TITLE:
Assessment of Physicochemical Characteristics of Sediment from Nwaja Creek, Niger Delta, Nigeria
AUTHORS:
Adeola Alex Adesuyi, Moses Okafor Ngwoke, Modupe Olatunde Akinola, Kelechi Longinus Njoku, Anuoluwapo Omosileola Jolaoso
KEYWORDS:
Sediments, physicochemical Assessment, Nwaja Creek, Nitrates, Conductivity
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.4 No.1,
December
30,
2015
ABSTRACT: Sediments
are complex environments, with varying physicochemical characteristics, such as
composition and type of organic matter, particle size distribution, and pH.
Contaminated sediment is a significant environmental problem affecting many
marine, estuarine and freshwater environments throughout the world. Most
assessments of water quality have historically focused on water-soluble
compounds, with relatively little attention paid to sediment. The aim of this
research is to assess the physical and chemical parameters of sediments from
Nwaja Creek, Niger Delta, Nigeria. Monitoring of this sediment quality is an
important part of preserving and restoring the biological integrity of water
bodies as well as protecting aquatic life, wild life and human health. Sediment
samples from Nwaja Creek were sampled from seven sampling stations along the
creek for over three months May to July, 2015, rainfall peak period, for
assessment of their physical and chemical characteristics, such as grain size,
organic carbon, pH, conductivity, nitrate and phosphate. These parameters are
known to influence the interactions and dynamics of pollutants within sediment
matrix. Sediment particle size distribution indicates that they have higher
proportion of clay (clay > silt > sand), the mean percentage composition
of clay, silt and sand ranged between 64.28% ± 22.04% - 72.36% ± 14.00%, 18.71%
± 12.03% - 27.32% ± 22.17% and 8.40% ± 6.28% - 9.76% ± 4.59% respectively. TOC
in the study area is generally above 1% across all stations during the study
period with a range between 0.98% and 4.58%. Minimal monthly and spatial
variations are observed in particle distribution, pH (3.9 - 8.5) and phosphate
(5.5 - 15.5 kg/mg) while significant variations are observed in conductivity
(23.0 - 567.0 uS/cm), total organic carbon (0.98% - 4.58%) and nitrate (0.45 -
11.9 mg/kg) concentration. It is concluded that physicochemical characteristics
of the sediments from Nwaja Creek are influenced by anthropogenic sources
rather than natural as shown by the elevated phosphate and nitrate levels because
the Niger Delta geology is not essentially rich in nitrate and its excess in
surface or groundwater is considered as pollutant.