Cleaning up pollution, whey down deep.Lab and field tests hint that dairy whey whey liquid residue from milk after the removal of cheese curds in the manufacture of cheese. An excellent protein supplement but difficult to handle in the liquid form, except to pigs maintained close to the cheese factory. Dried whey is easy to handle but processing costs are high. , a lactose-rich by-product of the dairy industry, could be used to clean up underground water supplies tainted with the solvent trichloroethylene trichloroethylene /tri·chlo·ro·eth·y·lene/ (-eth´i-len) a clear, mobile liquid used as an industrial solvent; formerly used as an inhalant anesthetic. tri·chlo·ro·eth·yl·ene n. (TCE TCE trichloroethylene. TCE Environment A volatile chlorinated hydrocarbon that boils at 88ºC and is highly soluble–1000 ppm in water, with various industrial uses Toxicity Peripheral neuropathy, carcinogenic. ), an industrial degreaser. Consuming TCE or inhaling its fumes fumes odorous gases and other volatile materials; inhalation of irritating fumes causes coughing and, if sufficiently severe, irreversible pulmonary edema. can cause liver and kidney damage, affect heart function, and possibly cause cancer (SN: 5/29/99, p. 343). The chemical is in groundwater at more than half of the Environmental Protection Agency's Superfund sites. To treat the tainted groundwater, engineers often pump hydrogen-yielding substances such as sodium lactate Lactate A salt or ester of lactic acid (CH3CHOHCOOH). In lactates, the acidic hydrogen of the carboxyl group has been replaced by a metal or an organic radical. Lactates are optically active, with a chiral center at carbon 2. into the ground, where they react with TCE by removing its chlorine atoms. That turns it into a relatively harmless hydrocarbon, says Elizabeth S. Semkiw, a chemist at Western Michigan University Western Michigan University, at Kalamazoo, Mich.; coeducational; founded in 1903 as Western State Normal School, became accredited in 1927 as a college, gained university status in 1957. in Kalamazoo. Her team's tests indicate that a slurry of whey pumped into the ground may do the same trick, if sufficient numbers of bacteria are added. Whey-munching microbes generate lactate compounds as well as acetates, butyrates, and other substances that can strip chlorine atoms from TCE. In the lab, a whey-microbe mix eliminated a 10-parts-per-million concentration of the pollutant from simulated groundwater in less than 2 weeks, says Semkiw. Also, field tests showed that groundwater laced with TCE, after flowing through a subterranean curtain of whey, contained breakdown products of the chemical. Further tests will assess whether remediation with whey is more cost-effective than the use of chemicals such as sodium lactate, says Semkiw.--S.P. |
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