Tighter waste water standards lead to more plant orders

The contract calls for a bespoke advanced wastewater system to be installed on board Pearl of Scandinavia, replacing an existing sewage treatment plant that dates back to the vessel’s delivery in 1989.

The first stage of the job, scheduled to be undertaken in January 2011, during the vessel’s docking period, comprises the installation of steelwork materials for a new process, permeate and cleaning tanks.

Due to the short dry-dock time, Hamworthy decided to manufacture the process tank, pump skids and pipework in kit form at the Hamworthy Water Systems plant in the UK, to enable it to be retrofitted through the ship’s existing hatches and doorways. The next stage planned was assembly, welding and pressure-testing in dry-dock under the supervision of Hamworthy’s engineers. The remaining equipment is to be delivered by April 2011.

Hamworthy Project Manager, Julian Nicholas, said that the MBR would be one of the first new generation Hamworthy Mark IV MBRs to be delivered, the new version being expected to achieve lower operating costs, less operator intervention and to help protect the environment.

“This MBR was sized to utilise the existing structure from the old sewage plant, thus minimising disruption and additional work needed by the owner,” he said. “With a bit of ingenuity we have been able to integrate the permeate and cleaning tanks with the process tank, making for a more compact installation and minimising any disruption. Normally the domain of large cruise ships operating in environmentally sensitive areas, advanced water treatment technologies are increasingly finding wider appeal in the commercial freight market. This order demonstrates the way that more and more operators are turning to environmentally-friendly technology, ahead of regulations that will have an impact across the passenger ship market.”

Based on biological degradation and membrane separation, the Hamworthy MBR process is claimed to achieve high-quality discharge without requiring any addition or generation of chemicals hazardous to the maritime or shipboard environment. International standards on wastewater discharge have steadily tightened and Hamworthy says it expects this will continue over the coming years, hence the continuing development in anticipation of new regulations.

The company says that since introducing its MBR technology in 2000, over 100 MBR units have been supplied to cruise ships, ferries, offshore rigs, naval ships, and yachts. Some 58 MBR plants are in operation on board 27 cruise ships and a further 19 plants are on order for 10 cruise ships in various stages of installation and commissioning. Having just completed projects for the Pacific Sun and Pacific Jewel, all of the Carnival Australia cruise fleet is now fitted with Hamworthy MBRs.

Meanwhile, Hamworthy has secured an important contract with Al Fattan Goltens Shipbuilding & Repair to supply sewage treatment plant to a vessel under construction for the UAE Navy.

The STC-2A unit is being installed in a 75m long, 15,000dwt propelled landing craft, first in a series being built at the Al Sadr Port Shipyard at Taweelah, near Abu Dhabi, with delivery due to take place in mid-2011.

The company says that in 2008 it became one of the first companies to receive type approval in accordance with MEPC 159 (55) for its enhanced ST-C series. It says that a significant number of orders have been placed for its sewage plants meeting these standards, which conform to the revised MARPOL Annex IV related guideline. The MEPC 159 (55) standards apply to equipment installed on existing ships on or after 1 January 2010, and new ships whose keels are laid on or after this date, superseding the previous MEPC 2(VI) guidelines adopted in 1976. The new regulations call for higher discharge standards for all effluent quality parameters.

Hamworthy’s ST-C sewage plant uses an extended aeration process which the company says has been steadily optimised for marine application over the past four decades. The technology, which is fully compatible with gravity and vacuum collection systems, features an automatic control system for unattended operation and minimum maintenance and is available in a modular compact construction for retrofit applications. Hamworthy has received both EC Marine Equipment Directive (‘Wheelmark’) certification from the UK Marine & Coastguard Agency and type-approval certification from Lloyd’s Register for the enhanced ST-C range of sewage treatment plants.