ISSN:0730-7268    

DOI:10.1002/etc.5620051101

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe uptake of copper by water hyacinth (Eichornia crassipes) was studied using solution culture techniques in the greenhouse. The bioassays indicated that the uptake of copper was a direct function of its speciation. For example, only free Cu2+was absorbed by the plant in the presence of strong ligands such as EDTA and humic acid. Other ligands tested (fulvic acid, amino acids and simple organic acids), however, failed to suppress the uptake of copper even when the free Cu2+in solution initially was negligibly small. Copper could have been taken up directly by the plant as various complexes or in the free Cu2+form after dissociation from the ligands prior to uptake. Complete inhibition of copper uptake in the presence of humic acid, in contrast to fulvic acid, suggests that the chemical stability constants of these complexes with copper were not correlated to the metal's bioavailability. The potential ofEichorniafor removing heavy metals from wastewaters is demonstrated by its tremendous capacity to bioaccumulate copper. Depending on the presence or absence of ligands, from 200 to more than 2,400 μg Cu g−1dry matter could be taken up by the pla

ISSN:0730-7268    

DOI:10.1002/etc.5620051102

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractSorption plays a significant role in the transport of low‐polarity organic compounds by ground water. Most contaminant movement is through saturated aquifers of low organic carbon content. Sorption processes on these materials may be different from those on high‐organic surface soils. Batch sorption isotherms using14C‐labeled compounds were determined on mineral oxides and aquifer materials; the sorbents used were Al2O3, Al(OH)3, FeO(OH) (goethite) and aquifer material. A surface soil sorbate was used for comparison with the sorption of the low‐carbon materials; the sorbates used were 1‐methylnaphthalene, naphthalene, trichloroethylene ando‐dichlorobenzene. The acidity and ionic strength were varied to simulate different ground water conditions. The order of sorption coefficients for all sorbents was 1‐methylnaphthalene>naphthalene>o‐dichlorobenzene>trichloroethylene. In general, sorption of each compound was strongest for the surface soil and decreased in the order of surface soil>>FeO(OH)>aquifer material>aluminum oxides. Under basic conditions, the sorption coefficients were significantly reduced in all cases. Sorption increased slightly at high

ISSN:0730-7268    

DOI:10.1002/etc.5620051103

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractBroad‐scale comparative data for sediment chemistry, sediment bioassays and bottom fish histopathology are used to derive quantitative site‐specific sediment criteria for three representative chemical contaminants in Puget Sound, Washington. The criteria, in terms of concentrations at or below which biological effects have been shown to be minimal, are (dry weight sediment): lead, 50 μg/g (ppm); combustion polyaromatic hydrocarbons, 3.8 μg/g; total polychlorinated biphenyls, 0.1

ISSN:0730-7268    

DOI:10.1002/etc.5620051104

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe concentrations of seven widespread, volatile, halocarbon contaminants–tetrachloroethylene (C2Cl4), carbon tetrachloride (CCl4), 1,1,1‐trichloroethane (C2H3Cl3), trichloroethylene (C2HCl3), chloroform (CHCl3), bromodichloromethane (CHBrCl2) and Freon 12 (CCl2F2)–were determined in the lower reaches of the St. Clair River and throughout Lake St. Clair. The results indicate large inputs of carbon tetrachloride and tetrachloroethylene and smaller loadings of chloroform, 1,1,1‐trichloroethane and trichloroethylene from the St. Clair River, particularly the South Channel, Bassett Channel and Chenal Ecarte, to Lake St. Clair. In total, daily loadings of more than 100 kg are indicated, resulting in a lake burden of approximately 1,000 kg of these halocarbons.The plumes of contaminated river water, particularly for carbon tetrachloride and tetrachloroethylene, extend approximately 15 km into the shallow, well‐mixed lake. At that range, the halocarbon levels generally drop to near‐background concentrations, suggesting significant removal of the waterborne contaminants through vol

