Prospects strong for wastewater oxygenation Oxygen aeration of wastewater is going places. At the present time there are more than 45 oxygen treatment systems in operation and about another 100 under contract in the U.S. As recently as 1970, there were no oxygen systems in operation. Two years ago there were fewer than 25 operating systems (C&EN, July 15, 1974, page 7). Three of the makers of these systems, Airco, Union Carbide, and Air Products & Chemicals, are predicting even greater gains in the next few years. It seems to be a safe bet that by 1985 from 10 to 15% of all oxygen produced in the U.S. will go to wastewater treatment. A fourth, FMC Corp., declined to discuss its activities in this market. The growth in use of oxygen treatment in the wastewater field is somewhat of a surprise, inasmuch as the field operates under a kind of Catch-22 philosophy. New systems and processes must be proven in treatment plants before they are accepted by the consulting sanitary engineers who specify the equipment for municipalities. But the processes must be specified by the engineers before they can be installed in treatment plants. (For this reason manufacturers often try to get new equipment installed in industrial wastewater treatment plants.) The producers reason that if the equipment works well at the new site it will be accepted by the engineers. The engineer then will place it into municipal treatment—the heart of the market. (But even such placement does not always guarantee success. There exists a large graveyard of systems that never made it in the municipal market as well as companies with one primary product that was found lacking.)
Workmen install Airco F30 module in an existing aeration tank
Why then the acceptance of oxygen aeration systems? There are a number of reasons. But behind most of them stands the Water Pollution Control Act Amendment of 1972 (P.L. 92-500). When this law was passed mandating much stricter wastewater effluent standards, many municipalities found themselves with a large problem. Many of the communities—especially larger cities— found that, although they had to expand their facilities, land near their treatment plant sites was at a premium. They then discovered oxygen aeration, which in some cases could as much as double their capacity while requiring very little additional space. And the systems could provide greater BOD (biochemical oxygen demand) removal, sludge digestion, and nitrification. Another factor in the relative success of oxygen systems is cost. Promising greater removal efficiencies at lower operating costs than air aeration, manufacturers have stirred considerable interest. Capital cost is higher than with air aeration systems because of the oxygen generation equipment needed. But here again, P.L. 92-500 enters the picture. The law calls for 75% financing of eligible capital costs by the federal government, greatly reducing the municipalities' portion. In addition, some states provide up to an additional 15% of the capital costs. This means that some communities get by paying as little as 10% of the cost of sewage treatment plant expansion. However, they must pay all operating and maintenance costs. Hence, it is advantageous for communities to buy the system that will give them the greatest operating efficiencies regardless of what the system costs in the first place. The systems provide a number of benefits for wastewater treatment plants. Because they are covered systems, air pollution in the form of odors and possible virus contaminants is reduced if not eliminated. Manufacturers also claim the elimination of icing, which always has been a problem in cold climates. Sludge disposal problems are reduced with oxygenation because of denser, low-volume sludge coming out of the system. Although the big market is, of course, municipal wastewater treatment, there is some incentive for system sellers' pushing into industries that discharge biological wastes. All of the oxygen aeration systems makers say that they are interested in industrial markets but only Carbide has made any inroads. One of the first plants that Carbide built was for Lederle Laboratories in Pearl River, N.Y. However, the big industrial market seems to be in the pulp and paper field. Here the oxygen generators used for the wastewater system often are used for in-plant processes as well. About one third of Carbide's Unox plants that are operating in the U.S. are in industry. Outside the U.S. Carbide has made significant inroads in Japan where
CHECKOFF NEW PLANTS • Isocyanurate foam—Jim Walter Corp.'s Celotex building materials division will spend $33 million on three units, each of which will have capacity to make 200 million sq ft annually of proprietary cellular plastic foam products. Plants, first of which will be in Philadelphia and completed in 1978 with others to be at unspecified locations in South and West, will make insulation board product, glass-fiber-reinforced isocyanurate foam core with aluminum vapor barrier on both sides. • Polyester resins—USS Chemicals division of U.S. Steel will build facility at Neville Island, Pa., chemical complex to make 90 million lb a year of unsaturated polyester resins; unit is to be on stream in early 1979. • Sulfuric acid—Asarco will build 800 ton-a-day plant at El Paso, Tex., at cost of $13 million with startup planned for mid-1978. Plant will be designed and constructed by Monsanto Enviro-Chem Systems; feedstock will be sulfur dioxide off-gases from Asarco's on-site lead and copper roasting processes.
PLANTS COMPLETED • Ethylene—Gulf Oil Chemicals has started up 1.2 billion lb-a-year plant at Cedar Bayou, Tex. Besides ethylene, plant will make up to 800 million lb a year of other olefins, including polymer-grade propylene and large volume of aromatics concentrates. • Iodine—Houston Chemical unit of PPG Industries has started up 2 million lb-per-year plant at Woodward, Okla. Plant's output, about a fourth of annual U.S. needs, is form of crude iodine flakes having minimum purity of 99.5%. • Pigments research—Chemetron Corp.'s pigments division is completing expansion and modernization of research headquarters at Holland, Mich. Space has been expanded 25% and more than 20 professional people have been added to lab staff. • Synthetic rutile—Kerr-McGee Chemical has dedicated new $53 million plant to make synthetic raw material for titanium dioxide. Plant will produce 110,000 tons of synthetic rutile annually using as feedstock ilmenite now purchased, but ultimately to come from company's deposits in Tennessee.
