Desalination of the Monitor’s Turret Begins…


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After a successful season of hands on work removing concretion from the Monitor’s Turret, conservators have cleaned the tank fitted anodes for electrolytic reduction, and added 90,000 gallons of water purified by reverse osmosis.   When the electrolyte had been added, everything was ready to begin active desalination and start the process of removing the chloride salts which had accumulated in the turret over 140 years on the sea floor.  Power was switched on to the electrolytic reduction system and on September 23rd the level of chlorides was measured after 1 week at  4.5 parts per million (ppm).   This doesn’t sound like a lot at first, but this concentration of chloride in 90,000 gallons of water is equivalent to 1.5kg, or 3.3 pounds of chloride removed!  After the second week of desalination, the turret treatment solution was tested again on September 30th and had increased to 7.9 ppm, equivalent to 2.7kg or almost 6 pounds of chloride.  These first few weeks of Turret desalination are graphed below:



So far the trend is in the right direction- an increasing concentration of chlorides in the treatment solution as they are removed from the turret.  The more chlorides we can remove, the better the turret can be preserved for the future.  Stay tuned for future updates on the progress of desalinating the turret!

2 thoughts on “Desalination of the Monitor’s Turret Begins…”

  1. As always, very cool. According to my calculations, which could be wrong, in the “desalination” process I always think of salt, and these 2.7kg of chloride equal almost 10 pounds of salt removed (9.86 lbs). So I guess the turret is a bit lighter now.

    1. Fran, yes, with an object as large as the turret, the mass of salt lost adds up. Though we are tracking the chloride, you are right that factoring in the sodium, the mass of salt (as sodium chloride) removed is about 4.4kg or closer to 10 pounds!