Publications

The secondary waste water treatment facility in Mutiara Central Plant, VICO Indonesia, is a phenol treatment plant (PTP). It is processing approximately 8000 BPD waste water before being released to the Dondang River. A biologically activated sludge process is applied to reduce the pollutant content so the disposed water complies with regulation Permen LH 04/2007. The process reduces chemical oxygen demand (COD), ammonia, phenol, sulfide, and oil and grease content in the produced water. Frequently since 2008, high COD and ammonia content above the regulated threshold in disposed produced water has been observed.The root causes limiting the phenol treatment performance were poor engineering design and modifications to the secondary clarifier pond and return sludge system, higher oil content and COD in the inlet stream, and lack of oxygen supply. Following minor mitigation actions in January 2010 such as chemical process optimization, adjusting nutrient dose, adding sugar and fresh microbes, and routine maintenance, the effluent quality data has improved to just bellow the threshold. Four major improvements are planned for commissioning at the end of 2011, e.g. repair of preheater at upstream process, construction of new secondary clarifier, reactivation of return sludge system and installation of additional aerators.Keywords: produced water treatment, COD, activated sludge, Permen LH 04/2007