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Статті в журналах з теми "628.5:66.002.8"
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Majumder, Manish, B. Gopinath, Girish Koni, and Sanjeev Kumar Singh. "New Spectrophotometric Determination of Tinofovir in Bulk and Pharmaceutical Dosage Form." E-Journal of Chemistry 6, no. 2 (2009): 537–40. http://dx.doi.org/10.1155/2009/796402.
Повний текст джерелаАнотація:
Two new, selective and sensitive visible spectrophotometric methods (method A and B) have been developed for the estimation of tinofovir in bulk and in pharmaceutical preparations. Tinofovir was subjected to acid hydrolysis and this acid hydrolyzed drug was used for the estimation. Method A is based on the reaction with 3-methyl-2-benzothiazolinone hydrazone in the presence of ferric chloride, to form a colored species with a λmaxat 628.5 nm. Method B is based on the reaction with Folin-ciocalteu phenol’s reagent under alkaline condition with a λmaxat 768 nm. Beer’s law is obeyed in the concentration range of 5-40 µg/mL for method A and 2-30 µg/mL for method B, respectively. The methods were extended to pharmaceutical formulations and there was no interference from any common pharmaceutical excepients and diluents. The result of analysis has been validated statistically and by recovery studies.
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Rusydiana, Aam, and Salman Al Parisi. "The Measurement of Islamic Bank Performance: A Study Using Maqasid Index and Profitability." Global Review of Islamic Economics and Business 4, no. 1 (December 8, 2016): 001. http://dx.doi.org/10.14421/grieb.2016.041-01.
Повний текст джерелаАнотація:
This study aims to 1) measure Syariah Maqasid Index (SMI) and Profitability Index (PI) of Islamic Banks, and 2) compare the Syariah Maqasid and Profitability Index of Islamic Banks during 2011-2014 with cartesian diagram. This research consists of 2 methods: syariah maqasid index weighting (sekaran method), and Comparative Performance Index (CPI). The object of research consist of 11 Islamic Banks (BUS) in Indonesia with annual data 2011 to 2014. Result: Syariah Maqasid Index of BUS during 2011-2014 from the highest to the lowest, namely Panin Syariah (0254), BCAS (0212), BMI (0208), BRIS (0207), BSM (0202), BSB (0.2008), BJBS ( 0.2006), Victoria Syariah (0199), Maybank Syariah (0197), BNIS (0195), Mega Syariah Bank (0172). Then Profitability Index of BUS in 2011-2014 from the highest to the lowest, namely Maybank Syariah (628.5), Bank Mega Syariah (472.1), BSM (459.9), Panin Syariah (395.5), Victoria Sharia (355.4), BNIS (252.6), BMI (218.2), BCAS (155.4), BSB (150.9), BRIS (135.3), and BJBS (122.3). Conclusion: The highest of Syariah Maqasid Index is Panin Syariah Bank in period 2011-2014, while the highest of Profitability Index is Maybank Syariah in period 2011-2014.
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Bralewska, Karolina, and Joanna Rakowska. "Concentrations of Particulate Matter and PM-Bound Polycyclic Aromatic Hydrocarbons Released during Combustion of Various Types of Materials and Possible Toxicological Potential of the Emissions: The Results of Preliminary Studies." International Journal of Environmental Research and Public Health 17, no. 9 (May 5, 2020): 3202. http://dx.doi.org/10.3390/ijerph17093202.
