MARPOL 73/78 is the International Convention for the Prevention of Pollution from Ships. Its stated objective is "to preserve the marine environment through the complete elimination of pollution by oil and other harmful substances and the minimization of accidental discharge of such substances."
Veolia Zuhai, 威立雅珠海, MARPOL, 海洋污染

Veolia’s Hong Kong Chemical Waste Treatment Centre provides collection and treatment for marine pollutants (MARPOL waste) generated from ocean-going and local vessels at the highest health, safety and environmental standards. It also offers technical support so as to ensure complete compliance with stringent MARPOL legislation.

Veolia’s Hong Kong Chemical Waste Treatment Centre treats two types of MARPOL waste as defined in annex I and II of the MARPOL Convention:

Annex I waste is defined as liquid oil waste or any other mixture which contains oil.

Annex II waste is defined as noxious liquid substances or any other mixtures which contain residues from any noxious liquid substance.