TECHNOLOGY IS POLLUTION

There are yet other ways in which ultrasound is used to combat both the energy crisis and pollution.

At present, most sewage plants do no more than treat the polluted water by sedimentation and filtering through sand and gravel; they then add chlorine to the "purified" sewage and pipe it to a river or lake. This will neither kill bacteria and viruses in the sewage, nor decompose the phosphates and nitrates which fertilize lakes and cause eutrophication (rapid growth of algae which use up oxygen for other forms of life).

In a new process called Sonozone, the sewage is first treated with high power ultrasound, which tears up clumps of bacteria and viruses as well as breaking up chemical compounds with longer molecules. At the same time, ozone is bubbled through the sewage.

Ozone is oxygen with three, instead of the usual two, molecules to the atom. It gives rise to the peculiar smell that can be observed near an electric discharge, and that is how it is produced in the Sonozone process from the oxygen of the air by passing an electric arc through it. Ozone is chemically highly active, i.e., quick to oxidize other substances, which is as good as burning them.

Within 60 seconds, the ultrasound-ozone treatment will desstroy 100% fecal bacteria, 72% of the nitrates, and 93% of the phosphates. In a pilot project at the University of Notre Dame, 20,000 gallons of sewage per day are now treated by the Sonozone process.

Avco Corporation is now marketing equipment for industrial pollution control based on another principle. It literally freezes out the dirt from the polluted water. The water is agitated and Freon injected into it, turning the water into a slurry of minute ice crystals. The dirt is frozen out to the surface of the crystals, whence it can easily be washed away. A demonstration system handles 7,000 gallons per day, but Avco promises capacities of 100,000 gallons/day by this summer. A pilot plant is also being installed at the Office of Saline Water's desalination test facility at Wrightsville Beach, N.C., which should turn out 75,000 gallons of fresh water by February of next year.

Both systems prove the wisdom of the back-tothe caves lifestyle, which is based on the philosophy that more technology means more pollution.