Vermifiltration of Sewage Wastewater for Potential Use in Irrigation Purposes Using Eisenia fetida Earthworms

Abstract

—Vermifiltration was used for treatment of sewage wastewater using the Eisenia fetida earthworm species. The earthworms’ gut acted as a bioreactor and they reduced the sewage wastewater solid and liquid organic wastes through ingestion and expelling these as vermicompost. 500 earthworms were used in the vermifilter over a 5 period of days. The treated water pH increased from being acidic to neutral. The sewage wastewater biological oxygen demand (BOD5), chemical oxygen demand (COD), total dissolved and soluble solids (TDSS) and turbidity decreased by 98%, 70%, 95% and 98% respectively through vermifiltration. Vermifiltration significantly decreased the sewage water physicochemical parameters compared to an ordinary bio-filter without earthworms. The vermi-treated sewage water compared well with the set standards for irrigation water. Vermifiltration technology can therefore be applied as an environmentally friendly technique for sewage water treatment for irrigation purposes