Environmental letters最新文献

Data for the major pollutants; carbon monoxide, nitrogen oxides, photochemical oxidants, suspended particulates, and total hydrocarbons, have been presented. In addition, lead analysis and a justification for no sulfur oxides data are also discussed. This study was an integral part of an Environmental Impact Study carried out by the Chemistry Department and the Institute of Transportation Studies a Villanova University. Some of the pollutants were found to cause a situation of concern; namely, photochemical oxidants, suspended particulates and nitrogen oxides. On the otherhand, carbon monoxide and total hydrocarbons were found to be well below limits set by the EPA. Although no standards are set for lead in ambient air, the data showed very low concentrations of this pollutant in our particulate samples. Since oxides ofsulfur are more an industrial, rather than transportation, pollutant little relevance could have been found for the type of study performed.

Assessment of the effects on land use, social, economic, historic and natural environment as a result of highway construction are discussed. Predictions of these effects on the various categories twenty years hence are also presented. Information of this type is a necessary segment of an environment impact study soas to conform to EPAand Department of Rransportation (DOT) guidelines.

A nine month study of current noise levels was made at twenty-two sites within a community in Eastern Pennsylvania to evaluate the noise pollution factors for a proposed highway. An attempt was made to correlateamnient noise levels for each day of theweek with each location. Computer programs were utilized for datareduction, statistical calculations, and prediction of future noise levels. The prediction analyses were composed of contour analyses, sensitive receptor sites analyses, and the "Do Nothing" analysis. Results indicated no noise pollution problems existed during the survey, but future noise levels may exceed Federal Standards for certain sections of the proposed alignments. Factors that cause the unacceptable future noise levels are identified and modifications may be incorporated for adherence to the standards.

Deciduous teeth were analyzed by atomic absorption spectroscopy for lead content to ascertain the extent of lead exposure in certain areas in Tennessee. The data were analyzed to clarify the relationships between tooth lead content and race, sex, age, tooth type, economic status, and place of residence. Results indicated that blacks had slightly higher lead concentrations than whites; however, the age and sex of the person or the type of tooth analyzed had little effect upon the lead content. The major factors were shown to be economic status and, indirectly, place of residence.

A simplified method for the analysis of total P(TP), total dissolved P(TDP) and dissolved reactive P (DRP) in multiple water samples has been developed. The reported modification utilizes a single digestion reagent and a single "mixed reagent" to eliminate neutralization, transfer and dilution steps normally required in total P analyses. The method results in a 70 percent decrease in analysis time for multiple samples, a reduction in the glassware required, and about a 30 percent increase in sensitivity. The method can be directly applied to water samples with P levels of 2 to 1100 ug P/l. Reproducibility and precision measurements compare to or exceed commonly used P techniques.

Methylmercuric chloride and phenylmercuric acetate extract very efficiently with quaternary amines dissolved in diethylbenzene or other simple solvents. The extraction is effective from either alkaline or acidic solution. The technique considerably extends the scope of conventional solvent extraction practice to permit the extraction and concentration of total mercury in environmental and biological matrices.

Quaternary amines are unique in their ability to extract metal cyanides from highly alkaline solutions. Cadmium cyanide extracts essentially quantitatively at both the subnanogram and macro levels. Regeneration of the amine solvent is achieved by stripping the cadmium with sodium hydroxide, sodium hypochlorite, or alkaline or acidic formaldehyde solutions. Because they readily extract free cyanide as well as anionic metab cyano complexes, the high-molecular-weight quaternary amines show considerable promise for industrial pollution abatement applications.

Chlorination of wastewaters can cause extensive transformations of organic contaminants. In the case of phenol, the reaction path is only partially understood. In an effort to elucidate this reaction, 2,4,6-trichlorophenol in dilute aqueous solution was treated with excess hypochlorous acid at pH 3.5-6. The major products were 2,6-dichloroquinone and 2,4,4,6-tetrachloro-2,5-cyclohexadienone. Additional polychlorinated species are formed in minor amounts by the addition of chlorine and/or hypochlorous acid to the aromatic ring.