Повний текст джерелаАнотація:
The aim of this study was to compare the concentrations of particulate matter (PM) and PM-bound polycyclic aromatic hydrocarbons (PAHs) during the combustion of various types of materials (i.e., oak, beech, and pine wood, polypropylene, polyurethane, paper, cotton, and oriented strand board (OSB)), and to compare the carcinogenic, mutagenic, and toxic potential of the emissions during the burning of these materials. Personal portable sampling devices were used to collect samples and to determine concentrations of PM4, total suspended particles (TSPs), PM-bound PAHs. The samples were collected during controlled fires under laboratory conditions. The highest PM concentration was recorded during the burning of polyurethane (PM4-1818 mg/m3, TSP-2800 mg/m3), while the highest concentration of PAH mixture was recorded when burning OSB (628.5 µg/m3 PM4-bound; 791.2 µg/m3 TSP-bound PAHs). Thus, the highest carcinogenic (85.5 µg/m3), mutagenic (68.2 µg/m3) and toxic equivalents (26.4 ng/m3) of the PAH mixture were noted during OSB combustion. Carcinogenic potential (CP) of PAH group was determined mainly by phenanthrene (CP on average 21.6%) and pyrene concentrations (13.3%). The results of the study express possible adverse effects from PM-bound PAHs released during combustion for firefighters and other people staying near a fire site.
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Pichler, Alexander, Michael Khalil, Christian Langkammer, Daniela Pinter, Stefan Ropele, Siegrid Fuchs, Gerhard Bachmaier, Christian Enzinger, and Franz Fazekas. "The impact of vascular risk factors on brain volume and lesion load in patients with early multiple sclerosis." Multiple Sclerosis Journal 25, no. 1 (October 13, 2017): 48–54. http://dx.doi.org/10.1177/1352458517736149.
Повний текст джерелаАнотація:
Background: Vascular risk factors (VRF) in multiple sclerosis (MS) patients have been associated with lower brain volumes. It is currently unknown if this association already exists in early MS and how it develops over time. Methods: We identified 82 patients with clinically isolated syndrome (CIS) ( n = 61) or with early relapsing-remitting MS ( n = 21) and assessed their VRF including arterial hypertension, hyperlipidaemia, diabetes mellitus and smoking. We analysed T2-lesion load, normalized brain volume (NBV), cortical grey (cGMV) and white matter volumes (WMV), thalamic and basal ganglia volumes at baseline and follow-up magnetic resonance imaging (MRI) and assessed the percentage of brain volume change (PBVC) using SIENA. Results: Patient mean age was 32.4 (±8.7) years and 54 (65%) were women. Median follow-up period was 42 (29–54) months. In total, 26 patients (31.7%) had one or more VRF (VRF+). At baseline, VRF+ patients had a lower NBV (1530.9 cm3 vs 1591.2 cm3, p = 0.001), a lower cGMV (628.5 cm3 vs 668.6 cm3, p = 0.002) and WMV (752.2 cm3 vs 783.9 cm3, p = 0.009) than VRF-negative patients. Similar results were obtained at follow-up. PBVC was comparable between patients with and without VRF. Conclusion: VRF are associated with lower brain volume already in early MS but do not lead to increased brain volume loss during 3.5 years of follow-up.
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Pieczka, Adam, Frank C. Hawthorne, Neil Ball, Yassir Abdu, Bożena Gołębiowska, Adam Włodek, and Jan Żukrowski. "Graftonite-(Mn), ideallyM1MnM2,M3Fe2(PO4)2, and graftonite-(Ca), ideallyM1CaM2,M3Fe2(PO4)2, two new minerals of the graftonite group from Poland." Mineralogical Magazine 82, no. 6 (May 15, 2018): 1307–22. http://dx.doi.org/10.1180/minmag.2017.081.109.
