Efficiency assessment of rhizofiltration by Mentha aquatica L. of polluted water from urban rivers

Urban rivers in Bosnia and Herzegovina are under the influence of industrial as well as communal loads resulting in high concentrations of heavy metals as well as faecal bacteria, and investigating how this could be managed is essential. Mentha aquatica is a widely growing plant with the potential to be used in pollution management. In this study, a setup of artificial ponds using water from urban rivers was used to evaluate the efficacy of M. aquatica in rhizofiltration systems. During the 15-d trial various physico-chemical and microbiological parameters of water, as well as the removal rate of heavy metals and faecal bacteria, were evaluated. The chemical oxygen demand, dissolved oxygen, and pH values were reduced after the introduction of M. aquatica plants. Nitrite, nitrate, orthophos-phate, and total phosphorus were also decreased after 15 d post M. aquatica introduction for highly polluted water. Absorption of lead and cadmium by M. aquatica and 45% and 100% pathogen removal ratio were recorded. The results obtained from this study suggest that M. aquatica has the potential to remove heavy metals and pathogens from polluted river ecosystems and could be considered for phytoremediation purposes through the process of rhizofiltration.