Invited Talk

Ballast water treatment options in light of pending and proposed treatment standards
Waite TD^*
College of Engineering, Florida Institute of Technology, Melbourne, Florida, USA
^*Email: twaite@fit.edu

The past five years have marked a significant increase in global reactions to invasive species transport via ships’ ballasting operations. While scientific and engineering interest has not been obvious over this period, political and governmental activity has generated many proposed and pending regulations governing ships’ discharge of ballast water.  This activity was initiated in February of 2004, when the International Convention for the Control and Management of Ships’ Ballast Water & Sediments was adopted by consensus at a diplomatic conference at IMO in London. As originally drafted, the convention will enter into force 12 months after ratification by 30 states, representing 35% of world merchant shipping tonnage. These proposed global standards regulated ballast water discharge in terms of concentration of viable organisms segregated by size, e.g. < 10 viable organisms of a size greater than or equal to 50 microns per cubic meter of water. This type of discharge standard mandated that a re-thinking of ballast water treatment technology design was required. Since this time in the USA, individual States, as well as the Federal government have all been working on ballast water discharge standards.  The States of California, and Michigan have been especially active in creating and adopting ballast water management requirements for ships visiting ports in these States. Overlaying these initiatives, is the caveat that the US EPA has recently been ordered by a U.S. District Court to regulate ballast water under the Clean Water Act. While this directive is being appealed, the US EPA has issued a notice of intent to develop a permit program for the discharge of ballast water in USA waters. Finally, Federal standards (Coast Guard Authorization Act) are also being generated.  From a ballast water treatment point of view, these various proposed standards generate significant challenges to the development of effective and reliable shipboard systems.  For example, the proposed Federal standards require that ballast water discharged in the USA meets far more stringent standards than those proposed by IMO.  Specifically, the proposed Federal standard regulates the number of viable organisms of size greater than or equal to 50 microns per cubic meter of water to less than 0.1 viable organisms.

The creation of these significantly different ballast water discharge standards through-out the world has the potential to set back work on ballast water treatment technology development. Development of effective treatment systems to address the requirements of these different standards will not be easily achieved.  In addition, as the adoption of the IMO standards has shown; a critical component of the process is the certification of treatment systems to achieve the individual treatment goals.  While technology developers have already struggled with the poorly defined ”certification process” creation of new ballast water treatment standards will further exacerbate the situation.

This paper will discuss the status of global ballast water discharge requirements, and its effect on development of ballast water treatment technologies.  Various treatment types will be evaluated, and the potential for effective treatment in terms of meeting the proposed standards will be compared amongst treatment types.

Keywords: Global ballast water discharge requirements, Treatment technologies

FlowCAM® technology – the integrated system for ballast water analysis and regulatory compliance
Peterson Kent A¹^*, Poulton Nicole J²
¹Fluid Imaging Technologies,
²Bigelow Laboratory for Ocean Sciences, USA
^*Email: kent@fluidimaging.com

The FlowCAM® is a continuous imaging flow cytometer now being used for monitoring of microorganisms and particles in water. It combines microscopy, flow cytometry, imaging and fluorescence technologies. A laser interacts with a high resolution digital camera to capture images and data of passing cells or particles. It offers cell counts, size data, pattern recognition, organism classification and image management. It has been used in numerous ballast water treatment projects worldwide. FlowCAM applications include pre-treatment, post-treatment, IMO D-2 standards validation and sampling protocols. It can detect bacteria-size microorganisms; image and count phytoplankton and zooplankton. The fluorescence capability can be used to differentiate live versus dead organisms. An overview of the technology will be presented along with various case studies.

Keywords: FlowCAM®; Ballast water; Viability; Imaging; IMO, Microorganisms

Practical challenges to ballast water management and treatment
Dahlstrom Alisha ¹^*, Jenkins Phillip², Shilling Spencer³, Snell Tony⁴, Stubbs John⁵, Parsons Mike⁶
¹University of California, Sea Grant Extension,
²Philip T. Jenkins and Associates,
³Herbert Engineering, Corp.,
⁴Australian Quarantine and Inspection Service,
⁵FedNav International,
⁶University of Mic.
^*Email: adahlstrom@ucdavis.edu

This presentation will cover the general “theory” underlying the designs of ballast water systems and the range of specific scenarios that occur when ballast is managed on different types of commercial vessels. For specific types of vessels and routes, it will include consideration of how ballast water is taken on, handled, and discharged; volumes and rates of ballast water management; the degree to which water from different tanks is combined during discharge or released directly without passage through the internal piping and pumps; and how these variables impact the efficacy of aquatic invasive species removal and/or treatment. It will describe and provide solutions to the logistics that affect the practicality of ballast water management treatment technologies, as well as approaches to determining compliance with discharge standards.

Keywords: Ballast water management, Ballast water treatment technology, Aquatic invasive species

Pioneering Biofouling Management in the LNG Industry: Plant Cooling Seawater System and Carrier Hulls
Ian MacDonald^*
Qatargas Operating Company Limited, Doha, Qatar
^*Email: IMacdonald@qatargas.com.qa

Qatargas have developed two pioneering technologies within the Liquefied Natural Gas (LNG) industry to control fouling. Qatargas currently operates a three-train LNG plant at Ras Laffan Industrial City with a fleet of 11 Moss-type LNG carriers. Fouling is an issue within the plants cooling seawater system and on the hulls of the carriers. Both cases demonstrate win-win scenarios: operational improvements that lead to enhanced environmental performance.

