Showing papers in "Environmental Science & Technology in 1977"
TL;DR: In this article, standards for reporting C-14 age determinations are discussed, and the statistical uncertainty (plus or minus one standard deviation) expresses counting errors, inaccuracies in voltage, pressure, temperature, dilution, and should include errors in C-13 ratios.
Abstract: Standards for reporting C-14 age determinations are discussed. All dates should be related either directly or indirectly to the NBS oxalic acid standard. Corrections for isotopic fractionation are also desirable. For some materials, particularly marine shell, corrections for reservoir effect are necessary, but these should always be reported separately from the conventional radiocarbon age. The statistical uncertainty (plus or minus one standard deviation) expresses counting errors, inaccuracies in voltage, pressure, temperature, dilution, and should include errors in C-13 ratios. Errors can be significant when isotope ratios are estimated rather than measured directly. The error in the conventional C-14 half life is not included. The article includes tables indicating what data should be reported.
5,579 citations
2,626 citations
531 citations
530 citations
TL;DR: In this article, an empirical equation is established to relate the experimental n-octanol/water partition coefficients to the aqueous solubilities of a wide variety of chemicals including aliphatic and aromatic hydrocarbons, aromatic acids, organochlorine and organophosphate pesticides, and polychlorinated biphenyls.
Abstract: An empirical equation is established to relate the experimental n-octanol/water partition coefficients to the aqueous solubilities of a wide variety of chemicals including aliphatic and aromatic hydrocarbons, aromatic acids, organochlorine and organophosphate pesticides, and polychlorinated biphenyls. Such a correlation, covering more than eight orders of magnitude in solubility (from 10-3 to 104 ppm) and six orders of magnitude in partition coefficient (from 10 to lo7), allows an assessment of partition coefficient from solubility with a predicted error of less than one order of magnitude. A correlation is observed between the bioconcentration factors in rainbow trout and the aqueous solubilities for some stable organic compounds.
510 citations
TL;DR: In this article, four procedures employing 0.3 M HCl, pH 3 or pH 7 citrate-dithionite, or acetic acid-hydroxylamine solutions are evaluated for their potential to remove the surface coatings from aquatic sediment particles.
Abstract: Four procedures employing 0.3 M HCl, pH 3 or pH 7 citrate-dithionite, or acetic acid-hydroxylamine solutions are evaluated for their potential to remove the surface coatings from aquatic sediment particles. Ten test samples representing a range of sediment types and broad geographic distribution are examined. Data on the relative recovery efficiency of each method are reported. Selection of a procedure for use on large numbers of samples is made on the basis of recovery efficiency, limitation of structural degradation, and operational simplicity. Single operator precision data for the more efficient methods are reported.
199 citations
TL;DR: In this paper, 11 different fly ashes from coal-fired power plants were subjected to various chemical extractions and washings for determination of their acid-base and heavy metal chemistry, and the results suggested that the relative amounts of lime and amorphous iron oxides on the surface define the ultimate acidic or basic character of fly ash in solution.
Abstract: Eleven different fly ashes from coal-fired power plants were subjected to various chemical extractions and washings for determination of their acid-base and heavy metal chemistry. Results suggested that the relative amounts of lime and amorphous iron oxides on the surface define the ultimate acidic or basic character of fly ash in solution. In spite of wide variations in heavy metal content, most metals displayed an association with a specific surface oxide of either iron, manganese, or aluminum. Desorption of metals in aqueous solution followed a predictable pattern of decreasing release with increasing pH. Arsenic was an exception to this at high pH. Mercury behaved anomalously due to the presence of the elemental form. Ranges in reported values are attributed primarily to the variable geochemical matrix in which the heavy metals are found before mining.
191 citations
TL;DR: In this paper, the kinetics of oxygenation of reduced sulfur species in aqueous solution, e.g., petroleum wastes, were studied at pH values of 4, 7.55, and 10.
