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Document Type |
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Article In Journal |
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Document Title |
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BIOREMEDIATION OF CRUDE OIL - CONTAMINATED EFFLUENTS USING FREE AND FIXED BACTERIA UNDER AEROBIC CONDITIONS BIOREMEDIATION OF CRUDE OIL - CONTAMINATED EFFLUENTS USING FREE AND FIXED BACTERIA UNDER AEROBIC CONDITIONS |
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Subject |
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BIOREMEDIATION OF CRUDE OIL - CONTAMINATED EFFLUENTS USING FREE AND FIXED BACTERIA UNDER AEROBIC CONDITIONS |
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Document Language |
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English |
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Abstract |
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The main objective of the present study is investigating the bioremediation or
minimization potential for oil wastes in the contaminated effluents before discharging
into aquatic systems. Four bacterial isolates [X, Y, Z and Pseudomonas cepacia (P)]
were investigated as free-living (batch) or fixed cells (biofilm) and as individuals or
mixed cultures to decontaminate crude oil contaminated effluents. Free-living
experiment was carried out for 8 exposure days while biofilm experiment was carried
out at different flow rates 40, 60 and 100 ml/hr. Quality of wastewater was determined
by measuring oil residue, BOD5, COD, TSS and TDS. Results indicated that bacterial
biofilm system exhibited more advantages over that of the free-living system
respecting time (only 6 running hr) and removal efficiency of the investigated
pollutants. The highest recorded removal efficiency percentage (RE %) of oil residue,
BOD5, COD, TSS and TDS achieved by the biofilm were 69.0, 58.8, 50.0, 100.0 and
40.3 respectively compared to 50.9, 40.0, 38.2, 87.5 for oil residue, BOD5, COD and
TSS respectively by the free-living bacterial cells. Results also indicated that for the
fixed biofilm, RE% of the investigated pollutants increased with increasing the flow
rate up to 100 ml/hr while bacteria-free system (control) showed the opposite trend
although it achieved higher RE% for all the parameters at 40 ml/hr. In the non-fixed
bacterial system, the RE% had positive correlation with exposure time achieving their
maximum RE% after 8 exposure days. Also, using mixed cultures of the four selected
isolates did not significantly enhance biodegradation efficiency or rate where they
achieved intermediate RE % between the least efficient isolate (X) and the most
efficient isolate (Z). Although the proposed biofilm system achieved high RE% of all
the investigated parameters especially at the high levels recorded in the raw water,
levels of oil, BOD5 and COD in the treated water still higher than the highest
permissible limits (by Egyptian law) for discharging. Therefore, a sequence biofilm
system is suggested where more than one-biofilm units are used in sequence to bring
raw wastewater to acceptable discharging quality. |
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ISSN |
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000 |
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Journal Name |
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BIOREMEDIATION OF CRUDE OIL - CONTAMINATED EFFLUENTS USING FREE AND FIXED BACTERIA UNDER AEROBIC CON |
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Volume |
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34 |
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Issue Number |
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2 |
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Publishing Year |
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1426 AH
2005 AD |
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Number Of Pages |
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22 |
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Article Type |
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Article |
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Added Date |
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Sunday, June 21, 2009 |
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