Example: Groundwater A brownfield is contaminated with pollutants including PCBs. The water table declines in the...
A site has groundwater contaminated with 1 mg/L hexavalent chromium, Cr(VI). A permeable reactive barrier (PRB) measuring 8 m × 8 m is placed across the path of the groundwater flow and loaded with 30 kg of iron metal Fe0 , which can reduce Cr(VI) to the much less toxic trivalent chromium, Cr(III), by this reaction: Cr(VI) + Fe0 → Cr(III) + Fe(III) In the direction of flow, the hydraulic head declines by 8 m per 1000 m. The soil...
QUESTION 6 Equi-potential groundwater table elevations are given as contour lines. This aquifer has the total porosity of 0.35 and the hydraulic conductivity of 5 meters per day. Flow direction 62 m 64 m 66 m 68m Spill site 500 m Assuming there is no dispersion, estimate an average travel time as years when the contaminant arrives at the house located at 500 m downstream from the contaminated spill site.
Contaminant sorption and flow in subsurface environment (12 points) An aquifer is contaminated due to a recent spill of a certain industrial solvent. The aquifer has a hydraulic head difference of 0.01 m as measured by two piezometers about 2 m apart along the direction of groundwater flow. The aquifer has a porosity of 0.3, organic carbon бс) of 1.7%, soil particle density of 2.6 g/cm3, and hydraulic conductivity (K) of 2.5 x 103 cm/sec The solvent has a log...
Contaminant sorption and flow in subsurface environment (12 points) An aquifer is contaminated due to a recent spill of a certain industrial solvent. The aquifer has a hydraulic head difference of 0.01 m as measured by two piezometers about 2 m apart along the direction of groundwater flow. The aquifer has a porosity of 0.3, organic carbon (foc) of 1.7%, soil particle density of 2.6 g/cm, and hydraulic conductivity (K) of 2.5 x 10-3 cm/sec The solvent has a log...
A mixture of benzene, Napthalene, trichloroethylene and chlorobenzene were found in a groundwater plume. Consider the partitioning of these four compounds in a contaminated soil. Assume that the hydrocarbon mixture has contaminated the soil at an average of 0.09 liters of the mixture per cubic meter of soil. Considering the soil above and below the water table (ie. each cubic meter is 60% saturated with water by volume). The soil contains 0.75% organic carbon and has a porosity of 30%...
1. Some pond water contains 20.O mg/L of some algae, which can be represented by the chemical formula CsHisO&N. Using the following reactions: CoHisO&N606CO2 6H2ONHa NHs 202 NOs H2O (a) Find the theoretical carbonaceous oxygen demand CBOD (b) Find the nitrogenous oxygen demand NBOD (c) Find the total theoretical biochemical oxygen demand BOD 2. A sandy soil has a hydraulic conductivity of 6.1 x104 m/d, a hydraulic gradient of 0.00141, and porosity of 20%. (a)what is the Darcy velocity (b)what...