The shipping industry, as a fundamental economic branch for maritime transport, is developing at a great speed, which inevitably makes the aquatic ecological system exposed to various types of waste and pollution. Ships and other vessels significantly contribute to environmental pollution. This thesis describes and analyzes the most important factors affecting sea pollution by sewage wastewater from ships. The division, properties, and characteristics of sewage wastewater on vessels and their harmful impact on humans, marine life, and the economy are explained. The impact of large passenger ships on the environment, as well as the methods and types of coastal and marine ecosystem pollution and the harmful consequences that arise from it, are particularly highlighted. International, regional, and national legal regulations governing the handling of sewage wastewater on vessels are listed. Devices and systems for the treatment and purification of sewage wastewater on vessels and their mode of operation are presented. By applying new materials, accepting innovative solutions, and following prescribed procedures, certain results are achieved despite the fact that increased activity at sea increases the amount of pollution.