The project identified potential methods for the removal of dissolved dispersants from Ohmsett tank water using membrane filtration technology. The goal was to lower the dispersant concentration in the tank water to undetectable levels after dispersant effectiveness testing at Ohmsett. Previously, after a series of dispersant test in the Ohmsett tank, the only effective method for removing dissolved dispersant was to entirely drain the tank, then refill the tank, filter the water and add sufficient salt to bring the tank water up to open ocean salinities. Sine the tanks holds 2.6 million gallons of water, it is time consuming, cumbersome and expensive process that effectively stops testing and training activities at the tank for 4 to 6 weeks. The project also identified analytical methods to determine dispersant removal efficiency of selected membrane filtration processes.
The final report was accepted in July 2003. The report summarizes different analytical methodologies to determine both anionic and ionic surfactants dissolved in Ohmsett tank water. Laboratory testing was conducted on different membranes types for removal of dissolved dispersant. There was a comprehensive literature review of different candidate membrane filtration technologies. Advance oxidation techniques were also examined as a possible polishing step for the tank water. The final report provides rough estimates of cost to use the recommended filtration technology on an operational basis. For the filtration systems evaluated, either the throughput rates were not conducive to regular operational use of the cost was prohibitive.