Dissertations / Theses on the topic 'Refractory nitrogen and COD'

Le traitement des boues générées dans les stations d’épuration représente un enjeu majeur d’optimisation globale énergétique et de flux de matières. Parmi les procédés émergents, les traitements thermiques de boues peuvent conduire à divers avantages : production de méthane plus élevée en digestion anaérobie, meilleure déshydratabilité en centrifugation ou hygiénisation des boues. Ils produisent cependant des composés bioréfractaires au travers des réactions de Maillard. Ces composés appelés mélanoïdines sont des polymères issus de processus de chimie combinatoire. Ils sont de poids moléculaires élevés, très insaturés, azotés et de structures très variées. Leur caractère bioréfractaire et soluble conduit à une absence de leur dégradation dans la filière eau de la station d’épuration et une augmentation significative de la DCO et du NTK en sortie.A partir de ces considérations, les questions auxquelles la thèse devait répondre sont les suivantes :- Comment quantifier et qualifier les composés réfractaires générés par les procédés thermiques ?- Comment dégrader ou mieux rendre biodégradables les composés réfractaires générés par les traitements thermiques ?Dans la première partie de la thèse, une méthode analytique a été développée pour caractériser les mélanoïdines. La méthode s’appuie sur une analyse par chromatographie à exclusion stérique (UPLC-SEC) avec détection par absorbance UV et fluorescence. Le couplage des résultats obtenus avec du traitement de données statistiques par analyse en composante principale et réseau de neurones mène à une approche innovante de la caractérisation de ces composés.Après validation, la méthode a montré sa capacité de différenciation des composés réfractaires entre eux et par rapport à des composés biodégradables pour des surnageants de boues de deux stations (110000 et 950000 EH) traitées thermiquement. Il a ainsi été montré que les boues biologiques produisent jusqu’à 2 fois plus de composés réfractaires que des boues primaires lors d’un traitement thermique. De plus, la structure des composés réfractaires formés dépend de la température et de la station d’origine des boues.Dans la deuxième partie de la thèse, le traitement et/ou l’amélioration de la biodégradabilité des composés réfractaires issus du traitement thermique par ozonation ou électro-oxydation ont été étudiés.L’étude d’ozonation a été menée au travers d’un plan d’expérience qui a permis de quantifier et caractériser l’impact du pH et des concentrations en DCO bioréfractaire, biodégradable et en N-NH4+ sur la transformation des molécules réfractaires. Les résultats ont montré que l’ozonation améliore nettement la biodégradabilité mais les performances observées sont influencées par la valeur du pH et la concentration en DCO réfractaire : la dose d’ozone nécessaire peut varier d’un facteur 2 à 3 en fonction des valeurs de ces paramètres. Enfin, la méthode UPLC-SEC développée permet d’identifier les structures chimiques et catégories de molécules conduisant à la prédiction de la biodégradabilité des échantillons en cours d’ozonation.L’électro-oxydation est une technologie encore peu déployée à échelle industrielle. Sur électrode en Diamant Dopé au Bore (DDB) dans un premier temps, le traitement de nos matrices par électro-oxydation montre qu’une minéralisation totale de la DCO et azote est possible. Par la suite d’autres essais ont été menés avec différents matériaux d’électrode et ont montré des résultats encourageants.Les deux technologies d’oxydation présentent donc des potentiels d’abattement de DCO et d’azote organique supérieurs à 70%, réduisant nettement les retours de composés réfractaires en tête de station d’épuration et permettant à celle-ci de respecter les normes en vigueurs.Dans une troisième partie de la thèse, une discussion analyse les avantages et inconvénients des technologies, montre des perspectives intéressantes à explorer pour approfondir les connaissances développées dans la thèse
The treatment of sludge produced by wastewater treatment plants (WWTP) represents a major challenge for the optimization of energy consumption and material flows. Among emerging processes, thermal treatments have many interests: increased methane production in anaerobic digestion, improved dewaterability by centrifugation and hygienization of sludges. However, they produce biorefractory organic compounds, also called melanoidins, through Maillard reactions. Those very diversified compounds are characterized by a high molecular weight, a polymeric and unsaturated structure, and a high nitrogen content. Their refractoriness prevents their biodegradation in common WWTP biological processes, leading to an increase of COD and TKN in the plant discharge.This thesis aimed to answer two main questions:- How to quantify and qualify biorefractory compounds formed by thermal processes?- How to degrade or to enhance the biodegradability of biorefractory compounds formed by thermal processes?First, an analytical method has been developed to characterize melanoidins, based on size exclusion liquid chromatography with UV and fluorescence detection (UPLC-SEC-UV-Fluo). Statistical treatment of the data by artificial neural network and principal component analysis led to an innovative characterization of melanoidins.Centrates of thermaly treated sludge from two WWTP (110,000 and 950,000p.e.) were studied. The method displayed a good ability to differentiate refractory compounds from each other and from biodegradable compounds.Our study exhibited that biological sludge produces twice as much refractory compounds than primary sludge. Moreover, the structure of refractory compound is linked to the process’ temperature and the sludge’s origin from, but it does not depend on the type of sludge thermally treated.Then, the degradation or biodegradability enhancement of refractory compounds by both ozonation and electro-oxidation was investigated.The ozonation was studied through an experimental plan to evaluate the impact of pH and concentrations of refractory COD, biodegradable COD and N-NH4+, on refractory molecules. Our results showed that ozonation can increase the biodegradability; its performances are influenced by pH and concentration of refractory COD. Optimal conditions can reduce the dose of ozone needed by two to three times. The UPLC-SEC-UV/Fluo method was then used to identify the chemical structures and the parameters predicting the biodegradability of refractory compounds during ozonation.The feasibility of electro-oxidation of refractory compounds was first assessed with a boron doped diamond anode. As a result, a complete mineralization was achieved for both organic nitrogen and COD. Therefore, active anodes were tested and highlighted a biodegradability enhancement when adding chlorine as electrolyte.Both technologies demonstrated up to 70% of refractory COD and organic nitrogen removal, decreasing substantially their recycling to the head of the plant.In the last part, the whole UPLC-SEC-UV/Fluo characterization method has been discussed in its potential and with respect to the literature. Finally, the benefits and possible drawbacks of each oxidation technology and their implementation at industrial scale were discussed

