NEN's Seymour Rothchild Kilogram capacity in biochemicals
high-energy physics research. Pilot also makes organic fluorescent chemicals for liquid scintillation counting and polypeptides used as synthetic protein models in protein research. The company can turn out biochemicals in kilogram amounts (NEN works largely at the subgram level). Pilot netted about $85,000 on sales of about $550,000 in the year ended Dec. 31. The proposed merger calls for N E N to acquire Pilot's assets in exchange for NEN stock, says N E N president Seymour Rothchild. Pilot would operate as a corporate subsidiary of NEN, and Pilot chairman Mark Hyman, Jr., would join NEN's board. N E N chairman Robert Waterman was senior vice president at Schering Corp. until July 1962 and is still a director. However, there is no financial tie between NEN and the big drug maker. End-use sales of radiochemicals in the U.S. are estimated by those in the business at $6 million to $8 million annually. The higher figure probably is closer to the truth. The major factors in radiochemicals are New England Nuclear, Schwarz BioResearch, and Nuclear-Chicago. Nuclear-Chicago is the exclusive U.S. sales agent for the United Kingdom Atomic Energy Authority's Radiochemical Centre for compounds labeled with carbon-14 and tritium, and is a nonexclusive agent for that organization's other radiochemicals. End-use sales of radiopharmaceuticals in the U.S. run between $8 million and $10 million per year. The leaders are Abbott Laboratories, North Chicago, E. R. Squibb, a subsidiary of Olin Mathieson, New York, and Nuclear Consultants Corp. This picture could change, how12 C&EN FEB. 13, 1967
ever, as a result of moves that have taken place in the past few years: • I n November 1966, Mallinckrodt Chemical, St. Louis, acquired Nuclear Research Chemicals, Orlando, Fla., a maker of labeled compounds. A year earlier, Mallinckrodt had bought Nuclear Consultants Corp., St. Louis, a maker of radiopharmaceutical diagnostic and therapeutic agents. • In August 1966, drug maker G. D. Searle & Co. completed its acquisition of Nuclear-Chicago. Both companies are based in Chicago. • In December 1965, Schwarz BioResearch, Orangeburg, N.Y., a maker of life science biochemicals, both tagged and untagged, was acquired by Becton, Dickinson, East Rutherford, N.J., a maker of hospital supplies. • In fall 1963, Volk Radiochemical merged into U.S. Nuclear Corp. In fall 1965, Nuclear Consultants bought from U.S. Nuclear the radiopharmaceutical part of what had been Volk. In December 1966, U.S. Nuclear, including the radiochemical part of Volk, merged into International Chemical & Nuclear, City of Industry, Calif. In September 1966, meanwhile, ICN had bought ChemTrac, a Cambridge, Mass., producer of radiochemicals, from Baird-Atomic. • Finally, Neisler Laboratories, a subsidiary of Union Carbide, is moving into radiopharmaceuticals with a technetium-99 generator.
HEW proposes evaporation limits John W. Gardner, Secretary of Health, Education, and Welfare, has proposed additional standards to control air pollution from new motor vehicles. The standards prescribe limitations on evaporative losses from fuel tanks and carburetors and would be effective for new model automobiles and light trucks sold in the U.S. beginning in 1969. On an average trip, an automobile evaporates about 10 grams of gasoline from its carburetor. It also loses about 30 grams daily through the tank cap as a result of pressure changes from the tank's thermal expansion and contraction. H E W estimates that 1 billion gallons of gasoline annually pollute the atmosphere as a result of these evaporations. The new standards limit these losses to 2 grams of gasoline per "test," as specified to manufacturers. The testing procedure simulates an average trip and one gas-tank volume change per day. Recent technological improvements have been made that could reduce these evaporative losses by more than 90%, H E W says. Already, Esso Research and Engi-
neering scientists have developed an evaporation-loss control device (ELCD) which first adsorbs gasoline vapors on charcoal and then feeds the vapors to the engine for combustion (C&EN, Jan. 23, page 18). One technical problem which Ford Motor finds in testing E L C D is that the device alters the carburetion airfuel ratio by about 5%. This change results from purging the canister and does not contribute to carburetor performance. The tolerance of engine air-fuel requirements is from 3 to 6%, based on exhaust emission control, economy, and drivability. This stringent requirement is forcing a trend to design engines with fewer accessory systems. Moreover, says Arthur M. Smith (manager of Ford's advance emission control engineering department), ELCD fails to deal with the whole problem of gasoline vapor pollution. Losses in distributing and marketing the gasoline amount to about 37% of the total emission. General Motors, which has been testing charcoal adsorption-desorption systems for several years, finds similar problems with charcoal devices. During acceleration, when desorption occurs, vapor entering the engine is too rich with fuel. During this short period, carbon monoxide is increased in the exhaust. Other emission controls show good potential, GM's Max M. Roensch, executive engineer of emission control, points out. An important factor in developing a system is not only original cost to the customer but also the cost of periodically inspecting the system as regulations will probably require, he says.
