Annual Research & Review in Biology

Aim: This research work aimed to determine the impact of industrial effluent discharge on the physicochemical properties of Aleto Stream, Eleme and Rivers State.

Study Design: Random sampling technique was applied in this study. The study area was divided into three sites; upstream, downstream all of Aleto Stream and Agbonchia Stream which serves for the control experiment. Water samples for eleven physical and six chemical parameters were collected in a Completely Randomized Design.

Place and Duration of Study: This study was carried out on Aleto and Agbonchia streams at Eleme, Rivers State, Nigeria from 2017 to 2018.

Methodology: Two samples were collected; one sample at the Aleto stream where the industrial effluent is being channelled into the stream and the other sample was collected from Agbonchia stream, which was used as a control. In the Aleto Stream, sampling was made at two points; point A (upstream) point B (downstream) and each of these points had their Physico-chemical properties tested while only one sample was collected from the Agbonchia Stream. Physico-chemical properties were analyzed in the samples using pH meter for pH, Turbidity meter for turbidity, Conductivity meter for electrical conductivity, phosphate by colourimetric method, total dissolved solids (TDS) and total suspended solids (TSS) by gravimetric method, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) by standard method, chloride, alkalinity, dissolved oxygen (DO), calcium hardness, total hardness by titrimetric method, colour, odour and taste by sensory method.

Results: Results obtained on the Physico-chemical properties had varying concentrations of Temperature, Total hardness, Chloride, Alkalinity, DO and Phosphate that were within world health organization (24)  and Federal Ministry of Environment (1991) permissible limits on both upstream and downstream with values ranging from 29.0-23.7^oC, 360-125 mg/l, 120-100 mg/l, 36-30 mg/l, 4.9-4.4 mg/l, 1.92-1.2 mg/l respectively while Electrical conductivity, Turbidity, TSS, TDS, Calcium hardness, COD, BOD, Colour, Taste and Odour were above permissible limits on both upstream and downstream with values ranging from 1660-1700 mg/l, 83-112NTU, 82-80 mg/l, 910-914 mg/l, 1590-1900 mg/l, 100-165 mg/l, 4.36-3.88 mg/l respectively. The pH values ranged from 9.0-6.3 mg/l showing a result on the upstream to be alkaline while the downstream was slightly acidic. The increase in the above parameters above their permissible limits is as a result of the impact of industrial effluent discharges drained into the stream. This indicates that the stream is unfit for both human and aquatic inmates.

Conclusion: Therefore, proper management of this effluent should be ensured and an acute test with lethal concentration (LC₅₀₎ as the endpoint is recommended to determine the degree of toxicity of the effluent waste.