Physicochemical and bacteriological quality of water from lotic and lentic ecosystems in Agbede Wetlands, Edo State, Southern Nigeria

Abstract

The bacteriological and physicochemical characteristics of surface water from three (3) sampling stations (SS) on Omodo stream and four (4) SS on three ponds all located in the Agbede wetlands was determined at monthly intervals between December, 2012 and May, 2014. Routine procedures such as; Usage of relevant meters, spectrophotometric-based analysis and multiple tube methods were employed in evaluating the physicochemical and coliform content of the water samples. Air temperature mean values ranged from 28.17 to 32.19 ^oC at station
1 and station 4, whilst, the mean values for water temperature ranged between 25.42 and 29.11 ^oC at stations 1 and 4 respectively. The pH values (5.10 – 7.20) ranged between slightly acid and slightly alkaline condition. The differences in the mean air temperature, water temperature, flow rate, electrical conductivity (2.67 - 140 μScm^-1 ), turbidity (0.00 – 78.20 NTU) and chemical oxygen demand (COD) values (12.15 – 96 mgL^-1  ) were significantly different (P<0.05, P<0.001) across the study stations. The Dissolved oxygen (DO) (1.20 – 14.80 mgL^-1 ) and Biochemical oxygen demand (BOD) (0.00 – 8.20 mgL^-1 ) had their values within the FMEnv set limits 0f 7.5 mgL^-1 and 30 mgL^-1 respectively. The study revealed varying levels of culturable coliform counts in the examined surface waters with values not exceeding 13 MPN100mL^-1 . Coliform values were slightly higher within the lentic environments. Sensitization of the communities residing within the wetlands by relevant governmental and non-governmental bodies on the urgent need to treat the water by boiling prior to drinking should be conducted.

Keywords: Coliform, Agbede wetlands, Environmental Condition, Set limits