No fewer than six new systems seeking approval under the G9 guidelines were being considered for basic approval at MEPC 68 in May, as this issue of BWTT was published.
No fewer than six new systems seeking approval under the G9 guidelines were being considered for basic approval at MEPC 68 in May, as this issue of BWTT was published.
One of these has been developed by the University of Strathclyde in the UK. This is a little unusual, in that the body behind it is not a commercial organisation, but the application for basic approval has been submitted by Denmark, which suggests that commercialisation will be handled by a Danish company.
The ClearBal system, as it is named, employs a chemical treatment that no other system is making use of. It uses a solution of two active substances, brilliant green and cetyltrimethyl ammonium bromide, in a 1:2 ratio to inactivate marine species in situ in a ship’s ballast tanks.
Brilliant green is commonly used as a dyeing agent for colouring silk and wool but is also used as a topical antiseptic that is effective against Gram-positive bacteria, which suggests another Danish link: these bacteria are named after a test developed by the Danish bacteriologist Hans Christian Gram, which identifies bacteria on the basis of the physical properties of their cell walls, which the Gram test identifies.
The ClearBal solution is contained in barrels and one barrel at a time will be connected to the dosing unit. This consists of a dosing pump and a control unit adjusting the amount of the disinfectant injected to the ballast system suction pipeline based on the flow rate measurement recorded by a flow meter. The water is carried to the ballast tanks to be held for 48 hours. The system includes a detoxification or neutralisation system operating on discharge. In neutralising the treated ballast water, a resin is used to remove the active substances from the aqueous phase.
A biodegradation analysis of ClearBal in seawater results in four relevant chemicals: benzoic acid, diethylamine, diethylaminobenzoic acid and acetaldehyde. There are no other chemicals added or included in the ClearBal system. During de-ballasting, the ballast water is treated in the detox system, which is installed in-line with the ballast system discharge pipe, so that the ClearBal compound is removed before discharge. A periodic cleaning of the detox system components is required and the collected ClearBal compound and resin will be stored and transported to shore facilities.
Another of the systems applying for basic approval is also a newcomer to the market, highlighting the fact that there is a perception that, despite the number of systems currently on offer, the market can still accommodate new players.
The Varuna system has been developed by Kadalneer Technologies of Singapore. It is described as a once-through electrochemical treatment system with a combination of filtration, electrochemical treatment and neutralisation processes. The primary and secondary treatments are performed during ballasting operations and the tertiary treatment is carried out during de-ballasting operations. The entire treatment process is monitored by a control unit that optimises the treatment process according to the treatment requirement.
Primary treatment is carried out by a self-cleaning filter equipped with automatic backwash actuated by a differential pressure switch/gauge/timer. The primary treatment aids in physical separation and removal of larger micro-organisms and particulate matter larger than 40µm and the separated particulate matter is removed by self-cleaning backwash cycles and discharged back to the source environment. This physical separation process not only reduces the magnitude of the required electrochemical treatment but also reduces the load of organic matter in the ballast tanks and the discharge water, making the system environmentally friendly.
The ballast water filtered by the primary treatment process passes through a bipolar electrolyser where the secondary treatment – electrochemical disinfection – occurs. The secondary treatment generates sodium hypochlorite by partial electrolysis of the sodium chloride naturally available in the ballast water. This sodium hypochlorite, along with the other oxidants formed during the electrolysis of ballast water, neutralises the micro-organisms, thereby disinfecting the entire ballast water before storing it in ballast tanks. The residual chlorine available in the form of sodium hypochlorite and other oxidants maintains the sterility of the ballast water during storage, until discharge. During discharge the residual oxidants, if any, are neutralised by dosing the water with sodium thiosulphate before discharge.
The third system seeking basic approval at MEPC 68 is being proposed by a company that already has a system in commercial production. South Korea’s NK Co, achieved type-approval for its BlueBallast ozonation system in 2009 putting it as one of the earliest to become approved and the system also has USCG AMS approval. The new system is called NK-Cl BlueBallast and makes use of chemical dosing.
The NK-Cl BlueBallast system works by injecting sodium dichloroisocyanurate (NaDCC) with concentration of 15 mg/l into the ballast water proportionally according to ballast pump capacity. The NK-Cl system consists of an active substance storage and dissolving system, an injection system, a neutraliser and a monitoring and control system. These ensure that the active substance concentration is kept at 15 mg/l as Cl2 when ballast water flows in and achieves a maximum allowable discharge concentration (MADC) of 0.2 mg/l as Cl2 when it is discharged.
The active substance storage and dissolving system is a cartridge-type device for storing and dissolving the active substance that is used as the disinfectant of the NK-Cl system. The injection system is for controlling the injection of NaDCC solution into the ballast water from the storage tank through an injection pump, injector and pipeline static mixer. The flow rate of the injection pump is controlled by an inverter so that the concentration of total residual oxidant (TRO) in the treated water conforms to the setting value. The active substance is introduced into the seawater by a combination of alternate vortex shedding and intense shear zone turbulence via injectors in order to realise rapid diffusion in the piping.
