Evaluation of Toxicity and Bioremediation of Contaminated Drinking Water Sources in Delta State, Nigeria

Drinking water samples were collected from boreholes in six locations in Ughelli and environs in Delta State of Nigeria and were treated by filtration through a substrate colonized with mycelium of Pleurotus tuber-regium. Water samples were analysed for pH, heavy metal concentration and microbiological content before and after filtration. Results obtained showed that the pH of unfiltered water samples were acidic (5.0 – 5.8) and below the WHO and SON permissible limits for drinking water. The same trend was followed by the concentrations of heavy metals such as lead, iron, zinc and chromium. Water samples from all six locations also had high total bacterial and coliform counts. Filtration through the mycelium colonized substrate showed adjustment of pH to a range within the WHO permissible limits. Reduction in heavy metal concentration ranged from 45.0 – 100%. Total bacterial count of mycofiltered water samples was impressively reduced by 77.3 – 100% and coliform count was not detected. The results obtained in this study makes mycofiltration a potential cost-effective and efficient technique for the treatment of potable water for domestic use.