Impact of tannery and textile effluent on the chemical characteristics of Challawa river, Kano state, Nigeria
Electronic Journal of Environmental, Agricultural and Food Chemistry
Department of Chemistry, Faculty of Science, University of Maiduguri, P.M.B 1069, Maiduguri, Borno state, Nigeria; Department of Chemistry, Bayero University, Kano State, Nigeria
The impact of effluent from tanneries and textile on the chemical characteristics of Challawa River was carried out for a periods of one year. Water samples were collected on quarterly basis beginning from the months of June to September, 2007 (Rainy season), November, 2007 - February, 2008 (Harmattan period) and March - May, 2008 (Dry season) to reflect the seasonal factors. Water samples from these areas were collected and designated S1 to S8 for the determinations of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), Dissolved oxygen (DO) total dissolved solid (TDS), anions and trace element. These parameters were determined using standard procedures. The concentrations of BOD (40.20±42.65 to 33.91±678.36mg/l.), COD (158.00±3439.11 to 15.41±210.33mg/l), %TOC (0.21 to 5.54%) were higher than the WHO limits for the protection of fish and other aquatic life. The concentrations of heavy metals in the water and sediment samples were higher than the WHO guideline values for the protection of aquatic life. This is expected owing to its location close to tanneries and textile industries. Results of Analysis of variance (ANOVA) results revealed that BOD, COD, DO, TOC, TDS, nitrate, nitrite, sulphate, phosphate, heavy metals and chloride were significantly different among the sampling points and seasons with exception of point S1-S3 where the was no marked seasonal variations. Point S5 which is the control point (upstream) recorded the lowest concentrations for all the parameters studied. The relationship between %TOC with BOD and COD; TDS with BOD and COD were also observed. The Pearson linear correlation analysis showed that the mean concentrations of heavy metals in the water and sediment samples revealed significantly positive correlated values. Base on the above results, the study underscores the need for immediate remediation programs to control the discharged of tanneries and textile effluent into Challawa River.