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Process integrated closed cycle water management system for dry docks (PI-WAMAS)


Scientific objectives and approach:

To reach the above stated objectives and frame conditions, the following three step treatment of the generated dock waste water is suggested:
- a new specific polyphase separator
- a new high active knitted carbon membrane technology
- a new low energy desalination system
Through a polyphase flow simulation, it is anticipated to optimise the lamella and reactor geometry and design in a way to use and optimise flow-, gravity- and coalescence effects for the simultaneous separation of particulates and oils over wide operational conditions. The objective of this computer-aided optimisation is the reduction of the unit's size by at least 30% compared to traditional systems and an optimisation of the separation of particulates and oils by at least 25%, which would lead to an extremely economic system. Another objective is to realise the separation of particulates of an particulate diameter of less than 5 m. The activated carbon membrane unit (geometry, size) will be designed based on lab-adsorption tests. The membrane unit shall have a reduced reactor size of at least 50% and an improved adsorption material utilisation of at least 30%. To prevent that salt will be enriched in the closed water loop, the desalination cell based on electrolysis is developed. Different electrode designs will be investigated with varying salt concentrations during lab tests to ensure highest separation efficiencies at lowest energy requirements. The pure mechanical treatment of PIWAMAS has the advantage of not employing chemical additives or energy intensive procedures. The different waste water compositions will be produced with a waste water simulation breadboard. For simplifying testing in different areas, the prototype PIWAMAS system will be build into a small container allowing it to be easily transported and tested after the experimental test phase at the End-Users site's.

Problems to be solved:

Although a lot of improvements have been made in the past decades to help minimising the negative effects of industrial operations on the environment, some sectors of the industry are still far behind the possibilities offered by process integrated environmental technologies. Naval repair and ship's maintenance are among them, certainly due to a tight and extremely competitive business where little room is left for innovative environmental technology. One of the main environmental aspect on a shipyard is the generation of large quantities of waste water, with high concentrations of a variety of contaminants (e.g. heavy metals, TBT-an extremely toxic antifouling agent, PCBs, oils) and a very large consumption of fresh water, mainly due to the surface treatment of ship hulls. Old paint layers, surface coatings, biological fouling (algae, muscles) and mineralogical depositions have to be removed in periodical cycles to maintain corrosion protection of the ship hull, to limit the surface roughness of the ship hull, and hence to reduce the specific fuel consumption of the ship.
Essentially, this surface treatment is carried out by high pressure (HP) water jetting mainly to wash down salts and prepare the ship hull for further treatment and by ultra high pressure (UHP) water jetting (up to 3000 bar) to remove old paint layers. Cur-rently, the bulk of the generated waste water is directly discharged into the waters around a ship repair and shipbuilding facility. Assuming that the average European shipyard generates 35.000 m3/a waste water in its dock environment will lead to a of highly contaminated waste water effluent of approx. 3255 Mio. m3/a in the European Community. Apart from environmental aspects, water discharge is also costly. Based on the German prices for water (5,20 DM/m3) and waste water (3,20 DM/m3) the above assumed water consumption is equivalent to 147.000 Euro/a. Due to increasing environmental standards as well as the pressure to decrease costs in drydock operations, new innovative technologies are needed. Existing waste water treatment technologies are not capable of fulfilling the shipbuilding industry's demands satisfactorily; especially with a view on the cost/benefit ratio.
Different from many other industries, the quality and quantity of the generated dock waste water is not steady, but strongly dependent on the work conducted in a dock and therefore varying in composition and quantity within large boundaries. The challenge for a waste water treatment is therefore, to treat the varying waste water compositions and quantities safely and to recycle them into a closed water loop.
The overall idea of the proposed project is to develop and implement an appropriate integrated closed cycle water management system including waste water treatment and desalination whereby considerable amounts of fresh water can be saved and the total environmental impact of dry dock operations can be reduced to a minimum.

The system has to fulfil the following requirements:
- Treatment of the generated waste water and recycling into a closed water loop without the addition of any chemicals
- Reduction/ substitution of fresh water by using the dock surface as rain water collection system
- Innovative and economic waste water treatment in dependence of the waste water composition (Degree of pollution, salt concentration etc.)
- Separation of particulate blasting materials (e.g. copper slag) and oils for recycling

Expected Impacts:

The SME repair yards BREDO and ENP as well as the UHP service company DUFFERIN will benefit from the developed technology which can markedly reduce their operation costs. The SME partners involved in the manufacturing of the PIWAMAS system or components will benefit from the exploitation of the PIWAMAS system. The unique approach has already attracted additional SMEs from other sectors such as cleaning oil tanks and UHP equipment which are participating in the project.
Currently, the technological expertise in Europe is not capable of manufacturing a closed cycle waste water management system for shipyards and UHP services. This project will enable European companies to manufacture such a system.
BREDO is one of the first European repair shipyard certified in accordance with the Environmental Management Standard ISO 14.001. BREDO is highly dedicated to design its processes as environmental friendly as possible, through which the idea of PIWAMAS has been born. After successful completion, the BREDO company will become one of the first industrial end user of PIWAMAS. This will give them a lead in environmentally friendly production, productivity and quality assurance in the European shipyard industry. Their annual throughput of fresh water is about 20.000-25.000 m3. By applying the new system they hope to reduce fresh water consumption and waste water emissions to almost zero which would mean for them a saving of at least 50.000 Euro per year not taking in account the non-measurable environmental benefits.
Recently, there is no such system readily available on the market, which could fulfil the demands as stated for the proposed system. In addition all existing alternatives to control water emissions are related to productivity losses and are generally very expensive. It can be foreseen that there is a high demand for such a water management system existing in shipyards, for tank cleaning services and similar production facilities. This means in a same way that there is great market potential, both on European as well as on international level for the system to be developed.
The main strategic interest of ProSys and INDECO is the extension of their existing know-how in the area of waste water treatment and process control through this new innovative development. Once the project is finalised, it is expected that ProSys and INDECO will own the patent rights to the PIWAMAS system. In addition, it is their intention to award licenses of the technology to industrial producers both in Europe and world-wide. IXCO as a wholesaler is interested in the marketing of this innovative technology.
Besides the particular advantages for the participants in this project, the new system strengthen the competitiveness of both the European shipyard and UHP service industries and marks a considerable lead against foreign industries, for example from the United States or Asia.
The massive cost savings which would be made by the shipyards and UHP service companies if fresh water consumption is reduced to nearly zero, provide an opportunity for BREDO, ENP and DUFFERIN which, despite its high risk, cannot be ignored.


Fahreheitstrasse 1
28359 Bremen

Participants (8)

Dockstrasse 19
27572 Bremerhaven
United Kingdom
Sydenham Road 75
BT3 9DJ Belfast
Molhe Leste
2520.000 Peniche
73-79,Travessera De Gracia 73-79 4T 7A
08006 Barcelona
Km 3,Avenida Do Professor Doutorcavaco Silva 33Parque D
2740-120 Porto Salvo
Hemelinger Strasse 3
28359 Bremen
United Kingdom
Stranmillis Road, David Keir Building
BT9 5AG Belfast
An Der Karlstadt 10