Design, fabrication, and evaluation of produced water treatment system for effective removal of oil and salt

Abstract

Inappropriate disposal of Produced Water is one of the causes of degradation of the environment in the Niger-Delta. The effect on farmlands and aquatic life has been disastrous and this disposal continues because of lack of treatment equipment or inability to maintain treatment equipment. This work has developed a method for produced water treatment focusing on oil and salt removal. A small scale produced water treatment system was fabricated. The system’s processes were based on thermal energy; thermal phase separation was used for oil removal and humidification-dehumidification was used for salt removal. The water obtained at the various process stages was tested to ascertain the oil content and salinity. Results obtained showed that oil levels in the produced water dropped from 3034.28mg/l to 380.58mg/ after phase separation which is significant but not meeting the Department of Petroleum Resources (DPR) requirement. However, after the humidification – dehumidification process, it was reduced to 4.02mg/l which meets the DPR requirement of 10mg/l. The salinity also reduced from 887.50mg/l to 35mg/l, this meets DPR acceptable limits for land disposal of 600mg/l.