Physicochemical Assessment of Omambala and Ezu Rivers in Anambra State, Nigeria, Using Artificial Neural Networks and Fuzzy Logic

This study analytically assesses the water quality of the Omambala and Ezu Rivers, both of which are subject to significant anthropogenic influences and surface runoff, resulting in pronounced pollution. The primary objective was to assess the water quality using the Water Quality Index (WQI) methodology, focusing on both physicochemical parameters and toxic elements. A total of thirty water samples were collected, fifteen from each river, at three strategically selected sampling locations. Physicochemical analyses were conducted following the American Public Health Association (APHA) standard methods, and the findings were evaluated against the permissible limits established by the World Health Organization (WHO) and the Nigerian Standard for Drinking Water Quality (NSDWQ). Results revealed that both rivers are heavily polluted, with WQI values indicating severe degradation: 568.269 for River Omambala and 672.99 for River Ezu, the latter demonstrating a higher level of pollution. Conversely, the assessment of potentially toxic elements yielded WQI values of 423.67 for River Omambala and 289.93 for River Ezu, suggesting greater contamination in River Omambala regarding these elements. Notably, parameters such as pH, temperature, dissolved oxygen, total dissolved solids, total hardness, chlorides, and sulfates fell below NSDWQ permissible limits, while electrical conductivity, biochemical oxygen demand, turbidity, and nitrates exceeded recommended thresholds for both rivers. Elevated concentrations of Arsenic and Iron were observed, posing additional health risks. These findings underscore the critical influence of anthropogenic activities on water quality. Comprehensive management strategies, including pollution mitigation measures and community engagement, are urgently recommended to restore the ecological integrity of these rivers. Further research is warranted to explore the long-term impacts of observed pollution and the effectiveness of implemented interventions.