Document Details
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Document Type |
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Thesis |
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Document Title |
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STUDY THE EXCHANGE OF SOME PERSISTENT ORGANIC POLLUTANTS IN THE MARINE ENVIRONMENT OF JEDDAH COAST, RED SEA دراسة تبادل بعض الملوثات العضوية المستديمة في البيئه البحريه لساحل مدينه جده على البحر الاحمر |
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Subject |
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Faculty of Marine Sciences |
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Document Language |
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Arabic |
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Abstract |
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Jeddah is the most significant and second biggest commercial city in the Kingdom of Saudi Arabia. The rapid growth in the last 50 years in the city, lead to the presence of some areas consider as environmentally unfriendly. Jeddah has extended with most residential areas in the north and industrial areas to the south, including development extended to sea along reef flats in order to utilize this coastal area for residential and corniche purposes. Disposing of treated or untreated sewage and wastewater, oil refineries, vehicular traffic, desalination plants, power generation plant and several industries within the city are among the most considerable sources for organic and inorganic pollutants to the coastal area of Jeddah city. Accordingly, many monitoring studies were done within the city with specific interest for heavy polluted areas like Al-Arbaeen and Al-Shabab lagoons. Very few studies focused on persistent organic pollutants and none were done on the air-water exchange of such pollutants.
The present work was aimed to one important family of persistent organic pollutants in the different marine compartments in Jeddah coast, which is polycyclic aromatic hydrocarbons (PAH). The goals of this study divided into two main parts, in the first part the levels, distribution and effect of environmental conditions on PAHs (parent and alkylated) in the surface sediments of Al-Arbaeen and Al-Shabab lagoons were monitored. PAH origin and toxicity were examined. In the second part of the study, it covers the air-water exchange, gas-particle partitioning and dry deposition flux of PAHs within the lagoons and nearby area. In addition to examining the rate of fluxes for total and individual PAH compounds in this polluted area. PAH origin in air samples (gas and particulate) and seawater (dissolved) samples from both lagoons and surrounding area were also examined.
Part I
The concentration ranges for total polycyclic aromatic hydrocarbons (∑38-PAHs) in Al-Arbaeen and Al-Shabab lagoons were 5.4-5372 ng/g (mean: 1637 ng/g) and 60-7927 ng/g (mean: 1323 ng/g dw), respectively. Pollution level in both lagoons was in low-very high range with the dominance of three and four rings PAH congeners. Pyrene was the dominant congener and benzo (a) pyrene was the dominant carcinogenic congener in both lagoons. Carcinogenic PAHs contributed 59.9 and 23.6% for Al-Arbaeen and Al-Shabab lagoons, respectively. The disappearance of most of the low molecular weight congeners may attribute to the temperature and the aerobic and/or anaerobic microbial degradation. The diagnostic ratios for PAH origins revealed that PAH sources were mixed origin and site-specific. The probable toxic effects on organisms were examined for total and individual PAHs with sediment quality guidelines (ERL-ERM) and it was found that adverse biological effects hardly occur. However, adverse effects due to individual congeners may likely occur at specific stations. The low water circulation and semi-closed structure of the lagoons lead to accumulation of pollutants to great extent inside the lagoons; this conclusion supported by the great drop of total PAH concentrations outside the lagoons.
Part II
The air-water exchange of semi-volatile organic compounds (SVOC) is an important process determining the transport, fate and chemical loadings of these contaminants in the atmosphere and in large water bodies. Air (gas + particulate) and surface water samples were collected from the coastal marine environment of Jeddah city during March to May 2016 (22 days). The aims of this part of the study were to (1) examine the PAHs levels in air (gas and particulate) and surface water in Al-Arbeean and Al-Shabab lagoons (2) study the gas-particle partitioning of total and individual PAHs (3) study the air-water exchange and dry deposition fluxes of PAHs from the vicinity of two polluted lagoon environment of Jeddah city and (4) examine the probable sources of PAHs in the study area. To our knowledge, this is the first study on air-water exchange of PAHs within Jeddah city. The total PAH in air and surface water were ranged from 12.2-397.5 ng/m3 (∑18-PAH, Avg: 125.6±117.3) and 97.2-507.4 ng/L (∑10-PAH, Avg: 289.7±166.8), respectively. Three to four ring PAHs were dominated in both water and air phase with the dominance of phenanthrene followed by pyrene, fluoranthene and anthracene congeners. Statistical analysis (SPSS) indicated that, wind speed followed by wind direction were the major controlling factors of PAHs in the air. Diagnostic ratio revealed that pyrogenic and petrogenic mixing origin of PAHs in the air, with a predominantly pyrogenic origin which may attribute to the dominance of gasoline/petroleum emission. On the other hand, PAHs in the water of Al-Arbaeen lagoon showed pyrogenic source, while petrogenic sources were dominated in the surface water of Al-Shabab lagoon and outside part. The correlation between log KP vs log PL (Partition coefficient vs supercooled liquid vapor pressure) and log KP vs log Koa showed deviation of slope from Junge-Pankow model. Air-water gas exchange flux was higher at Arbaeen lagoon and outside part than Al-Shabab lagoon. The high PAHs concentrations in surface water suggest that volatilization of pollutants from these lagoons could be an important source of PAH deposition in adjacent areas. In addition, the dumping of wastewater to these inlets may increase volatilization fluxes through the changes in water salinity and Henry’s constant. |
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Supervisor |
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Dr. Amr El-Maradny |
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Thesis Type |
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Doctorate Thesis |
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Publishing Year |
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1439 AH
2018 AD |
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Added Date |
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Monday, May 7, 2018 |
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Researchers
| راسيق كيلا سانتودي | ssanthodi, Rasiq Kela | Researcher | Doctorate | |
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