SeaCURETM Ballast Water Management System
Evoqua Water Technologies’ SeaCURETM Ballast Water Management System (BWMS) secured approval under the Alternative Management System (AMS) of the United States Coast Guard (USCG) for operation in fresh, sea, and brackish water.
SeaCURE already possesses approvals from IMO and Federal Maritime and Hydrographic Agency (BSH) of Germany. This is good news for ship owners who now have a type-approved BWMS for all global shipping routes.
A BWMS can operate in U.S. waters only with full USCG approval or AMS approval. Presently, no BWMS has full USCG sanction. The AMS is a temporary measure under which the USCG accepts BWMS approved by another flag state and by the IMO. In April 2013, the USCG published a list of nine AMS-acceptable models.
Managing ballast water prevents the spread and proliferation of non-native species in coastal waters, lakes, and rivers. The IMO adopted the IMO Ballast Water Management Convention in 2004 but it becomes operational only after ratification by 30 states that make up 35% of global merchant shipping tonnage.
Freshwater ballast treatment systems are rare. Of the 50 odd systems type-approved by the IMO, only a few are recognized by Standards Developing Organizations (SDO) as fit for freshwater. This, despite the existence numerous freshwater ports and waterways.
A refined version of Siemens Chloropac® Marine Growth Prevention System (MGPS), SeaCURETM BWMS treats ballast water only on uptake. It is a safe, reliable, efficient, and economical BWMS.
SeaCURETM BWMS: Flow Diagram
Over the past 30 years, more than 2,500 Chloropac MGPS have been installed in power stations, FPSOs, onshore refineries, and offshore oil rigs. MGPS uses electro-chlorination biocide generation with injection treatment for seawater cooling systems.
Features and benefits of SeaCURE:
• Uptake Treatment Only cuts cost and power consumption
• In-Line Filtration
40µm Weave Screen filters out sediments and larger microbes
Patented Bio-Fouling Control eliminates biological clogging of filter. It introduces biocides in ballast seawater before this water reaches the filter surface. This drastically slashes microbe growth that clogs filters
• Off-Line Electro-Chlorination
Concentric Tube Electrode (CTE) Technology with Temperature-Insensitive Anodes minimize maintenance
Hydrogen Degassing erases explosion risk by ensuring hydrogen-free ballast tanks
• Side Stream Use lowers pressure drop and adds to the flexibility
• On-Demand Dosing slashes corrosion effects
• Self-Cleaning Cell eradicates the need for acid washes and cuts maintenance
• In-Situ Biocide Generation cancels the need to store and handle biocides. SeaCURE generates sodium hypochlorite from salts in water
Furthermore, making sodium hypochlorite in the side stream (generated from the main ballast water stream) makes SeaCURE compatible for retrofitting
Challenges @ Freshwater Ballast Systems
Freshwater organisms are smaller in size than their cousins in seawater. This allows them to pass through filters for seawater ballast treatment. SeaCURE is the first commercially available BWMS that passed the test in natural water. Most testing facilities across the globe use clear fresh water.
Chloropac®: SeaCURETM BWMSs Predecessor
With humic acid, tannins, and a flourishing aquatic life, the waters at the testing complex of the Great Ships Initiative located in Lake Superior are dark reddish and pose a challenge for Ultra Violet (UV) ballast water treatment systems.
UV disinfection mechanisms rely on the penetration and disinfection capacity of UV light – they use UV light at 254 nano-meter (nm) wavelength to eliminate disease causing microbes.
Ultra Violet Transmissivity (UV-T) indicates how much UV light can penetrate water. A UV-T of near 100% means clear water while less than 50% UV-T implies unclear water.
Such UV disinfection systems do not work effectively in unclear freshwater with low UV-T because:
• light does not penetrate and disinfect such water
• absence of salt (sodium chloride) means chlorine is not available for electrolysis
• freshwater with extreme high or low water temperatures and ice-laden freshwaters cut their efficacy
Non uniformity of regulations between different institutions leaves much to be desired. The IMO for example does not mandate testing UV
BWMS in freshwater, the USCG does. Then again, both fail to mention the term UV-T.
In practical operating conditions, UV-T of water ranges from 100% to 50% or lower. However, most UV ballast treatment systems can deal with water with UV-T between 100% and 80% only.
Evoqua Water Technologies provides clean water technologies to millions through reliable and economical systems. The company serves aquatic, industrial, institutional, and municipal clients around the world.
Through research and development, Evoqua focuses on desalination, waste reduction, water reuse, and process-energy efficiency. Evoqua services include systems for:
• water disinfection for aquatic applications
• town-city potable drinking water
• ultra-pure water for scientific and medicinal applications
• municipal and industrial wastewater treatment
• industrial process water
• water recycle and reuse
Despite inconsistent regulations, environmental concerns will drive similar developments. Already the BSH is basing its type approvals on the rate of flow of ballast water that further adds to the complexity of compliance.