Domestic wastewater treatment with a small-scale membrane bioreactor

A small-scale membrane plant for treating the domestic wastewater of a four-person household is presented. The membrane bioreactor has been in operation for 6 months and achieves elimination rates of 90, 95 and 80% for total organic carbon, chemical oxygen demand and total nitrogen, respectively. Only a small amount sludge is produced. The permeate is reused for flushing toilets and has a yellowish colour. After investigations of the effluent quality, decolourisation of the permeate, energy efficiency and control strategies in the first year, urine will be treated separately in an automated precipitation reactor where struvite is produced to improve the overall phosphate removal of the plant.