The neutraliser is designed to remove residual oxidants from the ship’s ballast water that has been treated by the NK-Cl System. The neutraliser brings the TRO concentration to below 0.2 mg/l by dosing with thiosulphate automatically prior to discharging the treated ballast water. The NK-Cl Blue Ballast will only inject neutraliser if the TRO concentration of the treated ballast water is higher than 0.2 mg/l.
All operations are controlled by the main control panel. The monitoring and control system itself uses standard off-the-shelf technology and includes a variety of sensors, alarms, meters, valves and switches connected to central control software that is integrated into the ship’s ballast water management system.
The other three systems are being submitted by the government of South Korea and are the products of a US$12 million project involving Techcross. The project was initiated in April 2013 and aims to develop the next generation of systems that can comply with the much stricter requirements of USCG Phase II treatment standards due to be finalised sometime next year.
The three systems are the ECS-Hybrid System, which combines multiple disinfection technology; the ECS-Hychlor System, which employs electrolysis side-stream technology, and the ECS-Hychem System with chemical injection technology.
In the ECS-Hybrid system three technologies are combined: filtration, UV and electrolytic treatment. The system consists of a filter unit, a UV/TiO2 unit, an electrolysis unit, a neutralisation unit and accessories.
During ballasting, ballast water flows in from the sea chest to the filter unit to eliminate the organisms and the suspended matter larger than 40µm, which are collected by the filter unit. These are returned with the back-wash water to the ambient water by automatic back-flushing of the filter unit when the difference between inflow pressure and outflow pressure of the filter exceeds 0.5 bar. During de-ballasting, the filter unit is bypassed.
After filtration, the remaining organisms are disinfected by oxidising OH radicals produced in the UV/TiO2 unit; the maximum dosage of UV/TiO2 is 300 mJ/cm3. The irradiation intensity of UV/TiO2 is measured by a UV sensor and is constantly maintained by its automatic control. The output of the UV lamp is automatically adjusted to maintain constant intensity and the UV/TiO2 unit operates during ballasting and de-ballasting.
After UV/TiO2 treatment, the ballast water is passed through the electrolysis unit, which disinfects the remaining organisms by generating hypochlorous acid and hypobromous acid. The TRO concentration is 15 mg/l as Cl2 and this concentration is constantly maintained by the automatic control.
During de-ballasting, the treated water is passed through the UV/TiO2 unit to disinfect any remaining organisms and is neutralised by using sodium thiosulphate to remove any chlorine remaining in ballast water. The maximum allowable discharge concentration is 0.2 mg/l of TRO as Cl2. The discharge concentration is measured by TRO sensor and is also constantly maintained by the automatic control.
In the second of the Techcross systems – the ECS-Hychlor – the same 40µm filtration as in the ECS-Hybrid is used as the initial treatment stage.
After filtration, a side stream of ballast water flows into an electrochlorination unit to generate the concentrated oxidant (sodium hypochlorite) in situ. The concentrated oxidant is injected to the main stream of the ballast water to disinfect the rest of the organisms and the maximum TRO concentration in the main stream is 1 mg/l as Cl2. The TRO concentration is measured by a sensor and is automatically controlled by adjusting the electrolysis current of the electrochlorination unit according to the measured TRO concentration. The residual chlorine property of the oxidant disinfects the rest of the organisms in the ballast water tank.
During de-ballasting, the treated ballast water is neutralised by using sodium thiosulphate as the neutralising agent. The maximum allowable discharge concentration is 0.2 mg/l TRO as Cl2. The discharge TRO concentration is automatically controlled by adjusting the dosing rate of the neutralising agent according to the measured discharge TRO concentration.
As with the previous two systems, the ECS-Hychem system makes use of an initial 40µm filter unit with automatic back-flushing that is used only during ballasting and bypassed when de-ballasting.
The ballast water is then dosed with an injection of sodium dichloroisocyanurate (NaDCC) to disinfect the rest of the organisms. The injected NaDCC is converted to hypochlorite and sodium isocyanuric acid by dissolving in water where the maximum concentration of NaDCC is 18 mg/l TRO as NaDCC. The TRO concentration is measured by a TRO sensor and is automatically controlled by adjusting the dosing rate of NaDCC according to the measured TRO concentration. The residual chlorine property of the NaDCC disinfects the rest of the organisms in the ballast water tank.
At de-ballasting the neutralisation unit neutralises the residual TRO by using sodium thiosulphate before discharging. The maximum allowable discharge concentration is 0.2 mg/l TRO as Cl2.
