tre) a n d available from the Ministry of Health's Institute of Environmental Health & Forensic Sciences, Ham Research Centre, P.O. Box 29181, Christchurch, N e w Zealand.
TECHNOLOGY
Two technologies have been developed to tackle recycling of rubber products, especially automobile tires. Of the 235 million tires d u m p e d annually in the United States only 1 7 % are recycled or b u r n e d for energy. T h e rest e n d u p in landfills. O p e n d u m p i n g can lead to tire fires, w h i c h produce hazardous combustion products (see Science Currents). Preliminary studies by Japanese researchers indicate that cured rubbers may be easily decomposed in supercritical water to potentially recyclable hydrocarbons. Toshinari T e n n o h (Nishikawa Rubber Co., Hiroshima) and his colleagues claim that rubber treated at temperatures above 400 °C in the presence of > 1 M NaOH will decompose within 15 m i n into an oily substance composed mainly of 20 carbon aliphatic a n d olefinic hydrocarbons. T h e sulfur is converted to H 2 S, w h i c h in t u r n reacts w i t h ZnO in the rubber to form ZnS. No sulfur-containing organics were identified in the decomposition mixture. Meanwhile, ECO 2 , Inc. (Hawthorne, FL), has received state approval to operate a tire pyrolysis reactor. The c o m p a n y shreds tires into " c r u m b rubber," separating out the steel and cotton from the tire. The c r u m b rubber is either sold for other uses or converted via pyrolysis into fuel oil a n d carbon black. Methane is collected from the pyrolysis and used to fuel the reactor. ECO 2 has already signed a contract to sell its a n n u a l output of fuel oil a n d half of its carbon black. The c o m p a n y is building additional pyrolysis reactors in Florida and Ohio.
Researchers from Oak Ridge National Laboratory (Oak Ridge, TN) have patented a simple and inexpensive heat exchange device that increases automobile air conditioner efficiency by 2 0 % . If fully i m p l e m e n t e d i n the United States, the n e w design could save 340 million gal of fuel annually a n d eliminate 6.5 billion lb of C 0 2 emissions. The heat exchanger allows the air conditioner coils to be "overfed" w i t h liquid coolant, t h u s increasing cooling capacity. Excess liquid coolant that exits the evaporator is routed back into the heat exchanger for vaporization, t h u s protecting the compressor a n d reducing its work load. Studies are n o w u n d e r way to apply this technology to stationary air conditioners, heat p u m p s , a n d refrigerators.
A single exhaust system modification could reduce soot and N O x emissions from diesel engines. Atsushi Tsutsumi (University of Tokyo, Japan) a n n o u n c e d at the November meeting of the American Institute of Chemical Engineers that adding a centrifugal fluidized bed removed soot in diesel exhaust and broke d o w n the N O x . Previous proposals for reducing N O x emissions from diesel engines have involved changes in the combustion process, w h i c h sacrifices fuel economy. Tsutsumi's modification to the exhaust system s h o u l d preserve fuel efficiency. In fact, soot collected on the fluidized b e d seems to improve the decomposition of N O x , making the process more efficient. Spurred by the growing efforts to remove chlorine from paper mills, University of Georgia biochemists have developed an enzyme technology to bleach paper. The EnZone process combines an enzyme treatment w i t h oxygen, ozone, a n d alkaline hydrogen peroxide bleaching stages. According to project leader Karl-Erik Eriks-
son, the process fully bleaches kraft p u l p s a n d produces p u l p w i t h physical characteristics similar to those p r o d u c e d by traditional chlorine-based technology. A pilot plant that will test the EnZone process is being built on the University of Georgia c a m p u s in Athens.
BUSINESS The expanding grass-roots movement to legislate a ban on chlorine and chlorine-containing chemicals in manufacturing (see Federal Currents) has p u t i n d u s try on the defensive. Paul Tippett, chair of the Council of Great Lakes Industries, recently labeled "irresponsible" one s u c h proposed b a n in the Great Lakes region that w o u l d affect Canada a n d the United States. Tippett claimed that eliminating chlorinated chemicals w o u l d cost U.S. and Canadian consumers $102 billion a year, w i t h an additional $67 billion n e e d e d for changes in the infrastructure a n d facilities to distribute chlorine substitutes. In the United States, 4 5 % of all industries use chlorine. Complains Tippett, "To make sweeping recomm e n d a t i o n s concerning a product as w i d e l y u s e d as chlorine without trying to u n d e r s t a n d the economic impact defies reason."
