In Washington state, a company called Tidal Vision has created a material out of crab shells that can treat wastewater.
Tidal Vision’s process converts seafood industry waste shells into chitosan, which is further processed into a liquid for wastewater treatment. “Essentially, chitosan works like a magnet on a microscopic level—with chitosan’s positive charge binding to the small negatively charged pollutants and coagulating them so they can easily be filtered out,” Craig Kasberg, CEO and founder of Tidal Vision, tells Forbes.
US treatment plants process 34 billion gallons of water daily using methods that can leech aluminum and iron into the environment. “Generally, the most consumed products (by volume) in wastewater treatment facilities are the coagulants and flocculants,” Kasberg says. “The traditional coagulants are non-biodegradable, metal-based chemicals … all non-biodegradable aluminum metals that end up in the wastewater sludge generated at the treatment sites.”
Tidal Vision’s product is also very efficient: 240 lbs of chitosan—the average yield from 1,000 pounds of shells—is enough to treat about 29 million gallons of contained stormwater or wastewater. Leftover material is sold as nitrogen fertilizer.