Effluent is a term that is often used in engineering, science, and the environment to describe wastewater that has been treated. The word Effluent can have many different meanings depending on who you are talking to or what context it is being used in. Effluent can mean any outflowing of water or gas from a structure such as a sewage treatment plant, sewer pipe, industrial wastewater treatment plant, or industrial outfall. Effluent can also be the stream exiting a chemical reactor as well as liquid materials coming from industry including coal-fired power plants and oil refineries. Effluent can have a negative connotation when speaking of industrial wastewater and is often associated with pollutants. Effluent in the engineering sense refers to the combined stream exiting a process unit such as an oil refinery or chemical plant after treatment has taken place. Effluent means different things depending on who you are talking to but it tends to be used more accurately for water and air pollution than other terms like sewage.
