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221.
Changes in contaminant mass discharge from DNAPL source mass depletion: evaluation at two field sites 总被引:1,自引:0,他引:1
Brooks MC Wood AL Annable MD Hatfield K Cho J Holbert C Rao PS Enfield CG Lynch K Smith RE 《Journal of contaminant hydrology》2008,102(1-2):140-153
Changes in contaminant fluxes resulting from aggressive remediation of dense nonaqueous phase liquid (DNAPL) source zone were investigated at two sites, one at Hill Air Force Base (AFB), Utah, and the other at Ft. Lewis Military Reservation, Washington. Passive Flux Meters (PFM) and a variation of the Integral Pumping Test (IPT) were used to measure fluxes in ten wells installed along a transect down-gradient of the trichloroethylene (TCE) source zone, and perpendicular to the mean groundwater flow direction. At both sites, groundwater and contaminant fluxes were measured before and after the source-zone treatment. The measured contaminant fluxes (J; ML(-2)T(-1)) were integrated across the well transect to estimate contaminant mass discharge (M(D); MT(-1)) from the source zone. Estimated M(D) before source treatment, based on both PFM and IPT methods, were approximately 76 g/day for TCE at the Hill AFB site; and approximately 640 g/day for TCE, and approximately 206 g/day for cis-dichloroethylene (DCE) at the Ft. Lewis site. TCE flux measurements made 1 year after source treatment at the Hill AFB site decreased to approximately 5 g/day. On the other hand, increased fluxes of DCE, a degradation byproduct of TCE, in tests subsequent to remediation at the Hill AFB site suggest enhanced microbial degradation after surfactant flooding. At the Ft. Lewis site, TCE mass discharge rates subsequent to remediation decreased to approximately 3 g/day for TCE and approximately 3 g/day for DCE approximately 1.8 years after remediation. At both field sites, PFM and IPT approaches provided comparable results for contaminant mass discharge rates, and show significant reductions (>90%) in TCE mass discharge as a result of DNAPL mass depletion from the source zone. 相似文献
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Co-present Pb(II) accelerates the oxidation of organic contaminants by permanganate: Role of Pb(III)
Lei Dong Pin Xie Xin Zhang Junlian Qiao Dandan Rao Yuankui Sun Xiaohong Guan 《Frontiers of Environmental Science & Engineering》2022,16(8):109
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S. Saravanan G. Nagarajan G. Lakshmi Narayana Rao 《International Journal of Sustainable Engineering》2016,9(3):182-188
The main objective of this work is to control the NOx emission of a stationary diesel engine fuelled with crude rice bran oil methyl ester blend with less sacrifice on smoke density and brake thermal efficiency (BTE) and also to investigate the factors influencing the objective. Fuel injection timing, percentage of exhaust gas recirculation and fuel injection pressure are chosen as the promising factors for the objective and NOx emission, smoke density and BTE are considered as response variables. Tests were conducted as per Taguchi’s L9 orthogonal array and the most influencing factor for each response variable and also the significance of each factor on the same was found out through analysis of variance (ANOVA). Response graph was drawn for each response variable and from the results of response graph and ANOVA the optimum combination of the factor levels in achieving the objective was obtained and the same was confirmed experimentally. 相似文献
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Chris X. Rao Edwin P Maurer 《Journal of the American Water Resources Association》1996,32(6):1139-1146
ABSTRACT: A simplified approach for modeling transmission losses in a stream is presented. A theory relating seepage from a channel with the depth of flow is simplified to a one-parameter relationship. A power relationship is then utilized for the stage-discharge relationship, which is coupled with the seepage relationship. This combined equation is integrated over the channel reach to arrive at a general model for seepage loss through the reach, with one parameter needing calibration. An example is provided showing the development of the relationship and the calibration technique for the parameter. The results are shown, emphasizing the use of the model for simulation of channel transmission losses at low and moderate flow conditions. 相似文献
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ModelingadsorptionofphosphatebysoilswhilethesolutionconcentrationdecreasedwithsorptionSuiHongjianResearchCenterofEnvironment... 相似文献
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