Sorption of Cyanide Anion on Soil and Sediment

As mentioned in Chapter 1, Sections 1.3.2.1 and 1.3.3.2 and Chapter 2, Section 2.9, anions can also be sorbed on rocks and soils. The sorption of anions can take place on the protonated sites of minerals (e.g., on the A10H2+ and FeOH2+) at acidic 

When dissolved cyanide ions, for example, in river water, interact with the geological environment (e.g., sediment, soil, air), the cyanide concentration of the solution may decrease if 

The quantity of the solvent (river water) increases (e.g., rain, other coming rivers), and therefore, the solution becomes diluted. 

As seen in the figure, the major portion of cyanide is present as hydrogen cyanide at the pH range of the rivers and soil solutions. (It is usually neutral or weakly alkaline pH 6-8.) The rate of evaporation decreases as pH increases. When studying these systems, it is important to decrease the rate of evaporation as much as possible, or else the evaporated quantity must be taken into consideration. The evaporation of cyanide, however, is slow the rate-determining step is diffusion, and it can be described with an exponential relation similar to a formally first-order kinetic equation. The evaporation of cyanide slightly increases as temperature increases. 

Since cyanide pollution usually originates from metal mines or galvanic plants, heavy-metal-ion pollution (e.g., copper, zinc ion) occurs simultaneously with that of cyanide. So, the complex formation and redox 

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