Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Theses/Dissertations

1996

Environmental Sciences

Institution
Keyword
Publication

Articles 1 - 30 of 92

Full-Text Articles in Physical Sciences and Mathematics

Hydrogeology And Stable Isotope Investigations Of A Landfill Impacted Site In Southwest Michigan, Eliot Anong Atekwana Dec 1996

Hydrogeology And Stable Isotope Investigations Of A Landfill Impacted Site In Southwest Michigan, Eliot Anong Atekwana

Dissertations

The Cork Street landfill in the City of Kalamazoo is unlined and constructed in glacial drift material. Although water quality in some of the landfill monitoring wells is poor, the degree of the landfill’s influence to groundwater, wetlands and Davis Creek located downgradient of the landfill is unknown. The objective of this study is to evaluate the degree of the landfill’s impact in this region through hydrologic and stable isotope analysis.

Site characterization using geophysical surveys and specific conductance measurements indicates highly conductive shallow groundwater probably attributable to groundwater contamination. Hydrologic evaluation of this region shows that groundwater flows towards …


Mass Transport Of Volatile Organic Compounds Between The Saturated And Vadose Zones, Monte S. Harner Dec 1996

Mass Transport Of Volatile Organic Compounds Between The Saturated And Vadose Zones, Monte S. Harner

Theses and Dissertations

Volatile organic compounds (VOCs) dissolved in the saturated zone are transported into the vadose zone primarily by gaseous phase diffusion. If the saturated zone is remediated, VOCs present in the vadose zone may become a secondary source of contamination for the groundwater. The amount of VOCs that remain in the vadose zone is dependent on site hydrology, soil properties, and the chemical properties of the contaminants. The purpose of this study was to determine what conditions caused VOC concentrations in the vadose zone to significantly recontaminate the saturated zone. A one-dimensional numerical model was developed to investigate the transport of …


Evaluating The Hazardous Materials (Hazmat) Pharmacy Among Air Force Majcoms Using Waste Reductions And Activity Indicators, W. Edward Iseman Jr. Dec 1996

Evaluating The Hazardous Materials (Hazmat) Pharmacy Among Air Force Majcoms Using Waste Reductions And Activity Indicators, W. Edward Iseman Jr.

Theses and Dissertations

The Hazardous Materials (HazMat) Pharmacy has been designed as an environmentally friendly vehicle to handle, store, dispense, track, recycle, and dispose of hazardous materials in the Air Force. This thesis effort proposed a method in which valuable feedback for the pharmacy can be obtained. Because it is still in the early stages of implementation, there has been little feedback on the pharmacy. An activity index that uses a variable most closely associated with the generation of hazardous waste in a MAJCOM is proposed. Using an aircraft maintenance related variable, like maximum take-off weight, the fluctuations in mission over time can …


Laser-Induced Breakdown Spectroscopy On Solution Samples Using Surface Excitation, Leonard M. Berman Dec 1996

Laser-Induced Breakdown Spectroscopy On Solution Samples Using Surface Excitation, Leonard M. Berman

Theses and Dissertations

Laser-induced breakdown spectroscopy (LIBS) is a spectroscopic technique where output from a pulsed laser is focused onto a target in order to create an intense plasma. The optical emission is characteristic of the elements in the focal volume and can be used for elemental analysis. Research on the detection of nickel in solution in addition to solvent detection of CCl4, CHCl3, C2Cl4, and C2HCl3 has been performed. Breakdown was formed at the sample surface via a Q-switched Nd:YAG laser. Initially, operation of the laser was at 1064 nm/repetition rate of 5 Hz. Experiments …


Local Effects Of Solid Rocket Motor Exhaust On Stratospheric Ozone Concentrations, Brian K. George Dec 1996

Local Effects Of Solid Rocket Motor Exhaust On Stratospheric Ozone Concentrations, Brian K. George

Theses and Dissertations

Solid Rocket Motors (SRMs) power the initial flight of the Space Shuttle and Titan IV rocket. During those first two minutes after liftoff, the exhaust plumes from these motors emit large quantities of chlorine compounds and alumina particles into the atmosphere. For years scientists have argued that such a large chlorine input, injected directly into the stratosphere, would photochemically react with the surrounding air to cause significant ozone depletion. To answer the question of whether SRM exhaust causes a significant ozone depletion, Version 7 data from the Total Ozone Mapping Spectrometer (TOMS) instrument was analyzed for the 30 days prior …


