Assessment Of Water Quality in Relation to Toxic Algal Species In Sedimentation Tanks Of Tamburawa Water Treatment Plant, Kano State

Abstract

Tap water serves as the principal source of potable water in Kano Metropolis, yet its quality is increasingly compromised by rapid urbanization, industrial discharges, and inadequate waste management. This study assessed the physicochemical quality of tap water in Tamburawa treatment plant for eight (8) months between January and August, 2024 using bio-indicator algal species composition Water samples were analyzed for algal species, physicochemical conditions using standard procedures. Three sampling sites from the treatment plant were selected based on the varying functions they served. The algal composition and physico-chemical parameters varied with months and seasons. The mean range of water temperature was 22±1.9 – 27.8±2.7 °C, pH (5.90±.01 – 9.30±1.1), DO (5.60±0.7 - 6.90±0.8 mg/L), BOD (2.10±0.12 – 3.70±0.7 mg/L), turbidity (26.7±1.9 – 62±2.50 NTU), Electrical Conductivity (1279±24.30 – 1960±32.10 µS/cm), Total Dissolved Solids (462±23.6 - 860±19.6 mg/L), phosphate (2.0±0.00 - 3.8±0.1 mg/L) and nitrate (12.6±1.60 - 20.02±1.90 mg/L). The mean of all the physiochemical parameters were within the standard limits of WHO (2023). Twenty three (23) algal belonging to the following classes: Cyanophyta (25%), Chlorophyta (37.5%), Bacillariophyta (25%) and Euglenophyta (12.5%) were identified during the study period in which Spirogyra communis predominates with 14.4% and Nostoc sp. recorded the least with 2.2%. Analysis of the algal community structure with respect to pollution status of the treatment plant using Palmer Pollution Index (P.P.I), a total of thirteen (13) genera out of the fifteen (15) were identified. The pollution tolerant species such as Microcystis aeruginosa, Oscillatoria chlorina, Cosmarium connatum, Scenedesmus quadricauda, Navicula radiosa, Euglena sp. Nitzchia sp. Palmella sp., Phormidium connatum, Cyclotella sp. and Phacus pleuronectes were considered as bio-indicator of pollution. The Biotic Indices analyses of Shannon-wiener Index, Evenness Index and Margalef’s Index showed that algal composition and abundance were highest during dry season than in wet season. Canonical correspondence analysis revealed strong positive correlation between pH and temperature, TDS and DO, turbidity and DO, Algal composition and Nitrate with respect to all of the sampling sites. Similarly Temperature and Dissolved Oxygen showed normal correlation while Turbidity and Biological Oxygen Demand had weak correlation. The present study revealed that the water body is impacted with various anthropogenic activities which affect the water quality negatively. It is therefore recommended that uncontrolled discharge of agrochemicals around the treatment plant through should be controlled in order to curtail degradation of the plant over a period of time.