Aliphatic chlorinated compounds, such as trichloroethylene (TCE) and tetrachloroethylene (PCE), are major contaminants of ground water. A single-pass packed-bed bioreactor was utilized to study the biodegradation of organic waste mixtures consisting of PCE, TCE, and other short-chain chlorinated organics. The bioreactor consisted of two 1960-mL glass columns joined in a series. One column was packed with sand containing a microbial consortia enriched from a contaminated site. The other column provided a reservoir for oxygen and a carbon source of methane/propane that was recirculated through the reactor. Sampling was accomplished by both direct headspace and liquid effluent concentration analyses. The reactor was operated in a single-pass mode. Greater than 99% degradation of trichloroethylene, approaching drinking water standards, was observed when the bioreactor residence time ranged from 1.9 to 3.2 d. Typically, when the reactor was pulse-fed with methane, propane, and air, 1 mol of TCE was degraded/110 mol of substrate utilized. Perturbation studies were performed to characterize reactor behavior. The system's degradation behavior was affected by providing different carbon sources, a pulse feeding regime, supplementing microbial biomass, and by altering flow rates.

Improper disposal practices of the once widely used short-chained chlorinated aliphatics have made them a major component of groundwater contamination. Historically, pump and treat technology has been implemented to remediate and contain such aquifer water. After being pumped to the surface, the water is frequently treated with stripper technology. As a result, there is a high volume, low concentration contaminated air stream to either be directly emitted or treated prior to release in an effort to meet regulatory compliance. This work studied the Ž. feasibility of using biofiltration technology to remediate trichloroethylene TCE contaminated air streams. Furthermore, work focused on operational schemes that influenced the TCE degradation potential within the system. The bench-scale biofilter system contained 42 l of organic packing material and was inoculated with a propane-oxidizing microbial consortium. Propane, the primary substrate, and TCE were introduced into the biofilter in two distinct modes. Initially, TCE and propane were both continuously added to the biofilter system. The maximum TCE degradation observed under this continuous feeding scheme was 25%. Secondly, the TCE and propane were alternately pulsed or cycled in a step-wise fashion into the biofilter system. Under this operating environment, greater than 98% removal of TCE from the air stream was achieved.

A semi-batch bubble column was used to evaluate the effect of ozonation on the removal of acid yellow 17 dye from water. Results indicate that ozonation is very effective at removing acid yellow 17 dye from synthetic textile wastewater. The ozone consumed to apparent dye removal ratio ranged from 2 to 15,000 mg ozone per mg of dye decolorized and was dependent on both ozonation time and apparent dye concentration. The biodegradability of the dye wastewater was evaluated by monitoring changes in 5-day biochemical oxygen demand (BOD 5) with respect to chemical oxygen demand (COD). Results indicate that the wastewater biodegradability increased with an increase in ozonation time. Film theory was used to kinetically model the gas-liquid reactions occurring in the reactor. Modeling results indicated that during the first 10-15 min of ozonation, the system could be characterized by a fast, pseudo-first-order regime. With continued ozonation, system kinetics transitioned through a moderate then to a slow regime. Successful modeling of this period required use of a kinetic equation corresponding to a more inclusive condition. Model results are presented.

Gas is delivered during laparoscopy by insufflation with a series of conduits or ducts starting from a gas cylinder, through an insufflator, into a tube connecting the insufflator to an intraabdominal entrance site. It is used to begin and maintain pneumoperitoneum. Little is written about the dynamics of gas flow and its characteristics as it enters the abdomen. Each component of the system has an effect on the flow properties and eventual entry of gas into the abdomen. Flow characteristics such as rate, pressure limits, insufflation supply outlet diameter, tubing diameter, trocar connecting diameter, and effective trocar or needle exit diameter influence the terminal velocity of gas as it enters the abdomen. The gas-delivery system must be evaluated as a whole to determine its effect on the final exiting characteristics of gas and the ultimate effect of gas on the laparoscopic procedure and outcome. Mathematic descriptions of how fluids flow through ducts have been available for over 2 centuries.

This project demonstrated the biofiltration of a trichloroethylene (TCE)-contaminated airstream generated by air stripping groundwater obtained from several wells located at the Anniston Army Depot, Anniston, AL. The effects of several critical process variables were investigated to evaluate technical and economic feasibility, define operating limits and preferred operating conditions, and develop design information for a full-scale biofilter system. Long-term operation of the demonstration biofilter system was conducted to evaluate the performance and reliability of the system under variable weather conditions. Propane was used as the primary substrate necessary to induce the production of a nonspecific oxygenase. Results indicated that the process scheme used to introduce propane into the biofiltration system had a significant impact on the observed TCE removal efficiency. TCE degradation rates were dependent on the inlet contaminant concentration as well as on the loading rate. No microbial inhibition was observed at inlet TCE concentrations as high as 87 parts per million on a volume basis.

