Transcript Impact Of Organic Waste Disposal On Water Quality

Paper Presentation By
Mrs Comfort Uchendu,
Chief Lecturer, Rivers State College of Science and
Technology, BSc, MSc
Breakfast networking meeting for International Year of Chemistry – University
of Cambridge Scientists sharing a chemical moment in time with scientists in
West Africa
Date: 18th January 2011, Time: 8 – 10: 00 am
Venue: Rivers State College of Science and Technology, Port Harcourt, Nigeria
and Department of Biochemistry, University of Cambridge
THE IMPACT OF ORGANIC WASTE
DISPOSAL ON THE WATER QUALITY
IN THE NEW CALABAR RIVER,
NIGER DELTA, NIGERIA.
MRS COMFORT UCHENDU
CHIEF LECTURER, RIVERS STATE COLLEGE OF
SCIENCE AND TECHNOLOGY,
BSC, BOTANY UNIVERSITY OF NIGERIA NSUKKA.
MSC, ENVIRONMENTAL BIOLOGY, UNIVERSITY OF
SCIENCE AND TECHNOLOGY, PORT HARCOURT.
MA, PUBLIC ADMINISTRTION, AMBROSE ALLI
UNIVERSITY, EKPOMA
INTRODUCTION
 A study of the physico-chemical parameters of’ tile New Calabar
River was carried out from January to June, 2007.
 The parameters studied were temperature, Ph, turbidity, salinity,
primary nutrients (nitrates and phosphates), DO, BOD, TDS,
conductivity, redox potential, and heavy metals (zinc, lead, copper
and cadmium).
 Five sampling stations were considered. Samples were collected with
appropriate containers for water quality analysis. Water temperature
varied slightly ranging from 24.5 to 31.1 degrees Celsius. The pH was
relatively constant ranging between 6.47 and 7.29.
 The trip provided an overview of the study area which enabled the
establishment of points of activities along the river banks (stations
one, two, three, four and five). Station one was a solid waste dump
site in the river where a jetty was also located. Station two was
occupied by Modant Engineering Limited and Pivot Nigeria Limited
while station three was occupied Delta Marine Company. Stations
four and five were river banks distant from these industrial sites and
therefore served as control stations.
RESULTS
RESULTS
 The following physico-chemical parameters showed significant
differences both in time and space:
 Nitrate
 BOD
 Conductivity
 Total dissolved solids (TDS), The highest DO value (8.00mg/L)
was obtained at station five (control station) while the lowest
(2.00mg/L) was recorded at station one which was a waste dump
site.
 Turbidity, salinity, redox potential, and phosphate showed no
significant differences both in time and space. Copper showed
significant difference in time.
METHODOLOGY

Surface Water Temperature: The measurement of surface temperature was done in-situ in
the field, using mercury in glass thermometer. The bulb of the thermometer was fully immersed in
the water at each sampling station and held still until a constant reading was established. The value
was noted and recorded in degrees Celsius.

pH: pH in water was determined in the laboratory using a Membrane pH meter. The sample was
shaken thoroughly to provide homogeneity and the pH electrode was standardize in a standard
buffer solution and then immersed in the sample and the result was read off from the pH meter
(Model H 18314 membrane, HANNA instruments).

Conductivity: The conductivity of the respective water samples was determined using a
conductivity meter. Samples were measured by putting a small quantity of the water sample into a
cup-like probe attached to the water with the pointer pressed down. The knob was adjusted until it
stabilized and the reading was recorded in µs/cm.

Turbidity: The turbidity of the water samples was measured using an electrical device (Water
Checker Model U-10 micron HORIBA). A small quantity of the water sample was poured in a
container, attached to the meter and the probe immersed into the water. The meter was allowed to
stabilize before recording the readings in NTU.
METHODOLOGY

Dissolved Oxygen (DO) (Using Winkler’s Modification Method) and Biological
Oxygen Demand (Bods): The methods used are as described in standard method for water and
wastewater analysis (APHA, 1975, Section 422). The results were expressed in mg/L.

Salinity: The salinity of the collected samples was determined following Argentomertic method as
described in the Standard Methods for Water and Wastewater Analysis (APHA, 1975, Section 408).
The salinity was measured in practical salinity unit (psu).

Nitrate in Water (Brucine Method): Nitrate (NO3) level in the water samples was determined
following the procedure described in the Standard Methods for Water and Wastewater Analysis
(APHA, 1975, Section 419). The concentration of Nitrate (NO3) was calculated in mg/L.

Phosphate in Water (Ascorbic Acid Method): Phosphate in water was determined by
Ascorbic Acid method as described in APHA (1975) section 425. The concentration of phosphorus
was recorded in mg/L by referring the absorbance values to a standard reference curve.

Heavy Metals Analysis: The concentration of each heavy metal in water and sediment was
determined from the samples after the calibration runs using appropriate salts of the metals to
investigate Cadmium (Cd), Lead (Pb), Zinc (Zn), and Copper (Cu). Atomic Absorption
Spectrophotometer (AAS, model 2380) was used to determine the values (precision + 0.01%).
Recommendations
 1)
The waste dump at station one should be removed and another
waste dump site provided for the people living along the New Calabar
River water front (lwofe) where the wastes can be separated and
recycled or incinerated.
 2)
The results of this study be used as a baseline study for
comparison with other waters in the Niger Delta region which are
already affected by human and industrial activities.
 3)
The Federal environmental regulatory body should evaluate
existing sources of coastal pollutants as well as to develop marine
monitoring programmes designed to generate information useful in
making management decisions to protect the coastal environment of
the Niger Delta.