Optimisation-based methodology for the design and operation of sustainable wastewater treatment facilities

The treatment of municipal and industrial wastewaters in conventional wastewater treatment plants (WWTPs) requires a significant amount of energy in order to meet ever more stringent discharge regulations. However, the wastewater treatment industry is undergoing a paradigm shift from a focus on waste-stream treatment and contaminant removal to a proactive interest in energy and resource recovery facilities, driven by both economic and environmental incentives. The main objective of this thesis is the development of a decision-making tool in order to identify improvement opportunities in existing WWTPs and to develop new concepts of sustainable wastewater treatment/recovery facilities. The first part of the thesis presents the application of a model-based methodology based on systematic optimisation for improved understanding of the tight interplay between effluent quality, energy use, and fugitive emissions in existing WWTPs. Plant-wide models are developed and calibrated in an objective to predict the performance of two conventional activated sludge plants owned and operated by Sydney Water, Australia. In the first plant, a simulation-based approach is applied to quantify the effect of key operating variables on the effluent quality, energy use, and fugitive emissions. The results show potential for reduced consumption of energy (up to 10-20%) through operational changes only, without compromising effluent quality. It is also found that nitrate (and hence total nitrogen) discharge could be signficantly reduced from its current level with a small increase in energy consumption. These results are also compared to an upgraded plant with reverse osmosis in terms of energy consumption and greenhouse gas emissions. In the second plant, a systematic model-based optimisation approach is applied to investigate the effect of key discharge constraints on the net power consumption. The results show a potential for reduction of energy (20-25%), without compromising the current effluent quality. The nitrate discharge could be reduced from its current level to less than 15 mg/L with no increase in net power consumption and could be further reduced to <5 mg/L subject to a 18% increase in net power consumption upon the addition of an external carbon source. This improved understanding of the relationship between nutrient removal and energy use for these two plants will feed into discussions with environmental regulators regarding nutrient discharge licensing.The second part of the thesis deals with the application of a systematic, model-based methodology for the development of wastewater treatment/resource recovery systems that are both economically and environmentally sustainable. With the array of available treatment and recovery options growing steadily, a superstructure modeling approach based on rigorous mathematical optimisation provides a natural approach for tackling these problems. The development of reliable, yet simple, performance and cost models is a key issue with this approach in order to allow for a reliable solution based on global optimisation. it is argued that commercial wastewater simulators can be used to derive such models. The superstructure modeling framework is also able to account for wastewater and sludge treatment in an integrated system and to incorporate LCA with multi-objective optimisation to identify the inherent trade-off between multiple economic and environmental objectives. This approach is illustrated with two case studies of resource recovery from industrial and municipal wastewaters. The results establish that the proposed methodology is computationally tractable, thereby supporting its application as a decision support system for selection of promising wastewater treatment/resource recovery systems whose development is worth pursuing. Our analysis also suggests that accounting for LCA considerations early on in the design process may lead to dramatic changes in the configuration of future wastewater treatment/recovery facilities.Open Acces

The Impacts of Attitude towards Speaking English on the Use of Communication Strategies by English Majors in Thailand

The aim of the present study was to explore the communication strategy employment by 949 Thai university students, majoring in English in the Northeast of Thailand, as well as the relationship between communication strategy use and students’ attitude towards speaking English. The communication strategy questionnaire (CSQ) and Attitudes towards Speaking English Questionnaire (ASEQ) were conducted. The data obtained through the questionnaires were analyzed by the descriptive statistics, the One-Way Analysis of Variance (ANOVA) and the Chi-square tests. The results demonstrate that significant variations were found in relation to students’ attitude towards speaking English.  Students with positive attitude towards speaking English reported significantly greater overall strategy use than those students with negative attitude

