Plume spreading

Despite these limitations, mobile monitoring systems have been used to obtain useful information, such as the verification and tracking of the St. Louis, Missouri, urban plume. The measurement of a well-defined urban plume spreading northeastward from St. Louis is shown in Fig. 15-2 (7). These data were collected by a combination of instrumented aircraft and mobile vans. Cross-sectional paths were flown by the aircraft at increasing distances downwind. Meteorological conditions of low wind speed in the same direction helped to maintain this urban plume in a well-defined... 

The concentrations of both parent surfactant and lipophilic metabolites decreased sharply with increasing distance from the sewage outlet. At a distance of 100 m, the concentrations had all dropped to below 0.5 and 0.1 pg L-1 for A9PEOn and metabolites, respectively. The decrease was mainly explained by an efficient dilution. The concentrations were significantly higher near the water surface, as a consequence of the wastewater plume spreading primarily into the upper freshwater layer, while leaving the saline layer less affected. 

As it was shown before that the wastewater plume spreads mainly in the upper fresh/brackish layer of the estuary [6], the difference between biotransformation rates in the two water layers is explained by a better pre-adaptation of the brackish water bacteria to A9PEO in their natural habitat, due to higher pre-exposures. It seems that the bacterial populations in these two physically very close habitats are quite different. 

Equation (4.22) is the expression for the mean concentration from a continuous point source of strength q at the origin in an infinite fluid when the standard deviations of plume spread are different in the different coordinate directions and when the slender-plume approximation is invoked. 

The dispersive contributions due to plume spreading (given by and Z ) are statistically independent of the contributions due to plume meandering (given by 5 and 5 ). The fluctuating plume model is depicted in Fig. 3. 

Burr DT, Sudicky EA, Naff RL (1984) Nonreactive and reactive solute transport in three-dimensional heterogeneous porous media mean displacement, plume spreading, and uncertainty. Water Resour Res 30 791-815... 

The third zone is at the top of tank where the plume spreads out. The numerical model again overestimates the gas velocity, probably because the... 

The assumptions made in the development of the above equation are (1) the plume spread has a Gaussian (normal) distribution in both the horizontal and vertical planes, with standard deviations of plume concentration distribution in the horizontal and vertical directions of Gy, and respectively (2) uniform emission rate of pollutants, m (3) total reflection of the plume at ground z = 0 conditions and (4) the plume moves downstream (horizontally in the x direction) with mean wind spead, u. Although any consistent set of units may be used, the cgs system is preferred. For concentrations calculated at ground level (z = 0), the equation simplifies to... 

Figure 3.20 shows the 24-h HPAC prediction using the MM5 simulated profile data in (1) the control and (2) FDDA runs. GB agents were released as a 500-kg bomb at 1200 UTC, 8 May 2005, at three separate locations indicted by the incident icons. The meteorological data was updated every 2 h during the 24-h HPAC computations. The GB plumes spreads along the direction of the prevailing low-level flow... 

Type 1 Young gasoline spill MTBE plume spreading corresponds to that of the BTEX... 

We have seen that when ct2 varies as t the crosswind eddy diffusion coefficient Kyy is related to the variance of plume spread by... 

In the example Fe(III) reduction takes place nearly within the whole plume, since iron minerals and contaminant are present and the major part of the plume is anaerobic. With a solid electron acceptor there is no problem of mixing, the minerals remain in place and are in contact with the contaminant as the plume spreads. Hence, the degradation via Fe(III) reduction increases with the volume of the plume, while degradation via mobile electron acceptors occurs only at the surface of the plume. Fe(lll) reduction is slow, since it is limited by microbial availability of the minerals. If the minerals are consumed, they cannot be refilled by an external source. In a more heterogeneous aquifer it is possible that reducible Fe(III) is embedded in low permeable lenses. In this case degradation is limited by diffusion of contaminant into the lens. 

On June 24, 2003, a major fire took place at the mine. After burning for a month, 300,000 tonnes of sulfur inventory had been destroyed. The massive sulfur dioxide plume spread over 1,000 km, and was tracked by satellite. The 600,000 tonne gas cloud was the largest man-made release of sulfur dioxide in history. Hussain s troops had added to the problem by flooding the mines with bitumen. 

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