends on the adjustment and optimisation of technological parameter as well as on the biological activity of limonene metabolizing microorganism microbiota in the carrier material. Though a wide range of limonene utilizing microorganisms are known, but the described bioconversion processes deal with mainly incomplete mineralization of these odourous compound resulting again in an accumulation of further volatile odourous substances. In this study four mixed bacterial population were successfully obtained from organic material samples (fir cone, fir needles, fir bark; coniferous forest soil; parings from citrus fruits; bio waste) by a simple enrichment technique (semicontinuous fed-batch principle) using limonene as the sole carbon and energy source, accompanied by microbial growth and mineralization. In consideration of the degradation kinetics of limonene all of the batch-cultures have shown high similarity. By initial concentrations of 536,5-889,5 mg/l after 41-59 hours and middle degradation rates of 48,1-51,0 mgl-1h-1limonene was degraded by bacterial cultures under the detection limit and samples have had a more neutral odourous impression. An accumulation of metabolites and other final products couldn''t be detected by gaschromatography and this indicates a complete limonene bioconversion. Substrate concentrations greater than 4042 mg/l inhibited outright the biodegradation of this odourous compound as well as the growth of these bacteria and entailed finally to a toxic effect of the cells. Through microbial characterization 44 aerobic pure strains were isolated which were individually tested on limonene degradation. The isolation of six bacteria strains that were capable of limonene degradation without accumulation of other intermediate odourous compounds were achieved. Physiological, biochemical as well as chemotaxonomic characterization tests assigned the bacterial isolates subject to additional tests to the genus Pseudomonas. Phylogenetic investigation by using polyacrylamid gel electrophoresis revealed through comparison of the several protein bands in the whole protein pattern of the isolates with each other as well as with reference strains the identity of the isolates L1,2, L2,4 and L4,10. The isolate L2,6 showed clear differences in the protein pattern to the other isolates and reference strains and was taken with regard to a comparison of the isolates L3,6 and L3,8 to a partial 16S rRNA sequence analysis. The complete 16S rRNA analysis of the isolate L3,6 led to an identity of 97 % with P. alcaligenes. It has to be assumed here that the isolate is different from species previously described and represents a new species of the genus Pseudomonas. Partial 16S rRNA analysis of the isolate L2,6 showed a similarity of 96 % between the isolate and P. mendocina and indicate that this isolate is a member of a new genus. Partial 16S rRNA sequence comparison of the isolate L3,8 with corresponding fragments from reference strains listed in the data bank of nucleotides resulted in a similarity of 97 % with Pseudomonas sp. B13. For the definitive taxonomic arrangement of these isolates DNA-DNA hybridization with related species are required. The limonene degrading isolates represent clearly different species provisionaly allocated to the genus Pseudomonas. The effectiveness of the strategy to enhance the removal capacity for limonene with an efficient enrichment culture (mix of the four batch cultures) was tested in two parallel running biofilters (one inoculated and one biofilter without inoculation) and the degradation of limonene was followed. Chemical analysis was carried out by gas chromatography mass spectrometry. From the inoculated biofilter an efficiency up to 100 % was determined after 67 days running time and the total cell count altered scarcely. Also after a discontinue of the inoculation the elimination capacity for limonene amounted up to 89 %. The adaption time of the inoculated biofilter was successfully reduced from 81 to 35 days compared to a conventional biofilter. A microbial characterization of the isolated bacterial cultures from biofilters did''nt show the expected differences concerning the microbial composition of the carrier material of both biofilters. The activity of the enrichment cultures could be clearly proved by gaschromatography and olfactometry by means of the eliminated limonene concentrations. Therefore the differences of the elimination capacity of both biofilters didn''t clearly appear in the taxonomic characteristics of the bacterial microbiota. Decisive is rather the physiological adaption of various bacterial species by formation of special enzyme systems to achieve an optimisation of the microbial degradation of limonene in biofilters.

In the recent century, a process of urbanization has increased globally. Previously rural or natural land have been converted into impervious surfaces to make way for housing, industries, and roads. This anthropogenic process has resulted in an increased amount of surface runoff from precipitation, so-called stormwater. Stormwater can accumulate a range of pollutants when it flows over the impervious surfaces of our cities. These pollutants can have a negative impact on the lakes and streams that receive the stormwater from the urban environments. To reduce the environmental problems associated with the content of stormwater, various techniques have been developed for stormwater treatment, with the aim of reducing the pollutant load in the runoff before it enters the receiving waterbody. One such technology is stormwater biofiltration, also known as bioretention. Stormwater biofilters were developed in the USA in the early 90's and they utilize the natural water remediation properties of plant-soil systems. They are generally characterized by a vegetated submerged filter bed with an underlying drainage layer. They have shown to be an effective method for stormwater pollutant removal. The treatment processes take place both in the vegetation and in filter material. As th ematerial choices and design of the biofilters can vary, so can its treatment performance. Stormwater biofilters have grown in popularity in the last decades since their development and numerous studies have been conducted to evaluate the systems’ treatment efficiency. However, knowledge gaps still exist regarding their implementation in colder climates and the suitability of different configurations and materials. This study examines the removal performance of total and dissolved heavy metals (Cd (cadmium),Cu (copper), Pb (lead) and Zn (zinc)), phosphorus, nitrogen and total suspended solids (TSS) in three stormwater biofilters in a Swedish climate, located in central Malmö. The current biofilters are designed with different configurations of their filter media and are built with 1) sand-basedfilter material 2) sand-based filter material with a submerged zone and 3) filter media consisting of 50% sand-based material in combination with 50% pumice. The results showed that the treatment capacity of the biofilters with a filter media of only sand (biofilter S) and with sand as well as a submerged zone (biofilter S_SZ) was similar for all pollutants. The reduction of total levels of metals (> 85 %) and TSS (>90 %) was consistently high and similar to levels achieved in previous studies for both temperate and colder climates. The removal of dissolved metals was lower in comparison to the removal of the total metal fractions, but the dissolved fractions were still generally reduced in the effluent. A positive removal of total phosphorus and total nitrogen was overall displayed in the effluent from the two biofilters; however,leaching was shown for the dissolved fractions. For nitrogen (N) species, the concentrations in the runoff were generally below the detection limit for the analysis making it difficult to establish probable removal percentages. For the biofilter S_P, which contained a mix of sand and pumice, the removal capacity was lowerfor all parameters compared to the other designs. Overall, the pollutant removal performances are regarded to be satisfactory for biofilters S andS_SZ and their implementation suitable for the given site. However, further investigations should be performed during warmer seasons, especially regarding the removal of nutrients.

