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  • 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

Removal Of 2, 4-dinitrophenol By Ferrate

Cooley, Gianna 01 January 2008 (has links)
Ferrate (molecular formula, FeVIO42-) has been studied increasingly since the 1970s as a disinfectant and coagulant for domestic wastewater and also as an oxidant for industrial wastewaters (Murmann and Roginson, 1974, Gilbert et al., 1978, Kazama, 1994, Jiang et al., 2002, and Sharmaet al., 2005). This research was performed to explore whether ferrate could possibly be used as chemical treatment for industrial wastewaters from plastic, chemical, dye, soap, and wood stain producing plants that contain 2, 4-Dinitrophenol (DNP). DNP is listed on the United States Environmental Protection Agency (EPA) Drinking Water Contaminant Candidate List (CCL). This list includes compounds which are not currently regulated at the national level, but there is a growing concern for the harm they may cause to the environment. Therefore, the EPA prioritizes these compounds and conducts extensive research to determine if these compounds should be regulated (USEPA, 2005). The effects of Ferrate on DNP were evaluated during these experiments. The effect of various dosages of Ferrate and different pH values was monitored over 17 minutes using UV 254 to determine the extent of oxidation of 300 mg L-1 DNP. Removal of DNP at all pHs and dosages was noted, however, a pH of 4 and a molar ratio of 14: 1 (Ferrate to DNP) removed the highest percentage of DNP at 87.3. The by-products of the 3.5 and 14: 1 molar ratio of Ferrate to DNP reactions at a pH of 4 and their toxicity were determined by measuring biochemical oxygen demand 5 day (BOD5), dissolved organic carbon (DOC), chlorine residual and chemical oxygen demand (COD), and gas chromatography/mass spectrometry (GC/MS) analysis. The BOD5 indicated toxicity, either from the residual chlorine or the organisms used for seeding not being acclimated to DNP and by-products. DOC of the 3.5 : 1 molar ratio was higher than calculated values indicating more ring breakage than was originally measured by UV 254. DOC of the 14: 1 molar ratio experiment was lower than calculated values, which indicated human error in measuring the DNP concentration. The chlorine residual was high for both experiments, 112 and 594 mg L-1, for the 3.5 and 14: 1 molar ratios, respectively. COD was unable to be measured due to chloride interference. The GC/MS data showed several chlorine-substituted benzene rings as well as carbon tetrachloride for the 3.5:1 molar ratio DNP experiments. The 14:1 GC/MS data indicated much more ring breakage with carbon tetrachloride, a substituted butane chain, many unknown straight chain chlorinated compounds and dichloro-pentane isomers as by-products.
2

Effects of Respiratory Perturbations on Aging and Healthspan in Daphnia magna

Ekwudo, Millicent Nkiruka 01 May 2021 (has links)
Aging is a degenerative process characterized by a decline in physiological functions and cellular activities. Environmental and pharmacological interventions affecting longevity pathways have been extensively studied in model organisms. This study investigated the effect of chronic mild intermittent hypoxia (4 mg O2/L) or mild mitochondrial uncoupling with three doses of 0 (control), 0.1, 1, and 5 μM of 2,4-Dinitrophenol (DNP), on life history and gene expression in four clones of Daphnia magna. Interestingly, clones from intermittent ponds displayed better tolerance to hypoxia and DNP. Although neither treatments extended longevity, hypoxia increased fecundity and body size, and decreased food consumption and respiration rate. We uncovered 12 candidate genes that were differentially expressed in hypoxia-tolerant and sensitive clones in response to hypoxia. Unexpectedly, DNP increased fecundity and mitochondrial membrane potential without affecting food intake. This work opens up an opportunity for genomic determination of the potentially important phenotypes in a model organism.

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