Conservative ions

Conservative ions are ones that do not undergo acid-base reactions at the pH values of interest. These include Na, K, Ca ", S04 , Cl, etc. Non-conservative ions do undergo acid base reactions. These include H30, OH , HCOs, ... 

The rate of diffusion is sensitive to a number of parameters. For conservative ions that are not attenuated, the transfer time is 1-3 decades. For ions that are attenuated, transfer time is much longer. The mass rate of transport by molecular diffusion, however, is so slow that even though chemicals begin to show up in 1-3 decades, the total amount released per unit of area is small. 

Because water is a universal solvent, at least some of virtually every element is present as a solute in seawater. As shown in Table 3.1, the most abundant substances in seawater are the major ions (Cl , Na", SO4 , Mg ", Ca ", and K" ). They are present in nearly constant proportions in the open ocean because their concentrations are largely controlled by physical processes associated with water movement, such as transport by currents, mixing via turbulence, evaporation, and rainfall. These solutes are also referred to as conservative ions. Most of the rest of the solutes in seawater are not present in constant proportions because their concentrations are altered by chemical reactions that occur faster than the physical processes responsible for water movement. These chemicals are said to be nonconservative. Though most substances in seawater are nonconservative, they collectively comprise only a small fraction of the total mass of solutes and solids in the ocean. 

Turbulence and advection can lead to the mixing of adjacent water masses (or types). These water motions create horizontal and vertical gradients in temperature and salinity. As illustrated in Figures 4.17a and 4.17b, vertical mixing at the boundary between two water types produces waters of intermediate temperature and salinity. Since mixing does not alter the ratios of the conservative ions, the water in the mixing zone acquires a salinity intermediate between that of the two water types. The salinity of... 

Conservative ions Ions that exhibit conservative behavior. These include the major ions in seawater. 

The transport Equations (1) are supplemented by mass conservation equations. Mass conservation for each conservative ion species is expressed by,... 

Disagreement between field and laboratory pH measurements places a question mark over the reported concentration of biologically involved ions such as HC03, NH4, S04, H2, and Ca. At the same time, the reported concentrations of more conservative ions—Cl, Br, Na, K, or Li—may be correct. 

Conclusion. Different ions travel at different velocities, the conservative ions moving fastest. The conservative ions are most helpful for the understanding of groundwater flow. 

Another approach to determine carbonate alkalinity is by using a charge balance expression for the major conservative ions in aqueous solution. 

In Table II, the compositions of surface-zone recycle water and fine tails pore water from Syncrude and Suncor are compared (2). Over time, the recycle process water is becoming more brackish (especially at Syncrude). Concentration of the major ions in the tailings ponds as a function of depth is shown in Figure 11. The concentrations of major ions in tailings water have increased with time for example, at Syncrude, from 1979 to 1993, there was a 200-300% increase in conserved ions such as Na+ and Cl. At Suncor, absolute changes were smaller (2, 3, 35, 40). However, no evidence exists of trace metal buildup over time (2). 

Gas hydrate formation involves the removal of water molecnles from the surrounding pore water, as they are seqnestered in the clathrate lattice. Removal of water, with the exclusion of the dissolved ions, leads to changes in the concentration of salts in the pore water. Becanse chloride is an abnndant and nsnally conservative ion in pore waters of shallow marine sediment, changes in dissolved chloride content are... 

The predissociation of NH3 from the planar X, B and C states has been discussed on the basis of synunetry conservation considerations by Runau, Buenker and Peyerimhoff >. As the H-NH2 distance increases the point group symme reduces to Cjp. Electronic symmetry conserv ion then allows formation of NH2(X fii)vw the A state and NH2 (A Ai) via the C state, but in practice both products are formed from all three states it is clear. that vibronic interactions must play a significant role. 

Because of the large volume of seawater, almost all ions are conservative, meaning it does not change its concentration over geological periods. However, there are differences for example, Cr is the most conservative ion in the climate system because it takes no part in any chemical reaction but Na", the counterpart is involved in rock weathering (it is a major constituent of silicate minerals), cation exchange, and possibly volcanic-seawater reactions and reverse weathering. 

The chloride ion is a so-called conservative ion, it is relatively unreactive, and will undergo little or no retention as it moves through waste. It acts as an indicator of dilution, and can be used to map the leading edge of a pollution plume. 

CONSERV ION EQaflTIONS AND MODELING OF CHEMICNL RND BIOCHEMICAL PROCESSES... 

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