Introduction
The discharge of refinery wastewater is an important problem that the refining industry needs to consider. Refinery wastewater is generated during the operation of petroleum refineries and can contain high concentrations of oil, grease, suspended solids, and sulfur-containing compounds. Refinery wastewater contains a wide range of contaminants, including organic and inorganic pollutants, which can have serious environmental impacts. Moreover, it may also have a significant impact on human health when discharged into surrounding water bodies or land. Therefore, it is important to carefully manage refinery wastewater to ensure that it is adequately treated before it is discharged.
Types of Refinery Wastewater
Refinery wastewater can be divided into two general categories, process wastewater and wastewater generated during cleaning activities. Process wastewater typically consists of waste generated during the refining process. It can be further classified into two types, crude oil or condensate wastewater, and chemical additives used in the refining process. Crude oil or condensate wastewater is generated due to the washing, cooling, and evaporation of crude oil during the refining process. This type of wastewater is often highly concentrated in oil, grease, and suspended solids. Chemical additives used in the refining process can also be found in the wastewater. These chemicals may include phenols, sulfides, benzene, toluene, ethylbenzene, and xylene (BTEX) compounds, as well as other compounds that can have an adverse environmental impact.
Wastewater generated during cleaning activities includes water used for cleaning the refinery’s process equipment and piping systems. This type of wastewater typically contains high concentrations of oil and grease, as well as a variety of other contaminants, including metals and surfactants.
Treatment of Refinery Wastewater
Refinery wastewater needs to be treated before it is discharged into the environment. The treatment process typically consists of two main stages: primary and secondary treatment. Primary treatment involves the use of physical and chemical processes to remove suspended solids and other large contaminants from the wastewater. This can be done using a variety of methods, such as sedimentation, flotation, and filtration. Secondary treatment involves the use of biological processes, such as activated sludge and trickling filter systems, to further reduce the level of pollutants in the wastewater.
Conclusion
Refinery wastewater needs to be carefully managed to ensure that it is adequately treated before it is discharged. Primary and secondary treatment processes are typically used to reduce the levels of pollutants in the wastewater. This can help to minimize the environmental and human health impacts associated with the discharge of refinery wastewater.