The Biodegradation Characteristics Of Proposed Fuel Systems Icing Inhibitors (Fsii), Charles E. Meshako Dec 1996

The Biodegradation Characteristics Of Proposed Fuel Systems Icing Inhibitors (Fsii), Charles E. Meshako

Theses and Dissertations

The biodegradation characteristics of three fuel system icing ihhibitors (FSII) were evaluated. FSII are jet fuel additives that partition into water readily and are present in the water drained from storage tank bottoms in concentrations approaching 40%. These concentrations raise concerns as to the disposal and handling of these wastes. The current FSII, DiEGME was evaluated along with two new candidates, dipropylene glycol and glycerol formal. DiEGME appeared to be moderately but not completely biodegradable. It is likely that much of it would be removed in a wastewater treatment plant. Dipropylene glycol only showed signs of degradation after more than …


Surfactant Enhanced Microbial Degradation Of Jp-8 Contaminated Soil, John D. Thomas Dec 1996

Surfactant Enhanced Microbial Degradation Of Jp-8 Contaminated Soil, John D. Thomas

Theses and Dissertations

This research effort used an automated respirometer to evaluate the enhancement of JP-8 fuel biodegradation, from surfactant addition. Two nonionic surfactants, Novell 1412-7 and Alfonic 810-4.5 were chosen for addition to contaminated JP-8, microcosms at three levels of treatment. The three levels of treatment included sub-CMC, CMC, and supra-CMC concentrations for each surfactant. The Novell II, nonionic surfactant, exhibited inhibitory characteristics, and was eliminated from the study. The focus of the study was to determine if JP-8 was actually degraded, and if enhancement of JP-8 biodegradation would be achieved from surfactant addition. The respirometer was found to be repeatable within …


Modeling Marine Exposure To Polychlorinated Biphenyls From Sunken Ships, Charles N. Wendt Dec 1996

Modeling Marine Exposure To Polychlorinated Biphenyls From Sunken Ships, Charles N. Wendt

Theses and Dissertations

In the past, the U.S. Navy has routinely conducted SINKing EXercises (SINKEX) for training, weapon effectiveness tests, and economic disposal of aging assets. Recent concern over polychlorinated biphenyl (PCB) chemicals aboard such target vessels has resulted in a suspension of SINKEX. The U.S. Navy has approximately 200 vessels currently requiring such disposal. Environmental legislation and health concerns preclude selling such vessels to foreign governments or scrapping. This work attempted to model the fate and transport of these PCBs by examining their transport to coastal water and their accumulation in the marine food chain. The model includes biodegradation, upwelling, partitioning of …


Evaluation Of Carcinogenic Potential Of Benzo(Α)Pyrene And Dimethylbenzanthracene In Mouse Leukemic Cells, Mohammad Sharif Sultan Al Ulama Dec 1996

Evaluation Of Carcinogenic Potential Of Benzo(Α)Pyrene And Dimethylbenzanthracene In Mouse Leukemic Cells, Mohammad Sharif Sultan Al Ulama

Theses

The carcinogenic potential of benzo[α]pyrene (B(α)P) and dimethylbenzanthracene (DMBA) was tested using mouse leukemic cell lines L-5178 R and S types in tissue culture condition. It was found that B(α)P and DMBA inhibited the synthesis of DNA of R and S types of cells to about 34%, at 10 mM concentration. While B(α)P and DMBA did not show any acute toxic effect on mouse cell line Rand S types at 1 mM concentration separately. Both R and S types of cells were allowed to grow for several days in the presence of 1 mM DMBA and B(α)P respectively. Several independent …


An Activity Driver Based Analysis Of Hazardous Materials Usage At Wright-Patterson Afb, Charles D. Perham Dec 1996

An Activity Driver Based Analysis Of Hazardous Materials Usage At Wright-Patterson Afb, Charles D. Perham

Theses and Dissertations

As the Air Force has progressed and succeeded in the realm of pollution prevention, the opportunities for further progress have become more challenging. With the 'low-hanging fruit' now gone from the pollution prevention tree, new methods to identify opportunities must be adopted. This research effort applied a subset of activity based costing, activity driver analysis, to reveal pollution prevention opportunities in regards to hazardous materials usage. A sample of base organizations (civil engineering and aircraft maintenance), and a sample of the hazardous chemicals (Class C or most hazardous) used by those organizations were investigated to determine the drivers behind usage.


