ENV-99-178 Refractory COD in Refinery Wastewater

Description:

Refinery wastewater contains high molecular weight organic compounds that are not removed in biological wastewater treatment systems. These compounds, also, are too large for economical removal using activated carbon. The fact that these compounds can not economically be removed has two types of implications: 1. The organic compounds show up as Chemical Oxygen Demand (COD) in the refinery effluent, and possibly even as oil and grease. This has permitting implications. 2. Currently there is a lot of pressure to recycle/reuse wastewater. There refractory compounds will tend to build up in the recycle systems. This paper presents information on: · Environmental regulations governing COD in the effluent from refinery wastewater systems. · The sources of COD in refinery wastewater. · Characteristics of the refractory COD. · Options for removing this refractory COD from refinery wastewater, economical or not. · Special problems with wastewater in California, because of the high concentrations of naphthenic or carboxylic acids in the California crudes.