PHYSICOCHEMICAL CHARACTERISTICS, HEAVY METAL CONTAMINATION, AND BACTERIAL OCCURRENCE IN RIVER DADIN-KOWA IN KWADON TOWN, GOMBE STATE, NIGERIA

Physicochemical characteristics are important indicators of the quality and condition of aquatic environments. This study evaluated the physicochemical properties, heavy metal contamination and bacterial occurrence in Dadin-Kowa River, Kwadon town, Yamaltu-Deba Local Government Area, Gombe State, Nigeria. Water samples were collected from three sampling sites along the river and analyzed for selected physicochemical parameters, heavy metals, and bacteria contamination. Physicochemical characteristics of the water sample were determined using standard procedures. Temperature, electrical conductivity (EC), Turbidity, total dissolved solids (TDS) and pH were determined using a multiparameter water quality meter. Metals and heavy metal concentrations were determined using anatomic absorption spectrophotometer (AAS). Bacteria were isolated using serial dilutions and pour plate technique on three selective media: MacConkey, Eosin Methylene Blue (EMB) and Salmonella-shigella (SS) agar. The results showed that turbidity value was higher (264.40 – 416.50 NTU), exceeding the WHO guideline value of 5 NTU at all the sampling sites. Total dissolved solids ranged from 48.10 – 48.75 mg/L, electrical conductivity from 74 – 75 µS/cm, temperature was 27.50 and pH ranged from 7.15 to 7.63. The pH, total dissolved solids and electrical conductivity values were within the ranged of WHO limit. Sodium, zinc and copper concentrations were below the WHO limit, with sodium having a concentration ranged from 97-100 mg/L while zinc and copper concentrations ranged from 1.70 to 2.00 mg/L and 0.02 to 1.01 mg/L respectively. Cadmium (1.52 – 1.93 mg/L) and lead (1.97 – 2.57 mg/L) concentration exceeded the WHO guideline values of 0.003 and 0.01 mg/L respectively. Bacterial growth was observed on all the three media, with counts ranging from 50 – 70 CFU/mL on MacConkey agar, 43 – 64 CFU/mL on SS agar and 42 – 92 CFU/mL on EMB agar. Statistical analysis was performed using Analysis of Variance (ANOVA) in the Statistical Package for the Social Sciences (SPSS). Significant differences (p< 0.05) were observed within the three sampling sites. This study revealed high turbidity, elevated cadmium and lead concentrations and also bacterial occurrence on the water samples. Although some physicochemical parameters and selected metals were within WHO guideline values, the observed contamination indicates that the river water may require adequate treatment before use. Regular monitoring and improved waste management and sanitation practices are recommended to reduce the risk of river contamination.