Reductive Dehalogenation Of Chlorinated Aromatic And Aliphatic Hydrocarbons Under Anaerobic Conditions, Monica Turner Togna Oct 1996

Reductive Dehalogenation Of Chlorinated Aromatic And Aliphatic Hydrocarbons Under Anaerobic Conditions, Monica Turner Togna

Dissertations

The process of reductive dehalogenation involves the removal of a halogen substituent from a molecule with the concurrent addition of electrons to the molecule, resulting in a more reduced and often less toxic product. Anaerobic bacteria have the potential to utilize hazardous chlorinated aromatic and aliphatic hydrocarbons as electron acceptors in metabolic reductive dehalogenation processes.

In experiments performed with chlorinated aromatic compounds a highly enriched anaerobic culture stoichiometrically converted 2,4,6-trichlorophenol (2,4,6-TCP) to 4-monochlorophenol. Dehalogenation occurred only in alkaline media (pH 8-9) at concentrations of 2,4,6-TCP up to 1 mM. Data indicated that the dehalogenating organism did not fit into any …


Scaling Up Of Water-Based Organic Reactions, Chen Gu Oct 1996

Scaling Up Of Water-Based Organic Reactions, Chen Gu

Dissertations

Three water-based organic reactions, Diels-Alder, epoxidation of olefins, and free-radical bromination have been investigated as an approach to pollution prevention. The first two systems were scaled-up by at least a factor of 20. These reactions are of special interest to the pharmaceutical and speciality chemical industries. The photo-induced free-radical bromination of alkanes with bromine in water was studied in a two-phase system. Experimental results show that all reactions have advantages resulting from being conducted in water, such as reaction rate acceleration, reaction selectivity increase, and the absorption of water-soluble gas byproduct by solvent water.

The effects of stirring rates, temperature, …


Effect Of Vitamin Supplementation On Biodegradation Of Aliphatic Hydrocarbons And Diesel Fuel, Susmita Guptapal Oct 1996

Effect Of Vitamin Supplementation On Biodegradation Of Aliphatic Hydrocarbons And Diesel Fuel, Susmita Guptapal

Dissertations

Bioremediation of hazardous wastes is proven to be environmentally benign and most cost effective technology when proper conditions are provided. However, commercialization of this method still requires comprehensive research to enhance the degradation rate to make the technology more acceptable for implementation. In this research a unique approach to increase the rate of biodegradation by vitamins supplementation was studied.

Five vitamins, niacin, biotin, folic acid, thiamin and pantothenic acid were selected for the present study. Different short chain (C8 and C9), and long chain (C16 and C17) aliphatic hydrocarbons and diesel fuel (a mixture …


Factors That Influence Changes In Temporal And Spatial Accumulation Of Debris On An Estuarine Shoreline, Cliftwood Beach, New Jersey, Usa, Laura Pace Oct 1996

Factors That Influence Changes In Temporal And Spatial Accumulation Of Debris On An Estuarine Shoreline, Cliftwood Beach, New Jersey, Usa, Laura Pace

Theses

A field investigation was conducted on an estuarine shoreline in Raritan Bay, New Jersey to identify the temporal and spatial distribution changes in accumulation of marine debris, and the factors that influence these changes. Methodology consists of 12-monthly collections of debris and profile data, and collection of local climatological and tide data. Debris was classified by type, length, weight, fragmentation, and probable function and weathering noted for each collected item. Wind roses were constructed to determine dominant wind speed and direction and wind characteristics for time intervals between field sampling.

Plastics are the primary component of debris; glass and styrofoam …


An Exploration Of Environmental Technology Transition From The Laboratory To The Field, Michael A. Greiner Sep 1996

An Exploration Of Environmental Technology Transition From The Laboratory To The Field, Michael A. Greiner

Theses and Dissertations

Environmental policy, social factors, individual behavior, and environmental technologies are key factors in improving the current condition of the environment. The Department of Defense (DoD) is not immune to these aspects, as its actions have and will continue to impact the environment in which they conduct operations. The objective of this research is to analyze the environmental technology aspect of improving environmental conditions. Of particular interest, what barriers and bridges are encountered when an Air Force laboratory transitions environmental technologies to an end-user: operational field organization or major weapon system. The research employs a case study methodology to analyze five …


