A concept for nanoparticle-based photocatalytic treatment of wastewater from textile industry

Industrial wastewater, such as the effluents from textile and garment companies, may contain toxic organic pollutants, which resist conventional wastewater treatment. Their complete and environmentally friendly degradation requires innovative technologies. Photocatalysis, an advanced oxidation process, can serve this purpose. Since 1972, when the photocatalytic activity of titanium dioxide was first noticed, photocatalysis has drawn the attention of scientists and engineers but it has not yet been widely applied in industrial practice. This is mainly related to the challenges of up-scaling from laboratory experiments to large production sites. The main goal of this thesis is to develop a concept of nanoparticle-based photocatalysis for the treatment of wastewater. Ideally, process parameters should be adjustable and process conditions should be well-defined. These constraints are prerequisite for establishing process models and comparing the photocatalytic efficiency of different photocatalysts or for different pollutants. More importantly, the configuration should be scalable, in order to cover a wide spectrum of applications. In response to these requirements, this thesis introduces a new reactor concept for photocatalytic wastewater treatment, which relies on finely dispersed photocatalysts as well as uniform and defined process conditions with regard to illumination and flow. The concept was realized in a photocatalytic setup with an illuminated flow reactor. The flow channel has a rectangular cross section and meanders in a plane exposed to two dimensional illumination. Crucial process parameters, e.g., volumetric flow rate and light intensity, can be adjusted in a defined manner. This facilitates the study on the photocatalytic degradation of different organic pollutants in the presence of various photocatalytic materials under arbitrary illumination. The thesis provides a comprehensive description of the operational procedures necessary to run photocatalytic reactions in the experimental setup. It includes three main steps: i) dispersion of photocatalysts, ii) equilibration with respect to pollutant adsorption and iii) accomplishing the photocatalytic reaction. Samples are collected in a mixing tank for online or offline analysis. The proceeding decrease in the concentration of organic pollutant is used to assess the activity of the photocatalytic materials. A particular focus lies on the first of these steps, the dispersion of photocatalysts, because it is ignored in most studies. Typically, photocatalysts are in an aggregated state. The thesis demonstrates that type, intensity and energy of dispersion exert a crucial influence on size and morphology of the photocatalyst particles and, thus, on their optical properties and, accordingly, macroscopic photocatalytic behavior. Apart from this, a proper dispersion is necessary to reduce speed of gravitational solid-liquid separation, at best, to prevent catalyst sedimentation and to avoid misleading results. The photocatalytic performance was intensively investigated for the color removal of a model dye substance, methylene blue. Commercial titanium dioxide nanoparticles, widely explored in literature, were used as a photocatalyst. Their characteristics (size, morphology, stability and optical properties) were determined. Photocatalytic experiments were carried out under UV irradiation. Influences of different factors, including the concentration of the photocatalyst, the concentration of the organic compounds, light intensity, optical pathlength and pH were examined. The degradation was quantified via the decrease of methylene blue concentration. This conversion is, however, an immediate result influenced by all process parameters, e.g., the volume, the light intensity, the optical pathlength. Hence, kinetic models on macroscopic and microscopic levels are established. Normalizations with respect to process conditions are proposed. The apparent reaction kinetics are traced back to volume- and intensity-related reaction rate constants, and the reaction rate constant at the illuminated surface of the reactor. Additionally, the model is modified to be used for time-variant UV intensities, as encountered for solar photocatalysis. These achievements allow for a comparison of the experimental results from different laboratories. Moreover, they are prerequisite for the translation of laboratory results into large scale plants. Selected case studies for further applications are introduced. The photocatalytic degradation of different organic molecules (one antibiotic and two commercial dyes) with different photocatalytic materials (commercial nanomaterials and self-synthesized magnetic particles) under artificial or natural light sources was performed. Additionally, photocatalysis was studied in a realistic application. Preliminary tests with dye solutions of a textile company in Danang, Vietnam, impressively showed the feasibility of wastewater treatment by means of photocatalysis. Based on the reported capacity of wastewater in the current treatment plant of the company, the necessary process parameters were assessed. The rough estimation showed that photocatalysis can improve the working ability of the current wastewater treatment plant. In conclusion, this thesis presents a concept for wastewater treatment by slurry photocatalysis. As the process conditions are adjustable and definable, the process can be ideally performed in laboratories for research purposes, where different materials need to be tested and the working volume can be lower than hundreds of milliliters. The photocatalytic configuration is expected to work with a capacity of hundreds of liters, although appropriate experimental evidences are reserved for further up-scaling studies

Assessing the Impact of Intergovernmental Grant Policies in Education - the Case of Florida