Nitrogen removal from wastewater is important for the revention of significant health and environmental impacts such as eutrophication. Nitrogen removal is achieved by the combined action of nitrification and denitrification. Nitrification is performed by autotrophic, slow growing microorganisms that require oxygen and are inhibited in the presence of denitrifiers when oxygen and COD are available due to competition for oxygen. Denitrification however, performed by relatively fast growing heterotrophic bacteria, is inhibited by oxygen and requires COD. This implies that nitrification and denitrification are mutually exclusive. The supply of oxygen to a fresh wastewater, high in ammonia and COD, causes waste of both oxygen and COD. Conservation of COD is therefore critical to efficient wastewater treatment. The approach investigated in this study to achieve complete nitrogen removal was to physically separate the nitrification and denitrification biomasses into separate bioreactors, supplying each with appropriate conditions for growth and activity. A storage driven denitrification sequencing batch biofilm reactor (SDDR) was established which exhibited a high level of COD storage (up to 80% of influent COD) as poly-B-hydroxybutyrate capable of removing >99% of nitrogen from wastewaters with a C/N ratio of 4.7 kg COD/kg N–NO3 –. The SDDR was combined in sequential operation with a nitrification reactor to achieve complete nitrogen removal. The multiple stage, multiple biomass reactor was operated in sequence, with Phase 1 - COD storage in the storage driven denitrification biofilm; Phase 2 - ammonia oxidation in the nitrification reactor; and Phase 3 - nitrate reduction using the stored COD in the storage driven denitrification reactor. The overall rate of nitrogen removal observed was up to 1.1 mmole NH3 L–1 h–1 and >99% of nitrogen could be removed from wastewaters with a low C/N ratio of 3.9 kg COD/kg N–NH3. The multiple stage, multiple biomass system was limited in overall nitrogen removal the reduction in pH caused by nitrification. A parallel nitrification-denitrificatio (PND) reactor was developed in response to the pH control issue. The PND reactor was operated with Phase 1 – COD storage in the storage driven denitrification biofilm and Phase 2 – simultaneous circulation of reactor liquor between the denitrification and nitrification biofilms to achieve complete nitrogen removal and transfer of protons. The PND reactor performed competitively with the multistage reactor (removal of >99% nitrogen from wastewaters with feed ratios of 3.4 kg COD/kg N–NH3) without the need for addition of buffering material to oderate the pH.

This research addresses refractory forms of nitrogen that, even with advanced biological nitrification-denitrification systems are not removed completely from domestic wastewater. TKN (Total Kjeldahl Nitrogen), ammonia plus organic nitrogen, is one of the forms to measure the levels of nitrogen present in effluent wastewaters. Ferrate, a strong oxidant, was used for the treatment of these nitrogen forms with the objective of producing nitrogen compounds that can be removed by subsequent biological processes. Bench-scale experiments were performed on effluent samples taken prior to chlorination from an Orlando, FL wastewater treatment facility, using a biological nutrient removal process. The samples were treated with doses of ferrate ranging from 1 to 50 mg/L as FeO4–2 under unbuffered conditions. TKN removal as high as 70% and COD removal greater than 55% was observed. The TSS production after ferrate treatment was in a range of 12 to 200 mg/L for doses between 10 and 50 mg/L FeO4-2. After an optimum dose of ferrate was determined, three bench-scale reactors were operated under anoxic conditions for 10 to 12 days, two as duplicates containing the treated effluent and one as a control with untreated sample. Two different doses of ferrate were used as optimum dose for these experiments, 10 and 25 mg/L as FeO4-2. The purpose of these reactors was to determine the potential for biological removal of remaining nitrogen after ferrate oxidation of refractory nitrogen. Treated and raw samples were analyzed for Total Kjeldahl Nitrogen (TKN) (filtered and unfiltered), chemical oxygen demand (COD) (filtered and unfiltered), total suspended solids (TSS), nitrate (NO3-N), nitrite (NO2-N), and heterotrophic plate count (HPC). As a result, more than 70% of the soluble TKN was removed by chemical and biological oxidation for a sample treated with a dose of 25 mg/L FeO4-2, and less than 50% when treated with 10 mg/L FeO4-2. For the control samples run parallel to the ferrate treated samples, a maximum of 48% of soluble TKN and a minimum of 12% was removed. A three-log increase was observed in heterotrophic bacteria numbers for both doses during the operation of the reactors. Sodium ferrate was found to be an effective oxidant that can enhance the biodegradability of recalcitrant TKN present in municipal wastewaters. As mentioned before this research was develop using batch reactor units at bench-scale, therefore it is recommended to follow the investigation of the biodegradability of recalcitrant TKN of a ferrate treated sample under continuous flow conditions so that results can be extrapolated to a full-scale treatment facility.
M.S.Env.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engineering

Onsite wastewater treatment systems in Sweden are getting old and many of them lack sufficient phosphorus, nitrogen and organic carbon reduction. Biochar is a material that has been suggested as an alternative to the common sand or soil used in onsite wastewater treatment systems. The objective of this study was to compare the phosphorus removal capacity between three different modified biochars and one untreated biochar in a batch adsorption and column filter experiment. The modifications included impregnation of ferric chloride (FeCl3), calcium oxide (CaO) and untreated biochar mixed with the commercial phosphorus removal product Polonite. To further study nitrogen removal a filter with one vertical unsaturated section followed by one saturated horizontal flow section was installed. The batch adsorption experiment showed that CaO impregnated biochar had the highest phosphorus adsorption, i.e. of 0.30 ± 0.03 mg/g in a 3.3 mg/L phosphorus solution. However, the maximum adsorption capacity was calculated to be higher for the FeCl3 impregnated biochar (3.21 ± 0.01 mg/g) than the other biochar types. The pseudo 2nd order kinetic model proved better fit than the pseudo 1st order model for all biochars which suggest that chemical adsorption was important. Phosphorus adsorption to the untreated and FeCl3 impregnated biochar fitted the Langmuir adsorption isotherm model best. This indicates that the adsorption can be modeled as a homogenous monolayer process. The CaO impregnated and Polonite mixed biochars fitted the Freundlich adsorption model best which is an indicative of heterogenic adsorption. CaO and FeCl3 impregnated biochars had the highest total phosphorus (Tot-P) reduction of 90 ± 8 % and 92 ± 4 % respectively. The Polonite mixed biochar had a Tot-P reduction of 65 ± 14 % and the untreated biochar had a reduction of 43 ± 24 %. However, the effluent of the CaO impregnated biochar filter acquired a red-brown tint and a precipitation that might be an indication of incomplete impregnation of the biochar. The FeCl3 effluent had a very low pH. This can be a problem if the material is to be used in full-scale treatment system together with biological treatment for nitrogen that require a higher pH. The nitrogen removal filter showed a total nitrogen removal of 62 ± 16 % which is high compared to conventional onsite wastewater treatment systems. Batch adsorption and filter experiment confirms impregnated biochar as a promising replacement or addition to onsite wastewater treatment systems for phosphorus removal. However the removal of organic carbon (as chemical oxygen demand COD) in the filters was lower than expected and further investigation of organic carbon removal needs to be studied to see if these four biochars are suitable in real onsite wastewater treatment systems.
Många av Sveriges små avloppssystem är gamla och saknar tillräcklig rening av fosfor, kväve och organiskt material. Följden är förorenat grundvatten samt övergödning i hav, sjöar och vattendrag. Lösningar för att förbättra fosfor- och kvävereningen finns på marknaden men många har visat brister i rening och robusthet. Biokol är ett material som har föreslagits som ersättare till jord eller sand i mark och infiltrationsbäddar. Denna studie syftade till att i skak- och kolonnfilterexperiment jämföra fosforreduktion mellan tre modifierade biokol och ett obehandlat biokol. Modifieringen av biokolet innebar impregnering med järnklorid (FeCl3), kalciumoxid (CaO) samt blandning med Polonite som är en kommersiell produkt för fosforrening. För att undersöka förbättring av kväverening installerades även ett filter med obehandlat biokol där en vertikal aerob modul kombinerades med en efterföljande horisontell anaerob modul. Skakstudien där biokolen skakades i 3.3 mg/L fosforlösning visade att adsorptionen var högst i det CaO-impregnerade biokolet, 0.3 ± 0.03 mg/g. Den maximala potentiella fosforadsorptionen beräknades dock vara högst för biokolet som impregnerats med FeCl3, 3.21 ± 0.01 mg/g. Skakförsöket visade också att fosforadsorptionen var främst kemisk då adsorptionen passade bättre med pseudo andra ordningens modell än pseudo första. Adsorption av fosfor på obehandlat biokol och FeCl3 impregnerat biokol modellerades bäst med Langmuir modellen, vilket tyder på en homogen adsorption. Det Polonite-blandade biokolet och CaO-impregnerade biokolet modellerades bäst med Freundlich modellen vilket är en indikation på en heterogen adsorptionsprocess. Biokol impregnerat med CaO och FeCl3 gav de högsta totalfosforreduktionerna på 90 ± 8 % respektive 92 ± 4 %. Biokolet som var blandat med Polonite hade en reduktion på 65 ± 14 % och det obehandlade biokolet 43 ± 24 %. Ett problem med filtratet från CaO-filtret var att det fick en rödbrun färg samt en fällning vilket kan ha berott på ofullständig pyrolysering och impregnering. Filtratet från det FeCl3 impregnerade biokolet hade mycket lågt pH vilket kan vara problematiskt om mikrobiologisk tillväxt i filtret för rening av kväve och organiskt material vill uppnås. Filtret för kväverening gav en total kvävereduktion på 62 ± 16 % vilket är högre än kommersiella system. Resultaten från skak och filterstudien visade på att impregnerade biokol kan ge en förbättrad fosforrening om de skulle användas i små avloppssystem. Rening av organiskt material, kemisk syreförbrukning (COD), var dock låg i alla filter och behöver studeras ytterligare för att avgöra om dessa biokol är lämpliga för småskalig avloppsvattenrening.