Abstract: The kinetics of oxygenation of reduced sulfur species in aqueous solution, e.g., petroleum wastes, were studied at pH values of 4, 7.55, and 10. The reaction was first order with respect to reduced sulfur at all pH values and nearly first order with respect to oxygen at pH 7.55. Reaction products were determined and an over-all kinetic model was developed which suggested parallel reaction between sulfide and polysulfide species and oxygen to form sulfite, thiosulfate, and sulfate. Reasonable predictions of reactant and product concentrations were obtained.
185 citations
164 citations
163 citations
TL;DR: In this paper, atomic absorption spectrophotometry in soils and pasture species along a major motorway in New Zealand was used to determine the concentrations of cadmium, chromium, copper, lead, nickel, and zinc.
Abstract: Concentrations of cadmium, chromium, copper, lead, nickel, and zinc were determined by atomic absorption spectrophotometry in soils and pasture species along a major motorway in New Zealand Enhanced levels of all elements were found and correlated well with traffic densities Concentrations in soil profiles decreased with depth and showed that the source of pollution was aerial deposition from motor vehicles About a third of the aerial burden of each element was removable by washing of vegetation species Highest accumulations of heavy metals were usually found on white clover, and the lowest on Paspalum grass Elemental concentrations in pasture species were usually well correlated with traffic densities, particularly in the case of the grass, Yorkshire fog Plant/soil correlations for individual heavy metals were in general poorer than for relationships involving traffic densities and concentrations in plants and soils
TL;DR: In this article, the authors studied the kinetics of the oxidation of hydrogen sulfide and hydrosulfide ion to sulfur and sulfate in aqueous solution by hydrogen peroxide.
Abstract: The kinetics of the oxidation of hydrogen sulfide and hydrosulfide ion to sulfur and sulfate in aqueous solution by hydrogen peroxide is studied potentiometrically. In the pH range 8-3, the rate law for the oxidation of H_2S is -d[H_2S]/dt = k_1[H_2S] [H_2O_2] + k_2K_(a1)[H_2S] [H_2O_2]/[H+] where K_(a1) is the first acid dissociation constant of H_S, k_2 = 29.0 M^(-1) min^(-1), and k_1= 0.5 M^(-1) min^(-1). The rate law and other data indicate that the reaction proceeds via a nucleophilic displacement by sulfide on hydrogen peroxide with the formation of polysulfide intermediates.
TL;DR: In this article, the migration of trace metals between the interface of seawater and polluted surficial sediments under different redox conditions was studied on three typically polluted nearshore surficial sediment.
Abstract: The migration of trace metals between the interface of seawater and polluted surficial sediments under different redox conditions was studied on three typically polluted nearshore surficial sediments. The experimental results obtained showed that under different sets of redox conditions over a period of 4-5 months of sediment/seawater contact time, three general trends could be observed; the released amount increased as the redox condition became progressively reducing(Fe and Mn), the released amount increased as the environment became more oxidizing (Cd, Cu, Ni, Pb, and Zn), and there was no significant change of concentration in interfacial water (Hg and Cr). An equilibrium model was set up to confirm the experimental results. After long-term incubation in a reducing environment, most of the trace metals analyzed closely followed the predictions from equilibrium calculations. Complex formation accounted mainly for the concentration levels analyzed. Under aerobic conditions after long-term incubation, most of the analyzed concentrations were either far below (Cd, Cu, Ni, and Pb) or far above (Fe and Mn) the equilibrium concentrations, probably due to the slowness in reaching the equilibrium condition or to the presence of unknown ligands.
TL;DR: A comparison of conventional fluorescence emission spectra and spectra produced by synchronously scanning both excitation and emission monochromators is made on a series of standard oils to demonstrate the increased resolution achieved by the synchronous technique.
Abstract: A comparison of conventional fluorescence emission spectra and spectra produced by synchronously scanning both excitation and emission monochromators is made on a series of standard oils to demonstrate the increased resolution achieved by the synchronous technique. Greater information on the aromatic content of the oils is obtained by separating the aromatic hydrocarbon fractions by liquid-solid column chromatography prior to fluorescence analysis. Fluorescence spectroscopy, in particular the synchronous method, is used to characterize the indigenous and petroleum-derived aromatic hydrocarbons in sediments of Lake Washington, Wash.
