ASSESSMENT OF THE CAPACITY OF ASPERGILLUS FLAVUS AND TRICHODERMA SP IN THE REMOVAL OF HYDROCARBONS AND HEAVY METALS FROM RAW REFINERY EFFLUENT
ASSESSMENT OF THE CAPACITY OF ASPERGILLUS FLAVUS AND TRICHODERMA SP IN THE REMOVAL OF HYDROCARBONS AND HEAVY METALS FROM RAW REFINERY EFFLUENT
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Date
2017-09
Authors
AZEEZ, ZAINAB
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Abstract
This study assessed the capacity of two fungi AspergillusflavusandTrichodermasp.individually
and synergistically to remove hydrocarbon, cadmium (Cd), lead (Pb), and nickel (Ni), from broth
cultures charged with raw refinery effluents. Raw effluent from refinery were collected in 200 ml
sample bottle and transported to the laboratory for isolation of
AspergillusflavusandTrichodermasp. using Potato Dextrose Agar (PDA). The physicochemical
qualities of the raw refinery effluent were investigated using standard methods. The effluent
contained very high concentrations of oil and grease (26.42 mg/l), COD (171.2 mg/l), Dissolved
solids (592.20 mg/l), Conductivity (866 μs/cm) and phosphate (8.1 mg/l), but low in
sulphate(39), nitrate(0.01) and pH(7.52) which were within the permissible limit. Biochemical
oxygen demand (BOD) was determined at intervals of five days for twenty days to assess the
capacity of Aspergillusflavusand Trichoderma sp. to remove hydrocarbon from raw refinery
effluent using the modified Winkler method. It was observed that the amount of hydrocarbon
removed increased from day 0 to day 20. The concentrations of the three metals in the raw
refinery effluents and tissues of the test fungi were determined both before and after the
mycoremediation studies using Microwave Plasma Atomic Emission Spectrophotometer (MPAES
AGILENT 4200). Both the percentage removal as well as the potential of the test isolates to
bioaccumulate the metals in their tissues were calculated following standard procedures. It was
observed that the two isolates tested could remove from 18 to 29% of Cd, 87 to 95% of Ni and
49 to 79% of Pb. Trichoderma sp. proved to be the most efficient in the removal of the three
metals from raw refinery effluent while Aspergillusflavus was consistently the least efficient. It
was also observed that co-culture ofAspergillusflavusand Trichoderma sp. proved to be more
efficient when compared to Aspergillusflavus alone but less efficient when compared to
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Trichoderma sp. alone. Trichodermasp had the highest potential to bioaccumulate the metals
than Aspergillusflavus. It was therefore concluded thatAspergillusflavusand Trichodermasp.
could be employed in the removal of hydrocarbons, Cd, Ni and Pb from heavy metal polluted
effluents generated by petroleum refineries and other petro-chemical industries.
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE FOR THE AWARD OF MASTER OF SCIENCE IN
MICROBIOLOGY DEPARTMENT OF MICROBIOLOGY, FACULTY OF LIFE SCIENCES, AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
Keywords
ASSESSMENT,, ASPERGILLUS FLAVUS,, TRICHODERMA SP,, HYDROCARBONS,, HEAVY METALS,, RAW REFINERY EFFLUENT