Despite a positive contribution to economic – social development, the growth of piggeries has caused heavily environmental pollution. Currently, treated wastewater of pig farms unfortunately does not meet the national discharge standards yet. This paper presents some research results on the removing COD, nitrogen and phosphorus in piggery wastewater after anaerobic (biogas) process at pilot scale by the combined system using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes. The experimental results showed that the wastewater loading rate of 47.35 l/m2.day with initial concentrations of 203.24 mg COD/l, 111.94 mgTN/l and 13.61 mgTP/l gave removal efficiency of 71.66 %, 79.26 % and 69.65 %, respectively. Thus, the removed quantity of total nitrogen (TN) and total phosphorus (TP) was of 4201.35 mg TN/m2.day và 448.76mg TP/m2.day. The obtained results indicated that the flow wetland system, using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes has a rather high COD, TN and TP removal efficiency with simple operation so that it could be feasible if applied for treating pig wastewater. However, the system should be functioned longer for taking data and for evaluating its stability.
Mặc dù có những đóng góp tích cực cho sự phát triển kinh tế - xã hội, việc phát triển chăn nuôi lợn đã gây ô nhiễm môi trường nghiêm trọng. Hiện nay, nước thải chăn nuôi lợn từ các cơ sở chăn nuôi sau xử lý vẫn chưa đáp ứng được các tiêu chuẩn thải của quốc gia và tiêu chuẩn ngành. Bài báo này trình bày kết quả nghiên cứu về khả năng loại bỏ COD, nitơ (N) và phôtpho (P) trong nước thải chăn nuôi lợn đã qua xử lý bằng hầm biogas của hệ thống phối hợp cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây ở qui mô pilot. Kết quả thực nghiệm ở tải lượng 47,35 l/m2.ngày, với COD, tổng nitơ (TN) và tổng phôtpho (TP) đầu vào trung bình là 203,24 mg/l, 111,94 mg/l và 13,61 mg/l, tương ứng, thì hiệu suất xử lý lần lượt là 71,66 %; 79,26 % và 69,65 %. Như vậy lượng TN và TP loại bỏ là 4201,35 mgN/m2.ngày và 448,76 mgP/m2.ngày. Kết quả nhận được cho thấy hệ thống sử dụng cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây có hiệu quả loại bỏ COD, TN và TP khá cao trong khi vận hành đơn giản nên có triển vọng áp dụng trong điều kiện thực tế để xử lý nước thải chăn nuôi lợn. Tuy nhiên để đánh giá tính ổn định, hệ thống cần được hoạt động với thời gian lâu dài hơn.

