Efficiency of natural reproduction of sturgeons in the lower Volga under current conditions

The results are presented that have been obtained during long-term studies (1991–2009) on the efficiency of natural reproduction of the beluga, Russian sturgeon, stellate sturgeon, and sterlet in different spawning zones of the Volga. The influence of major environmental factors on the formation of the offspring of these fishes is analyzed. It is shown that the productivity of Volga spawning grounds varies depending on the river flow volume during spring floods and the abundance of active spawners. Practical recommendations are proposed for enhancing sturgeon reproduction in the Volga.     

Effect of anthropogenic pollution on oxidative processes in the liver of fish from the Rybinsk Reservoir

The levels of total lipids, peroxidation products, and antioxidant activity in the liver were studied in fish species living in unequally polluted areas of the Rybinsk Reservoir and differing in their ecology and taxonomic position: the bream (Abramis brama L.), roach (Rutilus rutilus L.), burbot (Lota lota L.), and zander (Stizostedion lucioperca L.). The fish from polluted water areas were characterized by higher levels of total lipids and malonic dialdehyde and a deficiency of antioxidants. It is shown that the test parameters depend on the type of feeding and mode of life of the fish species.     

Simultaneous Removal of Nitrate and Natural Organic Matter from Drinking Water Using a Hybrid Heterotrophic/Autotrophic/Biological Activated Carbon Bioreactor

Simultaneous removal of nitrate ([Formula: see text]) and natural organic matter (NOM) from drinking water using a hybrid heterotrophic/autotrophic/BAC bioreactor (HHABB) was studied in continuous mode. The HHABB consisted of three compartments: ethanol heterotrophic part, sulfur autotrophic part, and biological activated carbon (BAC)-part (including anoxic and aerobic sections). Experiments were performed with [Formula: see text] concentration 30?mg N/L, [Formula: see text] loading rate 0.72?kg N/m(3)/d, C?:?N ratio 0.53, and three concentrations of NOM (0.6, 2.6, and 5.7?mg C/L). Overall denitrification rate and efficiency of the HHABB were not affected by NOM concentration and were in the suitable ranges of 0.69-0.70?kg N/m(3)/d and 96.0%-97.7%, respectively. NOM removal at concentration 0.6?mg C/L was not efficient because of organic carbon replacement as soluble microbial products. At higher NOM concentrations, total NOM removal efficiencies were 55%-65%, 55%-70%, and 55%-65% for dissolved organic carbon, trihalomethane formation potential, and UV absorbance at 254?nm (UV(254)), respectively. The more efficient compartments of the HHABB for the removal of NOM were the ethanol heterotrophic phase and aerobic BAC-phase. The efficiency of the HHABB in the removal of NOM was considerable, and the effluent dissolved organic carbon and trihalomethane formation potential concentrations were relatively low. This study indicated that the HHABB without the anoxic BAC-phase could be a feasible alternative for simultaneous removal of [Formula: see text] and NOM from drinking water at full scale.     

A Multivariable Model for Atmospheric Dispersion Predictions

In conjunction with a 15-month air quality survey of Jacksonville, Fia., a mathematical model has been developed to describe the dispersion of atmospheric pollutants. The source inventory used with the model was compiled, in part, from the data obtained from the sampling of all major sources within the area. The major sources were considered separately from the one-mile square area sources which accounted for the remainder of the emissions. Meteorological data was recorded continuously in the city including vertical temperature observations to 750 ft. The model was compiled in FORTRAN and can be used for both gaseous and particulate pollutants, by utilizing proper decay rates. The variant nature of meteorological parameters and emission rates are considered. The ground level concentrations of several pollutants which were determined for 24 hr periods at 11 sites and continuously at two other sites were used to check the model. A limited tracer study was carried out in conjunction with the project.     

