What is CEC mica?

High cation-exchange capacity (CEC) muscovite mica with a homoionic surface was prepared by replacing the Li(+) surface ions of partially delaminated Li-mica with K(+). The CEC of mica can be photometrically measured by exchanging its surface cations with Cu(trien)(2+).

What is cation exchange capacity of mica?

The experimental capacity of the cation exchange of these minerals is about 20-50 mmol equiv/100 g of mineral [26, 74] . The charge of large micas (clintonites) is still higher and marked by a prominent main pattern. …

What is a good CEC?

The five exchangeable cations are also shown in soil test results as percentages of CEC. The desirable ranges for them are: calcium 65–80% of CEC, magnesium 10–15%, potassium 1–5%, sodium 0–1% and aluminium 0%.

What is the value of CEC?

Cation Exchange Capacity (CEC) CEC, as reported by nearly all soil testing laboratories, is a calculated value that is an estimate of the soils ability to attract, retain, and exchange cation elements. It is reported in millequivalents per 100 grams of soil (meq/100g).

What is a high CEC for soil?

Organic matter has a very high CEC ranging from 250 to 400 meq/100 g (Moore 1998). Because a higher CEC usually indicates more clay and organic matter is present in the soil, high CEC soils generally have greater water holding capacity than low CEC soils.

Why does kaolinite have low CEC?

At 10–30 cm depth, however, organic matter content decreases and the soil also has a low clay content, and hence a low CEC. The CEC increases in the subsoil layers due to an increase in clay content. The dominant clay in this soil is kaolinite, however, so CEC values remain low compared to many clay soils.

What is the cation exchange capacity of vermiculite?

The cation exchange capacity of vermiculite ranges from 130 to 210 cmolc/kg1. The layer charge expressed per half unit cell (O10OH2) range from 0.6 to 0.9. The high CEC and layer charge of vermiculites thus dominates the exchange properties of sediments that contain it in significant amounts.

What is considered a low CEC?

The CEC of soil organic matter and some clay minerals varies with pH. Generally, the CEC is lowest at soil pHs of 3.5 to 4.0 and increases as the pH is increased by liming an acid soil, as shown in Figure 2. Because CEC may vary considerably with soil pH, it is a common practice to measure a soil’s CEC at a pH of 7.0.

What is CEC and ECEC?

The effective cation exchange capacity (ECEC) is defined as the total amount of exchangeable cations and exchangeable cations. Japanese comments on NWI “Soil quality. Determination of effective cation exchange capacity (CEC) and exchangeable cations using acobaltihexammine trichloride solution”

What is the unit of CEC?

CEC is measured in millequivalents per 100 grams of soil (meq/100g). A meq is the number of ions which total a specific quantity of electrical charges.

Can CEC be too high?

What is cation exchange capacity (CEC)?

The relative ability of soils to store one particular group of nutrients, the cations, is referred to as cation exchange capacity or CEC. Soils are composed of a mixture of sand, silt, clay and organic matter.

What is the role of CEC in soil exchange?

Cations on the soil’s exchange sites serve as a source of resupply for those in soil water which were removed by plant roots or lost through leaching. The higher the CEC, the more cations which can be supplied. This is called the soil’s buffer capacity.

What is the relationship between CEC and Meq?

The higher the CEC, the higher the negative charge and the more cations that can be held. CEC is measured in millequivalents per 100 grams of soil (meq/100g). A meq is the number of ions which total a specific quantity of electrical charges.

What is the difference between high CEC and low CEC?

For instance, soils having a high CEC and high buffer capacity change pH much more slowly under normal management than low-CEC soils. Therefore, high-CEC soils generally do not need to be limed as frequently as low-CEC soils; but when they do become acid and require liming, higher lime rates are needed to reach optimum pH.