ISSN:0730-7268    

DOI:10.1002/etc.5620051105

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe environmental fate/exposure data base (EFEDB) has been under development with U.S. Environmental Protection Agency support since 1979. It was initiated because of the difficulty of identifying environmental release, fate and exposure information using traditional literature searches. Two new components (BIOLOG and BIODEG), which contain microbial toxicity and biodegradation information, and an update of the overall EFEDB file are described. In addition, a chemical fate/exposure file (FATE/EXPOS) is discussed; it contains production and use data as well as physical‐chemical properties, chemical fate data and monitoring information. EFEDB has been greatly expanded since its initial development, and considerable conversions are planned to make most of the files available through the Chemical Information System (CIS). A major goal of EFEDB was to provide a source of data for constructing structure‐activity correlations and BIODEG is one of the first steps in providing evaluated data for such correlations. FATE/EXPOS provides sorting capabilities for setting priorities in testing or regulation based on easily obtainable information about exposure potent

ISSN:0730-7268    

DOI:10.1002/etc.5620051106

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe single and combined effects of cadmium, lead and zinc on δ‐aminolevulinic acid dehydratase (ALA‐D) activity, growth and hemoglobin content were studied inDaphnia magna.The ALA‐D activity was enhanced by Cd and inhibited by Pb. The binary combinations, Pb:Cd and Pb:Zn, were powerful inhibitors of ALA‐D. However, in the combination of the highest concentrations of lead and zinc the activity of ALA‐D was enhanced. The stimulation by cadmium was abolished in the presence of zinc. All tertiary combinations of Pb, Cd and Zn inhibited ALA‐D activity. Lead alone did not decrease the hemoglobin content inD. magnaeven at 260 μg/L Pb, but in combination with zinc the decrease was abolished. Tertiary combinations of Cd, Pb and Zn were not more powerful in affecting the hemoglobin content than were the binary combinations. Growth was not affected by Cd, Pb or Zn in any of the comb

ISSN:0730-7268    

DOI:10.1002/etc.5620051107

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractComparative acute toxicity values forCeriodaphnia dubia, Scapholeberissp. andPimephales promelasexposed to copper were used to calculate water effect ratios (e.g., site water LC50 value/reference water LC50 value), which reflect the difference in the biological availability and/or toxicity of copper between water from the Naugatuck River, Connecticut and Lake Superior reference water. These ratios were used to modify U.S. Environmental Protection Agency (EPA) ambient aquatic life criteria for copper to site‐ and station‐specific criteria, using the indicator procedure of the U.S. EPA guidelines for deriving site‐specific water quality criteria. A water effect ratio of 1.0 was established using unpolluted upstream water, resulting in a site‐specific criterion maximum concentration (CMC) and criterion continuous concentration (CCC) of 8.7 and 6.2 μg/L copper, respectively. Mean water effect ratios of 3.9 to 7.0, reflective of reduced biological availability and/or toxicity of copper, were determined for four successive downstream stations where the water contained copper and other industrial and domestic wastes. The resulting station‐specific CMCs and CCCs ranged from 32 to 57 and 22 to 39 μg/L copper, respectively. These copper criteria were compared with effluent‐contributed ambient copper concentrations and ecological survey data from each downstream station to ascertain impact on aquatic life. It was concluded that the national and site‐specific criteria derived for copper would be protective of the river's aquatic life because a relatively healthy aquatic community existed where these criteria were exceeded slightly. Whether or not the station‐specific criteria were protective could not be determined because these criteria were not exceeded at stations with healthy communities; however, where they were exceeded, impaired aquatic communities were evident.Generally,C. dubiasurvival and young production data from receiving water tests and copper addition tests, conducted just prior to the acute toxicity tests, were also indicative of reduced copper biological availability and/or toxicity in the Naugatuck River at do

ISSN:0730-7268    

DOI:10.1002/etc.5620051108

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractA 2‐d exposure test using the marine red algaChampia parvulawas developed to assess the toxic effects of pollutants entering the marine and estuarine environments. The initial exposure was followed by a 5‐ to 7‐d recovery period to allow the development of any cystocarps (evidence of sexual reproduction, the endpoint measured). The 2‐d exposure test was validated by comparison with a previously developed 2‐weed tests in which “no sexual reproduction” was used as the reproductive endpoint. The 2‐d procedure is intended for use in testing both single compounds and complex effluents. Complex effluents, however, cannot be accurately tested with the 2‐week test; therefore, only single compounds were used to compare the two procedures. Nine single compounds were tested. Concentrations that resulted in a 95% or greater decrease from the control response with the 2‐d exposure were considered the best estimate of the no sexual reproduction response from the 2‐week test. All of the single compounds tested, except cadmium, yielded essentially the same re

ISSN:0730-7268    

DOI:10.1002/etc.5620051109

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY