Abstract
The treatment of saline wastewater containing oil and organic matter of different biodegradability was examined for 35 days using a laboratory-scale membrane bioreactor (MBR) at a thermophilic condition (50°C). The performances were compared with those of a room-temperature reactor. The removal of COD was comparable for the two reactors. The half-life of mineral oil (C15 − C22 alkanes) was around 3 hours in the reactor. However, the operation at high temperature condition decreased the removal of dark brown (melanoidin) color from 58% to 44%. The fouling of the membrane was more severe for the thermophilic reactor. The room-temperature reactor maintained a volume flux of 0.22 m/day, while keeping the volume flux at the same level was difficult for the thermophilic reactor. It was suggested that lower flux operation of the membrane and worse effluent quality have to be considered, if high-temperature operation is required.
