Marine environmental solutions specialist Evac has launched a new advanced shipboard waste water treatment system, which produces crystal clear effluent that exceeds the requirements of all current quality standards, including those set by the IMO, Alaska, USCG and the Navy NIAG. It provides a compact, low
maintenance solution for ship operators squeezed between the twin pressures of increasingly stringent legislation to protect the environment, and spiralling costs for waste water management and disposal.
crew, at sea, without threat to health or the environment. It is based on proven, very low maintenance membrane bioreactor technology, which is capable of filtering out particles as small as viruses, and its compact footprint makes it ideal for retrofitting to existing vessels as well as for installing on new ships.
MBR represents a major advance in on-board waste water treatment compared with conventional solutions. These normally rely on various biological processes to treat ‘black’ waste water streams (from vacuum toilets and galley waters) to less stringent international standards, with ‘grey’ waste water streams (from accommodation, the laundry and possibly also swimming pools) discharged straight to the sea, untreated.
The MBR process is fully automated and highly controllable, and does not require monitoring by skilled personnel to work effectively. High volume grey water streams are first mixed with lower volume black waters in an equalising tank, to ensure a controlled and balanced flow of waste water into the system. The waste water stream then passes through a pre-treatment screening process, to remove solids. The stream is then circulated and recirculated through a
membrane bioreactor unit incorporating submerged flat sheet membranes, using bubble air diffusers, until the water is clear. A final-stage UV hygienisation process may be incorporated if required.
The final product, as demonstrated in a recent pilot study, is clear effluent with virtually no suspended solids, a biochemical oxygen demand of less than 3mg/ litre – the most
stringent current shipboard waste water treatment standard, the Navy NIAG, requires 15mg/litre or less – and no faecal coliforms.
“Environmental legislation can only get tougher, and a growing number of areas of the world will simply be closed to ships without advanced treatment facilities. Their navigable world is shrinking by the day”, says Juha Kiukas, Project Director at Evac. “At the same time, operators have to count the cost of compliance. This is why we’ve focused on creating a very adaptable, low-maintenance waste treatment platform that minimises operating costs and maximises flexibility for whatever future legislation may bring.”
“Today’s ship operators are keenly aware of environmental issues, but they also value the autonomy and flexibility that comes from a highly controllable and consistent waste water processing system”, adds Jari Jokela, Senior Process Specialist at Evac. “We developed the MBR system after very detailed study of the different types of waste and relative volumes, so we could really fine tune the load on the system
for maximum efficiency without the need for skilled monitoring or intervention.
“As a result, operators can be confident of meeting – and exceeding – current environmental requirements, without having to worry about managing or maintaining the treatment system, and free from reliance on harbour services.”
For larger vessels, grey and black waste water streams can be processed separately, increasing flexibility and open up
the potential for recycling grey water, for use in the laundry for example. MBR systems also supports the easy integration of further ‘polishing’ processes, such as nutrient removal.
Key to the low running costs is Evac’s choice of the Kubota membrane system, proven in domestic installations for over ten years. Unlike similar systems which require high pressures to operate effectively, the Kubota membrane needs only very gentle pressure: as a result, energy costs are kept low and the system requires only twice-yearly maintenance, with membranes normally replaced after ten or more years. /ins
Notes for the editor:
Evac is an international company which belongs to a worldwide French enterprise group Zodiac. Evac designs, manufactures and markets environmentally friendly water collecting and water treatment systems for shipbuilding industry. Skilled personnel, professional design and high-quality technical solutions have facilitated continuous growth, both in market share and in turnover. Evac Marine’s net sales were 35 MEUR in the fiscal year 2004/2005.
Evac Marine is the market leader in its field. More than 30 years in the business has resulted in vast experience - from sailing boats to big luxury cruise liners - and a good 8,500 references.
Evac Oy, supported by the other Evac companies and representatives in more than 40 countries, is responsible for the Marine-business worldwide. Evac Oy is certified by Lloyd’s according to ISO 9001:2000 quality assurance standards and ISO 14001:2004 environmental standards. Our premises are located in Espoo, Finland.
For additional information, please contact:
Director, Customer Projects
Evac Oy, Veininlaaksontie 1
FI-02620 Espoo, Finland
Tel.: +359 20 763 0250
Mobile: +358 50 468 7920
Fax: +358 20 763 0222