Повний текст джерелаАнотація:
AbstractTwo new minerals of the graftonite group, graftonite-(Mn), ideallyM(1)MnM(2),M(3)Fe2(PO4)2, and graftonite-(Ca), ideallyM(1)CaM(2),M(3)Fe2(PO4)2, were discovered in phosphate nodules of two beryl–columbite–phosphate pegmatites at Lutomia and Michałkowa, respectively, in the Góry Sowie Block, Lower Silesia, southwest Poland. Graftonite-(Mn) is pinkish brown, whereas graftonite-(Ca) shows more brownish colouration. Both minerals have a vitreous lustre, a good cleavage observed along (010) and irregular fracture; both are transparent and neither of them is fluorescent. They are brittle and have a Mohs hardness of ~5. The minerals are non-pleochroic, colourless in all orientations, biaxial (+), with mean refractive indices α = 1.710(2) and 1.690(2), β = 1.713(2) and 1.692(2), and γ = 1.725(2) and 1.710(5), respectively. With complete order of Ca at theM(1) site, the formulae of the holotype crystals areM(1)(Mn0.70Ca0.30)M(2),M(3)(Fe1.34Mn0.60Mg0.06Zn0.01)Σ3(PO4)2for graftonite-(Mn) andM(1)(Ca0.98Mn0.02)M(2),M(3)(Fe1.38Mn0.56Mg0.05)Σ3(PO4)2for graftonite-(Ca). Both crystal chemistry and crystal-structure refinement (R1= 2.34 and 1.63%, respectively) indicate that theM(1) site is occupied dominantly by Mn in graftonite-(Mn) and by Ca in graftonite-(Ca), and theM(2) andM(3) sites are occupied by Fe2+and Mn2+, with Fe2+dominant over Mn2+at the aggregateM(2) +M(3) sites. Graftonite-(Mn) and graftonite-(Ca) are isostructural with graftonite,M(1)FeM(2),M(3)Fe2(PO4)2(monoclinic system; space-group symmetryP21/c), with the unit-cell parametersa= 8.811(2) Å,b= 11.494(2) Å,c= 6.138(1) Å, β = 99.23(3)° and V = 613.5(4) Å3, anda= 8.792(2) Å,b= 11.743(2) Å,c= 6.169(1) Å, β = 99.35(3)° andV= 628.5(1) Å3, respectively. The densities calculated on the basis of molar weights and unit-cell volumes are 3.793 g/cm3for graftonite-(Mn) and 3.592 g/cm3for graftonite-(Ca). The eight strongest lines in powder X-ray diffraction patterns on the basis of single-crystal data are, respectively [d, Å,I(hkl)]: 2.874, 100, (230 + 040); 2.858, 79, (221); 3.506, 73, (130); 2.717, 79, ($\bar{3}$11); 2.952, 55, (131); 2.916, 53, ($\bar{1}$12); 2.899, 44, (300); 3.016, 35, ($\bar{1}$02); and 3.654, 100, (130); 2.979, 85, (221); 3.014, 77, (230); 3.042, 76, (040 +$\bar{1}$12); 2.834, 68, ($\bar{3}$11); 3.097, 57, (131); 3.133, 56, ($\bar{1}$02); 2.542, 30, (311). Both minerals are common primary phosphates in phosphate nodules, occurring as lamellar intergrowths with sarcopside ± triphylite/lithiophilite, products of exsolution from a (Li,Ca)-rich graftonite-like parent phase crystallized at high temperature from P-bearing hydrosaline melts.
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Faisal, Sobia, Manmeet Kaur, and Ashish Samat. "Presentation of ACTH Independent Cushing’s as Severe Insulin Resistance During Pregnancy." Journal of the Endocrine Society 5, Supplement_1 (May 1, 2021): A152. http://dx.doi.org/10.1210/jendso/bvab048.307.
