Domestic wastewater is one of the most interested environmental issues in Vietnam, especially in big cities and suburban residential areas. Most of the wastewater was not treated in the right way before discharging to environment. In this research, the author used water hyacinth as a main aquatic plant in aquatic pond model to treat wastewater. The experiment was operated continuously in 1 year with hydraulic retention time (HRT) is 11 and 18 days. Hydraulic loading rate (HRL) is 300 and 500 m3/ha/day, respectively. Treatment efficiency of the model for TSS is 90% (remaining 6 -12mg/l); COD, BOD5 is 63 - 81% (remaining 10 - 48mg/l); TP is 48 – 50% (remaining 3.5 - 9.8mg/l); TKN is 63 - 75% (remaining 8 - 17mg/l). Polluted parameters in effluent were lower than A and B levels of Vietnam standard QCVN 14: 2008/BTNMT and QCVN 40: 2011/BTNMT. The doubling time of water hyacinth in summer is 18days, and in autumn and winter is 28.5 days. Experiment results showed that we can use water hyacinth in aquatic pond to treat domestic wastewater with medium scale. We can apply this natural treatment method for residential areas by utilizing existing natural ponds and abandoned agricultural land with capacity up to 500m3/ha day. However, to get better efficiency we should combine with other aquatic plant species to treat wastewater and improve environmental landscape. / Nước thải – xử lý nước thải sinh hoạt hiện đang là một trong những vấn đề môi trường được quan tâm tại Việt Nam nhất là tại các thành phố lớn và các khu dân cư. Hầu hết lượng nước thải chưa được xử lý đúng cách trước khi thải ra môi trường. Trong nghiên cứu này, tác giả sử dụng mô hình hồ thủy sinh và sử dụng cây Bèo lục bình để xử lý nước thải sinh hoạt của một khu dân thuộc huyện Từ Liêm, tại khu vực này nước thải bị thải trực tiếp vào sông Nhuệ. Thực nghiệm đã được tiến hành trong khoảng thời gian một năm, trải qua các mùa của khu vực miền Bắc với hai chế độ vận hành HRT là 18 và 11 ngày, tương ứng với tải trọng thủy lực HRL là 300 và 500 m3/ha/ngày. Kết quả cho thấy mô hình thủy sinh sử dụng cây bèo lục bình cho kết quả tốt, hiệu suất xử lý với các chất ô nhiễm đạt được như sau: chất rắn lơ lửng đạt 90%, COD, BOD5 đạt 63 - 81%, Phốt pho tổng giảm tới 48 -50%, Nitơ tổng giảm tới 63 - 75%. Hàm lượng các chất ô nhiễm trong nước thải đầu ra của mô hình đều thấp hơn ngưỡng A và B của các tiêu chuẩn QCVN 14: 2008/BTNMT và QCVN 40: 2011/BTNMT. Bên cạnh đó tác giả cũng đã xác định định được tốc độ sinh trưởng của cây bèo tại khu vực miền Bắc là 18 ngày vào mùa hè và 28.5 ngày vào mùa thu đông. Kết quả nghiên cứu cho thấy có thể sử dụng bèo lục bình để xử lý nước thải sinh hoạt, với qui mô vừa và nhỏ và nên áp dụng cho các khu vực ven đô, nông thôn nơi có diện tích đất rộng hoặc tại các hồ sinh thái của các khu đô thị. Tuy nhiên, để hiệu quả tốt hơn ta cần kết hợp với nhiều loại thực vật thủy sinh khác để ngoài tác dụng xử lý nước thải mà còn tạo cảnh quan môi trường xung quanh.

<p>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.</p>

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.