An assessment of influent and effluent data from 24 wastewater treatment plants (WWTPs) in the state of Georgia with design capacities of 37,850 m 3 /d (10-mgd) or greater was undertaken. Twelve months of operating data from the 2003 calendar year were evaluated. The objectives of the study were to determine the effect of rainfall intensity on the volumetric flow rate to each WWTP and to determine the relationship between flow rate and the influent five-day, biochemical oxygen demand (BOD 5) and total suspended solids (TSS) concentrations. The relationships between rainfall intensity and influent BOD concentration, rainfall intensity and influent TSS concentration, influent BOD loading and effluent BOD concentration, and influent TSS loading and effluent TSS concentration were also evaluated. Moderate to strong correlations were observed between rainfall intensity and volumetric flow rate, volumetric flow rate and influent BOD and TSS concentrations, average monthly rainfall intensity and influent BOD and TSS concentrations, and between influent BOD and TSS loadings and effluent BOD and TSS concentrations. Weak correlations were observed for some of the relationships when applied to the complete data set however, stronger correlations were achieved by performing statistical analyses of variance and pooling subsets of the data. Peaking factors for flows and loadings were similar to those reported in the literature.

As a result of an expanding global marketplace and multidisciplinary technological advances, the successful, modern engineer must work effectively in teams. Further emphasis on the importance of preparing students for teamwork was promulgated by ABET's Engineering Criteria 2000. While the concept of team-based learning is valued among many educators, the quantitative evaluation of individual student performance associated with a team-based deliverable can be challenging. The focus of this research was to evaluate the ability of engineering students enrolled in a multidisciplinary, team-based capstone design course to evaluate their personal, peer and team performance. A team-based peer/self evaluation form, developed by the Synthesis Coalition and modified by the instructors to fit the needs of the course, was utilized to collect the assessment data. Data were collected for a two year period by a single faculty member that served as instructor. Data analyses were performed to sh...

Because senior engineering students have experienced a rigorous curriculum and lived in an academic engineering environment for at least four years, one can assume that they automatically associate engineering with a profession. Furthermore, it may be assumed that senior engineering students can distinguish between those occupations considered a profession and those considered a vocation or a trade. In 1998, Mercer University implemented a freshmen course titled EGR 108: Professional Practices to teach professional and ethical concepts and skills. Current seniors in Mercer's School of Engineering completed this course as part of their freshmen curriculum. To measure senior students' understanding of professions, Mercer Engineering and Technical Communication professors developed research questions and a survey regarding entering their understanding of professions and ability to distinguish professions from vocations and trade. The measurements taken by this study assume that senior students will identify engineering as a profession but may be less prepared to classify jobs across a broader spectrum as professions or trades. This paper reports the resulting data as a means of qualifying the senior engineering students' understanding of professions and to demonstrate any differences in their perceptions of professions, vocations, and trades. Data will also be used to modify the EGR 108 Professional Practices course as needed.

This project was primarily performed by Ms. This project was primarily performed by Ms. Jennie Sheppard, an undergraduate Jennie Sheppard, an undergraduate Environmental Engineering student at Environmental Engineering student at Mercer University. Mercer University. 3 3 Outline Outline Objectives Objectives Importance Importance Background & Literature Review Background & Literature Review Methods and Materials Methods and Materials Results and Discussion Results and Discussion Summary and Conclusions Summary and Conclusions 4 4

Data showing an increase in grade point average of 0.41 over the past 30 years at the Georgia Institute of Technology were presented. The GPA increased for virtually all departments. Graduate school GPA’s also increased. Several unexpected factors were shown to influence grades. For example, Summer school grades were higher than for other terms. Possible causes and consequences of increasing GPA’s are reviewed as well as actions which may be warranted to permit return to a grading system that permits greater differentiation between students’ performance.

The motivation for this project is to determine the most effective placement of a metallic biocide in a biological sand filter. The focus of the work presented here was to develop a relationship that describes coliform deactivation in river water spiked with a solution containing copper ions. These results can be used to predict the effect of copper ion concentration on the viability of the biofilm layer in a point-of-use biosand filter. A method for measuring copper concentration in solution was established. Copper was mixed with deionized water until it approached saturation in solution. Water was collected from the Ocmulgee River. The copper solution was diluted with river water and coliform concentration was measured over time. Six different solution concentrations ranging from 0.028 to 1.65 mg/L of copper were tested and it was determined that coliform deactivation was well characterized using a first-order kinetics model. First order rate constants varied from 0.15 to 19.0 hr,...

