Mechanical pumps require regular lubricant replacement, but what should be done with the used oil that is discarded?

This depends on the amount of used oil and whether it can be recycled, to determine the appropriate handling method. For example, the light oil used in large-scale light oil stations is used in large quantities; the issues associated with it usually include water content and solid impurities. Such renewable oils can be processed by specialized recycling facilities, or they can be filtered using special filtration equipment, with methods such as adsorption, heating, and drying being employed to remove impurities and bring them up to the required standards for use. Some also work in conjunction with other oil-using units within their own organization; for those units where the requirements regarding the physical and chemical properties of certain oils are not very strict, it is possible to use these oils at a lower grade, either as fuel or for other purposes, or to sell them as waste oil in the market, for reference.

Under normal circumstances, there is always recycling! The company regularly reprocesses the fuel that has been replaced!

Used oil can be purified and reused with filtration equipment

For small quantities, it can be sent to the light crude oil treatment system for reprocessing in the catalytic unit; for larger quantities, it goes into crude oil and is sent to the atmospheric and vacuum distillation units