Some 31 flag states (minimum of 30 required) and 26.44 per cent of the world tonnage (minimum 35 per cent required) had ratified the IMO Ballast Water Management Convention by December last year, with other large nations primed to sign. It is estimated that some 50,000-70,000 vessels will need to install approved ballast water treatment (BWT) systems in the years up to 2019.
The basic requirements of the convention’s D2 standard are applicable to newbuildings and eventually to all relevant existing tonnage under a rolling programme. Type-approved BWT systems must be installed with the capability to meet a cleaning standard that results in fewer than 10 viable organisms/m3 if the organisms are 50 micron or larger, or 10 viable organisms/ml if they are smaller than 50 microns. The USA has a stricter requirement requiring adherence to 1 viable organism/100ml.
No single BWT solution is suitable for all ship types, according to UK-based Hamworthy, which has developed two different treatment solutions to offer flexibility and choice from its Aquarius product range.
“We are currently the only OEM offering a choice to both the newbuilding and retrofit markets,” claims Dr Joe Thomas, managing director, Hamworthy Ballast Water Systems.
The company’s Aquarius-UV system is a two-stage approach featuring filtration followed by disinfection using ultraviolet light, thus avoiding the use of any active substance. As there is no detrimental effect on water quality, the ballast water can be safely discharged from the tank at any time; furthermore, maximum disinfection is ensured by exploiting UV treatment during the discharge cycle as well as on ballasting.
In developing the solution, Hamworthy formed a strategic partnership with UK-based Hanovia, a specialist in UV system design and production. Hamworthy assumed overall responsibility for performance compliance with the regulatory standards.
Also marketed by Hamworthy, the Aquarius-EC system similarly adopts a two-stage approach but with disinfection using an active substance generated by side stream electro-chlorination. The company collaborates with Magneto Special Anodes in developing the advanced electrolysis technology. When de-ballasting, the system neutralises any remaining active substance using sodium bisulphite, ensuring that the ballast water can be safely discharged to the sea.
“Both systems provide a robust solution for treating ballast water across a range of challenging ship operating and environmental conditions, exceeding the required IMO standards,” says Dr Thomas. “We have also adopted a modular approach to system design in both cases so that the equipment can be flexibly arranged to suit the conditions on board. Furthermore, both Aquarius systems are designed and supplied to treat ballast water across a full range of ballast pump sizes.”
Filtration is effected by the systems using automatic back-washing screen filter technology; the filter is designed specifically for ballast water applications and filters particulates down to 40 microns. Automatic back-washing ensures efficient removal of particles that are discharged back to the environment of origin, the systems PLC-controlled with user-friendly touch screen operation.
All relevant data is stored by the PLC in accordance with IMO requirements and the system can be fully integrated into the main control system to achieve complete ballast water management.
Land-based testing of both Aquarius systems was completed in early 2011 at the Royal Netherlands Institute for Sea Research. Sea trials are under way, the first official trial sampling resulting in a full pass against the requirements of the IMO D2 standard. Specific corrosion and paint coating tests on the Aquarius-EC system are also being conducted to MEPC requirements.
With all testing completed, Hamworthy expects to secure IMO type approval for the Aquarius programme during 2012.
A Sumitomo Ecomarine ultraviolet ballast water management system was due to be installed on NYK Cruises’ Asuka II for demonstration testing in January this year. The system developer, Sumitomo Electric, and the Japanese shipowner will co-operate in onboard testing to meet the requirements of the international convention on BWM.
The Ecomarine system incorporates filter units originally developed by Sumitomo Electric to separate large plankton and other aquatic organisms. Any remaining small organisms are then eliminated by a high-powered medium pressure UV process. Overall, the system is designed to save power and reliably remove organisms, while offering ease of use and low maintenance.
Tested on land in an arrangement comparable to actual onboard conditions with a water treatment rate of 200 m3/h, Sumitomo reports, the Ecomarine system demonstrated the anticipated reduction in power consumption and high organism removal. Basic approval from IMO is expected in March 2012, as specified in the G9 approval procedure; continuing land tests and sea trials will be pursued for G9 final approval in October and full type approval by the end of fiscal-2012.