The proposed solution is a Dual Media Biological Sand Filter with the addition of activated carbon. Considering the pesticides and other recalcitrant substances found in the Mekong River water, it becomes apparent that typical point-of-use filtration will not be an effective solution to treat the polluted water of Vietnam. In order to remove these uncommon substances, the system employs the use of two common filtration methods; a biosand filter and activated carbon filter. The filter is housed in a double bucket scheme. The first bucket contains mangrove charcoal produced in Vietnam that was activated using a 0.25 M NaCl solution; this adsorbent facilitated organic removal from the source water, while the traditional biosand filter removed potential microbial pathogens. A biosand filter is a simple, yet effective water purification system that uses cheap and readily available materials to create a sustainable and easily reconstructed system for developing countries [4]. The efficacy...

– The goal of this research was to evaluate the position of students and faculty woman engineers and to report their perception regarding belonging to the community of the School of Engineering at Mercer University. Women currently represent about 23 % of the engineering faculty, which is well above the national average of around 10%; yet out of six departments two have none and two have only one female representative each. Since the 1990s, the national average of female engineering students has been relatively stable and is approximately 20 % of the engineering student population; freshmen enrollment at the Mercer University School of Engineering follows this trend. However, according to ASEE Prism Magazine [1], Mercer University School of Engineering is number three in the United States for awarding the highest percentage of engineering bachelor's degrees to women. This paper consists of statistical analysis of employment and enrollment data and information obtained from inte...

Data showing an increase in grade point average of 0.41 over the past 30 years at the Georgia Institute of Technology were presented. The GPA increased for virtually all departments. Graduate school GPA's also increased. Several unexpected factors were shown to influence grades. For example, Summer school grades were higher than for other terms. Possible causes and consequences of increasing GPA's are reviewed as well as actions which may be warranted to permit return to a grading system that permits greater differentiation between students' performance.

This project demonstrated the biofiltration of a trichloroethylene (TCE)-contaminated airstream generated by air stripping groundwater obtained from several wells located at the Anniston Army Depot, Anniston, AL. The effects of several critical process variables were investigated to evaluate technical and economic feasibility, define operating limits and preferred operating conditions, and develop design information for a full-scale biofilter system. Long-term operation of the demonstration biofilter system was conducted to evaluate the performance and reliability of the system under variable weather conditions. Propane was used as the primary substrate necessary to induce the production of a nonspecific oxygenase. Results indicated that the process scheme used to introduce propane into the biofiltration system had a significant impact on the observed TCE removal efficiency. TCE degradation rates were dependent on the inlet contaminant concentration as well as on the loading rate. No microbial inhibition was observed at inlet TCE concentrations as high as 87 parts per million on a volume basis.

This research investigated and compared the use of both bench-and pilot-scale biofilters to determine the effectiveness of controlling styrene, methyl ethyl ketone (MEK), and acetone emissions from an industrial gas waste stream. Critical operating parameters, including contaminant loading rate, temperature, and empty bed contact time, were manipulated in both the laboratory and field. At steady-state conditions, the bench and pilot-scale biofilters showed a 99% removal efficiency for styrene when the contaminant loading rate was less than 50 g m-3 hr-1 and 40 g m-3 hr-1 , respectively. Although few data points were collected in the pilot-scale reactor where the styrene load was greater than 40 g m-3 hr-1 , the total organic contaminant load including both MEK and acetone typically ranged between 50 g m-3 hr-1 and 80 g m-3 hr-1. Greater than 99% removal efficiencies were observed for acetone and MEK in the pilot-scale biofilter at all evaluated loading rates. Also studied were biofilter acclimation and re-acclimation periods. In inoculated bench and pilot biofilter systems, microbial acclimation to styrene was achieved in less than five days. In comparison, no MEK degrading microbial inoculum was added, so during the first months of pilot-scale biofilter operation, MEK removal efficiencies lagged behind those noted with styrene. IMPLICATIONS As the regulatory trend moves toward more stringent control of volatile organic compounds, the demand will increase for cost-effective air pollution control technologies. Biofiltration, unlike more traditional technologies (scrubber, adsorption), destroys the contaminant and offers a potentially feasible, environmentally friendly, and cost-effective alternative solution. This research evaluated the potential use of biofilters at a boat manufacturing facility. Bench-and pilot-scale processes were utilized to study the effects of contaminant loading rate, potential acidic metabolite accumulation, acclimation and re-acclimation periods, and mixtures of organic wastes. Results will facilitate engineers in the design and operation of biofiltration systems.