Environmental letters最新文献

Drift loss rate was measured for three induced draft cooling towers by following the decrease in concentration of two conservative additives in the recirculating water during operation with no blowdown and normal makeup. The method described is simple and inexpensive and provides information essential in water use planning.

The Environmental Information System Office (EISO) at Oak Ridge National Laboratory (ORNL) provides information support for researchers and administrators involved with energy and environmental policy and progress. Multiple EISO activities for various governmental agencies have resulted in establishment of compatible data bases concerned with energy environmental information, methods for effectively developing these, development and computer display of numerical daya summaries, and reports evaluating published information. Direction is provided by continuing dialogue between users and information system staff.

Although the exact mechanisms and factors of red tides are not fully understood, red tides are essentially a coastal phenomenon. The role of land drainage in the modification of coastal waters is discussed. The role of other factors (salinity, biologically active substances, etc.) that are altered by the process of land drainage is analyzed and correlated to experimental evidence derived from laboratory-grown dinoflagellate cultures.

A study of the Flat Creek Embayment of Lake Sidney Lanier near Gainesville, Georgia revealed three genera of algae, Chlorococcum, Fragillaria and Nostoc, to be prominent in this eutrophic region of the lake. The algae was grown in phosphate-rich media and subsequently labelled with P-32. All species incorporated luxury amounts of phosphorus as determined by the uptake of P-32. The results indicate that the P-32 uptake is proportional to the surface-per-volume ratio. The higher surface-per-volume ratio resulted in greater uptake of P-32.

Arsenite ion, as arsenic trichloride was extracted into benzene from strongly acidified tissue homogenates. Following this, arsenite was extracted from the benzene into water, made up in 1N HCl and analyzed polarographically. Arsenate ion, left in the homogenate after arsenite extraction is isolated in exactly the same way following treatment of the homogenate with cuprous ion to reduce arsenate to arsenite ion. Treatment of the acidified homogenate with cuprous ion prior to extraction gives a homogenate which is readily analyzed for total "inorganic" arsenic. The method was efficient to a maximum level of about 20 mug inorganic arsenic since at higher levels lower recoveries were found. Analysis of a variety of marine biological specimens, with levels of total arsenic up to 40.5 ppm, indicated little of this arsenic was present in an inorganic form. Post mortem reduction of arsenate to arsenite was found to occur rapidly in fish tissue.

The marine blue green alga Trichodesmium sp is found in red-tide outbreaks in sub-tropical areas in the Pacific and Indian Oceans, the Arabian Seas and the equatorial currents of the Gulf of Mexico. Giberellic acid stimulated the growth of Trichodesmium cultures to a greater extent than in the diatom Melosira sulcata. While increasing either the nitrate or phosphate above the normal levels in the culture medium did not greatly stimulate the growth of this organism, Trichodesmium did thrive in nitrogen impoverished waters by nitrogen fixation. The relevance of these findings to the hydrological factors which favour red-tide outbreaks is discussed.

Infrared spectroscopy was used to follow the rates of the chemical changes in gaseous N(2)O(5)-SO(2) and N(2)O(5)-SO(2)-O(3) mixtures. Several results of interest to atmospheric scientists were obtained. (I) SO(3) was not a detectable product of these reaction systems, and no significant SO(2) removal occurred. From the kinetic treatment of these results, estimates were derived for the upper limits of the rate constants of the reactions 1 and 2: NO(3) + SO(2) leads to NO(2) + SO(3) (1); N2O5 +SO2 leads to N(2)O(4) + SO(3) (2); k(1) less than or equal to 4.2 1. mole-minus 1sec-minus 1; k(2) less than or equal to 2.5 x 10-minus 2 1. mole-minus1sec-minus 1 at 30 degrees C. These data suggest that reactions 1 and 2 are not important removal paths for SO(2) in the sunlight irradiated, NO(x)hydrocarbon polluted atmospheres. (II) The near ultraviolet absorption spectrum of pure N(2)O(5) has been determined. From these results and estimates of the actinic irradiance, it was shown that the rate of photochemical decomposition of N(2)O(5) by the absorption of solar light in the urban atmosphere is an unimportant factor among the reactions which establish the N(2)O(5) and NO(3) concentrations. (III) It has been observed that gaseous SO(3) and NO(2) react rapidly to form a relatively nonvolatile white solid. Preliminary data suggest a 1:1 mole ratio for this adduct. The significance, if any, of this and related compounds in urban aerosol formation must be evaluated.

Nitrate analyses were performed on ground water well samples originating from sources throughout Wisconsin. The data ranged from below the analytical detection limit up to 140 mg NO3-N/1. Over nine percent of all wells sampled has nitrate concentrations in excess of 10 mg NO3-N/1. Six individual counties had more than 10 mg NO3-N/1 in at least twenty percent of the wells covered in this survey. However, data reported for over eight thousand new wells driven in 1971-1972 showed only slightly more than two percent with nitrate levels above 10 mg NO3-N/1. This reflected the trend toward drilling deeper wells which are influenced less by nitrate seepage as well as adherence to new and stricter well construction codes.

Analysis of the stomach contents of 97 white perch, Morone americana, taken from the effluent canal of a steam electric station (S.E.S.) and 106 white perch from adjacent Patuxent River waters indicated similar food habits from September 1970 through August 1971. However, 35% of all white perch taken from the heated effluent canal contained small pieces of coal and cinders, whereas only 3% of the river specimens contained such items in their stomachs. Fly ash and coal dust are present on the bottom of the S.E.S. canal, whereas little such material, if any, can be found on the river bottom in the study area. This suggests the canal fish were actively feeding in the heated effluent and not simply moving into the canal after feeding in the river. No significant difference (Pgreater than0.05) was found between the average wet weight stomach contents of the river and canal fish within the same mouth.