Las Vegas Flamigo Hilton/Unlv Environmental Studies Program Environmental Resource Analysis & Optimization Plan, Dennis Nowlin Jul 1996

Las Vegas Flamigo Hilton/Unlv Environmental Studies Program Environmental Resource Analysis & Optimization Plan, Dennis Nowlin

UNLV Theses, Dissertations, Professional Papers, and Capstones

From 1987 through 1992 the Las Vegas Flamingo Hilton instituted resource efficiency improvements in electrical, natural gas, water and materials consumption. In 1992, the Flamingo Hilton commissioned the University of Nevada Las Vegas Environmental Studies Department to analyze and quantify the improvements made by The Flamingo Hilton and investigate the potential for further improvements.

Historical billing data from the periods 1987 - 1992 were used to analyze past and present (1992) electric, natural gas and water consumption. Materials disposal data was only available for a ten month period in 1992. Pollutant emissions data were supplied by Nevada Power Company.

The …


The Real Cost Of Beef: A Monetary Assessment Of The Environmental Degradation Caused By Beef Production, Carolyn Babcock Jul 1996

The Real Cost Of Beef: A Monetary Assessment Of The Environmental Degradation Caused By Beef Production, Carolyn Babcock

UNLV Theses, Dissertations, Professional Papers, and Capstones

The environmental degradation caused by beef production is severe. The current literature assesses the ecological damage, but falls short of assigning a per pound dollar amount to reflect the real cost of beef. In the United States, most of the environmental focus has been centered around the use of public lands for grazing and the grazing fee the government considers appropriate. The fee covers the maintenance of the grazing program, which includes maintenance of the actual land. This paper will concentrate on beef-related environmental degradation and select specific damage for monetary valuation.


Hepatic Cytochromes P450 Enzyme Activities Of Uae Coastal Rabbit Safi Fish Siganus Canaliculatus, Amna Mana Al-Otaiba Jun 1996

Hepatic Cytochromes P450 Enzyme Activities Of Uae Coastal Rabbit Safi Fish Siganus Canaliculatus, Amna Mana Al-Otaiba

Theses

The cytochrome P450 dependent metabolism of benzo(a)pyrene and other xenobiotics has been investigated in liver microsomes prepared from a local marine Safi fish Siganus canaliculatus caught from the Arabian Gulf of United Arab Emirates. The Safi fish was found to have a well developed liver microsomal monooxygenase system consisting of cytochrome P450, cytochrome b5 and NADPH-cytochrome c reductase. The fish microsomal enzyme system was able to metabolise benzo(a)pyrene, 7-ethoxycoumarin and 7- ethoxyresorufin. Male fish were found to exhibit a higher monooxygenase activity than female fish. Treatment of fish with β-naphthoflavone was found to induce (2-4 fold) the activities of aryl …


Environmental Study Indoor And Outdoor Of The Abu Dhabi Compost Plant, Jaber Eidha S. Aljabri Jun 1996

Environmental Study Indoor And Outdoor Of The Abu Dhabi Compost Plant, Jaber Eidha S. Aljabri

Theses

The transformation of municipal solid waste into compost is of double interest: on the one hand, it helps to avoid the deficiencies of natural manure, and on the other it eliminates this major polluting agent which is increasing progressively as a consequence of rising populations.

Domestic waste produced per person per annum amounts to 730 kg in Abu Dhabi city. Based on a population in 1992 of 574,745, this gives a current daily refuse collection that amounts to 1120 tons. Refuse is reported to contain a high proportion of organic materials and therefore to be suitable for recycling to produce …


Fluorescent Labeling Technique And Dna Amplification By The Polymerase Chain Reaction For The Detection Of Human Malaria Parasites., Maryam Mohd Ai-Shaikh Omer Ai-Ameri Jun 1996

Fluorescent Labeling Technique And Dna Amplification By The Polymerase Chain Reaction For The Detection Of Human Malaria Parasites., Maryam Mohd Ai-Shaikh Omer Ai-Ameri

Theses

The polymerase chain reaction (PCR) and fluorescence staining based diagnosis of Malaria infection was attempted. 187 samples in two groups: 135 and 52 patients Attending the Malaria Clinic (preventive Medicine and Al-Ain Hospital, UAE) were Collected Two PCR systems; using small subunit ribosomal RNA (ssrRNA) based primers And merozoite surface antigen (MSP) based primers were assessed, taking the Giemsa Stain as the reference test.

