Final answer:
An oily-water separator is used to separate oil and hydrocarbons from water based on density differences to prevent environmental pollution. It must be operated in line with specific regulations which dictate the permissible oil content in discharged water. These regulations are in place to ensure environmental protection.
Step-by-step explanation:
Purpose of an Oily-Water Separator
The purpose of an oily-water separator is to separate oil and other hydrocarbons from water before the water is discharged back into the environment. This is particularly important in industries such as shipping or manufacturing, where large quantities of oily water can be produced. The separator works on the principle of density differences, as shown in Figure 1.12.1 with a separatory funnel containing oil and colored water. Oil, being less dense than water, rises to the top and can be removed, leaving relatively clean water behind.
Regulations on Operating an Oily-Water Separator
Regarding the operation of an oily-water separator, it must be operated in accordance with environmental regulations that prescibe when and how such equipment can be used. These regulations ensure that the discharge of water does not exceed specific oil content limits, which are in place to protect the environment. The exact operation times and conditions will vary depending on local and international laws, such as those mandated by the International Maritime Organization (IMO) for vessels at sea.