<p> This report examines the dynamic response of a 0. 5 metre pilot scale rotating biological contactor when operated under transient influent conditions. Experimental data are presented for two modes of operation: carbon oxidation and carbon oxidation plus nitrification. During the carbon oxidation experimental runs, a 2.0 metre RBC was operated in parallel with the 0.5 metre RBC, thus allowing comparisons in the performance of the units. </p> <p> When the 0. 5 metre RBC was operated under nitrifying conditions, it was found that the effluent filterable TKN responded positively to influent variations in filterable TKN loading, TKN concentration and hydraulic loading. Transfer f unction noise models were developed which successfully predicted the time varying effluent TKN response. The response in effluent filterable TKN was predicted most precisely by influent TKN loading. Models based on influent TKN concentration and flow were not as precise in predicting effluent response. The effluent response of the 0.5 metre RBC was found to be greater than the response of activated sludge pilot units when operated at similar levels of removal. </p> <p> When the 0. 5 metre RBC was operated in the carbon oxidation 'mode, significant effluent responses were observed for carbon loading and concentration. Little correlation was found between influent flow and effluent carbon concentration. Operating under identical conditions, the 2.0 m RBC showed significant responses to carbon loading, carbon concentration and flow. </p> / Thesis / Master of Engineering (MEngr)

Domestic wastewater is one of the most interested environmental issues in Vietnam, especially in big cities and suburban residential areas. Most of the wastewater was not treated in the right way before discharging to environment. In this research, the author used water hyacinth as a main aquatic plant in aquatic pond model to treat wastewater. The experiment was operated continuously in 1 year with hydraulic retention time (HRT) is 11 and 18 days. Hydraulic loading rate (HRL) is 300 and 500 m3/ha/day, respectively. Treatment efficiency of the model for TSS is 90% (remaining 6 -12mg/l); COD, BOD5 is 63 - 81% (remaining 10 - 48mg/l); TP is 48 – 50% (remaining 3.5 - 9.8mg/l); TKN is 63 - 75% (remaining 8 - 17mg/l). Polluted parameters in effluent were lower than A and B levels of Vietnam standard QCVN 14: 2008/BTNMT and QCVN 40: 2011/BTNMT. The doubling time of water hyacinth in summer is 18days, and in autumn and winter is 28.5 days. Experiment results showed that we can use water hyacinth in aquatic pond to treat domestic wastewater with medium scale. We can apply this natural treatment method for residential areas by utilizing existing natural ponds and abandoned agricultural land with capacity up to 500m3/ha day. However, to get better efficiency we should combine with other aquatic plant species to treat wastewater and improve environmental landscape. / Nước thải – xử lý nước thải sinh hoạt hiện đang là một trong những vấn đề môi trường được quan tâm tại Việt Nam nhất là tại các thành phố lớn và các khu dân cư. Hầu hết lượng nước thải chưa được xử lý đúng cách trước khi thải ra môi trường. Trong nghiên cứu này, tác giả sử dụng mô hình hồ thủy sinh và sử dụng cây Bèo lục bình để xử lý nước thải sinh hoạt của một khu dân thuộc huyện Từ Liêm, tại khu vực này nước thải bị thải trực tiếp vào sông Nhuệ. Thực nghiệm đã được tiến hành trong khoảng thời gian một năm, trải qua các mùa của khu vực miền Bắc với hai chế độ vận hành HRT là 18 và 11 ngày, tương ứng với tải trọng thủy lực HRL là 300 và 500 m3/ha/ngày. Kết quả cho thấy mô hình thủy sinh sử dụng cây bèo lục bình cho kết quả tốt, hiệu suất xử lý với các chất ô nhiễm đạt được như sau: chất rắn lơ lửng đạt 90%, COD, BOD5 đạt 63 - 81%, Phốt pho tổng giảm tới 48 -50%, Nitơ tổng giảm tới 63 - 75%. Hàm lượng các chất ô nhiễm trong nước thải đầu ra của mô hình đều thấp hơn ngưỡng A và B của các tiêu chuẩn QCVN 14: 2008/BTNMT và QCVN 40: 2011/BTNMT. Bên cạnh đó tác giả cũng đã xác định định được tốc độ sinh trưởng của cây bèo tại khu vực miền Bắc là 18 ngày vào mùa hè và 28.5 ngày vào mùa thu đông. Kết quả nghiên cứu cho thấy có thể sử dụng bèo lục bình để xử lý nước thải sinh hoạt, với qui mô vừa và nhỏ và nên áp dụng cho các khu vực ven đô, nông thôn nơi có diện tích đất rộng hoặc tại các hồ sinh thái của các khu đô thị. Tuy nhiên, để hiệu quả tốt hơn ta cần kết hợp với nhiều loại thực vật thủy sinh khác để ngoài tác dụng xử lý nước thải mà còn tạo cảnh quan môi trường xung quanh.

