U.S. Water News Online
LAS CRUCES, N.M. -- Organically treated zeolite, a
commonly used in most varieties of "kitty litter," is
effectively removing petrochemicals from groundwater beneath a
former gasoline station in Las Cruces. The pilot research project
for the pump and treat process, being funded by a private oil
company consortium, incorporates both absorption by zeolite and
traditional air stripping.
Running the polluted groundwater through a 55-gallon drum
with organically treated zeolite "removes a good 80 percent
of the pollutants," including benzine, toluene, and xylene,
said Fernando Cadena, a civil engineering professor at New Mexico
State University in Las Cruces. Cadena and a graduate student
have treated over a thousand gallons of polluted water beneath
an old service station in the downtown district of the city. After
the water is filtered, it is treated again with air stripping.
By the end of the process, Cadena said, the groundwater meets
federal drinking water standards.
The process also allows for recycling of the filter, he
out. When the filter of treated zeolite becomes clogged, a hair
dryer-like device heats and destroys the pollutants. Thus, the
filter is reused indefinitely, Cardena said. "This problem
of leaking underground storage tanks is endemic nationwide, but
we have a bigger problem in the Southwest because 90 percent of
our communities get water supplies from the ground," he stated.
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