The use of natural system for the treatment of greywater: A case study of Kpeshie Lagoon, Accra, Ghana

Abstract

Handling of wastewater (greywater and blackwater) in urban areas is a big problem. The La Sub Metro in Ghana is no exception. Due to lack of wastewater treatment facilities, almost all the wastewater in the Sub Metro is discharged into the Kpeshie Lagoon without pre-treatment. The objective of this study was to characterise greywater and determine the potential of receiving environment (Kpeshie Lagoon and surrounding soil) to treat the greywater prior to discharge into the sea. The dominant plant species in the receiving area were also identified. Characterisation of greywater was carried out after four weeks of sampling. Laboratory analyses carried considered colour, turbidity, pH, salinity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), conductivity, total suspended solids (TSS), nutrients, faecal coliform, and trace metals. The results indicated that the lagoon had a high potential of treating greywater if managed well. High removal efficiencies were evident in nitrates (80%), colour (78%), BOD (74%), and turbidity (61%). The dominant species were Sesevium portulacastum, Avicennia germinans, and Paspalum polystachyum