LETTERS
Water cleanup posture
H E A T E D CHEMILUMINESCENTANALYLER FOR M E A S U R E M E N T OF O X I D E S O F N I T R O G E N The information presented in this article is to assist those engaged in measurement o f source emissions to understand the Thermo Electron chemiiuminescent analyzer flow control System and the simple equipment addendum w h i c h creates a heated instrument. T h e Thermo Electron Series 10 Chemiluminescent instrument f o r the measurement of the concentration of Oxides 0 1 Nitrogen in gases is designed l o r stable, continuous monitoring o f sources such as stacks and engines. These sources present a sample whose pressure may vary a n d w h i c h may contain moisture and particulate matter. T h e r m o Electron chemiluminescent analyzers contain a unique, patented flow control system, w h i c h causes the instrument to be insensitive to sample pressure fluctuations, and permits a
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simple equipment addition w h i c h converts the instrument to a heated analyzer, preventing sample moisture condensation and e l i m i n a t i n g errors resulting from N 0 2 . dissolving i n the condensed water.
CONDENSATION PREVENTION The Thermo Electron Series 10 chemiluminescent analyzer does not suffer f r o m "signal quenching" or other forms of interference from water vapor contained i n the gas sample. However, water may condense out of the sample gas stream as i t f l o w s from a hot source to a Series 10 instrument, and fill the sample l i n e and instrument p l u m b i n g , creating a simple physical obstruction to the flow of the sample. With the use of a l o w cost. optional, equipment addition to the instrument, essentially converting the Series 10 to a heated instrument, water is not permitted to condense out of the gas sample stream, because the sample i s maintained at a temperature above the dew polnt. T h e manner in w h i c h the heating is done is best c o m m e n c e d with an explanation of the instrument sample f l o w control system
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FLOW CONTROL SYSTEM SAMPLE FROM SOURCE DIRECTLY TO REACTION
CHAMBER -. ......- -. . The flow control system i s designed so that sample gas f l o w s f r o m its source directly into the chemiluminescent reaction chamber, e l i m i n ating the possibility of being contaminated by f l o w control elements such as valves a n d p i m p s - Figure 1 Ilustrates that sample f l o w upon entering the system is split b y capillaries i n t o two streams toward the Reaction Chamber and toward the Bypass pump T h e pressure differential i s maintained constant across the sample capillary b y the pressure regulator T h e geometry and des g n of the pressure regulator i s such that an increase i n sample pressure causes the regulator valve seat to tend to close The bypass pump operating at a constant flow rate then pulls l e s s f l o w from the
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Environmental Science & Technology
Dear Sir: In your editorial (ES&T, Sept. 1973, p 767) you state, "On one hand we wonder if the public is convinced that water pollution cleanup is really under way." The purpose of American Environmental Manufacturers Association (AEMA) is to do just that-convince the American public that industries are involved in a major cleanup, not just of the water, but of the air and land as well. The main objectives of AEMA are to point out to the consumer which industries do, in fact, take steps to ensure the quality of the air, land, and water during the production of their products, urge the consumers to buy those products in preference to others, thereby increasing sales to the AEMA members to offset the cost of the antipollution devices they may have had to install. At the present time, AEMA is engaged in a statistical market analysis in selected cities in Arkansas to determine the effectiveness of this program. These results will be made available later in the year to any and all prospective AEMA members, as well as the state, local, and federal governments. I t is the public who must be made ". , , aware of and happy with the cleanup . . . ," otherwise all efforts to make ecology economical must surely fail. James C. Starkel, President American Environmental Manufacturers Association Hot Springs, Ark. 71901
Oregon bottle ban
Dear Sir: My compliments to ES&T on Mr. Malin's survey on Oregon's "Bottle Bill" ( E S & T , Nov. 1973, p 1000). I especially appreciated the Cosmic Science Foundation report. There is one minor correction which I would like to make. The percentages quoted in regard to the People's Lobby Against Nonreturnables Litter Pickup are for the percentage of beverage-related liter, not total litter. That is, even though throwaways accounted for slightly over half of annual sales of beverage containers in
Oregon prior to the bill, they amounted to over 95% of the beverage-related litter prior to the effective date. Beverage-related litter amounted to approximately 60% of total litter sampled and consequently the throwaway cans and bottles amounted to slightly over half of the total litter sampled by volume. Mr. Van Keuren's remarks regarding the increases in soft drink and beer prices in Oregon also deserves comment. I t is true that beer prices have gone up approximately 68$ per case. However, to leave the impression that these price increases have been occasioned by the "Bottle Bill" is somewhat misleading. Prices also increased in Washington State where there is no "Bottle Bill" and are comparable to Oregon's at the present time. As regards soft drinks, there have been no general price increases in Oregon. Some of the smaller downstate and eastern bottlers have increased their prices, but in the metropolitan areas of Portland and Salem, no soft drink price raises have occurred. Again, prices are comparable between Oregon and Washington. Don Waggoner, President Oregon Environmental Council Portland, Ore. 97201 Air pollution special report
Dear Sir: I was disappointed to see that Koppers Co., Inc., was not listed as a supplier of air pollution control equipment in your special report on this area of business (ES&T. Nov. 1973, p 988). Koppers and our Environmental Systems Division were one of the earliest suppliers of electrostatic precipitators, with our expertise in this field dating back to 1946. Today, the Environmental Systems Division, which accounts for approximately $40 million or 6% of Koppers annual sales, can be considered a total environmental control division with activities in gas cleaning, sound control, and water treatment systems. The gas cleaning systems group, the largest contributor to Division sales, is a leader in electrostatic precipitation serving the rock products,
