Biological Treatment of Edible Oil Refinery Wastewater using Activated Sludge Process and Sequencing Batch Reactors - A Review

This review paper intends to provide an overall vision of ASP and SBR technology as an alternative method for biological treatment of edible oil refinery wastewater. Edible oil refinery effluent is considered the most harmful waste for the environment if discharged untreated. Edible oil effluent is a yellowish liquid that contains high Dissolved Solids, Oil and Grease, high COD and BOD values, low pH, Total Kjeldahl Nitrogen, Ammonia Nitrogen, and Total Phosphorus. The activated sludge process is used to treat waste stream that are high in organic loading and biodegradable compounds. It is most widely used biological process for the treatment of edible oil refinery wastewater. Sequencing batch reactor is a modification of activated sludge process which has been successfully used to treat edible oil refinery wastewater. The same can be successfully treated by sequencing batch reactor process.The advantages of SBR technology are single-tank configuration, easily expandable, flexibility in operation, feasibility of operation at low retention time, control over microbial population and various reactor configuration. Their studies resulted in very high percentage removal of BOD, COD, Total Dissolved Solids and Suspended Solids respectively. The review discusses some of the published works in addition to experiences of the authors.