• The Journal of Natural Sciences
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• 제13권1호
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• pp.35-50
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• 2003

Granular clay minerals for adsorption of the organic dye prepared a Na-Bentonite and optimum condition calcined temperature $700^{\circ}C$ and polyvinyl alcohol quantity was 25%. Granular clay mineral stable range was pH3 to pH9 and specific area was $83m^2/g$. The adsorption of the organic dye on the Granular clay mineral showed result good adsorption with acid medium and then enthalpy was -3.36 ~ -0.84 kcal/mol. It was exhibit typical physical adsorption.

• Korean Journal of Microbiology
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• 제24권3호
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• pp.308-316
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• 1986

Vertical distribution of heterotrophic bacteria and physico-chemical characteristics were measuted in Kum River estuarine sediments. And interrelationship between heterotrophic bacterka and environmental factors was also studied. The type of sediment of Site 1 was silty clay, and sand at Site 2. Annual pH ranges were between 7.1 and 7.7 in the clay type sediment (Site 1) and 6.9-7.2 in the sand type sediment (Site 2). It was shown that organic matter contents were higher in the clay type sediment than those of sand type sediment. Redox potential values of sediments were decreased rapidly with depth at Site 1, but those of Sete 2 showed vertical fluctuation. Nitrogens(ammonia+amino acid-N, nitrate-N, nitrite-N) and phosphate in the clay type sediment showed higher values than those of sand type sediment. Annual distribution of heterotrophic bacteria were ranged $6.71{\times}10^4$ cells/g dry wt. $-2.50{\times}10^6$ cells/g dry wt. In the clay type sediment and $2.67{\times}10^3$ cells/g dry wt. $-1.94{\times}10^6$ cells/g dry wt. in the sand type sediment. Distribution of proteolytic, lipolytic, and amylolytic bacteria were decreased with the depth and the highest density was found in April and the lowest in January. Bacterial populations in sediments were closely correlated with such environmental factors as pH, redox potential, moisture content, organic matter contents, and inorganic nutrients such as nitrite-N and phosphate-P.

• Journal of the Korean Chemical Society
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• 제50권4호
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• pp.321-327
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• 2006

red 1 and acid blue 92, anionic dyes, were removed from synthetic wastewater by the surfactant-modified clay minerals. Two different clays, such as Korean clay(M78) and Japanese clay(KJ) were treated with three different sulfactants, CTMA, DSDMA and TMSA. The surfactant-modified clay minerals such as M-1(CTMA), M-3(TMSA), KJ-1(CTMA) and KJ-3(TMSA), showed high removal efficiencies with dyes, while M-2(DSDMA) and KJ-2(DSDMA) could adsorb both dyes with relatively low efficiencies. Furthermore, almost 100% absorption of both dyes onto M-1(CTMA) and KJ-3(TMSA) revealed the possibility that these materials can be used for the removal of hazardous organic dyes from wastewater.

• Journal of the Korean Applied Science and Technology
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• 제20권2호
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• pp.165-172
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• 2003

Fireproofing polyolefin nanocomposite for the application of power distributing panel was prepared by compounding linear low density polyethylene(LLDPE), decabromodiphenyl oxide (DBDPO), $Sb_2O_3$ as flame retardant agents, and modified nano clay as filler. The optimized formulation ratio of compounds to prepare the fireproofing polyolefin nanocomposite was obtained. The flame retardant properties for nanocomposite prepared by compounding 22.5 phr of nano clay and 18 phr of DBDPO based on 100 phr of LLDPE were shown that the combustion time. 10${\sim}$18 s, combustion distance, 12${\sim}$15 mm and non-melt dropping characteristics. In particular. the content of DBDPO in nanocomposite could be decreased to 18 phr from 40 phr DBDPO for fireproofing composite containing 30 phr of clay. The electrical properties measured from tracking test, had an excellent antitracking properties by not showing the phenomenon of leakage current and sparking.

• Journal of Environmental Science International
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• 제8권1호
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• pp.69-74
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• 1999

Soil properties which affect the retention of Pb(I) were investigated in the laboratory. It was determined, through selective removal, that organic matter and Fe-oxides are of lesser importance in influencing Pb retention than are soil clay minerals. The following trend : clays ＞ organic matter ＞ Fe-oxides represents the relative importance of each constituent in the adsorption of Pb by soils. The consistently greater Pb uptake by surface over subsurface samples was apparently due to differences in organic matter content, inasmuch as organic matter removal from both resulted in similar adsorption characteristics. All five soils stooled exhibited a pH-dependent trend of adsorption. The extent of Pb adsorption was least at low pH values(4~5), was maximum in the neutral pH range, and leveled off or diminished under more alkaline conditions. There was no strong correlation between Pb uptake and soil cation exchange capacity as routinely measured by the NH$_4$OAc method. A knowledge of clay mineralogy in conjunction with soil pH is suggested as being the most reliable guide to predicting Pb retention by soils.