Fouling of the cooling seawater system (e.g., at strainers and heat exchangers) at Qatargas has only ever constituted a minor inconvenience. Fouling control has been adequately achieved within Qatargas using industry standard techniques, however, electrochlorinator (ECP) maintenance issues in combination with tough new environmental regulations provided the incentive to look for alternative anti-fouling strategies. Since 2004 Qatargas has investigated the use of a new chlorination technique, termed pulse-chlorination. The adoption of pulse-chlorination has allowed part of the ECP to be mothballed, reducing operational / maintenance requirements and reduced the amount of sodium hypochlorite added to the cooling seawater by 56%. Further system optimizations are on-going and shall be discussed.

Qatargas took the proactive steps towards compliance with the non-TBT antifouling paint international legislation recently introduced with the use of a silicon-based paint on the hulls of the LNG carrier fleet with sea trials being conducted in 2001. Fouling significantly increases the drag of a normally smooth hull and thus increases fuel consumption. This leads to increased transportation emissions and reduced profitability. The use of such technology has also allowed the extension of dry-dock periods for antifouling paint reapplication reducing waste production.

Continual improvement is a key factor of Qatargas’ vision of being an industry leader with high environmental standards. Preparation of the Qatargas LNG fleet for certification by the “green” award and the current / future implications of ballast water management shall be discussed.

Keywords: Qatargas, Electrochlorinator maintenance issues, Pulse-chlorination, Silicon-based paint

Modelling the dispersion of ballast water discharge off Visakhapatnam port, east coast of India
Babu MT^*, P Vethamony, KMF Kaise, S Ghatkar, PS Pednekar
National Institute of Oceanography, Dona Paula, Goa, India
^*Email: mtbabu@nio.org

Dispersion of suspended particles or organisms reaching the marine environment through ballast water depends on the hydrodynamic conditions prevailing in the region. Most of the planktonic larvae living in marine habitats are sessile or sedentary and can disperse over a large distance depending on the currents. The particles/organisms will advect along with the current and their net movement can be simulated using hydrodynamic model.  Dispersion of ballast water discharge off Visakhapatnam has been studied using numerical simulation of hydrodynamics of the region. MIKE21 2-dimensional model with hydrodynamics (HD) and particle analysis (PA) modules has been applied to study the dispersion around the discharge location.  HD simulates flow pattern prevailing in the region, and PA simulates the dispersion of dissolved and suspended particles present in the ballast water. The ballast water released at the spoil ground off Visakhapatnam is considered to be having different temperature-salinity characteristics as compared to the ambient water. The concentration and spreading of the dissolved and suspended particles around the discharge point are simulated to analyse the fate of the ballast water.

The model was forced by applying water level variations along the open boundaries and winds on the sea surface. A large model domain covering Kakinada in the south and Visakhapatnam in the north was selected for the simulation. Tides along the open boundaries were predicted at the coastal tidal stations using four major constituents M2, S2, K1 and O1. The tidal elevations required at the offshore boundaries were interpolated and applied to drive the model. The model results were validated with current measurement carried out during May 2006. The maximum water level obtained during spring tide was 1.72m, and the maximum observed current speed was 0.38 m/s (with a mean of 0.11 m/s). In general, both the u and v current components were negative, indicating the presence of southwestward current under the northeasterly winds prevailing during May 2006.

The model results as well as the measurements indicate that under the influence of the southwestward current, the discharged water and the particles flow southwestward, parallel to the coast and it does not advect towards the coast. The plume is seen at the source during the discharge period of 10h, and thereafter disappears from the source.

Keywords: Dispersion, Ballast water discharge, Hydrodynamic conditions, MIKE21 2-dimensional model

Invited Talk

Hydrodynamic cavitation for water treatment
Pandit AB^*
University Institute of Chemical Technology, University of Mumbai, Mumbai, India.
^*Email: abp@udct.org

Water as a resource is getting scarcer by day due to many environmental factors and also as a result of the pollution of the water bodies caused by the discharge of effluents as a result of industrial and anthropological activity. The recycle and rescue of water as well as the treatment of effluents to prevent pollution of water bodies is an area of active research for the past several decades.
A unique solution which is universally valid and carries out on-line treatment in variety of damaging situations has now emerged as a front runner. Hydrodynamic cavitation where the kinetic energy of water is used to create cavitating condition has shown a real promise. Cavitation, which can be described as generation growth and subsequent violent collapse of microscopic vapor or gas-vapor bubbles have shown to create following situations, which can be effectively used to treat water/effluent.

1. Generation of local conditions (the point of cavity collapse) which have temperature of several thousand degrees centigrade and pressure shock waves of several hundreds of atmosphere.
2. Creation of extreme microscopic turbulence on a near molecular scale and local fluid velocities of several hundreds of meters/second.
3. Creation of highly reactive free radicals capable of mineralizing (oxidizing) organic and inorganic matter in water bodies.

As can be seen from the conditions generated by the phenomena of cavitation, there exists a possibility of using these conditions for the following applications related to water treatment.

1. Local high temperature and pressure (shockwave) generated can effectively disrupt/sterilize a variety of microbes rendering them unviable. These shockwaves can also break large complex organic molecules making it possible to treat them by conventional biological treatment processes.
2. Microscopic turbulence can be effectively used to de-agglomerate microbial colonies exposing them to the disinfecting chemicals more effectively.
3. The reactive free radicals can oxidize many bio-refractory pollutants rendering them innocuous.

We will present various cases explaining the above applications where hydrodynamic cavitation has been successfully used for potable water disinfection, control of bio-fouling and oxidation of bio-refractory pollutants and demonstrate the efficacy of this emerging technology.

Keywords: Hydrodynamic cavitation, Potable water disinfection, Biofouling, Oxidation of bio-refractory pollutants, Emerging technology