In Scotland, environmental regulation restricts commercial cod culture to the equivalent of 66 % of that granted for commercial Atlantic salmon (Salmo salar L.) farms. This calculation is based on estimations of nitrogen discharge from the difference in protein content between salmon and cod diets, with the higher levels of protein in cod diets suggesting a higher nitrogen discharge compared to that observed for salmon diets. In turn, this could potentially result in increased nitrogen enrichment of a marine ecosystem. The aims of this study (quantifying and modeling of nitrogenous wastes associated with the commercial culture of Atlantic cod (Gadus morhua L.) were achieved through a series of tank and cage investigations, each of which studied juvenile and adult Atlantic cod. The study provided data with respect to nitrogen excretion from juvenile and adult fish in both systems. This would allow the development of dispersion models and the calculation of nitrogen budgets for commercial cod culture, thus providing environmental regulators data independent of salmon models to create regulations that would be specifically applied to cod farming. The tank - based studies investigated three diet formulations produced by EWOS® Innovation in Norway, as a 4 mm pellet (juvenile study) and as a 7 mm pellet (adult study). The three iso -energetic diets varied primarily in protein content (40%, 50% and 60%). Two tank studies, one on juvenile and one on adult cod, investigated growth, condition and tissue composition, and the production of dissolved nitrogenous wastes over a 5 and 7 month period respectively. At the beginning of the acclimation period prior to the adult tank study commencing, the fish had a mean weight of approximately 1275 g. The difference in the final weight promoted by each diet was not significant (with an approximate final weight of 2400g), suggesting that a low protein diet (40 % protein) promoted similar growth to a high protein diet (60 % protein). Other growth and condition parameters were also similar for all diets with the condition improving over the course of the study. As the fish completed spawning immediately prior to the commencement of the study, an increase in condition was not observed until approximately day 90 of the 210-day investigation. Over the course of the 5-month juvenile study, growth was approximately 224g for the 40% protein diet and approximately 275g for the 50% protein and 60% protein diets. This suggests that a higher protein diet is required for optimal growth of juvenile cod and that 50 % and 60% protein diets promote similar growth and condition, potentially reducing the protein requirement of juvenile diets. In the juvenile investigation, condition increased over the full range of the study. In both tank studies, nitrogen digestion was directly related to protein (and associated nitrogen) content of the diets in the juvenile study expressed as a percentage of the nitrogen content of the diet as 59.19% (40% protein), 56.90% (50% protein) and 52.23% (60 % protein) suggesting that nitrogen digestion is more efficient at lower protein content in the diet. When expressed as a percentage of the nitrogen content of the diet, nitrogen digestion observed in the adult study was 60.55%, (40% protein) 60.92% (50% protein) and 60.60% (60% protein) respectively, suggesting protein digestion is similar regardless of protein content in adult cod. In the adult tank study, under a manual feeding regime, a post-prandial-peak is observed at 105 min. following the cessation of feeding. Thereafter, ammonia levels drop over the course of the sampling period. Following the afternoon meal commencing at 420 min., ammonia levels rise at least until the final samples are collected at 450 min. Under an automated regime, a lesser post-prandial-peak is observed but the ammonia concentration is lower over the sampling period compared to the respective profile under a manual regime. The ammonia profile produced throughout the juvenile tank study follows a very similar trend to that observed in the adult study under the manual feeding regime. Two cage - based investigations took place at the No Catch® Ltd. commercial organic cod farm in Vidlin Voe on the east coast of Shetland. Both studies investigated growth, condition and tissue composition, as well as the production of dissolved nitrogenous and particulate wastes associated with the culture of juvenile and adult Atlantic cod in cage systems. Sampling for the adult study occurred over three days during three sampling trips (September 2005, November 2005 and February 2006). Sampling for the juvenile study took place over three days on a single trip to Vidlin in late April 2006. The diets used at No Catch® Ltd. were produced by Biomar® in Grangemouth. A relationship between feeding and ammonia concentration is less evident in the cage studies than in the tank studies, and similarly, the relationship between feeding and ammonia concentration is less evident in juvenile fish than in adult fish. As ammonia values were converted to (µg/L/tonne biomass), the ammonia concentration recorded is largely dependent upon the biomass of the sampled cages at both the nursery site and production site. Deposition rates of organic carbon and nitrogen around the production and nursery cage sites in Vidlin Voe are related to the position of the sediment trap relative to its location and proximity of the trap to the specific cage site. Weather condition also had an impact on deposition rates with calmer weather producing lesser deposition rates. Around the production site, deposition rates of organic carbon and nitrogen are greatest in the direction of the prevailing current. Deposition rates decrease with an increasing distance from the cages. Although sediment trap results were inconsistent, a similar trend is observed for each of the three sampling trips, although actual deposition values were different. Differences between the deposition rates at the highly dynamic production site and the low energy nursery site indicated that sedimentation of waste from cod culture is highly dependent on water currents. Models of particulate waste deposition associated with the production cage site in Vidlin Voe were produced using the spreadsheet - based Cage Aquaculture Particulate Output and Transport (CAPOT) model, developed at the Institute of Aquaculture. The models were parameterised using the data collected and tested against an established regulatory model, DEPOMOD. The similarity in results illustrated the robustness of the highly flexible spreadsheet waste model for cod culture.

Detta examensarbete är utfört på plats i Lajaedo, Brasilien och i anslutning till Sanitário de Lajeado – RS, Brasilien, mellan januari till maj 2010. I samband med denna rapport utfördes två andra examensarbeten inom samma områden. Det är menat att denna rapport skall ligga till grund för framtida projekt och beslut om utökad lakvattenrening.Lajeado ligger i södra Brasilien ca 100 km från atlantkusten. 10 km utanför Lajeado ligger en ung avfallsdeponi på ca 15 000 m2 till ytan med tillhörande lakvattenrening med ett utjämningsmagasin, en syrsättningsbassäng samt sedimentering. Deponin tar emot 42 ton fast kommunalt avfall per dag och har ett lakvattenflöde på genomsnitt 0,5 – 1,0 m3/h.Syftet med denna rapport är att undersöka vilken inverkan vegetation har på reningen av lakvatten inom parametrarna TKN, BOD5 och COD, i småskaliga våtmarker av typen rotzonsanläggning. Då den befintliga reningen på plats har svårt att uppfylla vissa uppsatta lagkrav.Sammansättningen på och mängden av lakvatten beror främst på faktorerna, nederbörd, Temperatur och nedbrytningen i deponin.Vegetationens har många olika betydelser i en rotzonsanläggning. Plantan transporter ner syre till dess rotsystem där syremolekyler diffunderar ut. Vegetation fungerar även som en extern kolkälla vid denitrifikationsteget. Det är viktigt att vegetationen trivs och rotsystemet är välutvecklat, för att få en maximal reduktion av föroreningar i våtmarken.Åtta småskaliga våtmarker byggdes upp i anslutning till lakvattenreningen, i avkapade plasttunnor. Alla våtmarker byggdes upp med unika förutsättningar för att kunna jämföra resultatet. Två olika substrat användes och jämfördes, i fyra kar planterades vegetation och fyra utan, fyra hade kontinuerligt flöde som jämfördes med fyra kar med batch flow.Resultaten visar att växterna inte har någon större inverkan på reningsgraden av BOD5, COD och TKN. Men såg tydliga tecken på högre vattenavdunstning i våtmarkerna med biomassa och generellt högre halter av BOD5, COD och TKN i jämförelse med våtmarkerna utan biomassa. Vegetationen hann inte acklimatisera sig till miljön i våtmarkerna, men det var på god väg. För att få ett bättre resultat och en mer signifikant skillnad mellan våtmarkerna skulle försöken ha pågått under en längre tid. Det behövs mer forskning och projekt under en längre period.Detta examensarbete är utfört på plats i Lajaedo, Brasilien och i anslutning till Sanitário de Lajeado – RS, Brasilien, mellan januari till maj 2010. I samband med denna rapport utfördes två andra examensarbeten inom samma områden. Det är menat att denna rapport skall ligga till grund för framtida projekt och beslut om utökad lakvattenrening.Lajeado ligger i södra Brasilien ca 100 km från atlantkusten. 10 km utanför Lajeado ligger en ung avfallsdeponi på ca 15 000 m2 till ytan med tillhörande lakvattenrening med ett utjämningsmagasin, en syrsättningsbassäng samt sedimentering. Deponin tar emot 42 ton fast kommunalt avfall per dag och har ett lakvattenflöde på genomsnitt 0,5 – 1,0 m3/h.Syftet med denna rapport är att undersöka vilken inverkan vegetation har på reningen av lakvatten inom parametrarna TKN, BOD5 och COD, i småskaliga våtmarker av typen rotzonsanläggning. Då den befintliga reningen på plats har svårt att uppfylla vissa uppsatta lagkrav.Sammansättningen på och mängden av lakvatten beror främst på faktorerna, nederbörd, Temperatur och nedbrytningen i deponin.Vegetationens har många olika betydelser i en rotzonsanläggning. Plantan transporter ner syre till dess rotsystem där syremolekyler diffunderar ut. Vegetation fungerar även som en extern kolkälla vid denitrifikationsteget. Det är viktigt att vegetationen trivs och rotsystemet är välutvecklat, för att få en maximal reduktion av föroreningar i våtmarken.Åtta småskaliga våtmarker byggdes upp i anslutning till lakvattenreningen, i avkapade plasttunnor. Alla våtmarker byggdes upp med unika förutsättningar för att kunna jämföra resultatet. Två olika substrat användes och jämfördes, i fyra kar planterades vegetation och fyra utan, fyra hade kontinuerligt flöde som jämfördes med fyra kar med batch flow.Resultaten visar att växterna inte har någon större inverkan på reningsgraden av BOD5, COD och TKN. Men såg tydliga tecken på högre vattenavdunstning i våtmarkerna med biomassa och generellt högre halter av BOD5, COD och TKN i jämförelse med våtmarkerna utan biomassa. Vegetationen hann inte acklimatisera sig till miljön i våtmarkerna, men det var på god väg. För att få ett bättre resultat och en mer signifikant skillnad mellan våtmarkerna skulle försöken ha pågått under en längre tid. Det behövs mer forskning och projekt under en längre period.

