AN INVESTIGATION OF AQUATIC MACROPHYTE-BASED AQUATIC WASTEWATER TREATMENT SYSTEMS FOR TEMPERATE CLIMATES (ELODEA NUTTALLII, PHOTOSYNTHESIS, NUTRIENT BUDGET, ACTIVE TRANSPORT, NITRIFICATION)

Aquatic treatment systems are a low cost, low energy alternative to conventional treatment systems; they can provide secondary and advanced secondary wastewater treatment capabilities for small communities. Their potential application in temperate climates has been ignored. The research presented here was conducted to examine their applicability for use in temperate regions. A pilot-scale aquatic macrophyte-based aquatic treatment system was designed to treat primary effluent. Four aquatic macrophytes (Elodea nuttallii, Lemna minor, Myriophyllum heterophyllum, Ceratophyllum demersum) were evaluated as candidates. The hydraulic, organic, and nutrient loadings to the reactors were similar to design values for water hyacinth (Eichornia crassipes) systems. Nitrification occurred on a year round basis. Elodea nuttallii was the best candidate. The plant was productive year round (0.5-4.5 g dry wt(.)m(\u27-2)(.)d(\u27-1)) and resistant to fouling by filamentous green algae. Percent removals and removal rates of wastewater constituents in Elodea reactors indicated that these systems can provide advanced secondary treatment capabilities. Removal rates were usually correlated to plant biomass and productivity. When productivities were high, plant uptake accounted for 28-56% of the nitrogen and 61-99% of the phosphorus removal. Detrital sedimentation accounted for a significant proportion of nitrogen and phosphorus removal when the plants were less productive. Denitrification was always an important nitrogen removal mechanism. The total nitrogen (TN) and total phosphorus (TP) content of the macrophytes was high (E. nutallii; 52.6 mg TN(.)g dry wt(\u27-1); 17.7 mg TP(.)g dry wt(\u27-1)), and were not rate-limiting to productivity. Ammonia- and nitrite-oxidizing bacteria were also present in high concentrations in the reactors, particularly in association with macrophyte and sediment samples (NH(,4)(\u27+)-oxidizers, 10(\u278)(.)g dry wt(\u27-1); NO(,2)(\u27-)-oxidizers, 10(\u277)(.)g dry wt(\u27-1)). E. nuttallii was shown to be photosynthetically robust; its CO(,2) compensation point ((GAMMA) = 44.4 (mu)l(.)L(\u27-1)), oxygen evolution kinetics (K(,m) (CO(,2)) = 96 (mu)M; V(,max) = 160 (mu)mol(.)mg Chl(\u27-1)(.)h(\u27-1)), and RUBISCO/PEPcase ratio (6.6) indicate that it was adapted to low carbon conditions in the reactor. Isotope disequilibria experiments and metabolic inhibitors were used to show the presence of an active transport HCO(,3)(\u27-)-H(\u27+) symport which provided high internal CO(,2) concentrations; making Elodea particularly well suited for use in aquatic treatment systems where inorganic carbon may, at times, be limiting

Capital Investment Requirements for a 500, 1,000 and 10,000 Head Cattle Feedlot

The purpose of this study is to figure the fixed costs of constructing and equipping a 500, 1,000 or 10,000 cattle feedlot given certain assumptions and restrictions, and to analyze those costs in terms of economic efficiency. The fixed costs are divided into six areas of analysis: the equipment of the feedlot, the pole buildings, the concrete flooring for the pole buildings, the feedlot building materials, the feedlot storage equipment and the waste disposal

Graduation Trends in Machinist and Machine Shop Technology Programs in Two-Year Colleges in Great Lakes and Plains States: 2000 – 2006

The purpose of this study was to determine how two-year colleges have responded to the transformation towards a greater percentage of high-skilled workers in manufacturing industry. About 147 two-year colleges in Great Lakes and Plains States were investigated, and the study found that graduation trends in the programs and regions studied have declined, and in some cases, states and schools have lost their capacity to offer certain programs

Probabilistic modeling of one dimensional water movement and leaching from highway embankments containing secondary materials

Predictive methods for contaminant release from virgin and secondary road construction materials are important for evaluating potential long-term soil and groundwater contamination from highways. The objective of this research was to describe the field hydrology in a highway embankment and to investigate leaching under unsaturated conditions by use of a contaminant fate and transport model. The HYDRUS2D code was used to solve the Richards equation and the advection–dispersion equation with retardation. Water flow in a Minnesota highway embankment was successfully modeled in one dimension for several rain events after Bayesian calibration of the hydraulic parameters against water content data at a point 0.32 m from the surface of the embankment. The hypothetical leaching of Cadmium from coal fly ash was probabilistically simulated in a scenario where the top 0.50 m of the embankment was replaced by coal fly ash. Simulation results were compared to the percolation equation method where the solubility is multiplied by the liquid-to-solid ratio to estimate total release. If a low solubility value is used for Cadmium, the release estimates obtained using the percolation/equilibrium model are close to those predicted from HYDRUS2D simulations (10–4–10–2 mg Cd/kg ash). If high solubility is used, the percolation equation over predicts the actual release (0.1–1.0 mg Cd/kg ash). At the 90th percentile of uncertainty, the 10-year liquid-to-solid ratio for the coal fly ash embankment was 9.48 L/kg, and the fraction of precipitation that infiltrated the coal fly ash embankment was 92%. Probabilistic modeling with HYDRUS2D appears to be a promising realistic approach to predicting field hydrology and subsequent leaching in embankments

