I feel these numbers are always a bit misleading. Sure the processes takes 10 million gallons a day, but much of that water can be reclaimed and recirculated.
> “Conventional treatment of wastewater at semiconductor plants had recycled anywhere from 40 percent to 70 percent of water used in their processes,” explains Govindan. “Some manufacturers still only recycle 40 percent of the water they use.”
> However, over the past two years Gradiant has been working with semiconductor plants, improving their water reuse so that they're able to recycle 98 percent of the water they use. So, instead of bringing in 10 million gallons of freshwater a day from outside, these new recycling technologies mean they need to draw only 200,000 gallons of water from outside the plant to operate.
Gradiant has this cool scheme (from MIT) for distilling water using a carrier gas. The special sauce was a "bubble tray condenser" that condenses water from the carrier gas by bubbling it through trays of progressively cooler water. This provides enormous surface area to get around the problem of mass transfer through the boundary layer.
I also can't take those numbers seriously, since I once saw a documentary about coffee... And they calculated the water of a small river nearby that was partly redirected to wash away the shells of the coffee beans.
> “Conventional treatment of wastewater at semiconductor plants had recycled anywhere from 40 percent to 70 percent of water used in their processes,” explains Govindan. “Some manufacturers still only recycle 40 percent of the water they use.”
> However, over the past two years Gradiant has been working with semiconductor plants, improving their water reuse so that they're able to recycle 98 percent of the water they use. So, instead of bringing in 10 million gallons of freshwater a day from outside, these new recycling technologies mean they need to draw only 200,000 gallons of water from outside the plant to operate.
https://spectrum.ieee.org/fabs-cut-back-water-use