The ability for a subsurface flow constructed wetland system to treat landfill leachate was evaluated in Lajeado, Rio Grande do Sul, Brazil. Eight 0.95 m x 0.6 m experimental (SSF) units with a depth 0.4 m were used. Each wetland had unique conditions. Four units were planted with Typha angustifolia L. and four units were unplanted. Two different substrate dimension were used, four units with sand and four with gravel. Four wetlands operated in batch mode and four units with continuous flow. Batch flow systems were drained and filled up each week. To review vegetations impact on BOD5, COD and nitrogen compounds reduced in a wetland. This project lasted between January until May 2010 and samples were analyzed in April to May in four weeks.The result from this project show higher evapotranspiration water loss in units with planted vegetation and higher effluents concentration of BOD5, COD and nitrogen compounds, than in unplanted units.The ability for a subsurface flow constructed wetland system to treat landfill leachate was evaluated in Lajeado, Rio Grande do Sul, Brazil. Eight 0.95 m x 0.6 m experimental (SSF) units with a depth 0.4 m were used. Each wetland had unique conditions. Four units were planted with Typha angustifolia L. and four units were unplanted. Two different substrate dimension were used, four units with sand and four with gravel. Four wetlands operated in batch mode and four units with continuous flow. Batch flow systems were drained and filled up each week. To review vegetations impact on BOD5, COD and nitrogen compounds reduced in a wetland. This project lasted between January until May 2010 and samples were analyzed in April to May in four weeks.The result from this project show higher evapotranspiration water loss in units with planted vegetation and higher effluents concentration of BOD5, COD and nitrogen compounds, than in unplanted units.

Lo scopo di tesi è valutare la rimozione dei composti azotati e degli elementi biochimici presenti all’interno di un’ impianto pilota, che rappresenta in scala ridotta il primo bacino di finissaggio.Il quale posto alla fine di una linea di trattamento reflui a fanghi attivi, riceve una parte delle acque di scarico ed effettua un trattamento di finissaggio grazie alla presenza di una macrofita galleggiante, la Lemna Minor. Infine si sono comparati i dati reali con dati modellati dal Qual 2K. Per lo studio sono state effettuate diverse campagne di campionamento ben sei, ed in ognuna delle quali sono stati prelevati campioni che sono stati analizzati al laboratorio del dipartimento DICAM dell’università di Bologna.I campionamenti sono stati effettuati nelle tre sezioni dell’impianto pilota, una iniziale IP_IN, una centrale IP_M e l’ultima posta alla fine, poco prima dello stramazzo IP_OUT;in questo modo si riesce a valutare i possibili cambiamenti che subiscono le componenti biologiche.Per valutare le variazioni sono stati utilizzati diversi strumenti: YSI 556 MPS una sonda multiparametrica e l'elettrodo selettivo d'ammonio ,infine sono stati applicati il metodo ispra 4060 per il calcolo del TN e TP e la norma ISO 15705 per la valutazione del COD,ultimo ma non ultimo il modello Qual2K che è servito solamente per poter effettuare la simulazione in modo da riuscire a fare il confronto con i dati realmente misurati.Dall’analisi dei risultati si evidenzia come la presenza della Lemna Minor sia fondamentale a garantire il livello d’equilibrio nell’ecosistema ricreato all’ interno dell’impianto pilota.In particolare nei periodi di aprile e maggio la combinazione Lemna-fitoplancton, producendo condizioni di ipossia o anossia in profondità consente di aprezzare fenomeni di denitrificazione come possiamo vedere dall’abbattimento del total nitrogen.Tramite l'ultilizzo e la corretta calibrazione del modello si è ottenuta una sostanziale e soddisfacente interpretazione dei dati.

This report deals with the performance of a batch flow treatment of landfillleachate compared with a continuous flow system. The parameters in focus were total Kjeldahl nitrogen (TKN), BOD5 and COD. The pilot-scale experiment used eight barrels with a volume of 150 liters. Each barrel was constructed differently concerning its flow, its bed material grain size and its presence of plants or not. Four of the barrels worked in batch mode, thus four in continuous flow mode. The continuous flow systems were provided with water trough small tubes with regulators. Samples were collected once a week and analysis was carried out yielding results of BOD5, COD, TKN, pH and conductivity of the effluents. The same parameters were analyzed for the influent every week. The result shows that a wetland is a good way of treating the landfill leachate as the BOD5, COD and TKN decreases. Moreover the color, which contravenes with legislative demands in the region, was distinctly decreased. Yet the report failed to show a significant difference between batch loaded and continuous flow wetlands. More studies have to be carried out in order to determine or contradict whether batch mode in fact provides a better treatment.