EST students and out-of-class strategy use

ผลงานในโครงการหนึ่งอาจารย์หนึ่งผลงาน ประจำปี 254

Connecting with Youth at Risk: Indigenous Organizations Use of Facebook

A qualitative study in which we conducted four interviews with two communication managers and two youth program managers of three indigenous organizations with offices in Ottawa, the data generated from the interviews were coded based on factors identified through thematic analysis. Indigenous organizations use Facebook for two main reasons. The first reason is to promote the work of these organizations to the public and for them, in turn to listen to the public’s opinions about news related to indigenous peoples’ wellbeing. Secondly, Facebook is also used to engage urban indigenous youth at risk with indigenous organizations that provide social programs and outreach. Indigenous organizations use Facebook because many urban indigenous youth in Ottawa are using Facebook and it is the fastest way to connect with them when they are or feel at risk

Improving Financial Literacy of Undergraduate Students with Supplementary Financial Lessons: A Case of Practical Economics for Daily Life

Financial literacy is a vital issue since individuals with financial literacy are able to manage their finance allowing them to live their lives stably with no worry about financial problems. Normally, courses provided by Department of Economics should include lessons to develop financial literacy of undergraduate students. This study aimed to compare financial behavior, attitude and financial literacy of 155 students who registered the Practical Economics for Daily Life Course before and after taking the course. The research instruments were a questionnaire and a test. The results revealed that the students increased their financial behavior and attitude after taking supplementary financial lessons in the course. Moreover, the result of the test about financial literary showed that the students gained significantly higher mean score after taking the custom-made financial lessons. However, the posttest score, despite the fact that it was higher than the pre-test score, was considered not quite very high. The researcher suggests integrating more financial knowledge content in many lessons of the course or if possible, the department should consider having a separate course about financial literacy in the curriculum of the program

A Study of Skid Resistance Efficiency of Cold Plastic Pavement Marking on Concrete Pavement

Weigh Station efficiency enhancement is highly important to the people who utilize the road ways around Weigh Station. This research emphasizes on A Study of Skid Resistance Efficiency of Cold Plastic Pavement Marking on Concrete Road at Sai Noi Weigh Station on the highways No.346 by study 1) internal factors, such as thickness, color 2) external factors, such as, time, traffic value, truck weight and climate that affect Skid Resistance (BPN) of cold plastic (Anti-Skid Resistance). Road marking paint is produced for another pavement to increase the safety around weigh station. To be aware of the factors that affect Skid Resistance of cold plastic on concrete pavement by Analytic Statistic to find Correlation of Skid Resistance. Found that factors related to skidding were traffic volume, length of service, rainfall and thickness decreases efficiency of cold plastic

Physicochemical and Microbiological Stability of Phenytoin Sodium Extemporaneous Suspension

ABSTRACTObjective: To study the physicochemical and microbiological stability of phenytoin sodium extemporaneous suspension. Methods: Theextemporaneous suspension was prepared from the prompt release capsules of phenytoin sodium (100 mg/capsule). Four capsuleswere uncapped and the granules were ground into fine powders using a mortar and pestle. The powders were dispersed in sugar-freesuspension structured vehicle to achieve the concentration of 10 mg/mL. The suspensions were stored in glass and polyethylene plasticbottles and kept at 4, 25, and 40 ºC. The percent initial drug remaining, pH, sedimentation volume, viscosity, X-ray-powderdiffractometry and microbial stability were evaluated. Results: The percent phenytoin sodium concentration remained above 90% ofinitial concentration up to 56 days at all temperatures. The pH of suspensions were rather constant in both glass and polyethylenecontainers. The sedimentation volumes were 0.39 - 0.41 and redispersibilities were 3.3 - 3.5 throughout the study. The rheology ofprepared suspension exhibited a shear-thining system. The X-ray powder diffractogram showed that sediment of phenytoin sodium insugar-free suspension structured vehicle was in free acid form and no change in polymorphic form was observed after storage at 25 ºCfor 56 days. Conclusion: The extemporaneous suspension was chemically stable up to 56 days at 4, 25, and 40 ºC. The preparedsuspension met USP specification in microbial examination of nonsterile product after storage at 25 ºC for 56 days.Keywords: extemporaneous, phenytoin, stabili

