Assessment of Water Quality in Imo River at Oyigbo Local Government Area, Rivers State

ABSTRACT

The water quality of the Imo River in Oyigbo local government area was ascertained using standard methods in this research. The important physicochemical characteristics of the river were investigated during the wet season of 2013 at six sampling locations. In situ measurements were made for water temperature, salinity, turbidity, dissolved oxygen (DO), biological oxygen demand (BOD), etc using the HORIBA U-10 water quality checker. The total dissolved solids and total soluble solids etc were determined with HACH conductivity/TDS meter. Water samples were collected in replicates with 2 liters plastic containers and taken to the laboratory in iced coolers for analysis. The test for homogeneity in mean variance was used to determine spatial variation in the physicochemical variables. The eckman grab sampler was used to acquire sediments to test for the physicochemical variability of the sediments from the river. The physicochemical variability for the Imo river from the six sample

locations indicated that Water temperature varied between (27.00- 28.00 ̊c), ph (6.3-6.6), turbidity (15-71 NTU), electrical conductivity (19.9- 82.0μs/cm),

dissolved oxygen (4.8- 7.05mg/l), biological oxygen demand (2.10- 3.20 mg/l), total dissolved solids (19.9-30.30mg/l), total hydrocarbon (0.010-0.031mg/l), total soluble solids (3.6- 9.1mg/l), nitrates (0.13-0.43mg/l), phosphates (0.07-0.11mg/l), sulphates (0.99-7.00mg/l), and chlorides(0.01-0.08mg/l), on the other hand the physicochemical variability of the sediments from the six sample locations indicated that ph varied between (6.85-6.98),total hydrocarbon(0.22-4.84mg/kg), nitrates(0.22-0.71mg/kg), phosphates (0.41-1.10mg/kg), and sulphates(30.80- 65.20mg/kg).While, the microbiological variability of the sediments indicated that total heterotrophic bacteria varied between(2.30-2.80x102), total heterotrophic fungi (5.0-6.3x102), hydrocarbon utilizing bacteria(1.40-1.95x102), and hydrocarbon utilizing fungi between(2.60-3.50x102). The results obtained for the physicochemical parameters and microbial variability agreed with the permissible limits set by both national and international bodies for drinking and domestic water and for the sustenance of aquatic life with few exceptions.

Keywords: Water quality, physicochemical, hydrocarbon, microbiological, and Heterotrophic.