The re sults of PCR using the merozoite surface antigen (MSP) primers specific for Pfalciparum, proved to be specific and accurate. These results were analyzed by agarose gel electrophoresis (AGE) and polyacrylamide gel electrophoresis (page) stained …


Application Of Tube Settlers In Secondary Wastewater Treatment, Abdulsalam Mohamed Saleh Kamalpoor Jun 1996

Application Of Tube Settlers In Secondary Wastewater Treatment, Abdulsalam Mohamed Saleh Kamalpoor

Theses

Secondary sedimentation is one of the most commonly used unit operations in wastewater treatment plants. It is customary designed to achieve solids separation from biologically treated effluent through clarification of biological solids and thickening of sludge. As treatment plants receive increasingly high wastewater flow, conventional sedimentation tanks suffer from overloading problems which result in poor performance. Inclined plate settlers, a form of tube settlers, may have good potential in upgrading sedimentation tanks. This study was conducted to examine the possibility of applying inclined plate settlers in secondary sedimentation in order to upgrade conventional rectangular sedimentation tanks and improve their performance. …


Environmental Management And Treatment Of Oily Water In Abu Dhabi Offshore Oil Fields, Mohamed Ali Saeed Al-Nuaimi Jun 1996

Environmental Management And Treatment Of Oily Water In Abu Dhabi Offshore Oil Fields, Mohamed Ali Saeed Al-Nuaimi

Theses

The purpose of this environmental case study is to evaluate the oily water treatment efficiency in the separation of oil from water in relation to the environmental impact to the marine environment. This study covers offshore oil fields production facilities in the Abu Dhabi Emirate. The study discusses the most commonly used methods in the separation of oily water disposals. It highlights in detail the different types of treatment systems currently in use at Abu Dhabi offshore oil fields production facilities. Emphasis is given to the performance of each treatment system, its deficiencies and possible areas of improvement.

The study …


Continuous Monitoring Of Volatile Organic Compounds Using Microtrap Based Gas Chromatographic Systems, Yonghua Xu May 1996

Continuous Monitoring Of Volatile Organic Compounds Using Microtrap Based Gas Chromatographic Systems, Yonghua Xu

Dissertations

Continuous analysis allows a representative portion of a sample to flow continuously through an analytical instrument, which gives analytical information with little or no delay in time. A microtrap is a small diameter tube packed with adsorbents in series. When a gaseous sample containing volatile organic compounds (VOCs) flows through the microtrap, the VOCs can be trapped selectively by adsorbents. Then a pulse of electrical current is applied to the microtrap. This rapid heating results in a desorption that can act as a sharp injection for GC separation. Thus the microtrapped sample is the total amount of VOC present in …


Stratospheric Ozone Layer Depletion : A Computer Aided Case Study, James M. Lipuma May 1996

Stratospheric Ozone Layer Depletion : A Computer Aided Case Study, James M. Lipuma

Theses

In industries today, there is a desire to stop pollution before it starts, through the process of pollution prevention. Unfortunately, many university level students are not exposed to the thinking process involved in environmental problem solving early enough in their academic career, if they are exposed to it at all. The goal of this thesis is to develop and to evaluate an interdisciplinary case-study about the depletion of the stratospheric ozone layer by chlorofluorocarbons (CFCs). This case-study will be used to teach first year chemistry students about environmental problem solving. The case study was assembled from existing literature according to …


Pollution Prevention In The New Jersey Chemical Industry : Motivations And Barriers To Commitment, Judith A. Thornton May 1996

Pollution Prevention In The New Jersey Chemical Industry : Motivations And Barriers To Commitment, Judith A. Thornton

Theses

This study of the New Jersey Chemical Industry identifies the primary elements that lead to or inhibit company commitments to pollution prevention. A direct measure of facility pollution prevention commitment is developed that takes into account: organizational support attributes, past reductions achievements, current methods implementation, process reduction goals, and special environmental initiatives. The "P2 Commitment Index" allows for categorization of facilities so that the needs and interests of varying groups may be differentiated.