Limitations of the Lead Acetate Impregnated Paper Tape Method for Hydrogen Sulfide

Field experience with the lead acetate impregnated paper tape sampler has indicated that large errors may arise in this method due to fading of the color of the precipitated lead sulfide spots. This fading is due to the action of light, sulfur dioxide, ozone, on other substances capable of oxidizing lead sulfide. The moisture content or relative humidity of the air sample must be maintained at an appropriate level to ensure reaction with the impregnated paper tape. The effects of the factors have been investigated in laboratory experiments with known concentrations of H₂S. A number of antioxidants were studied in relation to the stability of the resultant spots to light and oxidation Orthophenyl phenol was found to be the most effective antioxidant for this purpose. A number of necessary precautions to be employed in the use of the lead acetate method are recommended and the limitations are discussed.     

Ozone Dosage Response of Ponderosa Pine Seedlings

Photochemical oxidant injury to ponderosa pine (Pinus ponderosa Laws) is a severe problem in the southern California mountains. Three-year-old ponderosa pines fumigated in controlled environment chambers with ozone at 0.15, 0.30, or 0.45 ppm had apparent photosynthesis rates reduced by 10, 70, and 85%, respectively, after 30 days exposure. A fumigation with 0.30 ppm ozone for 33 days depressed the cold perchloric acid extracted polysaccharides of both current and one-year-old needles by 40%. The 80% ethanol soluble sugar concentration of current year, ozone-injured needles increased 16% and that of the one-year-old needles decreased slightly. Both carbohydrate fractions of control trees in carbon-filtered air increased moderately. Higher, endogenous concentrations of ascorbic acid in needles did not protect the tissue from ozone injury. Apparent photosynthesis rate was a sensitive index for ozone dosage response. Needle carbohydrate depletion probably induces premature abscission.     

Instrumenting Light Aircraft for Air Pollution Research

Light aircraft and helicopters have been occasionally used to conduct aerial traverses for a single pollutant or atmospheric tracer. The continuous analyzer or sample collector is temporarily tied down with a seat belt or hand held. Flight variables are visually observed and written on the recorder chart, a notebook or possibly voice-recorded on a portable tape recorder. The versatile airborne instrumentation package described can measure and record up to 27 pollutant and flight variables from a Cessna Skymaster center-line thrust, light twin. Real-time analysis instrumentation include non-dispersive infrared analyzers for CO₂, CO, and hydrocarbons, conductivity and coulometric analyzers for sulfur dioxide and sulfur-containing gases, and Charlson-Ahlquist visual range nephelometer. A Battelle “bulk sampler” is used to collect particulates for weighing and microscopic examination. Indicated air speed, altitude, rate of climb, magnetic heading, temperature, and relative humidity are continuously measured. All variables are sequentially recorded on a 7-track, 200 bit per second, 27-channel, magnetic tape data logging system. Measured variables are recorded once each 0.3 to 0.8 sec—equivalent to 33-100 ft of traversedepending upon the number of variables recorded (i.e., between 9 and 27) when flying at 90 mph. Tape data are reduced directly by IBM 360 computer to a digital print-out or from tape to an X-Y analog plot.     

Annotated Bibliography for Air Pollution Meteorology

This annotated bibliography was prepared for the purpose of directing interested persons to some of the more helpful references in the field of air pollution meteorology. It obviously is not a complete listing. The reader who requires more information is directed to the references in the articles listed.     

Appraisal of Odor-Measurement Techniques

All odor measurement methods may be conveniently grouped into three categories: (1) threshold; (2) suprathreshold; and (3) analytical. The threshold techniques include such methods as syringe dilution, scentometer, and osmoscope. Suprathreshold techniques include direct comparison methods and dilution methods involving subjective ratings of preference as opposed to intensity. Analytical techniques involve the use of physicochemrcal methods, e.g., for monitoring of process streams or identification of individual odorants. The relative advantages and disadvantages of each method, as presently used, are discussed. Recommended applications for the various methods and suggested modifications are also presented.