Published on November 7, 2007
Stopping the Invasion: Eliminating Aquatic Nuisance Species Using Ozone: Stopping the Invasion: Eliminating Aquatic Nuisance Species Using Ozone Overview: Overview Who is Nutech? Background information on Ozone What are the challenges/advantages? Testing Protocol/Floating Laboratory Test Results Focus of future testing The Nutech Team:: The Nutech Team: Marine Biologists Chemists Marine Engineers Naval Architects Academic Researchers Corrosion Engineers Environmental Scientists Ship Owners & Operators Background information…: Background information… What is ozone? How is it made? How does it work? Biologically Chemically Other proven applications This is Ozone (O3)…: This is Ozone (O3)… Ozone is a powerful oxidation agent Easily soluble in water Colorless gas, with distinctive odor Extremely short half-life; after which O3 reverts to O2 This is how you “make” Ozone…: This is how you “make” Ozone… Nitrogen is stripped from ambient air to concentrate the oxygen content Oxygen is passed through a high voltage or high frequency electrical field A percentage of the O2 molecules are converted to O3 molecules O3 is then injected into the water stream utilizing diffusers or venturi technology This is how it works – Biologically and Chemically…: This is how it works – Biologically and Chemically… O3 reacts with other constituents normally found in sea water The reaction creates Hypobromous acid (HOBr) and Hypobromite ion (OBR-) These oxidants are the “killing” mechanism when their levels exceed a toxic threshold Other water treatment uses for O3…: Other water treatment uses for O3… Municipal drinking water systems Bottled water suppliers Soda bottlers Breweries and Distilleries Commercial laundry facilities Sewage treatment plants Any place sterile water is needed Technical challenges related to O3: Technical challenges related to O3 Ozone is toxic to humans as well; how can we safely handle it on board ship? Ozone has a very short half-life in sea water (3-4 seconds); so how do we get it to do its job in such a short time? How do we make sufficient amounts of ozone to treat so much water? Latent toxicity, if any, needs to be neutralized Technical advantages related to O3: Technical advantages related to O3 Ozone is not sensitive to solids content in the water; therefore, no “pre-treatment” required Ozone has been proven NOT to accelerate corrosive forces already at work in sea water, at the dosage levels needed Ozone appears to be so effective at “killing” that it prevents re-growth Issues that all ANS technologies must show they can deal with…: Issues that all ANS technologies must show they can deal with… What is the efficacy of the treatment especially compared to BWE? What are the dosage rates required to achieve this? What are the re-growth rates, if any? What are the economics involved? Capital purchase costs Installation costs Operating and maintenance costs vs. cost of BWE Development of the testing protocol: Development of the testing protocol All members of the Team were involved: Academics Scientists Ship designers Ship operators Real world or laboratory testing? What exactly would we test for? Against what performance standard(s)? Peer reviewed and approved Engineering and Technical: Engineering and Technical Ozone had never been used on board ships in the treatment of ballast water Regulatory (USCG, ABS) review was intense Owner/Operator scrutiny was also intense; focus on personnel and operational safety Space on the subject vessel was at a premium How should the ozone be distributed? Who would operate the equipment and perform the testing? Our floating “Laboratory”: Our floating “Laboratory” T/V Tonsina, a 125,000 dwt tanker Owned by BP Oil Co.; operated by Alaska Tanker Co. 869’ LOA x 136’ beam Cargo capacity of 824,000 bbls (~ 34.6 million gallons) Ballast capacity of 306,500 bbls (~ 12.9 million gallons) Equipment Installation: Equipment Installation On board testing: On board testing Test Results: Test Results O3 concentration: 0.07 mg O3/ml Test results: Test results O3concentration: 0.07 mg O3/ml Focus of next stage of testing: Focus of next stage of testing Scientific: How much of the killing is being done by the ozone vs. the oxidants produced by the ozone? Will latent toxicity be an issue? How can we best measure, in real time, the ability of the water to support life, and therefore the efficiency of our dosage rate? Focus of next stage of testing (cont’d): Focus of next stage of testing (cont’d) Engineering: Our testing to date has proven that ozone works. Our focus is now turning towards what can be done to: Reduce the installation costs Maximize the production rate of ozone for the power consumed Optimize the distribution method of the ozone Determine the optimal quantity of ozone needed to achieve the desired “kill” rate Thank you!: Thank you! For more information….: For more information….