en |
Water quality index of the ground water of bitumen deposit impacted farm settlements using entropy weighted method
Fagbote, E. O.; Olanipekun, E. O. & Uyi, H. S.
Abstract
Ground water of the farm settlements in the
bitumen deposit area of Western Nigeria were tested for
pH, conductivity, turbidity, total dissolved solid, sulphate,
phosphate, nitrogen nitrate, chloride, alkalinity, total
hardness, calcium, magnesium, sodium, potassium and
total coliform in the dry season (March) and rainy season
(August) of years 2008 and 2009 using atomic absorption
spectrometer and standard analytical methods. Conductivity,
pH, turbidity, phosphate ions and total coliform values
obtained in some of the wells were out of the recommended
range for drinking water. Water quality index analysis was
carried out using information entropy method. Water
quality index of the wells when compared with the permissible
limits of international standards, ranked the bore
hole as ‘excellent’ in the dry season of year 2009 and just
‘good’ in the rainy season of the same year. Ground water
sampling stations were ranked extremely poor at least once
out of the four seasons considered. Water quality index
ranking also showed that the quality of the wells declined
over the years. The correlation coefficient matrix (p<0.05)
of water quality index and the parameters showed significant
relationships between water quality index and total
coliform (0.99), total dissolved solids and conductivity
(0.96), hardness and Ca2+ (0.68), hardness and Mg2+
(0.75). Water quality index also showed moderate significant
relationship with total dissolved solid, conductivity
and N-NO3
-. High concentration of total coliform in most
of the shallow wells in the environment, due to bitumen
deposit, renders them unfit for human consumption unless
properly treated.
Keywords
Correlation coefficient; Dry season; Parameters; Permissible limits; Rainy season; Wells
|