An evaluation of ballast water treatment technologies and systems on the market by Hamburg-based shipowner Peter Dohle in association with Hammonia Shipping led to the specification of RWO’s CleanBallast plant for four 4,800 TEU container ships contracted at the Jiangsu Yangzijiang yard in China. Each system will have a capacity of 500 m3/h.
The project extended RWO’s orders for the CleanBallast system to over 50, mainly involving Chinese applications, where the composition of the Yangtze river water poses a significant challenge. The programme currently offers systems with ballast water treatment capacities up to 3,750 m3/h, the merits claimed including very low energy consumption, simplicity and user-friendliness.
Bremen-based RWO is part of Veolia Water Solutions & Technologies, itself a subsidiary of Veolia Environment, which claims to be a world leader in water and wastewater services.
Type approval from ABS for its Hyde Guardian ballast water treatment system was received last September by US-based Hyde Marine, a Calgon Carbon group company. In April 2010, the system was reportedly the first BWTS to gain product design assessment (PDA) certification from the classification society (indicating technical approval for the equipment, PDA is the first step to gaining ABS type approval).
The Hyde Guardian system was type approved in 2009 by Lloyd’s Register on behalf of the UK’s Maritime and Coast Guard Agency, confirming compliance with IMO Resolution MEPC.174 (58) guidelines.
Efficient automatic back-flushing depth filtration is applied to remove sediment and organisms, with a powerful ultraviolet disinfection system provided to destroy or inactivate smaller organisms and bacteria. The combination of these technologies has proven both cost effective and reliable in shipboard operation, Hyde Marine asserts.
The fully automated system can be integrated into the ship’s ballast control system. Skid-mounted packages can be supplied for newbuildings or modules for easy retrofit installations in the tight machinery spaces of existing tonnage. Type-approved Hyde Guardian systems are offered with ballast water flow rates from 60 to 6,000 m3/h for vessels of all types and sizes. ATEX 100 explosion proof versions are also available.
Norway’s PG Marine group, which sells the Hyde Guardian system globally for offshore support vessel applications, recently entered into a frame agreement with the Norwegian operator DOF which plans to install BWT systems on a large number of vessels in its 75-strong fleet. PG Marine will provide installation design support and deliver and commission the hardware.
The DOF fleet includes platform supply vessels, anchor handlers and subsea ROV tonnage which are deployed in the North Sea, offshore Africa and South America, the Gulf of Mexico and the Asia Pacific.
Another framework agreement signed by DOF with the Norwegian BWT system supplier Optimarin also covers contracts to be placed during 2012-2015. Most of the projects will benefit existing vessels through retrofits – carried out during scheduled drydockings – but there are options for newbuilding installations.
“This framework agreement initiates a long-term relationship with DOF, whereby we will be working closely together to deliver solutions to meet their operational demands,” says Optimarin director Tore Andersen. “It saves DOF substantial time and cost in repeat negotiations but, most importantly, gives the company contractual certainty while creating a structure needed to measure and improve fleet-wide BWT performance.”
The Optimarin system is described as a standardised, highly modular solution with a small footprint that is easy to install.
“These are key advantages when serving DOF’s retrofit demands, where some installations will be made during vessel operation or during extremely tight drydocking deadlines,” adds Tore Andersen.
The latest generation of another Norwegian system, OceanSaver, recently received DNV type approval certification. Previously focused on serving larger ships, OceanSaver is now also addressing the medium-sized tonnage sector with a Mark II system.
OceanSaver Mark II is described as a tailored version of the already type-approved Mark I system but with most of its energy-demanding features removed. A higher performance filtration technology and considerably reduced piping are incorporated, while a lower installation time with less complexity will benefit both retrofit and newbuilding projects.
