Studies have shown wetlands act as filters for nutrient rich waters, in part due to macrophyte properties. Differences have been found in nitrogen removal rates among plant species in studies of monocultures grown in mesocosms mimicking wastewater treatment constructed wetlands, but little research has been done on assemblages in natural or restored wetlands. This study aims to identify differences in water quality among plant assemblages in natural and restored wetlands. Thirty natural and restored wetlands in the Mississippi portion of the Mississippi Alluvial Valley were sampled four times. Water quality was measured and plant assemblages identified. Significant differences in pH, conductivity, and turbidity were found among four different plant growth forms, but nutrient concentrations were not significantly different among growth forms. Because nutrient concentrations were low, data collected may not have adequately captured potential differences in nutrient concentrations among plant assemblages.

Increasing volumes of Chromated Copper Arsenate (CCA) treated wood materials are being removed from service, either as a result of reaching the end of their service life or being replaced with non-treated wood materials. These materials, while not regulated as hazardous wastes, have the potential to leach toxic metals into the environment. Incineration and landfilling are not ideal disposal methods as incineration could result in the volatilization of carcinogenic arsenic and chromium, while landfilling requires the waste to be sorted and placed in appropriately lined landfills to prevent contaminant release. Viable disposal methods must be considered to manage the significant waste stream of CCA-treated wood. This study investigates pyrolysis and electrokinetics (EK) as possible remediation techniques for the treatment of CCA-treated wood waste. A unique bench pyrolysis reactor was designed and optimized over three pyrolysis temperatures for retention of CCA metals within the char and bio-oil pyrolysis products. A batch pyrolysis system was constructed to produce large quantities of pyrolysis char for use in EK experiments. Mass balances were performed across both bench and batch pyrolysis systems, with metal distribution trends ascertained. EK experiments were performed on the char generated during batch pyrolysis as well as CCA-treated wood waste to evaluate the efficiency of coupling the two technologies. These EK studies were performed using pH regulation at the cathode and applying constant current. Distribution of the CCA metals post-EK experiment was determined and removal efficiencies were calculated. The mobility of the CCA metals was evaluated during all phases of this investigation using Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), and Deionized Water Leaches to determine the likelihood of metal leaching under different environmental conditions.

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No description available.

Sediments can act as both a sink for pollutants and a source for aquatic contaminants. Natural and human disturbances of the sediments can release the contaminants to the overlying water where bottom dwelling, or benthic, organisms may be exposed through direct contact, ingestion of sediment particles, or uptake of dissolved contaminants present in the water. Dredging, the most common remediation technology for heavy metals, exacerbates this process. The in situ use of emulsified metal has been studied for its ability to pull heavy metals from aqueous solution and from saturated soils. It has proven successful in the laboratory with removal of lead, cadmium, copper, nickel, and uranium from aqueous solution and removal of lead and cadmium from saturated spiked soils. The use of zero-valent metal particles, particularly those of zero-valent iron (Fe0), as an in situ remediation technique, is currently undergoing evaluation. The basic mechanism for removal appears to be reduction of contaminant metals followed by the subsequent precipitation of their insoluble forms. This is accompanied by the oxidation of the zero-valent metal. In the case of iron, Fe0 undergoes oxidation to Fe2+ and then to the Fe3+ state. Particulate Fe0 has been shown to precipitate Cr6+ to Cr3+ and Pb2+ undergoes reduction to Pb0. Initially, zero-valent iron filings were used to reduce the metal contaminants, but it has been shown that smaller size iron particles, such as nano-scale iron, have higher initial reduction rates as well as a higher concentration of contaminant removal per mole of iron. Emulsion liquid membrane (ELM) technology has been employed as a remediation technique for the removal of metals from wastewater where extraction and stripping processes are performed in a single operation. The ELMs are made by forming an emulsion between two immiscible liquids, such as oil and water, and are often stabilized by a surfactant. We have attempted to demonstrate the application of the combination of these two technologies through the use of emulsified zero-valent metal (EZVM) to treat sediments with heavy metal contamination. Emulsions were prepared using vegetable oil, water, Span 85, and either nanoscale Fe, 1-3 [micro]m Fe, 4 [micro]m Mg, or a 20 wt % Fe-Mg mixture. The results presented in this study demonstrate that EZVM is a viable technique for in situ remediation of heavy metals in sediments. Laboratory scale studies have shown high levels of removal of lead and cadmium from solution using emulsified zero-valent iron. Additionally, the use of emulsified magnesium has shown the ability for high levels of removal of copper, cadmium, nickel, lead, and uranium from solution. A variety of solution matrices were also explored for a lead solution including seawater, the presence of complexing agents and humic acids. Small-scale laboratory studies have shown 65% removal of lead and 45% removal of cadmium from saturated, spiked soils. A bench scale test to demonstrate the applicability of this technique in the environment revealed similar results for the removal of lead.

