Author(s)

M. A. R. M. M. Amin, S. R. M. Kutty & M. H. Isa

Abstract

Petroleum refinery wastewater has the characteristic of a high concentration of aliphatic and aromatic petroleum hydrocarbons, which could lead to heavy pollution to the environment. In this study, petroleum refinery wastewater was co-treated with municipal wastewater in continuous flow bench scale reactors. Two bench scale reactors, A and B each of liquid volume of 18 L treats municipal wastewater and a mixture of municipal and refinery wastewater, respectively. The flow rate, Q for both reactors was maintained at 9 L/day with the hydraulic retention time (HRT) and sludge retention time (SRT), set at 2 days and 40 days, respectively. Food to microorganism (F/M) ratio, concentration of effluent soluble chemical oxygen demand (sCOD), mixed liquor suspended solids (MLSS), and mixed liquor volatile suspended solids (MLVSS) were monitored throughout the study period. The result of a full five months operation show high removal efficiencies of organic matter of about 90% as sCOD with 30% loading of the refinery wastewater. Keywords: continuous flow, organic loading, refinery wastewater, extended aeration, biological treatment, activated sludge. 1 Introduction Petroleum refining involves the transformation of crude oil into final useful products such as gasoline, gas oil, kerosene and jet fuel, and petrochemical feed stocks. Petroleum refining uses relatively large quantities of water, especially for cooling systems, desalting water, stripping steam, and water used for flushing during maintenance and shut down. As a general rule, approximately 3.5–5m3 of

Keywords

continuous flow, organic loading, refinery wastewater, extendedaeration, biological treatment, activated sludge