Calgon Carbon Corporation has introduced a new granular activated carbon designed specifically for the removal of trace levels of methyl tertiary butyl ether (MTBE) and other organics from water.
Manufactured from select grades of bituminous coal, the company?s Filtrasorb 600 is designed for use in potable water and groundwater applications.
?With the growing need for effective removal of organic contaminants at lower and lower concentrations in water, this is truly an exciting new product for Calgon Carbon,? said Dan Brooks, market manager. ?Increasing health concerns surrounding the presence of MTBE in drinking water should stimulate growth for this new Filtrasorb product.
Concern over MTBE
Since the late 1970s, MTBE has been used as an octane enhancer in gasoline. Because it promotes more complete burning of gasoline, reducing carbon monoxide and ozone levels, it is used as a gasoline additive in localities that do not meet the National Ambient Air Quality Standards.
Studies have indicated that the use of fuels oxygenated with MTBE has led to significant air quality and public health benefits. However, MTBE poses new concerns for drinking water supplies as it has been detected in groundwater and surface water sources.
Santa Monica, Calif., for instance lost 80 percent of its local groundwater supply as a result of MTBE contamination in 1996. The city now must spend $3.3 million annually to buy alternative water supplies.
MTBE contamination of groundwater has occurred due to leaks from underground storage tanks (USTs) and pipelines. Surface waters are more likely contaminated by non-point sources, such as recreational watercraft.
MTBE is not currently a regulated drinking water contaminant, as there is currently little data on the effects of drinking MTBE-contaminated water. USEPA has tentatively classified MTBE as a possible human carcinogen based on inhalation studies and is researching the health effects of MTBE exposure.
Treatment Process
Filtrasorb 600 is manufactured to maximize the distribution of high-energy adsorption pores in the carbon structure. The amount of high-energy pores, as measured by Trace Capacity Number, directly relates to the carbon?s ability to adsorb organic contaminants at low concentrations, Brooks said.
Trace Capacity Number is a new way of measuring or predicting activated carbon performance. Traditional characterization methods, such as the Iodine Number, are not effective at gauging or controlling a carbon?s performance at adsorbing trace levels. The Trace Capacity Number measures a carbon?s capacity to adsorb acetoxime, a more realistic surrogate for low-level contaminant concentrations than iodine. Filtrasorb 600 products consistently exhibit high Trace Capacity Numbers, meaning they are ideally suited to treating low-levels of contaminants.
?Based on our fundamental understanding of pore size and pore energy of activated carbon, we were able to design a carbon to specifically target the capture of MTBE,? said Benjamin F. Ward Jr., Senior Vie President of Technology at Calgon. ?Early performance in the field has shown positive results, confirming our scientific findings in the laboratory.?
Filtrasorb 600 also is capable of withstanding the abrasion and dynamics associated with repeated reactivation, hydraulic transport, backwashing and mechanical handling. It meets the extractable metals requirements of ANSI/NSF Standard 61.
