Im. FLOCCULATION AND DISPERSION OF SOIL COLLOD A. Principles One of the characte
ID: 228167 • Letter: I
Question
Im. FLOCCULATION AND DISPERSION OF SOIL COLLOD A. Principles One of the characteristics of materials in the colloidal state is fineness of division. In the case of clay the minute particles may function separately (dispersed) or they may be associated or aggregates (coagulated or flocculated), depending upon their status. Some dispersed clay colloids will pass through a filter paper. Flocculated clay colloids will be filtered out completcly Under certain conditions the dispersed clay colloids may be floculated or filtered out by the soil itself. Migration of clay from the A horizon and accumulation in the B horizon to form a textural or argillic horizon are examples of this behavior in clumps Perform the following experiment to observe the effect of various cations on the flocculation of dispersed soil colloids. B. Procedure funnel No 1 1. Fit a filter paper in each of 2 funnels. 2. Add about 25 ml of the Na - dispersed clay to one funnel. 3. Add a small amount of Ca(OH, powder to a second portion of about 25 ml of the Na -dispersed clay, shake thoroughly, and allow to flocculate. 4. Add the Ca(OH) treated clay to the second funnel. Funnel No Creates mort ima cro ports so-t 2 C. Resuits 1. Does the Na dispersed clay pass through the filter paper? Could such clay be transported within the soil? ss thvough he iitr paper it cowrd not be eas 2. Based on your results, under what conditions would predict dispersed clay would flocculate in the B horizon? 3. What is the influence of excess adsorbed Na" upon the state of aggregation? 4. What is the influence of adsorbed Ca upon the state of aggregation?Explanation / Answer
3. excess sodium causes the aggregated soil particles to disperse. too many sodium ions and thier large size disrupts the binding forces between the soil particles and cause clay platelets and swelling which is not good for soil quality and plant growth. this soil dispersion also causes reduced soil permeability
4. calcium ions are smaller in size than sodium because of larger charge. calcium ions reduce the sodium incuded dispersion and help in binding soil particles together. they will just enhance aggregation.
2. i am not sure about this.