TL;DR: In this paper, soil cores, grasses, and ambient air aerosols were sampled in the vicinity of a Pb smelting complex in Kellogg, Idaho, where 34 elements analyzed by instrumental neutron activation and x-ray fluorescence were the most highly enriched, ranging in surface soils up to 7900 ppM Pb, 29,000 ppM Zn, and 140 ppM Cd.
Abstract: Soil cores, grasses, and ambient air aerosols were sampled in the vicinity of a Pb smelting complex in Kellogg, Idaho. Of 34 elements analyzed by instrumental neutron activation and x-ray fluorescence, Cd, Sb, Ag, Pb, Au, Zn, Se, As, In, Ni, Cu, and Hg were the most highly enriched, ranging in surface soils up to 7900 ppM Pb, 29,000 ppM Zn, and 140 ppM Cd. For grasses, Pb ranged up to 10,000 ppM, Zn to 12,000 ppM, and Cd to 4400 ppM. Aerosol enrichments above contributions from local resuspended soils were 4100 for Cd, 180 for As, 110 for Pb, and 60 for Zn. These soil profiles, grass analyses, and aerosol enrichments indicate that other toxic elements, Cd, Se, As, Ni, and Hg, in addition to Pb, have significantly contaminated the Kellogg environment as a result of the smelting operations.
TL;DR: In this paper, trace elements were extracted from a coal-fired power plant electrostatic precipitator ash with nitric acid, hydrochloric acid, citric acid and ammonium hydroxide as extractants.
Abstract: Trace elements were extracted from a coal-fired power plant electrostatic precipitator ash with nitric acid, hydrochloric acid, citric acid, redistilled water, and ammonium hydroxide as extractants. Effluent waters at this plant were sampled to assess the elevation of trace element concentrations compared with intake waters. The results showed a positive correlation between those elements most extractable by water (B, F, Mo, and Se) or acid (As, B, Cd, F, Mo, and Se) and those elements most elevated in effluent waters (As, B, F, Mo, and Se).
TL;DR: In this paper, a liquid membrane process is developed for application to a number of industrial waste treatment problems and the results of laboratory and pilot plant studies show that liquid membranes are capable of reducing the levels of NH/sub 4//sup +/, Cr/sup 6 +/, Cu/sup 2 +/, Hg/sup 3 +/, and Cd/sup 4 +/
Abstract: A liquid membrane process is being developed for application to a number of industrial waste treatment problems. The results of laboratory and pilot plant studies show that liquid membranes are capable of reducing the levels of NH/sub 4//sup +/, Cr/sup 6 +/, Cu/sup 2 +/, Hg/sup 2 +/, and Cd/sup 2 +/ from several hundred ppM to less than 1 ppM under batch or continuous flow conditions.
