Trichloroethylene fate and transport studies and biodegradation kinetics in the saturated zone

Permeable reactive barriers (PRB) are constructed from soil solid amendments to support the growth of bacteria that are capable of degrading organic contaminants. The objective of this study was to identify low-cost soil solid amendments that could retard the movement of trichloroethylene (TCE) while serving as long-lived carbon sources to foster its biodegradation in shallow groundwater through the use of a PRB. The natural amendments high in organic carbon content such as eucalyptus mulch, compost, wetland peat, organic humus were compared based on their geophysical characteristics, such as pHw, porosity and total organic carbon (TOC), and as well as TCE sorption potentials. The pHw values were within neutral range except for pine bark mulch and wetland peat. All other geophysical characteristics of the amendments showed suitability for use in a PRB. While the Freundlich model showed better fit for compost and pine bark mulch, the linear sorption model was adequate for eucalyptus mulch, wetland peat and Everglades muck within the concentration range studied (0.2-0.8 mg/L TCE). According to these results, two composts and eucalyptus mulch were selected for laboratory column experiments to evaluate their effectiveness at creating and maintaining conditions suitable for TCE anaerobic dechlorination. The columns were monitored for pH, ORP, TCE degradation, longevity of nutrients and soluble TOC to support TCE dechlorination. Native bacteria in the columns had the ability to convert TCE to DCEs; however, the inoculation with the TCE-degrading culture greatly increased the rate of biodegradation. This caused a significant increase in by-product concentration, mostly in the form of DCEs and VC followed by a slow degradation to ethylene. Of the tested amendments eucalyptus mulch was the most effective at supporting the TCE dechlorination. The experimental results of TCE sequential dechlorination took place in eucalyptus mulch and commercial compost from Savannah River Site columns were then simulated using the Hydrus-1D model. The simulations showed good fit with the experimental data. The results suggested that sorption and degradation were the dominant fate and transport mechanisms for TCE and DCEs in the column, supporting the use of these amendments in a permeable reactive barrier to remediate the TCE.

Life, Social Studies, and the Pursuit of Happiness: Using Classroom-based Multicultural Democratic Education to Challenge Conservative Notions of Civic Education

Bok (2010) argues civic understanding could improve student happiness by improving perceptions of politics and government, but the state of civic education in public schools keeps this from happening. This study argues that this notion of civic education is conservative by exploring Bok’s premises, social studies, and civic education.

Cognitive dissonance and the effect of acceptance of methodology, beliefs about religion, religious orientation, and dogmatism on the success of university students in a religious studies course

The problem investigated was negative effects on the ability of a university student to successfully complete a course in religious studies resulting from conflict between the methodologies and objectives of religious studies and the student's system of beliefs. Using Festinger's theory of cognitive dissonance as a theoretical framework, it was hypothesized that completing a course with a high level of success would be negatively affected by (1) failure to accept the methodologies and objectives of religious studies (methodology), (2) holding beliefs about religion that had potential conflicts with the methodologies and objectives (beliefs), (3) extrinsic religiousness, and (4) dogmatism. The causal comparative method was used. The independent variables were measured with four scales employing Likert-type items. An 8-item scale to measure acceptance of the methodologies and objectives of religious studies and a 16-item scale to measure holding of beliefs about religion having potential conflict with the methodologies were developed for this study. These scales together with a 20-item form of Rokeach's Dogmatism Scale and Feagin's 12-item Religious Orientation Scale to measure extrinsic religiousness were administered to 144 undergraduate students enrolled in randomly selected religious studies courses at Florida International University. Level of success was determined by course grade with the 27% of students receiving the highest grades classified as highly successful and the 27% receiving the lowest grades classified as not highly successful. A stepwise discriminant analysis produced a single significant function with methodology and dogmatism as the discriminants. Methodology was the principal discriminating variable. Beliefs and extrinsic religiousness failed to discriminate significantly. It was concluded that failing to accept the methodologies and objectives of religious studies and being highly dogmatic have significant negative effects on a student's success in a religious studies course. Recommendations were made for teaching to diminish these negative effects.

The effects of participation in an Internet -based project on the development of global knowledge, global mindedness, and global pedagogy among preservice social studies teachers

In order to prepare younger generations to live in a world characterized by interconnectedness, developing global and international perspectives for future teachers has been recommended by the National Council for the Social Studies and the National Council for the Accreditation of Teacher Education. The purpose of this study was to investigate the effects that participation in the International Communication and Negotiation Simulation (ICONS), an Internet-based communication project has on preservice social studies teachers' global knowledge, global mindedness, and global teaching strategies. ^ The study was conducted at a public university in South Florida. A combination of quantitative and qualitative approaches was employed. Two groups of preservice social studies teachers were chosen as participants: a control group composed of 14 preservice teachers who enrolled in a global education class in the summer semester of 1998 and an experimental group that included nine preservice teachers who took the same class in the fall semester of 1998. The summer class was conducted in a traditional format, which included lectures, classroom discussions, and student presentations. The fall class incorporated a five-week Internet-based communication project. The Global Mindedness Scale (Hett, 1993) and an adapted Test of Global Knowledge (ETS, 1981) were administered upon the completion of the class. ^ Contrasting case studies were utilized to investigate the impact of participation in the ICONS on the development of preservice teachers' global pedagogy. Four preservice teachers, two selected from each group were observed and interviewed to explore how they were infusing global perspectives into social studies curriculum and instruction during a 10-week student teaching internship in the spring semester of 1999. ^ This study had three major findings. First, preservice social studies teachers from the experimental group on average scored significantly higher than those from the control group on the global knowledge test. Second, no significant difference was found between the two groups in their mean scores on the Global Mindedness Scale. Third, all four selected preservice social studies teachers were infusing global perspectives into United States and world history curriculum and instruction during their student teaching internship. Using multiple resources was the common pedagogy. The two who participated in the ICONS were more aware of using the communication feature of the Internet and the web sites that reflect more international perspectives to facilitate teaching about the world. ^ Recommendations were made for further research and for preservice studies teacher education program development. ^