• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • Tagged with
  • 4
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Peroxone groundwater treatment of explosive contaminants demonstration and evaluation

McCrea, Michael V. 03 1900 (has links)
The purpose of this thesis is to evaluate the performance and cost effectiveness of a Peroxone Groundwater Treatment Plant (PGTP) designed and operated by Montgomery Watson, in support of the Defense Evaluation Support Agency's independent analysis for the United States Army Environmental Center (USAEC). Many Department of Defense installations have sites that contain groundwater contaminated with explosive materials. Primary methods for the removal of explosive materials involve the use of Granular Activated Carbon (GAC). This process, however, requires additional waste disposal and treatment of explosive laden GAC, thereby incurring additional costs. An alternate method for the treatment of contaminated groundwater involves the use of hydrogen peroxide (H2O2) in conjunction with ozone (03). This method is referred to as the Peroxone oxidation process. A demonstration of the PGTP was conducted from 19 August to 8 November, 1996, at Cornhusker Army Ammunition Plant (CAAP), Grand Island, Nebraska using a small scale version with a maximum flow rate of 25 gallons per minute. The explosive contaminants analyzed during the demonstration include 2,4,6-Trinitrotoluene (TNT), 1,3,5-Trinitrobenzene (TNB), 1,3,5-Triazine (RDX), and Total Nitrobodies. Peroxone cost effectiveness was evaluated using a 30 year life cycle cost comparison to GAC and Ultraviolet/Ozone processes
2

A study of pharmaceutical residues in wastewater from small municipalities in Northern Sweden : E-peroxone as a complementary tertiary removal technique

Hägglund, Mathias January 2021 (has links)
The conventional treatment processes used in Swedish sewage treatment plants (STPs) are not designed to remove micropollutants such as pharmaceuticals and biocides. This leads to STPs being a major source of pharmaceuticals in the environment including surface waters, coastal waters, and groundwaters all over the world. The occurrence of these compounds combined with their adverse ecological effects makes them problematic. This study aims to investigate the removal of pharmaceuticals and biocides from six conventional STPs from small municipalities in Northern Sweden. It also aims to evaluate the suitability and potential of an advanced treatment process called electro-peroxone (E-peroxone) as an additional tertiary treatment step complementing the current STPs configurations, through batch experiments. The removal of pharmaceuticals and biocides in the studied STPs showed great variability. The occurrence of pharmaceuticals was mainly in line with previous research apart from caffeine and paracetamol concentrations. Several pharmaceuticals were detected above their respective critical environmental concentration (CEC) in effluent wastewaters. The removal of pharmaceuticals was heavily influenced by paracetamol. When excluding paracetamol, the total removal of pharmaceuticals ranged from -23% to 80% in the conventional processes. After E-peroxone treatment, removals, excluding paracetamol, ranged from 61% to 93%, and no average effluent concentrations exceeded their respective CEC. In this study, E-peroxone was conducted in not optimized batch-experiments due to time constraints, but still with promising results. In a full-scale application, water matrix specific optimizing should be performed. Therefore, the removal efficiencies of pharmaceutical residues by the E-peroxone process in a plant-specific configuration would most likely be significantly increased.
3

REMOVAL OF EMERGING ORGANIC POLLUTANTS BY AN ADVANCED OXIDATION PROCESS

Bagga, Naina January 2023 (has links)
In this master thesis project, the removal of micro-pollutants (MPs) from water and wastewater were investigated by ozonation and the peroxone process O3/H2O2. Themain aim of the study was to compare the degradation efficiency of the two processes for a selection of organic biocides and active pharmaceutical ingredients (APIs) in wastewater and synthetic water. Synthetic water and wastewater effluent were spiked with fifteen compounds including twelve biocides and three APIs and samples were taken at different time points to determine degradation kinetics in treatment by the two processes, respectively. Most of the biocides tested in this study showed moderately reactivity, or were non-reactive, with O3 (e.g., Carbendazim, 1H-Benzotriazole, 1, 2-Benzisothiazol-3(2H)-one, 2, 4-Dinitrophenol, 4-nitrophenol) and some of the biocides and APIs were readily reactive with ozone (O3) and were removed from the water by direct O3 oxidationduring both processes. Trimethoprim was found to be an ozone reactive micropollutants and showed highest reactivity with O3. In the abatement mechanism, these micro-pollutants are removed based on the ozone-based processes and with hydroxyl radical •OH in peroxone process. Comparing the two processes, the peroxone process showed highest percentage removal of compounds (90-100%) within moderate time periods (30 s - 2 min) in synthetic water and (30 s to 10 min) in wastewater. The results revealed that the peroxone process showed highest removal efficiency and with higher reproducibility. Further, generally
4

Oxidation Of Acid Red 151 Solutions By Peroxone (o3/h2o2) Process

Acar, Ebru 01 September 2004 (has links) (PDF)
Wastewaters from textile industry contain organic dyes, which cannot be easily treated by biological methods. Therefore, pretreatment by an advanced oxidation process (AOP) is needed in order to produce more readily biodegradable compounds and to remove color and chemical oxygen demand (COD) simultaneously. In this research, ozone (O3) is combined with hydrogen peroxide (H2O2) for the advanced oxidation of an azo dye solution, namely aqueous solution of Acid Red 151, which is called as &ldquo / Peroxone process&rdquo / . The aim of the study is to enhance the ozonation efficiency in treating the waste dye solution. The effects of pH, initial dye and initial ozone concentrations and the concentration ratio of initial H2O2 to initial O3 on color and COD removals were investigated. Also, the kinetics of O3-dye reaction in the presence of H2O2 was approximately determined. As a result of the experimental study, it was seen that an increase in the initial dye concentration at a constant pH and initial ozone concentration did not change the COD % removal significantly, from a statistical analysis of the data. The results obtained at pH values of 2.5 and 7 gave higher oxidation efficiencies in terms of color and COD removals compared to those at pH of 10. The best initial molar ratio of H2O2 to O3 was found to be 0.5, which yielded highest treatment efficiency for each pH value studied. The results of the excess dye experiments suggest that the ozonation of Acid Red 151 follows an average first order reaction with respect to ozone at pH=2.5 and pH=7 whereas it is around 0.56 at pH=10. By Initial Rate Method, the orders with respect to individual reactants of O3 and dye were determined as one, the total order of the reaction being two for all the studied pH. As a conclusion, a further study of the peroxone process at a pH of 10 can be recommended to determine the reaction kinetics and mechanism at this pH, where radicals play an important role.

Page generated in 0.0423 seconds