• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.245-252
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• 2006

This experiment was conducted to investigate the distribution and compositions of clay mineral and to replenish the soil classification system in Korea. Soil layer samples were collected from 26 residuum and colluvium soil series out of 390 soil series in Korea, and then analyzed for soil physical and chemical characteristics, mineral and chemical compositions of clay in B horizon soils. Major clay minerals of residuum and colluvium were illite and chlorite in soils originated from the sedimentary rock such as limestone, shale, sandstone and conglomerate; quartz and kaolin in soils originated from rhyolite, neogene deposits, porphyry and tuff; and kaolin and quartz in the soils originated from granite, granite gneiss and anorthosite. Clay minerals in Korean soils were divided into 4 groups: mixed mineral group(MIX) mainly contained with illite, kaolin and vemiculite; kaolin group(KA) with kaolin and illite; chlorite group(CH) with chlorite and illite; and smectite group(SM) with kaolin, illite and smectite. The most predominant clay mineral group was kaolin group(KA) with kaolin and illite; an mixed mineral group(MIX) with illite, kaolin and vemiculite. Cation exchange capacity (CEC) of clay was low in the soils mainly composed with MIX and KA groups and silica-alumina molar ratio of clay was high in the soils composed with SM group

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.120-121
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• 2018

Radon is one of the substances that pollute the indoor air and is classified as a first-level carcinogen by the International Agency for Research on Cancer(IARC) together with asbestos, and it is reported that it can cause lung cancer. The World Health Organization(WHO) reports that lung cancer is the second leading cause of lung cancer, and 6-15% of lung cancer patients report lung cancer caused by radon. Radon occurs in cracks in concrete and aged buildings, and is detected in soil, rocks, groundwater, and so on. It is a colorless, odorless and tasteless gas which is adsorbed to dust in the air and enters through human respiratory system. This study used vermiculite (expanded vermiculite), which has excellent ion exchange ability and a large number of pores, and industrial by - product red mud which has heavy metal adsorption ability, in order to adsorb radon. A matrix capable of adsorbing radon was prepared, and the characteristics of each material were compared and analyzed.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.153-159
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• 1987

Adsorption and desorption characteristics of $^{42}K$ and $^{45}Ca$ were studied by making use of the natural zeolite, bentonite, and vermiculite. The work included that the fittness tests for the Freundlich and the Langmuir adsorption isotherms and desorption of the radionuclides from adsorbents by extracting with $NH^+_4$ ($1N-NH_4OAc$). The adsorption by the radionuclides are fitted well with both of the adsorption equations. The Langmuir adsorption maximum of $^{42}K$ is higher than that of $^{45}Ca$ by the zeolite and bentonite except vermiculite, and the values of $^{42}K$ decrease in the order of Zeolite (Zt)>Bentonite (Bt)>Vemiculite (Vt). As for $^{45}Ca$, the maximum adsorption values decrease in the order of Bt>Vt>Zt. The ionic radii of K and Ca seem to be closely related with fixation in the cavity of the zeolite that adsorb more $^{42}K$ than $^{45}Ca$. The smaller ionic size of Ca seems to be resulted in the lower adsorption of $^{45}Ca$ by the zeolite because Ca could leave easily from the cavity. Ionic size of K, however, seems to be similar with size of the cavity. $^{45}Ca$ adsorption by the bentonite, on the other hand, show higher adsorption than $^{42}K$. The higher charge density of the divalent cations than those of the monovalent cations seems to be the main consideration. For the retention strength of the adsorbed $^{42}K$ and $^{45}Ca$ by the adsorbents, a comparison is made by use of the Langmuir constant(k). The results indicated that the constant values for K are smaller than those of Ca in all the adsorbents. It seems that the smaller values of the constant, the weaker retention strength. For $^{42}K$, the percentage of desorption decrease in the order of Zt>Bt>Vt, but in the case of $^{45}Ca$, it decreases in the order of Vt>Zt>Bt. The results show that the weaker binding strength as represented by small value of the Langmuir constant, the higher percentage of the removal except fixing preferably $K^+$ by the vemiculite. In conclusion, the zeolite could adsorb much more $^{42}K$ and remove it more than others. For $^{45}Ca$, the bentonite could adsorb more and desorb less than others.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.3-9
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• 1994

Characterstics, genesis and classification of soils derived from coarse grain granitic materials were discussed with four soil series, such as Samgag, Sangju. Sachon and Yecheon which were distributed over the area of Gangdae-Ri, Nengseo-Myeon, Yeoju-Gun, Gyunggi-Do. The results are as follows. 1. Samgag, Sangju, Sachon and Yecheon had a soil of excessively, well, imperfectly and poorly drained, thus they had a soil drainage sequence. 2. Soil textural class were from sandy loam to loam. Silt and clay content were increased with descending to the local bottom, while sand content was decreased. 3. Soils were very strongly to strongly acid and OM, CEC, exchangeable cation, and available $P_2O_5$ in soils seemed to be increased with ascending to the local boctom. 4. Kaolinite and Quartz were the dominant clay mineral and the other was Vermiculite and Illite. 5. Samgag was classified as Typic Dystrochrepts, Sangju as Dystric-Fluventic Eutrochrepts, Sachon as Aeric-Fluventic Halpaquepts, and Yecheon as Fluventic Haplaquepts.