Distribution of heavy metals, hydrocarbons and hydrocarbon-degrading bacteria in freshwater sediments
Freshwater sediments from the Batang Ai hydroelectric Dam at Lubok Antu, Sri Aman were analyzed for heavy metals, hydrocarbons and hydrocarbon-degrading bacteria content. A total of 7 sampling sites within vicinity of Batang Ai Hydroelectric Reservoir were selected for investigation. The heavy me...
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| Format: | Final Year Project Report / IMRAD |
| Language: | English |
| Published: |
Universiti Malaysia Sarawak, (UNIMAS)
2012
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| Subjects: | |
| Online Access: | http://ir.unimas.my/id/eprint/7377/ http://ir.unimas.my/id/eprint/7377/4/NUR%20AFIQAH%20BINTI%20MOHAMAD%20ft.pdf |
| Summary: | Freshwater sediments from the Batang Ai hydroelectric Dam at Lubok Antu, Sri Aman were
analyzed for heavy metals, hydrocarbons and hydrocarbon-degrading bacteria content. A total of
7 sampling sites within vicinity of Batang Ai Hydroelectric Reservoir were selected for
investigation. The heavy metals content in sediment was analysed using atomic absorption
spectrophotometer (AAS), while the aliphatic and aromatic hydrocarbons in sediments were
analyzed by gas chromatography-flame ionization detector (GC-FID). Furthermore, distribution
of hydrocarbon-degrading bacteria in sediments was analyzed using molecular biological
technique. Heavy metal content in sediments show varying concentrations of nickel (Ni), copper
(Cu), manganese (Mn), zinc (Zn), chromium (Cr), argentum (Ag), stannum (Sn) and bismuth
(Bi). The highest concentration of Ni, Cu, Mn, Zn and Cr were detected at St2, while the highest
concentration of Ag and Sn wrere detected at St1 and St4, respectively. Bismuth (Bi) was only
detected at St5 and St6 with concentration 4.79 and 5.28 μg/g, respectively. Lead (Pb), cadmium
(Cd) and arsenic (As) was not detected in all sampling station. The aliphatic hydrocarbons were
ranged from 2 - 421145 ng/g dry weights. St1 and St2 indicate the higher content of aliphatic
hydrocarbons, while St3 showed the lowest n-alkanes content. The total PAHs concentration of
sediments in Batang Ai Dam ranged 2 - 5958 ng/g dry weights. The PAH composition pattern in
sediments of Batang Ai suggest dominance by medium to high molecular weight compounds,
and the ratio of certain related PAHs indicate anthropogenic sources and natural processes. The
highest number of bacterial colonies was detected at St7 with 9.9 × 105 CFU/ml. The number of
bacterial colonies in sediment is higher near the jetty than other sites of Batang Ai Hydroelectric
Dam. Other sediments show moderate bacterial number with the lowest bacteria count was at St3
(1.4 × 101 CFU/ml). |
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