Evaluation of a low cost technology to manage algal toxins in rural water supplies

Abstract

South Africa is a water scarce country with freshwater resources that are deteriorating mostly due to anthropogenic activities. Several dams in South Africa are eutrophic and present potential health risks to water consumers and users. Cyanobacteria (blue-green algae) are known to produce toxins that present a threat to human health and wildlife. In this review, a low technology method that can be applied to the management of rural water supplies that are contaminated with algal toxins such as microcystins is examined. The method uses aquatic macrophytes. The bioaccumulation potential of some aquatic macrophytes (the ‘Green liver’ concept) has commonly been applied in the phytoremediation of polluted water bodies. The use of aquatic macrophytes in the in-situ bioremediation of algal toxins can offer numerous advantages, among them; the ability to treat large areas and low costs. The main objective of this review was to assess the feasibilty of using selected species of naturally occurring aquatic macrophytes and their effectiveness in cyanotoxin elimination by using their bioaccumulation potential from raw surface water collected from rivers in Limpopo province, South Africa for the in-situbioremediation of the polluted water. Key words: microcystins, bio-accumulation, in-situ bioremediation, aquatic macrophytes, Green liver concept