Caigon process treats water Calgon Corp. has developed a wastewater treatment process which the company claims lowers costs, requires less land, and produces better water than conventional primary and secondary treatment. The process is a combination of recent advances in water treatment technology. It consists of a primary settling stage which is improved by the addition of polymeric coagulators and coagulant aids, followed by a secondary treatment consisting of beds or towers of regenerable granular activated carbon, which acts as an adsorber and a filter. The new combination can perform as well as many three-stage processes, Calgon says. But it can be installed on only 10% as much land. "This new water renewal process enables both cities and industries to discharge a better quality water to receiving streams at less total cost than is possible with
presently accepted conventional treatments, and it offers the flexibility of a built-in capacity to meet more stringent water quality standards in the future," says W. W. Hopwood, president of Calgon. The use of polymeric coagulators in primary treatment is a comparatively recent development which Dow Chemical has been spearheading (C&EN, Oct. 10, 1966, page 4 0 ) . Dow began marketing such polymers in 1964. Both Dow and Calgon point out that these polymers can greatly improve sewage treatment in plants using only primary treatment. Primary treatment typically removes about 35% of the biological oxygen demand (BOD) of raw sewage. Addition of polymeric flocculants can increase BOD removal to 50 to 70%. In the Calgon process, alum is added to the primary tanks; the presence of coagulators with the alum improves phosphate removal, too. Removal of suspended solids can be boosted from 45% to between 70 and 90%, Calgon says. The efficient removal of solids during primary treatment, the company notes, makes possible the elimination of conventional secondary treatment. These involve large aerators and clarifiers. Solids in the effluent from the modified primary treatment are at a level low enough to be filtered by the carbon and backwashed from it without difficulty. Activated carbon has been used as an adsorber for many years, but its use as a simultaneous filter and adsorber is a recent development of Calgon's Pittsburgh Activated Carbon Co. subsidiary. In 1962, Pittsburgh Activated Carbon installed a dual-purpose car-
Calgon's Hopwood Flexibility for the future
bon system in a potable water plant at Hopewell, Va. Two years ago, tertiary waste-water treatments using carbon were installed in a pilot plant at Corona, Calif., and a full-scale plant at South Lake Tahoe, Calif. The first full-scale use of the dual-purpose system for a potable water treatment occurred last year at Nitro, W.Va. The 15 million gallon-per-day Nitro plant includes an on-site, high-temperature furnace for regenerating spent carbon. Regeneration, also a part of the Calgon process, can be done 10 times or more. Its Filtrasorb carbon granules are strong enough to withstand repeated regeneration in the furnace and repeated backwashings in the filters, the company says. Activated carbon treatments as a tertiary process can improve BOD removal from 85 to 90% (conventional secondary quality) to 95 to 99%. In the process, Calgon says, primary treatment of effluent from which 50 to 70% of the BOD has been removed can be improved to whatever level is desired—(between 85 and 99%. Variation of final effluent quality is done by changing the amount of activated carbon on the beds, by regenerating the carbon fairly frequently, or by changing the number of filter beds. This flexibility, a key quality of the activated carbon system, enables the system to automatically handle sudden increases in the amount of pollutants caused by increased sewage volume or concentration of contaminants. The plant can also be easily expanded to meet future volume or quality demands.
GE launches roofing silicone Continuing a four-year campaign to sell construction silicones to individual consumers through distributors, General Electric is now selling a third line of construction silicones—a silicone rubber roofing compound. (The other two silicone products are construction sealants and traffic coatings.) Although conservative about immediate penetration of an estimated $1 billion-plus annual market for roofing materials, GE believes a modernizing construction field will eventually accommodate large volumes of the nowspecialty elastomers. Other silicone producers share GE's interest in the construction industry as a potential mass outlet for the historically small-volume, premium-quality silicone materials. Dow Corning, like GE, has had a construction sealant on the market for several years, and its interest in the construction field is growing. Similar interest
Silicone application Breathes but watertight is expressed by Stauffer, although the company has no product for construction now. The only other U.S. silicones maker, Union Carbide, also has no offerings directly to the construction industry. GE's new roofing material is a paintlike silicone polymer which goes on plywood, concrete, fiberboard, and other surfaces in the form of a continuous, breathing (but watertight) membrane 0.022 inch thick. The product, GE says, stays flexible down to - 6 5 ° F. and will not soften at 300° F. It adapts to any configuration and should last for 30 years (GE makes a limited guarantee of five years, however). GE is counting on such properties to counter the cost advantage of traditional asphalt materials. The latter can easily halve the silicone's estimated total cost of 55 cents per square foot. Even so, GE states, the silicones are competitive for some architectural designs and industrial repair needs. And the silicones are competitive with other roofing materials, such as neoprene. The silicone roofing compounds are applied as primer and two coats. The primer is a silicone polymer used to penetrate the base material surface and provide a bonding surface for the other layers. The next application (base coat) is a polymer-rich elastomer containing about 7 5 % solids and a volatile solvent. Top coat is a tougher surface with about 8 5 % solids. In application, roofing materials are mixed with a catalyst which crosslinks (hardens) the silicone polymer chains in about 30 minutes to two hours. Structure of the compounds is the normal silicon-oxygen backbone of silicones with organic substituents, mainly methyl groups. The chains are linked by oxygen bridges between silicon atoms. The bridges form tetrahedrally around the silicon centers, GE explains. FEB.
13, 1967 C&EN 13