This master thesis deals technology of floating islands and their application in practice. In the first theoretical part describes detail of physical and chemical properties of water, the cycle of substances in water and the distribution of standing water, which are considered the most suitable interest sites for the application and instalation of floating systems. The sekond part describes the measurement metodology, which was carried out in several stages on the research land of the Institute of Landscape Water Management. The measuremenr was focused on monitoring the quality characteristics of water in free artificial tanks (lysimeters). The first tank was with floating island, the sekond with floating rack without plants and the third tank with free surface (to ensure the simulation of the natural state). The measurement was under way in the calendar year 2017 and was divided into free stages (spring, summer, winter). During this period were monitored COD, total phosphorus, nitric and amoniacal nitrogen and dissolved oxygen, turbidity, pH, oxidation-reduction potential, water and air temperature and aggregate rainfall. Part of the master thesis is graphical and tabular evaluation of the results. The results are processed in the Minitab 16 statistical software, graphical representation is supplemented by the interlaced linear and cubic regression curves for easier search for the dependence of selected factors. The stages are compared at the end of the master thesis. At hhe end of summer 2017, the first application of the floating island according to utility model No. 31 169 was carried out within the Czech Republic on selected water reservoir in the Bílý Potok basin (Polička).

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
O Brasil produziu 12,2 milhões de toneladas de arroz em casca na safra 2013/2014, sendo a região sul responsável por 60% da produção. O arroz parboilizado representa 50% das exportações nacionais de arroz e aproximadamente 20% do arroz total comercializado no Brasil. No processo de parboilização, são gerados 2 L de efluente para cada quilograma de grão processado, gerando grandes volumes de efluente que contém nutrientes, como nitrogênio e fósforo, e matéria orgânica. As metodologias de tratamento utilizadas para o tratamento deste efluente são as lagoas aeróbias e anaeróbias, lodos ativados, precipitação química e reatores UASB. O cultivo de leveduras em efluentes tem sido empregado como forma de tratamento, gerando simultaneamente biomassa que pode ser usada como probiótico ou fonte de proteína unicelular. A levedura Saccharomyces boulardii é capaz de crescer em efluente de arroz parboilizado quando este é suplementado com uma fonte extra de carbono. O objetivo deste estudo foi avaliar o uso de Saccharomyces boulardii no tratamento do efluente de arroz parboilizado e a produção de biomassa. Realizaram-se ensaios para a seleção de um meio de cultivo de Saccharomyces boulardii, testando a adição de sacarose ou glicerol de biodiesel ao efluente da parboilização de arroz, coletado em uma indústria de beneficiamento de arroz. Os melhores resultados obtidos foram no cultivo em efluente suplementado com 1% de sacarose, que gerou viabilidade celular de 2,4 x 108 UFC.mL-1 e a remoção de 72% do fósforo, 50% do nitrogênio (N-NTK) e 56% da demanda química de oxigênio (DQO) em 24 h de cultivo. A partir do meio de cultivo selecionado, analisou-se em biorreator o crescimento e a produção de biomassa da levedura e sua influência na redução de parâmetros ambientais. Após 48 h de cultivo, foi produzido 3,8 g.L-1 de biomassa e 1,8 x 10 11 UFC. L-1. A eficiência de remoção foi de 74% da DQO e 78% do fósforo, alcançando as taxas de remoção de fósforo estabelecidas pelo Conselho Estadual do Meio Ambiente (CONSEMA 128/06). Além disso, a biomassa seca produzida e a viabilidade celular alcançada permitiriam obter probiótico suficiente para adicionar a 36 toneladas de ração a cada tonelada de grão processado. Estes resultados ressaltam os benefícios do cultivo de Saccharomyces boulardii em efluente de arroz parboilizado suplementado com sacarose como sistema de tratamento e produção de probiótico.
Brazil produced 12.2 million tons of paddy rice in 2013/2014, and the south region was responsible for 60% of the production. The parboiled rice represents 50% of the national rice exports and about 20% of the total rice sold in Brazil. During the parboiling process are generated 2 liters of effluent per kilo of processed grain, generating large volumes of effluent which contains nutrients such as nitrogen and phosphorus, and organic matter. The treatment methodologies used for the treatment of this effluent are aerobic and anaerobic lagoons, activated sludge, chemical precipitation and UASB reactors. Cultivation of yeasts in wastewater has been used as a treatment technique while generating biomass that can be used as probiotic or unicellular protein source. The yeast Saccharomyces boulardii is able to grow in parboiled rice effluent when it is supplemented with extra carbon source. The aim of this study was to evaluate the use of Saccharomyces boulardii on treatment of parboiled rice effluent and biomass production. Trials were carried out for the medium selection to Saccharomyces boulardii cultivation, testing the addition of sucrose or glycerol by-product of biodiesel industry into parboiled rice effluent, collected in a rice processing industry. The best results obtained were on cultivation in effluent supplemented with 1% sucrose, generating 2.4 x 108 CFU.mL-1 of cell viability and phosphorus, nitrogen and COD removal of 72%, 50% and 56%, respectively, after 24 h of culture. After medium selection, the cell growth, yeast biomass production and its influence on the reduction of environmental parameters was analyzed in bioreactor. After 48 h of culture, it was produced 3.8 g L-1 of biomass and 1.8 x 10 11 CFU. L-1. The removal efficiency was 74% for COD and 78% for phosphorus, reaching the phosphorus removal rates required by Conselho Estadual do Meio Ambiente (CONSEMA 128/06). Furthermore, the produced dry yeast biomass and cell viability reached would allow to obtain sufficient probiotics to add to 36 tons of feed for each ton of processed grain. These results show the advantages of Saccharomyces boulardii cultivation in parboiled rice effluent supplemented with sucrose as a treatment system and production of probiotic.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Given the potential of the use of physical-chemical process in wastewater treatment, this project aimed to study the reduction of phosphorus and / or nitrogen present in effluents and liquid manure from pigs, meat slaughter of cattle (bovine blood) and disposal of refrigerants. The technology used in the removal of ammonia and phosphorus is its precipitation in the form of struvite (Mg (NH4) PO4.6H2O). To enable the precipitation of ammonia and phosphorus as struvite, is necessary the presence of the participants such as Mg, which will be supplied by the addition of phosphoric acid, potassium phosphate, magnesium hydroxide, magnesium oxide and ammonium chloride concentrations varied. These concentrations were added in 2.0- liter beakers and kept under agitation using a jar-test equipment. Then the samples were filtered and the precipitates were analyzed by diffraction and X-ray. The supernatant was analyzed seen a removal of nitrogen and phosphorus above 80%. The removal of these components depends on the type of effluent tested. Nitrogen and phosphorus precipitated as struvite, can be used in the formulation of fertilizer with slow release of these elements.
Tendo em vista a potencialidade do emprego de processo fisico-químico no tratamento de efluentes, este projeto teve por objetivo estudar a remoção de fósforo e nitrogênio presente em efluentes como de dejetos líquidos de suínos, frigoríficos de abate de bovinos (sangue bovino) e descartes de refrigerantes. A tecnologia empregada na remoção de nitrogênio e fósforo é a sua precipitação sob a forma de estruvita (Mg(NH4)PO4.6H2O). Para possibilitar a precipitação do nitrogênio e do fósforo como estruvita, foi necess ria a presença de substâncias como o Mg e PO4, os quais foram supridos pela adição de cido fosfórico, fosfato de potássio, hidróxido de magnésio, óxido de magnésio e cloreto de amônia em concentrações variadas. Essas concentrações foram adicionadas em reator de 2,0 L e permanecem sob agitação utilizando um equipamento jar-test . Em seguida, as amostras foram filtradas e os precipitados foram analisados por difração de raios-X. Nos sobrenadantes analisados, foi verificada uma remoção de nitrogênio e fósforo acima de 80%. A remoção destes componentes depende do tipo de efluente ensaiado. O nitrogênio e fósforo, precipitados na forma de estruvita, podem ser utilizados na formulação de fertilizante com lenta liberação destes elementos.

