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结果 1-10 的 42
A biological test system for the evaluation of the phytotoxicity of metal-contaminated soils.
1990
Assche F. van | Clijsters H.
Water pollution | EPA needs to set priorities for water quality criteria issues
1994
Pollution prevention | EPA should reexamine the objectives and sustainability of state programs
1994
Water pollution | State revolving funds insufficient to meet wastewater treatment needs | State revolving fund program
1992
Can field portable X-ray fluorescence (pXRF) produce high quality data for application in environmental contamination research?
2016
Rouillon, Marek | Taylor, Mark P.
This research evaluates the analytical capabilities of a field portable X-ray fluorescence spectrometer (pXRF) for the measurement of contaminated soil samples using a matrix-matched calibration. The calibrated pXRF generated exceptional data quality from the measurement of ten soil reference materials. Elemental recoveries improved for all 11 elements post-calibration with reduced measurement variation and detection limits in most cases. Measurement repeatability of reference values ranged between 0.2 and 10% relative standard deviation, while the majority (82%) of reference recoveries were between 90 and 110%. Definitive data quality, the highest of the US EPA's three level quality ranking, was achieved for 15 of 19 elemental datasets. Measurement comparability against inductively coupled plasma atomic emission spectrometry (ICP-AES) values was excellent for most elements (e.g, r2 0.999 for Mn and Pb, r2 > 0.995 for Cu, Zn and Cd). Parallel measurement of reference materials revealed ICP-AES and ICP-MS measured Ti and Cr poorly when compared to pXRF. Individual recoveries of soil reference materials by both ICP-AES and pXRF showed that pXRF was equivalent to or better than ICP-AES values for all but two elements (Ni, As). This study demonstrates pXRF as a suitable alternative to ICP-AES analysis in the measurement of Ti, Cr, Mn, Fe, Cu, Zn, Sr, Cd, and Pb in metal-contaminated soils. Where funds are limited, pXRF provides a low-cost, high quality solution to increasing sample density for a more complete geochemical investigation.
显示更多 [+] 显示较少 [-]Protocols for evaluating the natural attenuation of fuel hydrocarbons and chlorinated aliphatic hydrocarbons in groundwater
1997
Wiedemeier, T.H.
Quantitative evaluation of in-situ bioremediation of compound pollution of oil and heavy metal in sediments from the Bohai Sea, China
2020
Wang, Chuanyuan | He, Shijie | Zou, Yanmei | Liu, Jialin | Zhao, Ruxiang | Yin, Xiaonan | Zhang, Haijiang | Li, Yuanwei
Owing to the semi-enclosed environment of the Bohai Sea, the ecological effects caused by an oil spill would be significant. A typical in- situ bioremediation engineering project for of oil-spilled marine sediments was performed in the Bohai Sea and a quantitative assessment of the ecological restoration was performed. The bioremediation efficiencies of n-alkane and PAHs in the sediment are 32.84 ± 21.66% and 50.42 ± 17.49% after 70 days of bioremediation, and 60.99 ± 10.14% and 68.01 ± 18.60% after 210 days, respectively. After 210 days of bioremediation, the degradation rates of two- to three ring PAHs and four-ring PAHs are 84.44 ± 23.03% and 26.62 ± 43.76%, respectively. In addition, the concentrations of the heavy metals first increased by 6.00% due to oil spill degradation and release, and then decreased by 72.60% with the degradation of oil caused by bioremediation or vertical migration. According to the continuous tracking monitoring, the composition of the microbial community in the restored area was similar to that in the control area and the clean area in Bohai Sea after 210 days of bioremediation. These results may provide some theoretical and scientific data to understand the degradation mechanism and assessing the ecological remediation efficiency for oil spills in open sea areas.
显示更多 [+] 显示较少 [-][Evaluation of air pollution exposition: needs in epidemiology and for executives] | Evaluer les expositions: les besoins des epidemiologistes et des decideurs
1999
Zmirou, D. (Universite de Grenoble 1, La Tronche (France). UFR de Medecine, Laboratoire de Sante)
Composting municipal sludge
1988
Benedict, Arthur H. | Epstein, Eliot | Alpert, Joel E.
Water pollution monitoring | EPA's Permit Compliance System could be used more effectively
1992