Jewelry manufacturers around Providence, R.I., pour an estimated $13 million in gold into the Atlantic Ocean every year. By using a microorganism, they may soon be able to recover the gold before their valuable wastewater goes down the drain.
The procedure was developed by Corale Brierley, a scientist formerly at the New Mexico Institute of Mining and Technology who had been studying how to use microbes to extract minerals from solutions. In 1982, she left the institute and founded Advanced Mineral Technologies Inc. (AMT,) which developed a commercial process that uses the bugs to extract metals -- including gold, silver, and lead -- from industrial wastewater. The microbes attach themselves to metals that have the same size and electrical charge as minerals the bugs need for their metabolism.
Brierley expects AMT's customers to fall into two groups: those who want to recover waste metal and those who have to. "A jewelry manufacturer losing $100 worth of gold every day has a big incentive," she says. Many businesses already recover some waste metal or sell their water to companies that extract the metal. AMT hasn't priced its system yet, but Brierley notes that "to attract these people, you have to make it very profitable for them."
Brierley will also target companies that are required by law to recover toxic metals from their wastewater.With the AMT system, a manufacturer could extract these metals without having to dispose of the toxic sludge generated by conventional treatments. "Sludge that has lead or chromium in it is considered a hazardous waste," says Brierley. "[A business owner] has to slap his name on a barrel of it and pay up to $200 to ship it away."
AMT started with less than $1 million in seed capital. In the next few months, the Socorro, N.Mex., company plans to raise more capital and start producing systems that can process up to 100,000 gallons of wastewater a day.