Assessment of iron concentrations in wastewater, soil and vegetable samples grown along Kubanni Stream Channels in Zaria, Kaduna State, Nigeria

Abstract

The concentration of iron was determined in wastewater, soil and vegetable (carrot, lettuce, onion, spinach, cabbage, tomato and okro) samples that were collected on seasonal basis from January, 2013 to September 2014 along Kubanni stream channels in Zaria. The results showed iron levels in wastewater were in the range of 3.85 – 42.33mg/L for the year 2013 and 15.60 – 72.08 mg/L in 2014; 0.96 – 12.73mg/Kg for the year 2013 and 4.93 – 18.24 mg/Kg in 2014 for the soil while the vegetables had concentrations in the range of 3.80 – 23.65mg/Kg for the year 2013 and 7.48 – 27.15 mg/Kg in 2014. Statistical analysis revealed no significant difference in iron levels across the locations and seasons for wastewater, soil and vegetables analyzed. Pearson correlation showed moderate (r = 0.527) relationship between iron levels in wastewater for the year 2013 and 2014, moderate (r = 0.526) relationship was also obtained for the soil between these two years likewise, moderate (r = 0.597) relationship was obtained for vegetables cultivated in 2013 and that of 2014 respectively. Iron concentrations obtained in this study was higher than maximum contaminant levels set by Standard Organizations such as W.H.O. and F.A.O for wastewater while the soil and vegetables were within the limits set by these bodies.

Keywords: Iron level, Kubanni River, Soil, Vegetable and Wastewater