Повний текст джерелаАнотація:
Abstract Introduction: Cushing’s syndrome is very rare in pregnancy with around 200 cases reported in literature. It remains a diagnostic dilemma as pregnancy itself is a hypercortisolemic state. Several clinical characteristics of Cushing’s syndrome such as insulin resistance and hirsutism may overlap with normal variants of pregnancy and therefore leading to a missed diagnosis. We hereby present a case of a young pregnant woman with severe insulin resistance, with workup consistent with Cushing’s syndrome. Clinical Case: This was a 27-year-old pregnant woman with DM type 2 diagnosed about 7 years ago. During her pregnancy she was started on insulin and was later admitted to the hospital at 32 weeks for inpatient management of pre-eclampsia and uncontrolled hyperglycemia. Endocrine was consulted for severe insulin resistance and persistent hyperglycemia. On exam patient was noted to be obese with facial plethora, frontal balding and significant facial hirsutism. During the pregnancy she had noted significant weight gain with substantial worsening of frontal balding and hirsutism. Her current pregnancy was spontaneous but was after many years of trying to conceive. Prior pregnancy 8 years ago was uncomplicated with no history for GDM at that time. Review of recent pre-pregnancy imaging revealed left adrenal mass measuring 3.5 cm with 40 HU which measured around 2 cm 8 years ago. Biochemical work up revealed elevated 8 am cortisol at 35.4 ug/dL (ref range 6.2 - 19.4) with suppressed ACTH <5 pg/mL (6 – 50). Testosterone was high at 299 ng/dL (8 – 48) and DHEAS was low normal at 37 mcg/dL (18 – 391). Plasma and 24 hour urine metanephrine collection results were normal. 24-hour urine free cortisol was measured and was elevated at 628.5 mcg/24(4.0–50.0). Midnight salivary cortisol was 0.87 mcg/dL (<OR=0.09). Patient was managed conservatively with plan for surgical intervention post-delivery. Pregnancy was complicated by PPROM at 35 weeks with subsequent cesarean section. Baby was of average weight but developed mild hyperbilirubinemia which required short NICU stay. On reevaluation at 4-week postpartum period, repeat biochemical workup revealed elevated cortisol of 22.5 mcg/dL, ACTH <5 pg/ml, elevated 24-hour urine cortisol 163.9 mcg/24h with appropriate urinary creatinine. Testosterone level was improved postpartum to 9 ng/dL. DHEAS was 39 mcg/dL. Repeat imaging with CT with adrenal protocol revealed left adrenal mass measuring 2.3 cm with 20 HU with absolute washout of 79%. She was started on ketoconazole is now awaiting surgical intervention. Conclusion: We suspect that this patient may have had pregestational subclinical Cushing’s syndrome which eventually progressed to Cushing’s syndrome during pregnancy. Although this is a rare finding during pregnancy, workup for Cushing’s should be considered in pregnant women with severe insulin resistance, hirsutism, hypertension and pre-eclampsia.
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Strack, Alison M., E. Carballo‐Jane, V. H. Mendoza, K. Gagen, L. McNamara, J. Gorski, G. Eiermann, et al. "Profiling across species for the identification of optimal animal models of dyslipidemia." FASEB Journal 24, S1 (April 2010). http://dx.doi.org/10.1096/fasebj.24.1_supplement.628.5.
Повний текст джерела
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Mansuri, Sudaba, Alaa Badawi, Sheena Kayaniyil, David Cole, Stewart Harris, Mary Mamakeesick, Jonathon Maguire, Bernard Zinman, and Anthony Hanley. "Associations of total, bioavailable, and free 25(OH)D concentrations with insulin resistance and beta cell function in an Aboriginal Canadian community (628.5)." FASEB Journal 28, S1 (April 2014). http://dx.doi.org/10.1096/fasebj.28.1_supplement.628.5.
Повний текст джерела
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Straight, Aaron, and Christopher Carroll. "Centromere assembly requires selective recognition of centromeric chromatin by centromere protein N." FASEB Journal 22, S1 (March 2008). http://dx.doi.org/10.1096/fasebj.22.1_supplement.628.5.
Повний текст джерела
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Yanaka, Akinori. "Acid Inhibitors Exacerbate H.pylori‐Induced Gastritis Both In Vitro And In Vivo." FASEB Journal 29, S1 (April 2015). http://dx.doi.org/10.1096/fasebj.29.1_supplement.628.5.
Повний текст джерелаДисертації з теми "628.5:66.002.8"
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Любека, Андрій Миколайович. "Гранулювання багатокомпонентних рідких систем в псевдозрідженому шарі". Thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/39467.
Повний текст джерелаАнотація:
Дисертаційна робота спрямована на вирішення важливої науково-технічної
задачі – підвищення ефективності процесу одержання інноваційних гранульованих
органо-мінеральних добрив необхідних для впровадження принципів раціонального
землекористування.The dissertation is aimed at solving an important scientific and technical problem - increasing the efficiency of the process of obtaining innovative granular organo-mineral fertilizers necessary for the implementation of the principles of rational land use. The dissertation is devoted to increase efficiency of process granulation in a fluidized bed of multicomponent heterogeneous liquid systems containing in equal quantities nutrients of an organic and mineral origin from obtaining complex granular humic-organomineral fertilizers with specified properties.
