Date of Award

2008

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Dr. Esam Abd EI-Gawad

Second Advisor

Dr. Mohamed Abdel-Moati

Third Advisor

Dr.Madduri Rao

Abstract

In 2006 a study was carried out to evaluate organic and petroleum pollutants including: Total Organic Carbon (TOC), Total Petroleum Hydrocarbon (TPH), Total Kjeldahl Nitrogen (TKN), Polycyclic Aromatic Hydrocarbons (PAHs) and PolyChlorinated Biphenyls (PCBs) in coastal bottom sediments of Qatar, as well to determine the source of petroleum pollutant in the environment.

The study included 15 stations along the coastline, at a 100 m distance from the shoreline. The average TOC % analyzed in the study area is 0.262 % which is less than other regional studies. The average TPH in Qatar sediment is around 133.46 mg/kg; this is lower than previous studies in UAE and there was no significant correlation observed between TPH and grain size distribution. The average concentration of total PCBs in the study area is 16.7 µg/kg showing decreasing value than observed in the region. For individual PCB's, PCB 18 has the highest value (19.9 µg/kg) detected in station S-004 (Mesaieed MIC).

The TKN concentration in sediments ranges from 0.0013 to 0.093 1 % with an average of 0.0442 %. Maximum concentration was observed in S-015 (Umm Bab) at the western coast. Concentrations tend to increase toward Northwestern coasts.

Total PAH's ranged between nd and 64. 8 µg/kg. The maximum value was recorded in station S-014 named Dukhan-2; this is higher than previous studies at the same location in 2001. In general, total PAH's concentrated in Southwestern and Southeastern (city activities and major port) coast of Qatar. In respect to individual PAH's, Pheneanthrene has the highest concentration among other individual PAHs with 79.55 µg/kg.

The concentrations of total aliphatic hydrocarbons in the studied stations fluctuate between 0.4 mg/kg at S-009 (Fuwairat) to 19.8 mg/kg at S-011 (AL-Ruwais) reflecting the impact of current movement. Fingerprints from GC-FID chromatograms for S-004 (Mesaieed MIC), S-005 (Ras Abu-Fontas- 1 ), S-007 (Lusail) and S-010 (Al-Mafjar) showed long chain alkanes than short chain alkanes, which reflected terrestrial sources from harbor and industrial activities. Carbon Preference Index (CPI) in samples ranged from 0.8 to 1.03, reflecting similar petrogenic (anthropogenic) sources of pollution rather than biogenic.

C17/Pr (n-C17/pristine) and C18/Ph (n- C18/phytane) ratios showed that most of the studied samples have 1 value; which may reflect the level of biodegradation and the natural climate at this region. (Pr/Ph) ratio for the studied samples ranged from 0 to 2.6. Samples S-001 (Khor Al-Odaid End), S-002 (Khor Al-Odaid Entrance), S003 (Mesaieed-Sealine), S-005 (Ras Abu-Fontas- 1), S-007(Lusail) and S-008 (Sumaisamah) have showed petroleum source, while in S -004 (Mesaieed MIC), S009 (Fuwairat) and S -011 (AL-Ruwais) was biogenic source. The petrogenic/biogenic ratio cleared that most of the studied samples were less than 1 meaning biogenic sources; in this case its not reflecting anthropogenic sources of n-alkanes.

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