Arsenic, Nickel and Iron Concentration levels in Water Samples from Hand-Dug Wells from Ugbe Akoko

Abstract

Problem statement: The concentration of Arsenic, Nickel and Iron from twenty water samples from Ugbe Akoko in Ondo state, Nigeria was determined with atomic absorption spectrometer and conductivity meter. Approach: The aims are to determine the level of concentration of the three heavy metals in the well water, the relationship between the WHO reference standard for pure water and the well water sample and the potential hazards in utilizing the water for their sole purposes of drinking and cooking. Results: The result showed that, water samples 2, 6 8, 14, 17, 18 and 19 have low level of Arsenic metal pollution with values below 0.05 ppm WHO standard. Samples 1, 4, 6, 8, 10, 13, 14 and 19 are with low level Nickel concentrations compare to WHO acceptable value of 0.02. The Fe occurrence in samples 1, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19 and 20 is below the WHO standard permissible level. Only water samples 2, 3 and 13 have higher Fe value (2-13 times) above WHO acceptable level. Water samples 6, 8, 14 and 19 have values of As, Ni and Fe below the WHO acceptable standard. Conclusion/Recommendations: However the conductivity result which is too high shows that other metals or salts can still be present. The As, Ni and Fe pollution result from human activities involving improper refuse and sewage disposal often at places with shallow well resulting from sediment overlying the impervious bedrock.