Диссертационная работа направлена на решение важной научно-технической задачи - повышение эффективности процесса получения инновационных гранулированных органо-минеральных удобрений необходимых для внедрения принципов рационального землепользования.
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Zaidi, Syed Azhar Mehdi. "The control of combustion and pollutant emissions of pulverised fuel flames through the implementation of fuzzy logic based embedded reasoning." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398941.
Повний текст джерела
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Handley-Sidhu, Stephanie. "Biogeochemical controls on the corrosion and fate of depleted uranium." Thesis, University of Plymouth, 2008. http://hdl.handle.net/10026.1/500.
Повний текст джерелаАнотація:
Depleted uranium (DU) is a by-product of the nuclear fuel industry and is used in anti-tank penetrators due to its high density, self-sharpening and pyrophoric properties. Military activities have left a legacy of DU waste in terrestrial and marine environments and presently there are no clean up procedures in place. In order to understand the fate of this DU, long term (500 days) microcosm experiments simulating key environments have been carried out for the first time to investigate the mechanisms and rates of DU corrosion as a function of the biogeochemical and environmental conditions.
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Leskinen, Anumaija. "Investigations of the use of natural organic matter as a remediation material." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8471.
Повний текст джерелаАнотація:
Industrial activities and accidental releases often introduce a large amount of inorganic and organic contaminants to the environment. Humic substances interact strongly with metals and organic pollutants. In this study, this property was exploited in order to establish new remediation materials in two environmental applications and in one pharmaceutical application. The two remediation materials under investigation were sludge and sediment, ST sludge and CE sludge, respectively. The first application aimed at investigating the use of the remediation materials to remove arsenic, iron, and uranium from the industrial effluents. The main results were the release of iron from ST sludge inhibited its usage as remediation material whereas CE sludge showed excellent performance. The extractions were both rapid and efficient. The second application studied the extraction of organic contaminants. The objective of this study was to find a new remediation material for removal of organic contaminants. The remediation materials showed similar and excellent performance on extraction of chlorinated anilines, phenols and benzenes. The third application investigated the extraction of iodine species from urine. It aimed at determining whether the radioactive iodine can be extracted from the urine and thereby concentrated into a smaller volume of solid. Even though the extraction percentages from urine were not as promising as from deionised water and synthetic urine, scientific interest was raised and further investigations on the effect of the composition of urine and solubility of sludges for the extraction of iodine species were recommended. The outcome of the presented study was interesting both scientifically and economically. The promising extraction results for arsenic, iron and uranium indicate that the CE sludge is ready to be tested in a field study. The extraction of organic compounds by both remediation materials was also promising. However, further studies on permeability and solubility were recommended.
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Elliott, Claire. "Novel electrochemical systems for asymmetric oxidation." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8491.
Повний текст джерелаАнотація:
Organic reactions, which can be carried out in water and in the absence of heavy metals, are becoming more important today due to concerns over safety and environmental impact. Thus if an oxidation reaction can be carried out, where the oxidant is generated in-situ using electrolysis, then this is advantageous over existing systems that use strong or large volumes of stoichiometric oxidant and solvent, that cannot be recycled. In this thesis a wide variety of conditions and methods for producing enantiomerically enriched epoxides and sulfoxides have been reported using both electrochemically generated percarbonate and hypochlorite. It has been possible to carry out a range of oxidation reactions both as a one-pot reaction and with the oxidant generated in a batch process. Carrying out sulfoxidation reactions as a batch process with a carbonate solution it is possible to obtain ees of 20%. Using our in-situ generation of oxidant, as a one-pot electrochemical reaction, has provided a wide range of sulfoxides in good to excellent yield, with the application of this system to the oxidation of alkenes using a chiral iminium salt resulting in 100% conversion, with up to 44% ee.
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Elekwachi, Chijioke Obioma. "Bioinformatics resources to support bioremediation research." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595818.