Esta pesquisa enfoca a avaliação do desempenho de nova configuração de unidade para tratamento biológico de esgoto sanitário por processo combinado, visando à remoção de nutrientes, especialmente nitrogênio. O sistema construído em escala piloto tem volume útil igual a 71,48 litros. Nesta nova configuração de reatores para tratamento terciário de esgoto sanitário, utilizaram-se três reatores sobrepostos, sendo: um reator UASB - “Upflow Anaerobic Sludge Blanket”; um reator de leito móvel e filme fixo aeróbio (com aplicação de oxigênio puro); e, um reator de leito móvel e filme fixo com ambiente anóxico. O material suporte utilizado nos reatores de leito móvel e filme fixo constituiu alternativa inédita no tratamento de efluentes líquidos. Foram utilizadas cavilhas “ranhuradas” de madeira, de dimensões aproximadas de 8,0 mm de diâmetro por 8,0 mm de comprimento. O desempenho geral do sistema quanto à remoção de matéria carbonácea e compostos nitrogenados, e as associações microbianas formadas nos três reatores são objetos principais de estudo deste trabalho. Foram obtidos resultados de remoção de DQO e de nitrogênio bastante satisfatórios, sobretudo quando o tempo de detenção hidráulica total esteve próximo a 20 horas, incluindo o compartimento de decantação (94,6 % para DQO; e 96,7 % para N-NTK, com formação de nitrato em concentrações inferiores a 10,0 mgN-NO3-/l). O TDH estudado variou entre 5 e 24 horas para os sistema completo. O estudo dos consórcios de microrganismos forneceu excelentes resultados quanto à quantidade, diversidade, e atividade das populações desenvolvidas nos diferentes ambientes, confirmando o bom desempenho do sistema e o fornecimento de ambiente adequado para o desenvolvimento das diferentes populações nos três reatores. A idealização desta configuração tem como finalidade realização de tratamento de esgoto sanitário até nível terciário em planta compacta, podendo ser utilizada por pequenas e grandes comunidades, devido à possibilidade de se construir diversos módulos do sistema proposto.
This research is focused on the performance evaluation of a new system configuration of combined biological reactors, treating domestic wastewater till tertiary level. The pilot scale proposed system had a total useful volume of 71,48 liters. This new configuration involves three types of superposed reactors: an Upflow Anaerobic Sludge Blanket reactor; an aerobic fixed film mobile bed reactor (fed with pure oxygen); and a fixed film mobile bed reactor at anoxic environment. The support material used inside the fixed film mobile bed reactors was wood made grooved dowels. The main purposes of this work are to evaluate the systems general performance regarding COD and nitrogen removal, and the microbial associations inside the reactors. It reached quite satisfactory results regarding COD and nitrogen removal when the total hydraulic retention time (HRT) was around 20 hours, including the clarification zone volume (94,6 % for the COD; and 96,7 % for the TKN-N, whit nitrate formation below 10,0 mgN-NO3-/l). HRTs from 5 to 20 hours were studied. The microbial associations were present in large number, with a great diversity and high specific activities at the different environments, confirming the good results obtained and the suitable environment provided for the growth of the different populations inside the three reactors. The idealization of this treatment system has the goal to treat domestic wastewater from small to large communities till tertiary level, in compact treatment plants, due to the possibility of constructing several modules of the system.

L'évolution des réserves de pétrole implique l'utilisation en raffinerie de pétroles bruts non conventionnels, bien souvent plus lourds et donc difficiles à caractériser. Les produits pétroliers sont en effet des mélanges chimiques extrêmement complexes. La partie légère et volatile peut être analysée par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC/MS), permettant l'identification des composés par l'utilisation de mesures de masses précises et de modèles de fragmentation. Cependant ces techniques sont inadaptées à l'analyse des fractions lourdes. Dans la pratique, la caractérisation des mélanges les plus complexes implique l'utilisation de spectromètres de masse à ultra-haute résolution généralement par analyse directe sans séparation chromatographique. La technique de référence est aujourd’hui la spectrométrie de masse à transformée de Fourier par résonance cyclotronique des ions (FTICR). Grâce à une résolution supérieure à 106 et à une précision de mesure de masse inférieure à 0,1 ppm, cet instrument permet de séparer toutes les espèces présentes dans un produit pétrolier et d'attribuer à chaque valeur de m/z une composition élémentaire unique. Ceci permet d'obtenir très facilement des cartes moléculaires qui peuvent être présentées graphiquement en utilisant le diagramme de Kendrick, le diagramme de van Krevelen ou le nombre d'insaturations (DBE) en fonction du nombre de carbones. Ce travail de thèse a permis grâce à la caractérisation moléculaire de produits pétroliers (Vacuum Gas Oil, Pétroles Bruts, Matériel Interfacial, Asphaltènes et Bio-Oil…) d'aborder la complexité de leur traitement dans l’outil de raffinage. Des protocoles d'analyses des échantillons ont été développés, à l'aide de différentes sources d'ionisation à pression atmosphérique (ESI, APCI et APPI) ainsi que par désorption/ionisation laser (LDI) sur le spectromètre de masse FTICR 12T. Les informations sur le contenu isomérique des produits pétroliers ont ensuite été déterminées grâce à l'apport de la spectrométrie de mobilité ionique (IMS)
The evolution of oil reserves requires the use in refineries of unconventional crude oils, which are often heavier and therefore difficult to characterize. Petroleum products are in fact extremely complex chemical mixtures. The light and volatile part can be analysed by gas chromatography coupled with mass spectrometry (GC/MS), allowing the identification of compounds by using precise mass measurements and fragmentation models. However, these techniques are inappropriate for the analysis of heavy fractions. In practice, the characterization of the most complex mixtures involves the use of ultra-high-resolution mass spectrometers generally by direct analysis without chromatographic separation. The reference technique today is Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR). With a resolution of more than 106 and a mass measurement accuracy of less than 0.1 ppm, this instrument can separate all the species present in a petroleum product and assign a unique elemental composition to each m/z value. This makes it very easy to obtain molecular maps that can be presented graphically using the Kendrick diagram, the van Krevelen diagram or the number of unsaturations (DBE) as a function of the number of carbons. This thesis work has allowed thanks to the molecular characterization of petroleum products (Vacuum Gas Oil, Crude Oil, Interfacial Material, Asphaltenes and Bio-Oil...) addressing the complexity of their treatment in the refining tool. Protocols for sample analysis have been developed, using different sources of ionization at atmospheric pressure (ESI, APCI and APPI) as well as laser desorption/ionization (LDI) on the FTICR 12T mass spectrometer. Information on the isomeric content of petroleum products was then determined using ion mobility spectrometry (IMS)

