BIOROCK multi-units: Delta Okavango wetlands, Botswana


Delta Okavango wetlands, Botswana.


Installation of a sewage treatment system in the middle of the swamps.  A unique project because of local constraints: The accommodations, restaurant and spa are built on islands which are completely inundated during the rainy season.


90 PE


SPA and Hotel / Restaurant


BIOBOX South Africa

Technical description

  1. Several pump stations receiving power from a solar plant and protruding above the water level during the flood season. These pump stations receive effluent from the guest accommodations, staff, accommodations, kitchen, spa and workshop.
  2. The primary tanks and Biorock units are installed above ground on a timber platform roughly central to the various pump stations.
  3. 3 off 10,000lt primary tanks are connected in series, receiving the macerated effluent from the pump stations. Each outlet on the primary tank to the next has a brush filter to retain inorganic solids.
  4. The outlet from the last primary tank flows into a baffle which feeds the 6 off Biorock-15 units.
  5. The outlets from the 6 off Biorock-15 units flow into a tank which has a low-wattage pump to recirculate a portion of the effluent to the primary tanks to aid nitrification.
  6. The overflow from this recirculation tank flows into a discharge tank where a low wattage pump reticulates the treated effluent into a sub-surface drain. This is necessary to prevent treated effluent from being disposed directly into surface waters during the flood season.

Project images