Повний текст джерелаАнотація:
Contamination of ecosystems by xenobiotic substances has led to significant negative impacts on the ecologies and on the health and economic livelihood of the human populations in affected environments. Bioremediation, particularly microbial bioremediation, has proven to be a safe, low-cost and environmentally friendly method for remediation of such areas. However, a lack of complete understanding of the metabolic, enzymatic and cellular processes involved has made it difficult to model and predict outcomes of field processes. The ability of researchers to make critical decisions capable of influencing the direction and outcomes of these processes is also hampered. This study outlines the results of a survey and describes the electronic Microbial BioRemediation (eMBR) web portal, designed to improve collaboration in the bioremediation research community. It describes the structure, algorithms and output of three bioinformatics resources developed and deployed via the portal. eMBRLitMine addresses the problem of identifying which microorganisms would be suitable for remediating sites contaminated by named compounds. It combines named-entity recognition algorithms, a mySQL database, graph rendering technologies and Perl scripts to create, from the vast information available within published literature, a statistical co-occurrence matrix which it uses to infer possible associations between microorganisms and particular contaminants. This provides valuable insights into possible bacteria/contaminant relationships and highlights bacterial species that could be used in remediation of specified contaminants. eMBRCatalogue is a moderated and searchable database cataloguing bioremediation case studies. Implemented as an eXtensible Markup Language (XML) database employing a user-generated-content framework, it provides background knowledge necessary for planning and execution of bioremediation activities. Developed following the construction of a comprehensive metabolic biodegradation network, eMBRHelper enables the delineation of possible biodegradation pathways for named contaminants. By integrating relevant chemical, enzymatic and genomics information, it attempts to model the interplay between contaminants, enzymes, microorganisms and degradation pathway, enabling researchers to make informed decisions for improved outcomes, particularly for remediation exercises involving bioaugmentation. The study also analysed usage of the portal and resources, made recommendations for future developments and highlights avenues for further informatics support for the bioremediation research sector.
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Olimah, Joseph Abah. "Mobility and bioavailability of arsenic in ochre amended soils." Thesis, University of Reading, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.632999.
Повний текст джерелаАнотація:
Contamination of soil with arsenic (As) is a global environmental concern because As is toxic and carcinogenic. Ochre, a waste generated from mine water processing, has great potential for the remediation of As contaminated soils due to its high iron (Fe) oxyhydroxides content. Iron oxyhydroxides have large reactive surface areas for As adsorption. This research investigated the potential of ochre to adsorb As in solution and in contaminated soils and also assessed the possibility of using ochre to eliminate As exposure transport pathways (leaching to groundwater, plant uptake and soil ingestion).
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Mariner, Richard Clive. "Development and characterisation of a novel biological system for removing managanese form contaminated waters." Thesis, Bangor University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488875.
Повний текст джерела
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Cai, Zhuo. "Characterisation of electrochemically activated solutions for use in environmental remediation." Thesis, University of the West of England, Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418216.
