The Effects of Solid Waste Dump on the Water Quality and Sediments of Ntawogba Creek, Rivers State, Nigeria

Abstract

The study of the effects of solid waste dump on the water quality and sediments of Ntawogba creek, Port-Harcourt was necessitated by regular dumping of solid wastes into the river which significantly affected the physical appearance of the water river. Ntawogba creek is located within PGS coordinates of N040 47' 48.1"and E0060 59' 57.4".This study aimed at determining the effects of solid waste dump on the water quality and sediments of Ntawogba creek, Port Harcourt. The study also determined the physicochemical parameters in water column and sediments of the Ntawogba Creek. This is to determine the suitability of water from Ntawogba River for domestic use by comparing the value of physicochemical parameters of the water with the WHO and NESREA standards. Ntawogba River was demarcated (stratified into) three parts; upper stream, midstream and lower stream of 2km interval where samples were collected using 1-liter plastic containers. The plastic containers were dipped in the river against the flow direction of the river water current. The following were used for sample analysis: X-Ray Florence , Atomic Absorption Spectrophotometer. The physicochemical parameters measured also varied across the sampling locations. In the composite samples, minimum level of temperature (25.000C), turbidity (57.0NTU), pH (6.90), Calcium hardness (15.2mg/l) and Magnesium hardness (22.8mg/l) were recorded at the Midstream, Downstream, Upstream, Upstream and Upstream sampling locations. However, their maximum levels of 25.500C, 63.0NTU, 7.44, 27.0mg/l and 40.6mg/l were recorded at the Downstream, Midstream, Downstream, Midstream and Midstream locations respectively. The minimum levels of colour (564.0 Pt- Co), TDS (135.00 mg/l), EC (225.00μS/cm), Alkalinity (45.2 mg/l) and TSS (3.00mg/l) were recorded at the Midstream, Upstream, Upstream, Upstream and Upstream of different sampling locations. Their maximum levels of 670.0 Pt-Co, 207.00 mg/l, 300.00 μS/cm, 88.9 mg/l and 43.0 mg/l were recorded at the Upstream, Downstream, Downstream, Downstream and Midstream locations respectively. Minimum levels of Pb (0.003 mg/l), Cu (0.003 mg/l), Zn (0.004 mg/l), Cr (0.002 mg/l) and Cd (0.0007 mg/l) were recorded at the Upstream, Upstream, Upstream, Downstream and Downstream locations, while their maximum levels of 0.007 mg/l, 0.01 mg/l, 0.32 mg/l, 0.005 mg/l and 0.015 mg/l were recorded at the Midstream, Midstream, Downstream, Upstream and Midstream locations respectively. The physicochemical parameters measured in sediments of the creek also varied across the sampling locations. In the composite samples, minimum level of pH (5.01), Ag (1.40 mg/kg) and NO32- (0.01 mg/kg) were recorded at the Upstream, Downstream and Downstream sampling locations. However, their maximum levels of 7.51, 3.70 mg/kg and 4.12 mg/kg were recorded at the Downstream, Downstream and Upstream locations respectively. Relationship between physicochemical parameters in water column and sediments was determined. The Pearson Correlations (r) between the physicochemical parameters in water column and sediments of the Ntawogba Creek. At P<0.05, Cu in water column correlated negatively with Cu in sediments (r = -0.633) and SO42- ions in water column correlated negatively with SO42- ions in sediments (r = -0.598). At P<0.01, pH in water column correlated positively with pH in sediments (r = 0.965). Finally, the test of homogeneity in mean variance of the physicochemical parameters in water samples revealed significant difference [F(12.62)>Fcrit (3.90)] across the sampling locations at P<0.05. A post-hoc structure of group means that utilized the Upstream location as predictor variable revealed that water colour (602.00 Pt.Co), TDS (136.00 mg/l) and electrical conductivity (226.00 μS/cm) contributed the observed significant difference most. The test of homogeneity in mean variance of the physicochemical parameters in sediments samples revealed significant difference [F(4.89)>F crit (3.94)] across the sampling locations at P<0.05. A post-hoc structure of group means that utilized the Upstream location as predictor variable revealed that at the Midstream location, total iron (3539.00mg/kg) and at the Downstream location, total Fe (3539.00mg/kg), electrical conductivity (418.00μS/cm) and extractible PO43- ions (21.3mg/kg) contributed the observed difference most.

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