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Membrane Wastewater Treatment System

IMO has adopted RESOLUTION MEPC 227(64) with revised guidelines for effluent standards and performance test procedures for sewage plants.

These guidelines include the standards of section §4.2 that specifically apply to passenger ships operating in MARPOL Annex IV special areas and which intend to discharge treated sewage effluent into the sea.

The ACO Maripur NF range of sewage treatment plants are fully certified to IMO MEPC 227 (64) including section §4.2 for passenger vessels operating in IMO designed special areas as defined in IMO MEPC 200 (62).

Manufacturing, Test and Quality Management are certified to ISO9001:2009/ISO9001:2008 and EC MED Module D.


ACO Maripur NF – the highest standard of wastewater treatment plants for all marine applications.

  • Type Approved to IMO MEPC 227(64) including section §4.2 for passenger vessels operating in IMO designated special areas.
  • Compatible with both gravity and vacuum systems
  • Modularisation - wastewater transfer pumps and vacuum collecting systems can be shelf mounted onto ACO Maripur NF body
  • Designed to treat both black and grey water in one single system
  • Compact process due to high concentration of activated sludge in the reactor enabling limited space on ships and other marine structures to be used more efficiently
  • Manufactured entirely in the EU from high performance materials which, unlike coated black steel, are completely corrosion resistant and light weight
  • Unaffected by ship movement or vibration
  • Bespoke newbuild and retrofit solutions with complete ship system integration

Retrofit Solution

ACO Maripur NF is available in modular sections to allow easier access to installation site.
Retrofit Maripur® Advanced Wastewater Treatment Systems

The Retrofit Maripur® advanced wastewater treatment plants are designed to reduce the cost of installing wastewater treatment equipment into existing vessels. Each standard Maripur® size in the range is available for adaptation to a bespoke retrofit requirement and all come fully certified to IMO MEPC 227(64). Dependent upon the design and access limitations for any given vessel, ACO Maripur® can be delivered in anything from two to five (for the larger Maripur® sizes) independent watertight tank modules which are fully tested for both hydrostatic and weld penetration requirements. Separate tank modules are then simply bolted together at the final installation site and connected by external piping. Under normal circumstances, there is no requirement for any hot work at the installation site. Dimensions for each component tank are arranged to permit its transportation through standard access ways or to minimise hull opening sizes during vessel dry docking.

Retrofit Maripur® is specified, installed and commissioned working in close co-operation with the world‘s leading ship owners, operators and shipyards. The combination of a biological process with ultra-filtration of the treated water – without any final clarification or additional disinfection – meets and exceeds the quality standards of IMO/MARPOL, HELCOM, USCG, US Federal Law Gazette No. 40, section 133, Australian ADNOC and Australian Federal Environmental agency and the Alaska requirement.

Standard Features
  • IMO MEPC 227(64) & MED Module B (wheel mark) certificate issued by DGUV, Germany
  • No requirement for chemicals, chlorination or de-chlorination in the treatment process
  • Compact Modular construction design optimised for marine applications
  • Single power supply input point, stand alone ‘PLUG & PLAY’ installation
  • Minimal maintenance requirement
  • High Head capability progressive cavity effluent discharge pump
  • Entirely EU sourced and manufactured
  • Tank materials al in stainless steel AISI 316
  • Fully automated PLC Logic Control System
  • Application range: 25 – 250 PE (or up to 625 PE on vacuum black water only)
  • Size range: ACO Maripur® 25, 50, 75, 100, 150, 200 & 250
Reference installations
  • Super and Mega Yachts
  • Cruise vessels (up to approx. 1500 people)
  • River Cruise Vessels
  • Military Vessels
  • Offshore Installations and Vessels
  • Specialist vessels such as sail training ships, survey vessels, conference ships, etc