Повний текст джерелаАнотація:
This thesis aims to investigate the production of electrochemically activated solution via electrolysis of diluted NaCI solution using a commercial electrochemical system (STEL device), characterise the activated solution, and evaluate the potential application of this solution in the treatment of water containing organic compounds. The research shows that the electrolytic cell in the STEL device consists of a titanium based metal oxide (Ir02, Sn02, and Ti02) coated anode, a tubular titanium cathode, and a tubular ceramic diaphragm that separates the anode and cathode. A model electrolytic cell using STEL anode material was designed and constructed for investigating reaction mechanisms occurring at the electrode and identifying the oxidising species generated at the anode during the electrolysis of NaCI solution. Experimental results show that chlorine and oxygen were two main oxidants contained in the anolyte, indicating that the generation of chlorine and oxygen are involved in the electrode reactions. The evolutions of chlorine and oxygen were found to be achieved via the formation of a series of adsorbed intermediates such as OHad, Oad on the anode surface during electrolysis. Evidences for the occurrence of the intermediates were obtained by several electrochemical observations. It is suggested that the evolution reaction of chlorine involves a mechanism in which an intermediate of OClad is formed instead of Clad. The adsorbed intermediates may also be released from the anode surface to form chlorine free radicals and hydroxyl radicals when the electrolysis is carried out at higher potentials. This was investigated using the electro-oxidation of salicylic acid (SA). It was found that in a buffer solution containing chloride ions, the oxidation processes of SA were dependent on the potential applied on the anode. At + l.5V, the reaction product was 2,4,6-trichlorophenol, indicating that chlorine free radicals were generated. At +2.5V, the obtained products included 2,5-dichloro-l,4-benzoquinone, indicating that a hydroxyl group is introduced to the benzene ring of SA. These results suggest chlorine free radicals were generated at + l.5 V while hydroxyl radicals were generated at +2.5V. The operating conditions of the STEL device were optimised with respect to the redox potential, pH, and chlorine concentration of the generated ECAS. Anolyte produced from the STEL system, using a 100/0 NaCI solution under optimised electrolysis conditions, is an acidic solution (PH 2.2) containing a mixture of oxidants with a redox potential of 1190 m V and an available free chlorine concentration of 280 mgIL. The catholyte solution is a reductive basic solution with a pH of 12.6 and a redox potential of -950m V. The anolyte solution can maintain the oxidation ability up to 6 days when it is stored in an air tight container. However, it will lose its oxidation ability in 30 min if is purged by nitrogen or in 60 min if is stirred in the atmosphere. The anolyte solution can degrade trace amounts of aromatic compounds in aqueous solution. The degradation products are dependent on the concentration and chemical nature of the reagents. Usually, 10-4M SA can be converted to ring opened compounds, while 10·3M SA can only be converted to quinonic compounds. A subsequent dechlorination step is required when using anolyte for treating aqueous solution containing organic compounds as the by products include chlorinated compounds.
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Obuekwe, Ifeyinwa S. "Biodegradation of polycyclic aromatic hydrocarbons in soils co-contaminated with metals." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.656325.
Повний текст джерелаАнотація:
Mixtures of polycyclic aromatic hydrocarbons (PARs) and heavy metals are of major concern in contaminated soil. The aim of this project was to investigate the impact of heavy metals and PAHs on microbial activity, concentrating on the mineralisation of PAHs and partitioning of phenanthrene in the presence of metals. Naphthalene and phenanthrene were used as model PAHs and Zn, Cu, Al and Fe were used as model heavy metals. 14C_ Naphthlene and 14C-phenanthrene mineralisation were followed in soil with varying concentrations of Zn, Cu, Al and Fe; a sequential aqueous\solvent extraction scheme was also used to assess the partitioning of phenanthrene in the presence of these metals. Zn and Cu (50 and 100 mg/kg) stimulated (p < 0.05) 14C-naphthalene mineralisation, but had no impact on 14C-phenanthrene mineralisation. Zn (500 and 1000 mg/kg) had no impact on 14C-phenanthrene mineralisation (p > 0.05), but Cu (500 and 1000 mg/kg) significantly reduced (p < 0.05) phenanthrene catabolism, particularly in aged Cu. Zn and Cu mixtures (500 and 1000 mg/kg) inhibited 14C-phenanthrene catabolism. 14C-Glucose mineralisation (maximum rates) and incorporation into the microbial biomass were significantly reduced at higher Zn and Cu concentrations (500 and 1000 mg/kg). Al and Fe (50 and 100 mg/kg) stimulated (p < 0.05) both 14C-naphthalene and phenanthrene mineralisation, however, Al (500 mg/kg) significantly reduced (p < 0.05) mineralisation of both PAHs. Fe (500 mg/kg) stimulated both 14C-naphthalene and phenanthrene mineralisation. Cu and Al (500 mg/kg) significantly increased (p < 0.05) 14C-phenanthrene extractable CaCh and HPCD fractions, this could be because of their great affinity for the organic and mineral soil components. The impact of metals on the biodegradation of PAHs depends on the type and concentrations of the metals, as well as the incubation time. Studies on metal-P AH impact in soil facilitates the assessment of risk, hazard and bioremediation potential at sites contaminated with both contaminants.