Die vorliegende Studie untersuchte die Wiederholbarkeit der Aufzeichnung von Unterkiefer-bewegungen und die Steilheit der Kiefergelenkbahn in Abhängigkeit von der Befestigungs-methode der Registrierapparatur an der Unterkieferzahnreihe. Der Untersucher zeichnete dazu in zwei zeitlich getrennten Sitzungen Protrusions- und Mediotrusionsbewegungen von Probanden auf. Er befestigte dabei den Registrierbogen mit drei unterschiedlichen Verfah-ren am Unterkiefer: mit einem okklusionsbedeckenden, periokklusalen Löffel, mit einer Okklusionsklemme und einem paraokklusalen Löffel. Zwei Methoden bedecken die Unterkie-ferzahnreihe und erhöhen die vertikale Kieferrelation. Bei der dritten Methode hingegen befestigte der Untersucher den Unterkieferbogen an den Labialflächen der Unterkieferzähne mit ungestörter habitueller Interkuspidation. Die mittlere, über alle Befestigungsmethoden gemessene, sagittale Gelenkbahnneigung be-trug 44,74 ° bei 3 mm und 42,65 ° bei 5 mm Gelenkbahn. Der Bennett-Winkel nahm Werte von 10,96 ° (3 mm) und 10,17 ° (5 mm) an. Die sagittale Kiefergelenkbahn differierte bei den unterschiedlichen Befestigungsmethoden statistisch signifikant und klinisch relevant. Die Messung mit paraokklusaler Befestigung des Unterkieferbogens erzielte sagittale Kondylen-bahnneigungen, die im Mittel 7,94 ° (3 mm) und 9,46 ° (5 mm) steiler waren als die mit der Okklusionsklemme gemessenen Neigungen. Die Wiederholbarkeit war bei allen Gruppen innerhalb einer Sitzung exzellent, unterschied sich jedoch beim Vergleich beider Sitzungen statistisch signifikant. Die Gelenkbahnaufzeichnung mittels paraokklusaler Befestigung des Unterkieferbogens war exzellent wiederholbar. Unter Benutzung des periokklusalen Löffels und der Okklusionsklemme sank die Reliabilität statistisch signifikant und klinisch relevant ab. Die Untersuchung zeigte darüber hinaus, dass verschiedene Messsysteme mit unterschiedli-chen Bezugsebenen und -punkten arbeiten und die in der Literatur zu findenden Werte für Gelenkbahnneigungen daher kaum vergleichbar sind. Für die Programmierung virtueller und voll adjustierbarer Artikulatoren sollte daher, wenn möglich, die paraokklusale Befestigung für die Messung der Kiefergelenkbahnen Anwendung finden.

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.