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Urban areas are affected by anthropogenic activities and produce pollutants that are transported to recipients and receiving waters during precipitation. Untreated stormwater runoff is a main driver of environmental degradation, and the interest in stormwater quality treatment has increased with the awareness of stormwater pollution. Several pollutants, including metals PAHs, PCBs, phthalates, and phenols, pose a hazard to aquatic life and are listed among the 45 priority substances in The European Water Framework Directive list (Directive 2013/39/EU). Stormwater bioretention technology is employed to efficiently remove pollutants during stormwater treatment in urban areas. However, the resulting accumulation of pollutants in bioretention facilities could ultimately create a pollutant depot. Hence, it is important to understand the occurrence, availability, and mobility of pollutants in bioretention facilities, as well as the processes that control their accumulation and mobility over time. The aim of the work in this licentiate thesis was to investigate the occurrence, accumulation, distribution, and concentration of organic micropollutants and metals inbioretention facilities after long-term stormwater treatment in urban areas of Ohio, Michigan, and Kentucky in November 2019. Samples were collected from 29 bioretention facilities, 20 of which were equipped with forebays. A total of 269 samples were analysed for metals commonly found in stormwater (Cr, Cu, Ni, Pb, and Zn), and a five-step sequential extraction method was used to assess the metal mobility in the filter material. Additionally, 116 samples from 12 sites were analysed for 38 organic micropollutants (OMPs), including 16 PAHs, 7 PCBs, 13 phthalates, and 2 alkylphenols. All studied metals were found in all samples, except for Cd, which was detected in 245 samples (91%). For the OMPs, 32 of 38 analytes were detected in at least one sample. PAHs and PCBs were the most frequently detected pollutants, and were found in 12 and 10 sites, respectively. The bioretention sites showed large variations in the concentrations of pollutants. The concentration of OMPs was highest in the upper 10 cm of the filter material and decreased with increasing depth, while a similar, but less obvious trend was observed for Cr, Cu, Pb, and Zn. A trend of decreasing concentration with increasing distance from the inlet was observed for OMPs but was less clear for the metals. Thefore bays, which contain sediment but no filter material, had the highest concentrations of OMPs. A strong correlation was observed between the pollutant concentrations and the ratio between the filter area and catchment area in a Principle Component Analysis. The accumulation and pathways of particle-bound OMPs and particle-bound metals showed similarities. These results will assist with improving the methods used for stormwater management. Importantly, regular replacement of the top filter layer and regular forebay maintenance may prevent pollutant accumulation and clogging, thereby extending the filters’ treatment function.

Methane (CH4) source of Greenhouse Gases should be considered; CH4 is formed by composting under anaerobic conditions. Using microbial Methane oxidation is a solution with low cost and effective. In this study, 27 bio-filters and 18 laboratory-scale bioreactors were used to investigate the potential for CH4 removal in biogas. The CH4, Dinitrogen monoxide (N2O) and Carbon dioxide (CO2) concentrations at the inlet and outlet of the air purifier were measured by gas chromatography. The results showed that the CH4 concentration decreased in experiments while the CO2 and N2O content increased in all experiments. An experiment was conducted with 1 kg of biofilter material with the input of 800 ppm CH4 contained in a 5-liter flask for 49 hours containing. The results also showed that the CH4 concentration decreased by 71% after 20 hours and N2O was formed in the reactor. / Mê-tan (CH4) là nguồn khí gây nên hiệu ứng nhà kính cần được quan tâm, khí CH4 được sinh ra trong quá trình ủ vi sinh trong điều kiện kị khí. Một giải pháp với chi phí thấp là sử dụng vi sinh vật oxy hóa khí CH4 cố định trên giá thể là vật liệu sử dụng trong thiết bị lọc sinh học. Trong nghiên cứu này, 27 thiết bị lọc sinh học trên thực tế và 19 bình lọc tại phòng thí nghiệm đã được sử dụng nhằm mục đích khảo sát khả năng loại bỏ CH4 có trong khí sinh học. Nồng độ khí CH4, N2O và CO2 ở đầu vào và đầu ra bể lọc khí được đo đạc bằng phương pháp sắc ký khí. Kết quả cho thấy nồng độ khí CH4 giảm sau khi qua hệ thống lọc sinh học ở một số bình, trong khi nồng độ khí CO2 và N2O lại tăng lên ở tất cả các bình. Khi khảo sát khả năng oxi hóa CH4 ở nồng độ 800 ppm của 1kg vật liệu thiết bị lọc sinh học chứa trong bình phản ứng thể tích 5L với thời gian 49 giờ. Kết quả cho thấy nồng nồng độ CH4 giảm 71% sau 20 giờ. Tuy nhiên, N2O đã được ghi nhận có hình thành trong bình phản ứng đó.

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