PHOSPHATES:
New Removal Process In excess of 90% of the phosphates in sewage streams are removed by the new PhoStrip process of Biospherics, Inc., of Rockville, Md. According to the inventor, Dr. Gilbert V. Levin, president of Biospherics, the new proc ess may eliminate the need for much of the projected tertiary treatment fa cilities now being proposed for con struction across the country. The key to the process is the cycling of the activated sludge bacteria through alternate aerobic and anaero bic portions of the treatment plant. It has been found that the bacteria take up the incoming phosphates during the aeration of the activated sludge. In conventional treatment the bacteria then pass through the treatment plant and release the phosphate in the ground water environment. In the PhoStrip process, the bacteria are cy cled into a holding tank where the available oxygen is greatly reduced. The bacteria give up the phosphates and are recycled for further use. The accumulated phosphates in the holding tank are chemically precipi tated. Since the flow through the holding tank is only about 10% of the total plant throughput, a very small tank is all that is required. The chem icals addition tank is the only equip ment required beyond that already available in the conventional sewage treatment plant. Dr. Levin believes that his process will substantially reduce the amount of solids that must be disposed of in the conventional processes. He also suggests that the products from the PhoStrip process will be more salable. There is little or no reduction of the basic oxygen demand in the process.
Primary tank: sludge Phosphates
PhoStrip has been piloted for about six months and the results have ex ceeded the expectations of the inven tor. Biospherics is now embarking on the next step of a marketing plan which is to run demonstration proj ects for sewage plant operators. Of prime interest is the possible demonstration project in the District of Columbia where the release of phosphates in sewage effluent is caus ing eutrophication of the lower Poto mac River. Dr. Levin would like to find sewage plants that are now undergoing expan sion so that he could prove the efficacy of PhoStrip. While confident that his process will work in practice, Dr. Levin also recognizes that municipal sewage effluents are not the only source of phosphates in the ground water. However, municipal sewage is a readily available place to begin the long awaited attack on the phosphate problem. If PhoStrip works as well as expected, and if other sources of phos phates can be similarly controlled, the need for removal of phosphate build ers in detergents may suddenly be come but a minor problem.
ELEMENTS:
Promethium in the Stars Promethium, an element not known to exist naturally on earth, has been found in the stars. Heretofore, the unstable, short-lived element, one of the lanthanoid series of rare earths, has been found only as one of the fission products of uranium. Now, Dr. Margo Friedel Aller and Dr. Charles R. Cowley, both of Uni versity of Michigan's astronomy de partment, reveal that they have iden-
Aeration tank: Bacteria take up phosphate and consume organic ί
Secondary tank: activated sludge settles
Waste activate sludge
Phosphatefree water
tified lines characteristic of prome thium in spectrograms of HR 465, a faintly visible star in the constella tion Andromeda, at the edge of the Milky Way. The discovery is signifi cant, the two astronomers assert, be cause the longest-lived isotope of pro methium has a half-life of only 18 years; therefore, the element must have been made fairly recently in the star, and probably near the star's sur face. HR 465 is one of a group of hot stars known as "peculiar A-type" stars. Such stars are peculiar, Dr. Aller tells C&EN, because they have measur able magnetic fields, because they seem to rotate slowly, and because their spectra indicate an "overabun dance" of the rare-earth elements. The discovery of promethium tends to confirm one of the theories advanced to explain this overabundance: that rareearth elements are produced by nu clear reactions on the surface of the star. Dr. Aller and Dr. Cowley found the lines identifying promethium in the 3400 to 4700 A. region of two spectrograms of HR 465 taken in 1960 and 1961 at Lick Observatory in Cal ifornia. Dr. W. P. Bidelman, now at Case Western Reserve University, had examined the wave lengths and in tensities of the spectral lines and had identified 12 of the rare-earth ele ments, all stable, in the star's spec trum. However, he could not then identify about one fourth of the lines, including those of promethium. Fortuitously and fortunately, the Michigan workers observe, the spec trograms were made at a time when the rare-earth lines were very strong. They point out that the light emitted by the star varies both in type and in quantity, and that similar spectro grams made today would not permit detection of any of the rare-earth ele ments. Dr. Aller and Dr. Cowley made the promethium identification in the course of research, supported by a National Science Foundation grant, on atmospheric structure and chemical abundance in stars. The current is sue of Astrophysical Journal contains a full account of the promethium dis covery.
WAGE-PRICE CONTROLS:
Split in CPI Bacteria release phosphate
Phosphate· rich water
Phosphate is chemically precipitated
Phosphate is discarded
Industry, Government, and labor came together in agreement on the need for wage and price controls at the Manu facturing Chemists Association's (MCA) 20th semiannual meeting in New York City. The question of whether the Government should adopt a policy of freezing wages and prices NOV. 30, 1970 C&EN 9