Die vorliegende Studie untersuchte die Wiederholbarkeit der Aufzeichnung von Unterkiefer-bewegungen und die Steilheit der Kiefergelenkbahn in Abhängigkeit von der Befestigungs-methode der Registrierapparatur an der Unterkieferzahnreihe. Der Untersucher zeichnete dazu in zwei zeitlich getrennten Sitzungen Protrusions- und Mediotrusionsbewegungen von Probanden auf. Er befestigte dabei den Registrierbogen mit drei unterschiedlichen Verfah-ren am Unterkiefer: mit einem okklusionsbedeckenden, periokklusalen Löffel, mit einer Okklusionsklemme und einem paraokklusalen Löffel. Zwei Methoden bedecken die Unterkie-ferzahnreihe und erhöhen die vertikale Kieferrelation. Bei der dritten Methode hingegen befestigte der Untersucher den Unterkieferbogen an den Labialflächen der Unterkieferzähne mit ungestörter habitueller Interkuspidation. Die mittlere, über alle Befestigungsmethoden gemessene, sagittale Gelenkbahnneigung be-trug 44,74 ° bei 3 mm und 42,65 ° bei 5 mm Gelenkbahn. Der Bennett-Winkel nahm Werte von 10,96 ° (3 mm) und 10,17 ° (5 mm) an. Die sagittale Kiefergelenkbahn differierte bei den unterschiedlichen Befestigungsmethoden statistisch signifikant und klinisch relevant. Die Messung mit paraokklusaler Befestigung des Unterkieferbogens erzielte sagittale Kondylen-bahnneigungen, die im Mittel 7,94 ° (3 mm) und 9,46 ° (5 mm) steiler waren als die mit der Okklusionsklemme gemessenen Neigungen. Die Wiederholbarkeit war bei allen Gruppen innerhalb einer Sitzung exzellent, unterschied sich jedoch beim Vergleich beider Sitzungen statistisch signifikant. Die Gelenkbahnaufzeichnung mittels paraokklusaler Befestigung des Unterkieferbogens war exzellent wiederholbar. Unter Benutzung des periokklusalen Löffels und der Okklusionsklemme sank die Reliabilität statistisch signifikant und klinisch relevant ab. Die Untersuchung zeigte darüber hinaus, dass verschiedene Messsysteme mit unterschiedli-chen Bezugsebenen und -punkten arbeiten und die in der Literatur zu findenden Werte für Gelenkbahnneigungen daher kaum vergleichbar sind. Für die Programmierung virtueller und voll adjustierbarer Artikulatoren sollte daher, wenn möglich, die paraokklusale Befestigung für die Messung der Kiefergelenkbahnen Anwendung finden.:Inhaltsverzeichnis Abbildungsverzeichnis III Tabellenverzeichnis III Abkürzungsverzeichnis IV 1 Einleitung 1 2 Literaturübersicht der Registriersysteme 4 2.1 Einteilung 4 2.2 Photographische Verfahren 4 2.3 Mechanisch-graphische Verfahren 5 2.4 Elektronische Registrierverfahren 7 3 Befestigung der Registriersysteme 11 3.1 Befestigung mit einem paraokklusalen Löffel 11 3.1.1 Indirekte Methode 11 3.1.2 Direkte Methoden 11 3.2 Befestigung mit einem okklusionsbedeckenden (periokklusalen) Löffel 13 3.3 Befestigung mit einer Okklusionsklemme 14 4 Das Kiefergelenk 16 4.1 Anatomische Besonderheiten 16 4.2 Funktionen 17 4.3 Bewegungsabläufe des Kiefergelenks 18 4.3.1 Bewegungsspektrum 18 4.3.2 Habituelle und zentrische Okklusion 19 4.3.3 Schädelbezugsebenen 19 4.3.4 Bezugspunkt 20 4.4 Kondylenbahnen 22 4.4.1 Sagittale Kondylenbahn 22 4.4.2 Transversale Kondylenbahnneigung 27 5 Material und Methode 28 5.1 Untersuchungsdesign 28 5.2 Stichprobenumfang 28 5.3 Messung mit dem „CADIAX Compact 2“ 29 5.4 Versuchsablauf 29 5.5 Statistische Methoden zur Analyse 32 6 Ergebnisse 34 6.1 Absolutwerte der Kondylenbahnneigung 34 6.2 Zuverlässigkeit der Wiederholung 36 6.2.1 Mittelwertunterschiede 36 6.2.2 Intraklass-Korrelationskoeffizient 40 7 Diskussion der Ergebnisse 42 7.1 Interpretation der wichtigsten Ergebnisse 42 7.2 Vergleich mit Ergebnissen aus der Literatur 43 7.2.1 Steilheit der sagittalen Kiefergelenkbahnneigung 43 7.2.2 Einfluss der Befestigung auf die Steilheit der sagittalen Kiefergelenkbahn 43 7.2.3 Reliabilität der Messung der Gelenkbahnneigung 45 7.2.4 Einfluss der Befestigung auf die Reliabilität der Messung 46 7.3 Stärken und Schwächen dieser Untersuchung 47 8 Ausblick 49 9 Zusammenfassung der Arbeit 50 Literaturverzeichnis 55