In recent decades, grant funding from federal and state governments has played an increasing role in school finance. However, prior research shows that education grants are not always effective, and the resources distributed to school districts are often not efficient. Increased federal and state funding does not always improve schools’ effectiveness but instead may trigger greater bureaucracy and a mass-production vision in local education administration. This research aims to provide a theoretical foundation for and empirical evidence on the impact of intergovernmental aid in education and inform future policy reforms. This study investigates the effects of federal and state grant policies on the quality of and access to local education services in relation to the grant designs and context of recipient local governments. This research evaluates two programs: the Foundation Program, an equalization aid, and the Race to the Top, a results-based grant. This research relies on fiscal transfer theories to analyze these programs. The analysis employs quantitative and qualitative data from 67 Florida school districts during 2005–2016. It applies different approaches, including a goal-free evaluation, a case study, and a quasi-experimental design. The various tools and methods utilized are difference-in-differences, spatial analysis, interaction analysis, mediation analysis, a survey, and in-depth interviews. This dissertation’s contribution to the literature on intergovernmental grants is threefold. First, this study can significantly fill the literature gaps on the impact of results-based transfers and foundation grants. Second, this research is the first empirical study considering the simultaneous implementation of the two aforementioned programs at the local level. Last, because Florida offers a representative case of both programs, these research findings could benefit public policy and administration reform across the nation. Research findings in this study indicate limited effects of the grants, resulting from a lack of a clear and singular focus on the specified output, an absence of citizen-based accountability in the implementation, and grant fungibility at the local level. This research emphasizes the importance of grant policy formulation and the determinant role of local discretion and implementation in using higher-level government funding

DIESEL OIL UTILIZING-BIOSURACTANT PRODUCING BACTERIAL ISOLATE AND CHARACTERISTICS OF PRODUCED BIOSURFACTANTS TOWARD BIOREMEDIATION APPLICATION

Joint Research on Environmental Science and Technology for the Eart

Common Errors in Speaking of English-Majored Sophomores at Tay do University, in Vietnam

It is undeniable that speaking skill is very important in learning English It is a tool to help students to find good jobs in the future especially if they expect to work for a foreign company However in the process of learning and practicing speaking English students get a lot of difficulties Therefore the research Common Errors in Speaking of English-Majored Sophomores at Tay Do University Vietnam was conducted to investigate common mistakes of English-majored sophomores from English classes course 14 at Tay Do University The questionnaire and interview were two main instruments Research results showed that Englishmajored sophomores made some common errors about pronunciation vocabulary and grammar It is hoped that sophomores can recognize and correct their errors to make the necessary changes to improve speaking skill

Avec Orima - Designing the brand identity

The thesis is a document in building the brand image for the authors’ own start-up Avec Orima. It is motivated by the need to take the company from the planning stage to the next very first step of implementing the business – designing the company’s brand identity. The thesis focused on the process of designing the brand identity. The process began with analysing the company and Finnish target market to have the insights on what the company stands for and wants to achieve. The study then continued to examine the competition in Finnish market and identify the points of differences, in order to establish the brand positioning. Upon understanding the Avec Orima brand and what it stands for, the thesis study integrated the brand identity strategy with design skills to create the basic elements of Avec Orima’s visual brand identity – logotype, typography, colours, look and feel, and imagery. Using a sample of 57 people, the authors collected data from a survey. Also, data from market research was presented. As predicted, the results justify the authors’ points on the existing behaviours, trends and rising demands in Finnish market. The authors conclude that, despite a limitation in existing customer behaviours at the moment, there are rising awareness and demand for such a service provider like Avec Orima. This conclusion is the foundation for all further studies, which are based on theoretical data, in defining the company, then brand positioning and brand identity design

Factors Affecting Consumers’ Intention in Vietnam-China Cross-border E-commerce: An Empirical Study in Hanoi, Vietnam

In the era of innovative technologies, the physical border is no longer a concern in exchanging goods thanks to the widespread use of internet connections. On this basis, the study explores the determinants that impact cross-border online consumers’ purchase intentions in Hanoi, Vietnam. As fundamental ideas, the Theory of Planned Behavior (TPB) and the Technology Acceptance Model (TAM) are integrated with the influence of the Regional Comprehensive Economic Partnership (RCEP). The examined factors consist of Consumer Attitude, Subjective Norms, Perceived Behavioral Control, Perceived Usefulness, Perceived Ease of Use, Perceived Risk, Trust, and RCEP. The research was conducted on a survey questionnaire of 253 online shoppers in Hanoi who have experienced cross-border purchasing. The data was processed using several statistical methods, namely descriptive statistics, exploratory factor analysis (EFA), correlation analysis, and regression analysis. The analysis reveals that Consumer Attitude, Subjective Norms, Perceived Behavioral Control, Perceived Usefulness, Perceived Ease of Use, and Trust have a positive influence on the consumer’s intention to cross-border e-commerce (CBEC), while perceived risk and RCEP do not exert any force on the intention. Among these variables, Risk perception and trust have been demonstrated to have the most significant impact on online purchase intention. The outcomes of the study indicate that online retailers or intermediaries adopt a third-party payment processor and publish policies to protect consumers’ private information. It is also suggested that the government should educate the public on the benefits of RCEP, implement the relevant policies, and provide guidance for the sellers to follow to utilize the advantages of RCEP

О позиции Вьетнама по вопросу сохранения мира и безопасности в связи с территориальным спором в Восточном море

The problem of territorial contradictions among different countries towards belonging of Spratly and Paracel archipelagoes is examined in the article. The Vietnamese position is proved.В статье рассматриваются вопросы, связанные с территориальными противоречиями между группой стран по вопросу принадлежности архипелага Спратли и Парасельских островов. Обосновывается позиция Вьетнамской стороны по этому вопросу