March 28, 1977 C&EN
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Actinides in the Environment ACS Symposium Series No. 35 Arnold M. Friedman, Editor A symposium sponsored by the Division of Nuclear Chemistry and Technology of the American Chemical Society. This important compilation, the first of its kind, presents the current state of knowledge about the behavior of actinides, especially plutonium and americium, in the environment. Environmentalists, nuclear power planners, and nuclear waste planners will value this timely collection of the latest actinide research, delivered by experts from the world's most advanced nuclear laboratories. The book provides a comprehensive look at the: • role of actinides in waste management • moisture and solute transport in porous media • migration of actinides in rocks, soils, ground water, and biosystems • biological pathways and chemical reactions • Box Model Theory, geological storage, and geochemistry 107 pages (1976) $14.25 clothbound ISBN 0-8412-0340-7 LC 76-44867 SIS / American Chemical Society 1155 16th St., N.W. / Wash., D.C. 20336 .copies of SS No. 35 Please send . Actinides in the Environment at $14.25 per copy. • Check enclosed for $ • Bill me. Postage at 40 cents per copy if other than U.S. or Canada. Name Address City
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18 C&EN March 28, 1977
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Morganton, N.C., wastewater treatment plant uses Carbide's Unox system it has 16 plants operating with more on the way. Worldwide, Carbide has more than 200 plants in operation, under construction, or in the design stage. Airco, a newcomer to the field, has only two plants under construction or in design. One of these just announced is for reaeration of a river low in dissolved oxygen. However, the company is confident that the modular concept of its F 3 0 system will increase its acceptance. The modular approach, according to Airco, is expected to appeal to smaller users and those that will be expanding their units as time progresses. The small user, whether it be industry or municipalities, is of prime concern to all the systems manufacturers. They realize that not every contract can be for a big city-sized, 300 million gal-per-day wastewater treatment plant. There are many sewage plants treating less than 20 million gal per day. Air Products has introduced what it calls a "Mini-Cryo" plant, which is a small cryogenic oxygen generator capable of producing from 6 to 16 tons per day of oxygen. According to Richard H. Oeler, manager of wastewater treatment systems for Air Products, the company's "new MiniCryo oxygen generator now makes oxygen wastewater systems economically feasible for small-sized wastewater treatment plants. The mechanical simplicity of the new gftfierator as compared with adsorption generators substantially reduces operating costs and complexity." T h e other manufacturers counter that pressure swing adsorption generators '(PSA) can go even lower in output than the 6 tons per day of many cryo plants. Carbide says that it has PSA plants producing as little as 1 ton per day of gaseous oxygen. PSA plants use a molecular sieve to pull out water, carbon dioxide, and nitrogen from air to leave oxygen, which is then put into the system. The generator-oxygen aeration system hookup opens an interesting area in oxygenation. The units are sold separately, not as a package, so that one manufacturer's oxygen generator may be used with another company's oxygen aeration system. For example, Air Products has 14 municipal contracts. Eleven of these call for
the Oases system and 10 specify oxygen plants. What the other three systems and other four generators are, even Air Products is not sure. In addition, there are a number of other manufacturers—Burdox Liquid Air, Lotepro, and Process Systems Inc.— supplying cryogenic oxygen plants to the field. Further compounding the situation, a few small wastewater treatment plants use liquid oxygen that is purchased from an oxygen supplier in their system. In sum, within the next 10 years when all the plants currently under contract go on line, some 7 billion gal per day of wastewater will be treated by more than 9000 tons per day of oxygen. All in all, the picture for oxygen looks good. However, this optimism must be tempered by a few uncertainties over the next few years. There are tremendous lead times in construction of sewage treatment plants. Some plants often take as much as seven years from the start of design to final completion of the project. Construction alone can take as much as three to five years. Thus, makers of oxygen aeration systems are reluctant to make solid predictions of market trends even though they say the market will "have good growth" over the next few years. Often the makers do not know that an oxygen plant is definitely planned for a certain municipal job until the bid specifications are released. The other cloud on the horizon is the government. How much money will EPA release? Will there be any increase in funds when Congress takes up revisions to P.L. 92-500? The impoundments of a few years ago slowed wastewater plant building substantially. Another reduction of funding would have the same effect. This could bring the oxygen aeration market as well as all equipment for wastewater treatment to a standstill. As for municipal construction, although a lowering of funding does not seem to be in the cards at this time, it is a possibility. The hue and cry over energy, if it gets bad enough, also could cause the questioning of energy-using secondary sewage treatment and the Carter Administration pledge to balance the federal budget could cause a slowdown in funding. William J. Storck, C&EN New York
