September 14, 2017
Cost-effective, chemical-free biological sewage treatment for marine applications
The Evac EcoTreat biological wastewater treatment plant delivers the best of both worlds for owners of small vessels, with cost-effective treatment of black and gray water that meets and exceeds the latest environmental standards.
Balancing cost effectiveness and compliance with increasingly strict environmental requirements can often be challenging for ship owners when it comes to the treatment of waste water generated on board. The compact Evac EcoTreat represents the next generation of biological sewage plants and is the ideal solution for smaller vessels. Available in capacities from 2–11 m3/day, the plant is compatible with both gravity and vacuum-based wastewater collection systems.
Chemical and membrane-free treatment of all wastewater streams
Evac EcoTreat is a 100% biological system for the efficient treatment of black wastewater from toilets and urinals and gray wastewater from washbasins, sinks, and showers. Treating wasterwater in this way completely eliminates the need for any chemicals, filters, or membranes. The plant has been designed to make operation and maintenance as easy and cost effective as possible, while its compact footprint and low weight means it is suitable for smaller vessels where space restrictions may be tight.
Picture 1: Evac EcoTreat is a 100% biological system for the efficient treatment of black and gray wastewater.
Evac EcoTreat uses the submerged fixed-film bacteria principle. Black and gray water waste streams are fed to the inlet mixing tank either by gravity or by a vacuum pump. From there, the wastewater is transferred to the bioreactor tank by a macerating pump, which mixes gray and black water and cuts up solids. The wastewater is then driven through the matrix in the bioreactor tank by compressed air that is supplied by diffusers in the bottom of the tank. The air supplies oxygen and also enhances the biological process.
The treated water flows from the bioreactor tank into the settling tank by gravity, where it passes through the settling matrix. Before being transferred to the clean water tank, the water is exposed to an advanced UV light filter to eradicate all heat-resistant coli bacteria. Any organic or mineral sludge that accumulates in the settling tank is transferred back to the bioreactor tank for further treatment or removal from the system.
Meeting and exceeding the latest standards
Evac EcoTreat is type approved and wheel-mark certified by DNV in accordance with IMO MEPC 227(64). Furthermore, the plant is also approved by the U.S. Coastguard and Transport Canada.
“We’re delighted to introduce Evac EcoTreat to our extensive range of biological wastewater treatment solutions,” says Mats Riska, Product Manager, Wastewater Treatment Systems at Evac. “This new solution together with our existing advanced wastewater treatment solutions such as Evac EcoOcean MBBR (moving bed biofilm reactor) and Evac MBR (membrane bioreactor) means we can address the various needs of all our customers in the marine sector.”
Picture 2: “We’re delighted to introduce Evac EcoTreat to our extensive range of biological wastewater treatment solutions,” says Mats Riska, Product Manager, Wastewater Treatment Systems at Evac.