Efficiency of a Decentralised System in the Treatment of Rainwater in South Africa

Abstract

Rainwater harvesting provides a low-cost and flexible alternative for drinking water provision in decentralised settings in urban and rural areas of developing countries. Efficiency of a decentralised low-cost filter, i.e. Grifaid® filter, in the treatment of rainwater harvested at various sites at the Rhodes University campus in South Africa, was tested in this study. Sampling took place between beginning of August and end of October 2016. The treatment efficiency results indicate that Grifaid® filters remove 100 % of the faecal bacterial indicators and 100 % of turbidity from the treated rainwater. The pH values of the treated rainwater remain unaffected by the Grifaid® treatment. Ammonium and aluminium concentrations, measured in the harvested rainwater, were not considered dangerous for human health. However, nitrate concentrations surpassed the World Health Organisation of 50 mg/L and will require to be treated using ion exhcnage in further research.

Keywords

• Grifaid® filter
• E. coli
• chemical indicators
• university campus
• rainwater