Thermodynamic study of heavy metals behavior during municipal waste incineration

The incineration of municipal solid waste (MSW) contributes significantly to the presence of heavy metals in urban area aerosols. It is thus important to ascertain the quantities and chemical forms of the heavy metals (HM) that are emitted from the incineration plant stacks. The behaviour of HM, which depends strongly on the thermal and chemical environments, was investigated herein with a modelling approach, consisting of several parts. First, a refuse bed combustion model was developed for simulating on-grate MSW incineration. It describes most of the physico-chemical and thermal phenomena occurring during waste combustion. Second, results from the bed model were taken as boundary conditions to perform 3D simulations of the post-combustion zone and of the boiler. The case studied was of the Strasbourg incineration plant. Finally, the local thermal conditions and the local elementary compositions of gas and solid phases obtained from these simulations were used to carry out thermodynamic calculations of the speciation of HM at each point in the incinerator. The results for four metals (Cd, Zn, Pb, Cr) are presented, discussed and compared to available data. Predicted species are in agreement with observations for volatile metals, except lead, whose volatilization seems overestimated

The Relationship Between Social Integration and Physical Activity, Diet, and Sleep Among Youths: Cross-sectional Survey Study

Background: Social integration has been shown to predict physical activity (PA), diet, and sleep in adults. However, these associations have not been well-studied in youth samples. Using a life course perspective, it is imperative to study this in youths as social and health behaviors are established early in life. Objective: The purpose of this study was to understand the relationship between social integration and PA, diet, and sleep for urban, middle-school youth. Methods: Cross-sectional baseline data from middle-school youths (N=73) who participated in an afterschool health behavior intervention were included in this study. Results: Time with friends significantly predicted moderate to vigorous intensity PA (β=.33, P=.02). Time spent with family was significantly related to fruit consumption (t66=1.38, P=.005) and vegetable consumption (t72=1.96, P=.01). Conclusions: Social integration appears to be related to both PA and nutrition behaviors in youths. Future research should expand on our findings to explain how different domains of social integration may impact youths’ health behaviors

A Study Of Connective Leadership In Five Midwestern School Districts

92 leavesExtending the work of Lipman-Blumen (1996) in the field of leadership, this study focused on the operationalization of connective leadership in school superintendents. The question pursued in this study concentrated on how school superintendents operationalize the achieving styles of Lipman-Blumen’s (1996) connective leadership model. This qualitative, phenomenological research centered on educational leadership in a Midwestern state. The central research question, “How are the three main achieving styles of Connective Leadership (direct, instrumental, and relational) operationalized in school superintendents?” guided my study. Data were collected from five semi-structured interviews of school superintendents in a Midwestern state. These school leaders were specifically selected through an identification process with School Administrators of Iowa. Data analysis was conducted through the process of using predetermined themes, searching for additional themes through coding; triangulation; member checking and data interpretation. This study found that connective leadership and the operationalization of the achieving styles exists in these five participants. The participants utilized each achieving style as they maneuvered through their leadership responsibilities on a daily basis. Participants accessed the achieving styles differently and some felt more comfortable in specific achieving styles than others. The participants felt that the direct achieving styles were the most difficult to access but did acknowledge their relevancy in their work as educational leaders. From local issues with teachers or community members to working with local and state leaders, the achieving styles were important for each district leader. It is the conclusion of this study that in order to achieve all of the different areas of educational leadership, adopting a leadership model and being reflective in one’s leadership is essential. Quality leadership in the field of education requires a multi-leveled leadership approach that involves all stakeholders from multiple leadership styles

Multi-regime transport model for leaching behavior of heterogeneous porous materials

Abstract Utilization of secondary materials in civil engineering applications (e.g. as substitutes for natural aggregates or binder constituents) requires assessment of the physical and environment properties of the product. Environmental assessment often necessitates evaluation of the potential for constituent release through leaching. Currently most leaching models used to estimate long-term field performance assume that the species of concern is uniformly dispersed in a homogeneous porous material. However, waste materials are often comprised of distinct components such as coarse or fine aggregates in a cement concrete or waste encapsulated in a stabilized matrix. The specific objectives of the research presented here were to (1) develop a one-dimensional, multi-regime transport model (i.e. MRT model) to describe the release of species from heterogeneous porous materials and, (2) evaluate simple limit cases using the model for species when release is not dependent on pH. Two different idealized model systems were considered: (1) a porous material contaminated with the species of interest and containing inert aggregates and, (2) a porous material containing the contaminant of interest only in the aggregates. The effect of three factors on constituent release were examined: (1) volume fraction of material occupied by the aggregates compared to a homogeneous porous material, (2) aggregate size and, (3) differences in mass transfer rates between the binder and the aggregates. Simulation results confirmed that assuming homogeneous materials to evaluate the release of contaminants from porous waste materials may result in erroneous long-term field performance assessment.

The 4-H Youth Development Professionals Workload Relationship to Job Satisfaction

A study to determine what job responsibilities Extension 4-H youth development professionals (n=241) chose to spend their work time doing and how the workload related to their job satisfaction and burnout is discussed in this paper. Workload was determined using the 4-H Professional, Research, Knowledge, and Competencies (4-H PRKC). Professionals identified their level of job satisfaction and burnout. Based on the previous research on workload, burnout, and job satisfaction, 4-H youth development professionals are prime candidates for experiencing low job satisfaction and increased burnout, which may lead to professionals leaving the organization early. 4-H youth development professionals reported being satisfied with their job and felt very little burnout. Even with the positive job satisfaction and low burnout, there are strategies shared for each of the 4-H PRKC domains to help 4-H professionals continue to have a high level of job satisfaction and low burnout. Many of the strategies that are shared in this paper are applicable to not only 4-H youth development professionals but to any professional who works in the field of youth development