Total Reducing Antioxidant Capacity of Thai Herbal Aromatic Powder (Ya-Hom) Measured by FRAP Assay

Objective: To investigate the total reducing antioxidant capacity of fivebrands of Ya-hom preparations using FRAP method.Methods: Aqueous extracts of five Thai herbal aromatic powder (Ya-hom) preparations were tested for the total phenolic compounds using Folin-Ciocalteu reagent. The antioxidant activity was examined using FRAP assay. FRAP values were expressed as micromolar of Fe(II)/g of dry powder. The total reducing capacity was compared to two standard reducing agents, ascorbic acid and a synthetic water soluble vitamin E (Trolox).Results: The total phenolic compounds of each preparation resulted in moderate to high levels of gallic acid equivalent values varying from 17.6 4.3 to 50.8 10.9 mg/g dry powder. The FRAP values were found to range from 2040 140 to 7110 136 micromolar/g dry powder. The ascorbic acid equivalent ranged from 123 16 to 401 82 micromol/g dry powder and Trolox equivalent values varied from 100 5 to 353 69 micromol/g dry powder. Conclusion: This study suggests that the selected Ya-hom preparations contain high amounts of total phenolic compounds and high FRAP values. The high FRAP values may return a potential benefit as a natural antioxidant.Keywords: Ya-hom, antioxidation, FRAP, total phenolic compounds บทค้ดย่อวัตถุประสงค์: เพื่อทดสอบความสามารถในการเป็นสารต้านออกซิเดชันของตำรับยาหอม 5 ตำรับ โดยวิธี FRAPวิธีการศึกษา: ทดสอบฤทธิต์ ้านออกซิเดชันของสารสกัดเหลวของผงยาหอม 5 ตำรับ โดยการวัด total phenolic compoundsโดยใช้ Folin-Ciocalteu reagent วัดฤทธิต์ ้านออกซิเดชันโดยโดย FRAP assayแล้วแสดงเป็นค่า micromolar ของ Fe(II) ต่อน้ำหนักผงแห้ง 1 กรัม โดยเทียบกับสารที่เป็น reducing agent มาตรฐานสองชนิด คือ ascorbic acid และ วิตามินอีชนิดละลาย (Trolox®)ผลการศึกษา: พบปริมาณ total phenolic compounds ในแต่ละตำรับในระดับปานกลางถึงสูง ตามปริมาณ gallic acid equivalent (GAE) ที่พบค่าจาก 17.6 4.3 ถึง 50.8 10.9 มก. ต่อผงแห้ง 1 กรัม พบว่าค่า FRAP มีค่าตั้งแต่ 2040 140 ถึง 7110 136 micromolar ต่อผงแห้ง 1 กรัม ค่าascorbic acid equivalent พบตั้งแต่ 123 16 to 401 82 micromol ต่อผงแห้ง1 กรัม และค่า Trolox equivalent ตั้งแต่ 100 5 ถึง 353 69 micromol ต่อผงแห้ง 1 กรัม สรุป: ตำรับยาหอม 5 ชนิดมีทัง้ total phenolic compounds และค่าFRAP ในระดับสูง ซึ่งค่า FRAP ที่สูงชี้แนะว่าน่าจะมีศักยภาพในการพัฒนาเป็นผลิตภัณฑ์ธรรมชาติเพื่อต้านออกซิเดชันคำสำคัญ: ยาหอม, ฤทธิต์ ้านออกซิเดชัน, FRAP, total phenolic compound

Earthquake Activities in the Thailand-Laos-Myanmar Border Region: A Statistical Approach

A large number of earthquakes have been recorded by instrument in the past along the Thailand-Laos-Myanmar border region. However, the locations of most of these earthquakes do not coincide with the location of morphological features which indicate seismogenic faults. Thus, a statistical evaluation of the earthquake record is focused upon in this earthquake hazard study. The spatial distributions of the a- and b-values from the frequency-magnitude distribution relationship were investigated from the complete earthquake catalogue