This study is an attempt to address the problem associated with a high percentage of freshman students, at a private Christian high school in Florida, who either fail Algebra 1 or pass with a low percentage rate. As a result, these students either retake Algebra 1 or continue on—being inadequately prepared to successfully pass Geometry and Algebra 2. This study concentrates on the student background knowledge of mathematics, which is among the causes associated with this problem, and proposes remediation. As such, a mathematics remediation course is designed and implemented for a select number of incoming freshmen. This study includes a correlational examination to determine a possible correlation between students' background knowledge of the middle school mathematics and predicts a possible failure or successful completion of Algebra I in high school. In addition, it purposes a two-stage evolution plan in order to determine the effectiveness of the design of the remedial course as well as its effectiveness. Undertaking the design evaluation, this study uses a mixed-modes design consisting of a qualitative (interview and observation) of a number of participants and a quantitative examination (survey) of a larger sample. The correlational study indicates that there is a positive and moderately strong correlation between students' background knowledge in (middles school) mathematics and their grades in Algebra 1. The evaluation concludes that students find the design of the MIP program helpful and aesthetically appealing; however, its usability did not meet the evaluation criteria. Furthermore, the MIP Program Manager and teacher are fully satisfied with its design, content, and components.

Polychlorinated Biphenyls (PCBs) are a group of 209 congeners that are regulated under the Toxic Substance Control Act. They enter the environment as a result of industrial processes and can travel long distances. PCBs are environmentally persistent and bioaccumulate in animal populations. Painted surfaces are a common point source for PCBs and there are few options for remediating structures painted with PCB-contaminated paint. Removal of the paint can often spread contamination and disposing or burning of large structures is expensive. Experiments employing reductive dehalogenation through the use of a bimetal have shown that PCBs can be degraded in mild laboratory conditions. This dissertation describes the process of developing an application media that will enable the degradation process reported in literature to be used in a field application. An environmentally friendly reaction environment had to be established as well as the treatment‟s operating parameters. In collaboration with researchers at the National Aeronautics Space Administration (NASA), Kenney Space Center (KSC), researchers at the University of Central Florida (UCF) developed a bimetallic treatment system (BTS) that can remove and degrade PCBs from painted surfaces. The technology was evaluated during a field demonstration at a decommissioned Department of Defense facility in Badger, Wisconsin. Samples of treatment paste, paint and concrete were analyzed over a three week period. The PCB concentrations in both the paint and concrete dropped dramatically as a result of the demonstration, and in many instances, were lowered below the EPA action limit of 50ppm. In the laboratory, additional studies were conducted to further the degradation in the treatment system. Through this process, a novel degradation system was established containing zero-valent magnesium and ethanol acidified with acetic acid. The use of acidified ethanol permitted the degradation to occur with iv just magnesium powder and eliminated the use of a bimetal and therefore palladium. The technology was incorporated into a modified treatment system termed Activate Metal Treatment System (AMTS). The AMTS was used on samples from a second field site where paint chips from an manufacturing warehouse in New York state were degraded to thousands of mg/kg (ppm) below their starting concentrations.