Techcross was one of the first companies to achieve type-approval with its Electro-Cleen System (ECS) and has won contracts for installation in over 800 vessels. In addition to its ECS model, the company says that, based on experience and know-how gained during the process of developing the three new systems for the Korean government project, it is certain that it can provide different types of products to satisfy shipowners’ diverse needs.
As well as the six new systems detailed above, two systems the ATPS-BLUEsys Ballast and Ecomarine-EC – both from Japan – are looking to achieve final approval for active substance at MEPC.
Approval gives Coldharbour a lift
Type-approval by the UK’s MCA has recently been awarded to Coldharbour Marine’s system designed specifically for tankers and LNG carriers.
Coldharbour believes its innovative ‘in tank-in voyage’ approach offers significant benefits for operators of large tankers, LNG carriers and large crude carriers, which typically carry thousands of tonnes of ballast water that cannot readily be treated by a two-step system relying on filtration followed by electro-chlorination or UV disinfection.
The company’s system has no filtration and no connection to the ballast pumps or ballast lines. It is therefore immune to pump flow rates, pressure losses and power shortages, and guarantees zero disruption during cargo and ballast operations, including gravity ballasting and de-ballasting. Furthermore, by treating ballast water during the voyage, which can be up to 30 days for tanker operators, the risk of regrowth is eliminated.
In 2012, the Coldharbour gas lift diffusion technology was the first ballast water treatment system to be retrofitted to a VLCC and it was on this vessel that the first ship testing was completed in 2014 under the guidance of Lloyd’s Register.
Coldharbour’s chief executive, Andrew Marshall, said: “We were keen that UK MCA undertook the type-approval as it has a worldwide reputation for rigour, thoroughness and probity that will be welcomed by owners and operators.”
Mr Marshall went on to say that the company is now looking at USCG AMS approval and, because of the additional effort invested in the UK MCA/IMO testing, believes it is very well placed to move forward to full USCG type-approval within a reasonable timeframe.
• Coldharbour’s GLD technology won the Innovation Award at the 2015 Marine Propulsion Awards, presented at a gala dinner during the Annual Marine Propulsion Conference in April, organised by BWTT’s sister publication, Marine Propulsion
USCG appoints non-US BWMS laboratories
The US Coast Guard (USCG) has begun authorising non-US organisations to serve as independent laboratories for ballast water management systems (BWMSs). Its online list of approved laboratories identifies two classification societies – Korean Register (KR) and DNV GL – each with a number of sub-laboratories.
They can now issue type-approvals for ballast water management systems (BWMSs) in accordance with the US Code of Federal Regulations, which sets more stringent standards than IMO’s Ballast Water Management Convention. KR said in a statement that it expects these to become the benchmark for BWMSs.
The Korean society has three sub-laboratories: SGS Korea, the Korea Marine Equipment Research Institute and the Korea Testing Laboratory.
DNV GL has eight sub-laboratories, covering Europe, Asia and North America, including the DHI Ballast Water Centre in Singapore, which received its accreditation at the end of February, and the Norwegian Institute for Water Research (NIVA) which was approved in mid-March.
“NIVA has already started official USCG testing of a BWMS developed by Optimarin in fresh water, brackish water and sea water qualities for land-based and shipboard testing,” NIVA said in a statement.
KR explained that, under US rules, at least five valid and successful test repetitions at differing levels of salinity must be performed during land-based testing. Dr B S Park, chairman and chief executive of KR, said that the organisation was committed “to the development of all relevant technologies and will continue to contribute to the implementation of US Coast Guard regulations.”
US and German checks under one roof
Ballast treatment system makers seeking type-approval for their products valid in Germany and the USA can now do so with a single test.
Michigan-based NSF International, the first independent laboratory (IL) designated by the USCG to evaluate and test systems under its rules, can also provide testing to Germany’s Federal Maritime and Hydrographic Agency (Bundesamt für Seeschifffahrt und Hydrographie; BSH) requirements, which are based on IMO guidelines.
NSF said that manufacturers may now submit for required type-approvals to NSF International IL and in parallel to BSH using the same set of test data. This will reduce test costs and approval time and allow ships to navigate to US and international shipping destinations.
“This agreement with Germany’s BSH provides manufacturers a more economical and streamlined process for achieving two key BWMS type-approvals in the industry. The BSH is key to making our programme even more advantageous to ballast water management systems manufacturers,” said Tom Bruursema, general manager of NSF International’s Sustainability Division, which manages the NSF International IL.
NSF International’s IL partnership, formed in 2012, includes Retlif Testing Laboratories, Curtis-Straus Bureau Veritas, the Great Ships Initiative, the Maritime Environmental Resource Center and the American Bureau of Shipping (ABS). As a USCG-approved IL, NSF International coordinates testing among all partner organisations, including oversight of the testing, review of test data (technical and quality assurance) and preparation of the final report for submission to the USCG and BSH. BWTT
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