Marine Sewage Treatment Plant belongs to the key devices for prevention of pollution form ships in seas and oceans according to the revised Annex IV of the International Convention of the Prevention of Pollution (MARPOL 73/78).The resolution MEPC.2 (VI) adopted on 3 December 1976 is the present guidelines on implementation of effluent standards and performance tests for STP, which is called “old standards”. This device is according to the resolution MEPC.159(55) enacted on 13 October 2006, which is called “new standards” .The convention (MARPOL 73/78) provides that all STPs installed on board on or after 1 January 2010 should meet the resolution MEPC159(55).The different effluent standards and days for type test in some organizations are as follows:

船用生活污水处理装置属IMO国际防止船舶造成海洋污染公约《MARPOL 73/78》附则IV的关键设备。现行的排放标准和性能试验准则是1976年12月3日颁布的MEPC.2(VI)决议（称为老标准），本系列装置遵守2006年10月13日 颁布的MEPC.159(55)决议（称为新标准），公约规定自2010年1月1日起凡是吊装到不论新老船舶上的船用生活污水处理装置都应满足新标准的要求。