TL;DR: In this paper, the thermal reactions occurring in mixtures containing peroxyacetyl nitrate and nitric oxide at part-per-million concentrations in synthetic air were investigated, and the results can be explained by a mechanism involving the following reactions: CH/sub 3/COO/sub 2/NO/sub2/
Abstract: The thermal reactions occurring in mixtures containing peroxyacetyl nitrate and nitric oxide at part-per-million concentrations in synthetic air are investigated. In the presence of NO, peroxyacetylnitrate decomposes at a measurable rate at room temperature, with accompanying oxidation of NO to NO/sub 2/. The results can be explained by a mechanism involving the following reactions: CH/sub 3/COO/sub 2/NO/sub 2/ = CH/sub 3/COO/sub 2/ + NO/sub 2/ (1), CH/sub 3/COO/sub 2/ + NO/sub 2/ = CH/sub 2/COO/sub 2/NO/sub 2/ (2), and CH/sub 3/COO/sub 2/ + NO = CH/sub 3/CO/sub 2/ + NO/sub 2/ (3). The effect of variation of the NO/NO/sub 2/ ratio and the temperature on the rate of oxidation of NO to NO/sub 2/ allows evaluation of the rate constant ratio K2/k3 = 0.54 + or - 0.17 and the Arrhenius expression k1 = 10+(14.90 + or - 0.60) exp (-104.0 + or - 3.2 kj/rt)/s. Thermochemical kinetic considerations give an approximate value for the heat of formation of peroxyacetyl nitrate, (=-241 + or - 40 kj/mol) and for the absolute value of the rate constant k2 = 1.4 x 10-12 cm/sup 3//molecule/s at 300 K. The implications of these results for the behavior of peroxyacetyl nitrate in the laboratorymore » and in the atmosphere are discussed.« less
TL;DR: An analytical survey of 45 elements was conducted in fly ashes from 21 states in the US, using several instrumental methods as discussed by the authors, and a high degree of correlation was found between the concentrations of pairs of chemically similar elements in the fly ashes and between the magnitude of gamma emission of the fly ash and their respective concentrations o th or U. Cabbage was grown to maturity in potted soil amended with 7% w/w of the various fly ashes.
Abstract: An analytical survey of 45 elements was conducted in fly ashes from 21 states in the US, using several instrumental methods. A high degree of correlation was found between the concentrations of pairs of chemically similar elements in the fly ashes and between the magnitude of gamma emission of the fly ashes and their respective concentrations o th or U. Cabbage was grown to maturity in potted soil amended with 7% w/w of the various fly ashes. The concentrations of As, B, Mo, Se and Sr in the cabbage showed a high degree of correlation with those in the fly ashes in which the plants were cultured.
TL;DR: Oxygenated compounds toxic to baker's yeast and relatively soluble in water were formed upon simulated environmental ultraviolet irradiation of a No. 2 fuel oil and appeared to be principally due to reactive peroxides; addition of a mild reducing agent eliminated a large percentage of the light-induced toxicity.
Abstract: Oxygenated compounds toxic to baker's yeast and relatively soluble in water were formed upon simulated environmental ultraviolet irradiation of a No. 2 fuel oil. Toxicity reached a maximum within 24 h and appeared to be principally due to reactive peroxides; addition of a mild reducing agent (thiacyclohexane) eliminated a large percentage of the light-induced toxicity. On continued irradiation, other classes of toxic compounds were produced. Carbonyl compounds (largely derived from benzylic hydrocarbons) and phenols increased at approximately linear rates for at least seven days. The phenolic compounds present in the original oil were largely destroyed and replaced by higher-boiling phenols (including hydroxyl-substituted aryl ketones). Quinones were not detected. The acids present included some with phenolic substituents.
TL;DR: Ozone analyses with a modified potassium iodide absorbent (BKI: 0.1 M Na/sub 2/HPO/sub 4//0.1% KI) give results that increase with time and are 15 to 30% larger than those obtained by uv or BKI as discussed by the authors.
Abstract: Ozone analyses with a modified potassium iodide absorbent (BKI: 0.1 M H/sub 3/BO/sub 3//1% KI) give consistent agreement with uv photometry over the concentration range 0.1 to 3.5 ppM. The colorimetric iodine response with this BKI solution is both precise and stable. Trace reducing contaminants (ozone demand) in the potassium iodide reagents are a major problem in the work at 0.1 ppM. Iodometric analyses with NBKI (0.1 M Na/sub 2/HPO/sub 4//0.1 M KH/sub 2/PO/sub 4//1% KI) give results that increase with time and are 15 to 30% larger than those obtained by uv or BKI. These data are explained by the formation of a second product, P, in addition to iodine, when ozone is absorbed in NBKI and certain other buffered KI solutions; P slowly liberates additional iodine. At room temperature the kinetic rate of H/sub 2/O/sub 2/ + NBKI agrees with that of P + NBKI. Since other potential products have been excluded on this basis, P is tentatively identified as H/sub 2/O/sub 2/.