Evaluation of water quality pollution indices for heavy metal contamination monitoring. A study case from Akpabuyo-Odukpani area, Lower Cross River Basin (southeastern Nigeria)

摘要: Two documented methods, Contamination index (Cd) and the Heavy metal potential (HPI) were evaluated for their suitability contamination monitoring of surface water in parts southeastern Nigeria. Results show that despite significant correlation between data generated from these indices, final classification gave two extreme results. Thus a third model (Heavy evaluation index, HEI) was developed to accommodate this deficiency. The HEI values with Cd HPI but categorised into semi quantitative classes proper assessment pollution level. 65.5% sites are classed as low lower than mean remaining 34.5% greater medium. In contrast, samples all 32 locations classified high using respectively. However, reclassification categories criteria good comparison HEI. differences former can be attributed variations concentrations heavy metals used different schemes.