The reduction of sulphur in transportation fuel has gained significant importance as the regulatory agencies worldwide react to air quality concerns and the impact of sulphur oxides on the environment. The overall objective of this research was to identify, develop and characterize, based on underlying scientific principles, sorbents that are effective in removal of refractory sulphur compounds from fuel through the process of selective adsorption. It was determined that impregnation of powdered activated carbon with a transition metal (TM) significantly boosted the adsorption performance of the activated carbon. It is hypothesized that the impregnation resulted in the formation of new adsorptive sites that strongly interacted with the lone pairs of electrons on sulphur and nitrogen while having minor impact on the existing oxygen functional groups on the surface of the activated carbon. The percent loading of the TM was determined through wet adsorption study. The best performing sorbent was shown to have maximum adsorption capacities of approximately 1.77 and 0.76 mmol-S/g-sorbent for DBT and 4,6 DMDBT, respectively, with approximately 100% regenerability through solvent wash and thermal treatment. On average, the PTM impregnation showed approximately 137% increase in adsorption capacity of the activated carbon. The sorbent also has good adsorption capacities for organo-nitrogen compounds (i.e., quinoline and carbazole) and a low selectivity towards aromatics, which is desired in adsorptive desulphurization. The surface morphology of the activated carbon, the oxygen functional groups on the surface of the activated carbon, as well as strong (chemisorption) interaction between the TM???s partly vacant and far reaching ???d??? orbital and lone pair electrons on sulphur and nitrogen are considered to be the main contributing factors to the observed enhancement. It was established in this study that the adsorption isotherms of the impregnated activated carbons best fit Sips isotherm equation, which is a combination of the Langmuir and Freundlich equations. This finding fits well with our initial hypothesis regarding the introduction of new adsorptive sites as a result of TM impregnation and that the sites did not fit well with Langmuir???s monolayer and uniform adsorption mechanism. A kinetic study of the sulphur adsorption using a flow reactor showed a good fit with pseudo second order kinetic model, indicative of an adsorption that is highly dependent on the concentration of available sites on the surface of the sorbent. On average, as expected, the TM impregnated ACC exhibited a higher initial rate of adsorption. The adsorption onto TM sites tends to be more exothermic than adsorption (mainly physisorption) on activated carbon. Therefore, more thermodynamically favoured chemisorption is expected to occur more rapidly than physisorption. It was determined that on average, the initial adsorption rate does not change significantly with temperature while the sulphur adsorption capacity decreases with increase in temperature. It is postulated that the increase in temperature increases surface diffusivity but impedes diffusion flux. The impediment of the diffusion flux will result in reduction in adsorbed quantity. It was also shown that the intra-particle diffusion exists in the adsorption of DBT on TM impregnated activated carbon, however, it is not likely that the overall adsorption is controlled or noticeable impacted by it. As the temperature of the reactor increases the Weber-Morris intra-particle diffusion plot moves away from the origin, and thus intra-particle diffusion becomes less of a controlling mechanism. This further confirms the fact that the boundary layer (i.e., surface diffusion) and potentially adsorptive interactions at the surface are the dominating mechanisms in the sulphur adsorption onto TM impregnated activated carbon. It was determined that the distribution of TM species on the surface of the activated carbon is relatively inhomogeneous, with some areas showing well dispersed TM species while other areas showing large clusters. Different impregnation method that can improve dispersion on the surface may significantly enhance adsorption performance of the sorbent. Furthermore, in this study impregnation of activated carbon using several other transition metals were examined. It was determined that other less expensive transition metals can also improve the adsorption performance of the activated carbon. Further study on less expensive options for impregnating the activated carbon may be beneficial.

碩士
嘉南藥理科技大學
環境工程與科學系
101
Biological processes integrated with membrane separation are one of the fastest growing technologies in the wastewater treatment. MBR has many advantages include small footprint, reactor volume requirement, less sludge production and high effluent quality in term of nutrient removal. Normally, intensive aeration is carried out in a submerged MBR for supplying oxygen to microorganisms and scouring of the membrane surface. However, one obvious drawback in the use of intensive aeration is poor removal of nitrogen in the submerged MBR. An aerobic, anoxic and aerobic-membrane bioreactor (A2O-MBR) system was applied in laboratory scale by Yeom et al. (1), which the study seemed to indicate that the operating condition was advantageous for phosphorus removal, not nitrogen. By this way we try to find an alternative related to a hybrid MBR system to have the function for organic and nitrogen removal. The main goal of this study was to investigate a biocarrier-aerobic-MBR process in place of A2O-MBR process. Two different operating conditions, sludge recycling rate and COD/N ratio for removing organic and nitrogen from domestic wastewater, were assessed in this study. The biocarrier-aerobic-MBR process has two compartments including an anoxic and an oxic biological reactor with integrated membrane for solid-liquid separation. Domestic wastewater may contain a considerable amount of nutrient and organic matter. The research was conducted to investigate the possibility in using continuous biocarrier-aerobic-MBR process in place of A2O-MBR process for treating synthetic domestic wastewater by studying its performance in terms of organic and nitrogen removal. The biocarrier- II aerobic-MBR process was operated for 260 days with 5 stages and differentoperating conditions. (1) anoxic (sponge)-MBR with 3Q recirculation rate (2) anoxic (sponge)-MBR with 3Q recirculation rate and extra alkalinity (NaHCO3) addition (3) anoxic (new model sponge)-MBR with 3Q recirculation rate, extra alkalinity (NaHCO3) addition and pH (NaOH) adjustment (4) anoxic (new model sponge)-MBR with 2Q recirculation rate, extra alkalinity (NaHCO3) addition and pH (NaOH) adjustment (5) anoxic (new model sponge)-MBR with 2Q recirculation rate, extra alkalinity (NaHCO3) addition, pH (NaOH) adjustment and adjusted COD/N ratio to 7. The results showed that the highest TCOD, SCOD, ammonia and TN removal of 100%, 100%, 100% and 85% can be achieved under a specific operating mode (sludge recycling rate of 2Q and COD/N ratio of 7). The concentration of ammonia in MBR tank, nitrite and nitrate in anoxic tank were almost non-detected, which indicated that this operating condition can reach complete nitrification and high efficiency of denitrification. The sponge addition in the anoxic tank was functional for reduce membrane fouling which the result show that sustainable operation up to 55 days was maintained without any cleaning. The biomass in anoxic and MBR tank increase gradually when organic loading increased, which cause of microorganisms produced more extra-cellular polymeric substance (EPS) and effect to membrane fouling in this study.