Particle resuspension

Baskaran and Santschi (1993) examined " Th from six shallow Texas estuaries. They found dissolved residence times ranged from 0.08 to 4.9 days and the total residence time ranged from 0.9 and 7.8 days. They found the Th dissolved and total water column residence times were much shorter in the summer. This was attributed to the more energetic particle resuspension rates during the summer sampling. They also observed an inverse relation between distribution coefficients and particle concentrations, implying that kinetic factors control Th distribution. Baskaran et al. (1993) and Baskaran and Santschi (2002) showed that the residence time of colloidal and particulate " Th residence time in the coastal waters are considerably lower (1.4 days) than those in the surface waters in the shelf and open ocean (9.1 days) of the Western Arctic Ocean (Baskaran et al. 2003). Based on the mass concentrations of colloidal and particulate matter, it was concluded that only a small portion of the colloidal " Th actively participates in Arctic Th cycling (Baskaran et al. 2003). 

Note The contribution of particle resuspension followed by desorption to the total sediment-water exchange will be further discussed in Chapter 23 (Box 23.2 and Table 23.6). 

Figure 23.3 The processes which contribute to the exchange flux between open water (op) and sediment column (sc) (a) settling of suspended particles (b) exchange flux of dissolved phase across a stagnant bottom boundary layer, (c) particle resuspension followed by equilibration between particle and open water.

Thorpe A, Harrison RM, Boulter PG, McCrae IS (2007) Estimation of particle resuspension source strength on a major London Road. Atmos Environ 41 8007-8020... 

Stallard and Edmond 1983). However, other processes must come into play. For example, distributions of most particulate components (and dissolved nitrate and oxygen) are relatively uniform during falling water. This constancy demonstrates the importance of physical processes, such as particle resuspension and in-channel chemical reactions. 

Terrestrial loss Volatilization, particle resuspension, dissolved and suspended load to oceans 1.538... 

Sticky films or other adhesive material sometimes used to minimize particle resuspension. 

Many different designs of surrogate surfaces have been used to measure dry deposition in the field. These include smooth flat surfaces, rough flat surfaces, and collectors with complex geometries. Examples of additional design modifications include application of an adhesive coating to minimize particle resuspension, covering the surface with a film of water to study... 

Strontium is widely distributed in the earth s crust and oceans. It is released into the atmosphere as a result of natural processes such as entrainment of dust particles, resuspension of soil by wind, and sea spray. Strontium is released into surface water and groundwater from the natural weathering of rocks and soils. Human activities, including milling and processing of strontium compounds, burning of coal, land application of phosphate fertilizers, and use of pyrotechnic devices, release strontium into the atmosphere. Discharges of industrial waste water and runoff from land treated with phosphate fertilizers are human-related processes that release strontium into streams and aquifers. 

Thibodeaux LJ, Reible DD, Valsaraj KT (2002) Non-particle resuspension chemical transport from stream beds. Chap 7. In Lipnick R, Mason R, Phillips M, Pittman C (eds) Chemicals in the environment fate, impacts and remediation. ACS Symposium Series 806. American Chemical Society, Washington... 

Once an aerosol particle is deposited on a structural surface it is subjected, on the one hand, to gravitational and electrostatic (Van der Waals) adhesive forces, which tend to hold the particle to the surface and, on the other hand, to forces that tend to effect resuspension of the particle. Resuspension in the reactor primary system may reduce the retention effectiveness and, consequently, enhance the source term to the containment. According to Benson and Bowsher (1988), resu-pension of deposited aerosols can be caused by one of three processes ... 

Nicholson, K.W., 1988a. A review of particle resuspension. Atmos. Environ. 22, 2639—2651. 

Sehmel, G. a. Particle resuspension from an asphalt road caused by car and truck traffic. Atmos. Environ. 7, 291 (1973). 

Non-Particle Resuspension Chemical Transport from Stream Beds... 

Water column model. A comprehensive chemical mass balance in the water column should account for mass change with time, advection and dispersion, particle deposition, soluble release, particle resuspension from the bed, evaporation to air and degradation. Over a differential distance x in the direction of flow (L) these processes are. 

The dispersion term is absent since dividing the reach into Ax completely mixed segments accomplishes dispersion numerically. In equation 1 t is time (t), Ct is soluble, particulate, and colloidal, concentration (M/L ), U is average water velocity (M/t), Ds is particle deposition flux (M/L t), h is water column depth (L), m v is suspended solids concentration (M/L ), fp and fd are fractions chemical on particles and in solution, kf is the soluble fraction bed release mass-transfer coefficient (L/t), Cs is the total, soluble and colloidal, concentration at the sediment-water interface (M/L ), Rs is particle resuspension flux (M/L t), ms is the particulate chemical concentration in the surface sediment (M/L ), fps Cts is the fraction on particles and total chemical concentration in the surface sediment (M/L ), Kl is the evaporation mass-transfer coefficient (L/t), Ca is chemical vapor concentration in air (M/L ), H is Henry s constant (L / L ) and Sx is the chemical lost by reaction (M/L t). It is conventional to use the local or instantaneous equilibrium theory to quantify the dissolved fraction, fd, particulate fraction, fp, and colloidal fraction, fooM in both the water column and bed. The equations needed to quantify these fractions appear elsewhere (4, 5, 6) and are omitted here for brevity. 

What follows is a theoretical underpinning of the non-particle resuspension, soluble release processes represented by Eq. 3 and 4. A broad approach will be taken in that numerous transport processes will be considered. These will include the individual processes plus several combined processes that operate in series or parallel on both sides of the interface. 

Including the particle resuspenion velocity, the details of five individual mass-transfer coefficients were presented above. These appear in Table I normalized to the chemical concentration on solid particles in the bed. Although the particle resuspension and particle biodiffusion transport coefficients remain unchanged the ones defined with solute concentrations require the msKo term for conversions to the equivalent particle concentration form. The Kd is the particle-to-porewater chemical partition coefficient (L /M). In doing so all can be compared on the same numerical basis. 

The objective of this paper was to develop a theoretically sound process framework for quantifying the release rate of the soluble chemical fraction from bed-sediment in the absence of particle resuspension. Both Equations 6 and 7 represent the final algorithm of this discussion. First, a brief review of what has gone before. 

Information on several other transport processes and MTCs at the sediment-water interface appear elsewhere in this handbook. Due to special nature of these subjects and the complexity of the processes, individual chapters are devoted to three of them. Chapter 10 is concerned with particle resuspension and deposition as it affects chemical transport in flowing water streams. Chapter 11 is concerned with water advection processes that contribute to enhanced chemical transport in the various aquatic-sediment bed systems. Chapter 13 is concerned with chemical biodiffusion processes in the sediment bed as a consequence of the presence of macrofauna in the surface layers (i.e., bioturbation). These three processes do not fit nicely into a chapter devoted to the more conventional diffusive process the contents of this chapter are as follows. 

This chapter is concerned with molecular diffusion-related chemical transport parameter estimation procedures at the water-sediment interface. Transport coefficients for particle resuspension and settling are in Chapter 10. Chapter 11 is concerned with the bed porewater advective process and Chapter 13 covers macrofauna driven... 

Relations from Empirical Studies of Particle Resuspension.472... 

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