No / In their book, Remediation: Understanding New Media, Jay David Bolter and Richard Grusin argue that digital visual media can best be understood by examining the ways in which they relate to earlier technologies of representation, a relationship that is a complex mix of homage, critique and revision. They also suggest that this process, referred to as `remediation' takes two main forms: immediacy, in which the presence of the medium is downplayed in order to achieve an effect of transparency and realism, and hypermediacy, in which the medium is foregrounded and draws attention to its own artificiality. In this paper, we explore Bolter and Grusin's ideas using the BBC series Walking with Dinosaurs, the related documentary entitled The Making of `Walking with Dinosaurs' and the official supporting BBC Online web site. We have focused on the process of remediation, by analysing the various ways in which Walking with Dinosaurs, one of the first television series to fully exploit the potential of digital technology, utilized codes and conventions from earlier media forms and technologies. We examine whether the overall effect achieved in these programmes can best be described as immediacy or hypermediacy, and have contrasted this with the associated documentary and web site. We conclude by exploring some of the broader issues relating to media representation that are raised by this ground-breaking television concept.

Providing safe drinking water and wastewater remediation are constant worldwide challenges. Adsorption is an attractive alternative to conventional techniques such as coagulation, precipitation (chemically or electrochemically), hybrid membranes, and ion-exchange for the purification of water. Biochar-based composite sorbents are increasingly popular because a range of surface chemical and physical treatments can impart performance and environmental benefits to the material. This is ideal for rural areas where more costly conventional methods may not be readily available or affordable. This dissertation focused on three different projects involving high surface area (~700 m2/g) Douglas fir biochar based multifunctional engineered adsorbents. Chapter II focuses on arsenic (III) adsorptive removal onto magnetic iron oxide dispersed onto biochar. This chapter highlights the adsorptive and redox properties of biochar composites for pollutant toxicity reduction. Chapter III focuses on pollutant toxicity neutralization after adsorption, simultaneous adsorption, and multi-phase adsorption. A MIL-53-MOF magnetite/magnetic biochar composite model system was used to demonstrate simultaneous chromium (VI) adsorption and organic pollutant rhodamine (RhB) degradation. Chapter IV is focused on tailoring the biochar to change its physical properties (enhance hydrophobicity) to achieve a specific pollutant treatment requirement (buoyancy). Oil spill remediation was used as a model example for this purpose and lauric acid-decorated magnetite biochar composite was introduced. The composites and their pollutant-loaded analogues were extensively characterized using BET, SEM, TEM, EDS, XRD, VSM, PZC, Elemental analysis, TGA, DSC, FT-IR and XPS.

Many soil and aquifer systems in the United States have been subjected to chemical contamination from past industrial and military activities. While many remediation technologies are currently being applied, in situ chemical oxidation (ISCO) is one option that is often favored because of its potential for fast remediation times and high user control. This technology involves the direct injection of chemical oxidizers (e.g. hydrogen peroxide, ozone, or permanganate) into targeted contaminant zones within the subsurface, and it has been proven to be amenable to both BTEX compounds and other volatile organic compounds such as chlorinated solvents. This study had several key objectives. Firstly, multiple soil samples, each containing an elevated level of a targeted chemical constituent, were successfully collected in order to provide a wide range of soil types in order to make important comparisons and correlations related to ISCO?s impacts. Secondly, the impact of common soil constituents on process reagent transport was studied in order to determine which soil constituents would act as primary hindrances for the transport of hydrogen peroxide and ozone into the subsurface. Thirdly, experiments were performed to pinpoint certain personnel safety threats such as excess oxygen and heat generation that might arise during process application. Fourthly, the impact of ISCO process application on soil fabric properties was examined. Soil aerobic microbial populations, soil hydraulic conductivity, soil natural organic matter constituents, and soil adsorptive properties were all shown to be impacted following the application of chemical oxidizers.