Higher level commitments are associated with: establishment of company pollution prevention policy, setting of prioritized facility goals, and measurement and reporting on pollution prevention progress. Facilities at …


Oxidation Of Isobutane And Isobutene Reaction Pathways And Detailed Mechanism, Chiung-Ju Chen May 1996

Oxidation Of Isobutane And Isobutene Reaction Pathways And Detailed Mechanism, Chiung-Ju Chen

Theses

A reaction mechanism consisting of 248 elementary reactions and 138 species has been developed to model experimental systems - decomposition of 2,2,3,3 tetramethylbutane in the presence of oxygen and oxidation of isobutene. This elementary reaction mechanism based on two important reaction systems: tert-butyl radical with O2 and allylic isobutenyl radical with O2, plus their subsystems, such as isobutene + HO2, isobutene + OH and allylic isobuteny1hydroxy + O2. Thermochernical kinetic parameters are developed for each elementary reaction and a chemical activation kinetic analysis using quantum RiceRamsperger-Kassel (QRRK) theory for k(E) and modified strong …


A Comparative Analysis Of Viable Solar Thermal Technologies For Solar Field Development And Commercialization, Sean M. Crawford May 1996

A Comparative Analysis Of Viable Solar Thermal Technologies For Solar Field Development And Commercialization, Sean M. Crawford

UNLV Theses, Dissertations, Professional Papers, and Capstones

Diminishing fossil fuels and concerns about the quality of the environment has lead the recent drive to establish a commercialized solar field in Southern Nevada. The competing solar thermal technologies for the Solar Enterprise Zone (SEZ) are Parabolic Dish-Stirling, Central Receiver Power Towers, and Parabolic Trough Systems. It is important to compare the technologies based on the guidelines set by the Corporation for Solar Technology and Renewable Resources. The variables weighted are solar conversion performances, initial capital investment, operation and maintenance costs, water and land use, and electricity production costs. All technologies have been proven to viable power sources and …


Spatial And Temporal Dynamics Of Plant Populations In Salt-Desert Shrub Vegetation Grazed By Sheep, Humberto Alzérreca-Angelo May 1996

Spatial And Temporal Dynamics Of Plant Populations In Salt-Desert Shrub Vegetation Grazed By Sheep, Humberto Alzérreca-Angelo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied the effect of moderate sheep grazing on a shadscale plant community at the Desert Experimental Range, southwestern Utah, USA, using a 61-yr data set with two grazing treatments (yes vs. no), two seasons (spring vs. winter), and two soil types (loamy-skeletal vs. coarse-loamy). I studied precipitation, total species cover, annuals, shrub survival, seedling recruitment, plant succession, and plant spatial relationships.

Precipitation showed high variability (CV=31%) masking on short-term cycles, resulting in study intervals with average (1935-58), dry (1958-69), driest (1969-75), and wet (1980-94[5]) regimes. Total cover in both grazed and ungrazed pastures increased between 1935 and 1975 before …


A Test Of An Alternate Calibration Matrix For Niosh Method 7300, Robert T. Vitek May 1996

A Test Of An Alternate Calibration Matrix For Niosh Method 7300, Robert T. Vitek

Community & Environmental Health Theses & Dissertations

The purpose of this study was to determine if the analytical results (when determining cadmium, lead, and zinc concentrations) for air sample filters prepared and analyzed according to N:OSH Method 7300, differ significantly, from those obtained when the instrument is calibrated using EPA Method 200.7 acid matrix standards. The null hypothesis was that no statistically significant difference, measured at the 95% confidence level, would exist between results obtained from the two calibration standards. Careful standard and sample preparation, the use of an internal standard, and the application of working standard and working internal standard correction factors served to isolate the …


Extraction, Recovery And Separation Of Some Organic And Inorganic Pollutants By Polyurethane Foams And Other Extracting Agents, Mahboob Hassan Saleh May 1996

Extraction, Recovery And Separation Of Some Organic And Inorganic Pollutants By Polyurethane Foams And Other Extracting Agents, Mahboob Hassan Saleh

Theses

Many substances pollute the marine and air environments but non-biodegradable compounds are the most dangerous. Heavy metals and most of the pesticides are known for their high toxicity. Mercury and lead in particular tend to accumulate in liver and kidney and inhibit the biosynthesis of heme protein because of their affinity for thiol and phosphate containing ligands. Thus, it affects the permeability of the membranes of kidney, liver and brain cells. Soluble inorganic mercury (II) species can be transformed into methylmercury under aerobic conditions by the actions of microorganisms. The target organ of methylmercury in humans is the brain where …