Controling Turbidity in Water

[DetectorGuy]

This is not really dive related but someday it could be... Maybe. I am on a construction site for a 250,000 sf building in clay ground. The site is obviously muddy and the dewatering of the site here is trickier than most sites because of the clay. We have several sediment ponds dug to control the sediment as it leaves our site. The particles of clay are not dropping out of the ground water fast enough to be pumped from the first sediment pond to the second and eventually off the site. We found this product that is made from the exoskeletons of crustaceans (mostly shrimp shells) that takes the negatively charged clay particles of the clay in the ground water and changes it to a positively charged particle. When these particles are positively charged they cling together and then drop to the bottom. The clear, less turbid water can then be pumped into the next sediment pond and pass the MPCA's stringent requirements. One gallon treats 30,000 to 40,000 gallons of water, but one gallon costs about $38. I would probably need to be a union electrician to afford enough to treat an entire lake  ;D . Our original tests looked good and we are now trying it on a much larger scale. I am not a chemist and I don't know much about chemistry but I thought it is interesting. Here is a PFD file with more info about it.

[DiverQueen]

There is an article in Sunday 3-20-2011 Star Tribune about a new company that is using barley straw as a means of preventing blue green algae bloom. 

[DetectorGuy]

There must be something to the crustacean exoskeletons helping with the turbidity because the shipwrecks with the zebra muscles have better viz than the areas not near the zebra muscles. I wish I would have put two and two together on this a few years ago. I would not be working now if I did.

[ballfrog]

The zebra mussels filter the water as their means of dining.  It's a different process from the electrostatic accretion.

And blue-green algae in Minnesota is showing resistance to copper sulfate treatments, so the barley straw might be the alternative.

[popolarbear]

Yes this works really well. I'm going to try to document my rain baisin clarity cycling from this effect.

also there is a japanese product that you can dump into  a bad pond and it will instantly bind up and drop out of soultion. but it is expensive.used on expensive koi ponds. works well.