Cuts in procurement costs will be accompanied by lower life-cycle costs, taking into account spares, energy consumption and manpower requirements. The energy required by the complete Mark II system and related equipment is said to be 50 per cent less than that for the Mark I system. Cost effectiveness is enhanced by no treatment during de-ballasting.
Mark II systems will be supplied to a pair of Suezmax tankers under construction at Bohai Shipbuilding in China and four bulk carriers building at the SPP Shipyard in Korea. The latter projects mark OceanSaver’s first installations in bulkers, each BWT system having a treatment capacity of 2 x 800 m3/h.
A valuable reference was secured at end-2011 with the delivery of the 159,000 dwt Suezmax tanker Ottoman Integrity from a Korean yard for the Turkish owner Gungen Maritime & Trading. The OceanSaver Mark I system installation incorporates filtration, cavitation, disinfection and nitrogen super saturation.
The filter and cavitation units are installed in the pumproom, while the disinfection unit and nitrogen system are respectively arranged in the engineroom and casing area. Filtration of the sediment and biological material from the uptake water is achieved by fully automatic inorganic back-flushing filters.
At the shipowner’s request, the filters were operated for over 70 hours during sea trials and reportedly performed according to specification and the full satisfaction of the owner, class, charterer and OceanSaver.
“In order to get the best possible system for your type of vessel it is important to keep close co-operation with your selected maker all the way through the project from the early sales stage until the first cargo is on board,” Osman Gungen advises other operators.
“The nitrogen super saturation component offers potential for reduced vessel maintenance costs through improved corrosion performance of the inerted ballast tanks,” says Tor Atle Eiken, OceanSaver’s senior vice president, sales and marketing. “It is particularly suited to newbuildings and high-spec specialist vessels and is an optional item in the Mark II system.”
The key features of the OceanSaver system are summarised as: large flow capacity capability; EX approval for gas hazardous areas; small footprint and high modularity (fostering flexibility in component location); and maintenance cost savings through reduced corrosion.
Having successfully completed land-based testing of its BWT system, Desmi Ocean Guard of Denmark has proceeded with shipboard trials and expected full approval and certification by early 2012. The system exploits 40-micron filtration, low pressure UV radiation and the onboard generation of ozone for injection into the ballast water stream.
Testing has been performed to IMO requirements with sea water of all salinities as well as fresh water. (Desmi believes it is the first UV system successfully tested with fresh water according to IMO requirements).
As the treatment parameters for salt water and fresh water are very different, online monitoring of water salinity is performed and the treatment automatically adjusted. The power consumption fulfilled expectations, monitoring under real conditions showing less than 11 kWh per 100m3 of treated ballast water being required.
Aalborg-based Desmi Ocean Guard was established by the Danish companies AP Møller-Maersk, Desmi and Skjolstrup & Gronborg to focus on developing systems to remove organisms from ballast water.
Hyundai Heavy Industries contests the market with its EcoBallast system, which received type approval from the Korean government in March 2011. The system features a filter unit and a UV stage to remove and deactivate micro-organisms in the ballast water; chemical-free disinfection uses physicochemical inactivation by irradiation with ultraviolet light.
A high-powered UV light from medium pressure lamps ‘denatures’ the DNA of the organisms, preventing them from reproducing. The UV reactor was specially designed to deliver even flow distribution and maximise UV dosage with minimal pressure loss. Each system installation can be customised to the specific project.
The Korean group also offers its HiBallast system, which received final approval last June. An electrochemical process disinfects organisms, the overall system comprising three stages: filtration to remove organisms larger than 50 microns; seawater electrolysis to produce and inject hypochlorite into the main ballast pipe during ballasting; and neutralisation to neutralise the ballast water during deballasting.
HiBallast is designed for installation in container ships, bulk carriers and tankers, offering treatment flow capacities up to 8,000 m3/h. Installation is eased by a side-stream piping arrangement branched from the main ballast piping, which also facilitates retrofits in existing tonnage. Systems have been installed in container ships and bulkers. MP