Industry experts are predicting that the market for air pollution controls will increase over the next two years by 86%. A market forecast by the Institute of Clean Air Companies (ICAC) found that expanding markets for NO x and volatile organic emissions conEnviron. Sci. Technol., Vol. 28, No. 1, 1994
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trois, as well as compliance w i t h facets of the Clean Air Act, will trigger the sales increase. However, Jeff Smith, ICAC's director, w a r n e d that the increased market activity may not pull the air control industry out of its " c u r r e n t doldrums." Representatives of businesses and insurance companies say they are willing to pay higher taxes to hind reform of the Superfund liability system. Testifying before the Senate on Nov. 4, these business representatives also argued for an e n d to retroactive liability for site pollution. On the other h a n d , environmental groups were joined by an unlikely partner, the Chemical Manufacturers Association (CMA), in supporting retroactive liability. Speaking for the CMA, Bernard Reilly said that if this liability is eliminated, EPA will have to clean u p older sites— something that industry can do more efficiently.
In November, Mobil Corporation ended its 19-year commitment to solar energy. The oil c o m p a n y a n n o u n c e d that it is shutting d o w n its solar demonstration project in Billerica, MA, a n d putting its solar subsidiary, Mobil Solar Energy Corp., u p for sale. Mobil's move leaves Amoco as the only U.S. oil c o m p a n y in the solar business. The Department of Energy has awarded funding to 33 small, high-tech firms for developing environmentally related technologies. The grant topics i n c l u d e d monitoring sensors for remediation activities, in situ treatment of heavy-metal-contaminated soils a n d groundwater, waste stream diagnostics a n d controls, on-site treatment of surface water a n d groundwater, a n d in situ bioremediation of contaminated sites. The grants are funded through the Small Business Innovation Research Program; Phase I grants, to
determine the feasibility of the concept, will average about $75,000 for about six m o n t h s of work. DOE expects b e t w e e n one-third a n d one-half of these concepts to move into Phase II development, u n d e r w h i c h two-year grants of $600,000 w o u l d b e awarded. In a first-of-its-kind program, the Federal Deposit Insurance Corporation is selling 58 environmentally distressed properties. The properties, in five N e w England states, all have contamination problems a n d have been foreclosed by a financial institution. None of the properties is u n d e r a federal or state c l e a n u p m a n d a t e , such as Superfund, but n e w owners w o u l d have to deal w i t h the contamination. Properties range from single-family dwellings w i t h asbestos to large industrial sites w i t h groundwater contamination. If the sale is a success, the federal government might repeat the offer in other regions.
Environment-Friendly agriculture BY A L A N
NEWMAN
S
ix decades of U.S. agricultural programs designed to stem soil erosion m a y soon be changed to address broader environmental concerns. In November the National Academy of Science's National Research Council (NRC) released a report outlining four n e w principles for agriculture that are designed to protect soil and water quality as well as halt soil erosion (2). The report r e c o m m e n d s n e w m e t h o d s of farm management and federal programs targeted at farms in environmentally sensitive areas or w h e r e pollution is most severe. "In the last decade it has become increasingly obvious that intertwining soil erosion programs with income programs has been an ineffective way to achieve environmental goals," said Sandra Batie (Michigan State University), chair of the committee that wrote the NRC report. "Moreover, it is n o w clear that the environmental effects of farming can be broader than erosion." Such effects include increased levels of salt in soils as a result of irrigation in Western states, soil compaction caused by heavy farm equipment, and the loss of organic matter in soils. 14 A
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To promote environmentfriendly farms, the committee reco m m e n d s four national policy goals: conserve and e n h a n c e soil quality; increase nutrient, pesti-
cide, a n d water efficiency; make farms less susceptible to erosion a n d runoff; a n d create more buffer zones to r e d u c e runoff. These concepts m e s h nicely w i t h pollution prevention in watersheds, w h i c h EPA is n o w promoting. The report calls for the U.S. Department of Agriculture (USDA) a n d EPA to w o r k together to develop better monitoring tools a n d
standards for evaluating farm management. In addition, the report asks USDA a n d EPA to give high priority to the development of n e w farming technologies. " T h e n e w w a y s of farming may be as different from current practices as current practices are from those used just a generation ago," said Batie. The committee reported that only 3 0 % of U.S. croplands are n o w farmed w i t h reduced tillage a n d residue m a n a g e m e n t practices designed to limit runoff a n d erosion. The committee also took aim at several current policies that inhibit environmental improvements. High on that list are the traditional single-focus, best management practices designed to maximize farm yields. The report calls for a farming system plan that w o u l d take a broader environmental view. Implementation of such a p l a n w o u l d then become the basis for farm assistance a n d compliance w i t h regulatory programs. Batie labeled s u c h a plan, " t h e road m a p that cuts across all types of farms." For instance, a farming system plan w o u l d monitor soil levels of organic matter, nitrogen, and p h o s p h o r o u s . The data w o u l d be used to determine h o w m u c h a n d