• Korean Journal of Organic Agriculture
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• 제14권1호
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• pp.97-108
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• 2006

These studies were conducted to evaluate the feasibility of spent bleaching clay (SBC) as a feed resource for ruminants. Three Holstein dairy cows, surgically fitted with ruminal cannula, were used in a $3{\times}3$ Latin Square design. Dietary treatments were 1) basal diet, 2) basal diet plus 2% of SBC and 3) basal diet plus 4% of SBC. Rumen fluid was sampled at 0, 3, 6, 9 and 12 hours following the start of the morning feeding. Nylon bags containing experimental diets were used to determine ruminal nutrient disappearance at 0, 3, 6, 12 and 24 hours. The values of ruminal pH in cows receiving 4% of SBC was lower than those of the control and 2% SBC supplement. The $NH_3-N$ concentration in the rumen was higher at the 3 hour than for cows of control and 2% of SBC supplement. Total VFA concentrations in the rumen were not affected by the addition of SBC. Dry matter and organic matter disappearance in the rumen was lower at the 6 hours than the control and 2% SBC treatment, but no difference at the end of the 24 hour.

• Korean Journal of Soil Science and Fertilizer
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• 제28권3호
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• pp.241-248
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• 1995

This experiment was conducted to obtain basic information for the management of soil and fertilization for plastic-house soil cultivated Khwari green pepper in Dang Jin area of Chung Nam Province. The range of pH with highest frequency for 36 sites investigated was 6.1~6.5, OM 1.6~2.5%, available phosphorous 601~800mg/kg, CEC 12.1~14.0 c mol/kg, clay 16.1~18.0% and below 2.0ds/m for electical conductivity of soil. Fesh fruit weight of green pepper showed very high significant positive correlation with organic matter, clay content and cation exchange capacity, while negaive correlation with electrical conductivity. Electrical conductivity showed highly significant negative correlation with CEC, clay content and organic matter in soil, respectively. To decrease below 2.0 dS/m of electrical conductivity in plastic-house soil, the content of clay and organic matter could be maintained at above 1.8% and 2.3%, respectively.

• Journal of Environmental Science International
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• 제11권9호
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• pp.961-969
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• 2002

This study was performed : 1) to establish the experimental analysis conditions for the sorption and desorption of toxic organic contaminants to/from the activated sludge, sediment, and clay, and 2) to determine the sorption and desorption equilibrium coefficients of some representative halogenated aliphatic compounds. Through the preliminary sorption test using Azo dye, a setting of quantitative experimental conditions to determine the sorption and desorption characteristics was decided as follows; equilibration time of 180 minutes, centrifuge for 15 minutes at 5000$\times$g, and 500mg/$\ell$ of TOC concentration. The sorption and desorption characteristics of halogenated aliphatic compounds onto activated sludge, sediment and clay could be described very well using the Freundlich isotherm. The preference of the average sorption capacity of the overall compounds showed in the sequence sediment 0.26mg/g, clay 0.23mg/g, and activated sludge 0.11 mg/g. The desorption rate of the sorbed compounds onto activated sludge, sediment and clay was approximately 89.8%, 35.3%, and 66.4%, respectively.

• Macromolecular Research
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• 제8권4호
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• pp.186-191
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• 2000

Clay-dispersed nanocomposites have been prepared by simple melt-mixing of three components, i.e. poly (styrene co-acrylonitrile) copolymer (SAN), poly ($\xi$-caprolactone ) (PCL), and an organophilic clay(Cloisite(R) 30A). In the present study, poly($\xi$-caprolactone) was added in the mixtures in order to facilitate the intercalation of SAN into the gallery of silicate layers, and the molecular weight effects of PCL on the dispersion of silicate layers were compared by changing the amount of added PCL. The degree of dispersion of 10-$\AA$-thick silicate layers of clay in the nanocomposites was investigated by using an X-ray diffractometer and a transmission electron microscope. It was found that PCL added in the mixture facilitate the intercalation of SAN copolymers into the galleries of silicate layers modified with an organic intercalant, resulting in the better dispersion of clay. It was, also, observed that the processing temperature influences the degree of clay dispersion.

• Journal of Environmental Science International
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• 제9권2호
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• pp.125-129
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• 2000

As one of the fundamental survey to evaluate purification capacity of pollutants at the tidal flat sediments, we studied vertical environmental characteristics in three tidal flat sediments, Chunjangdae, Eueunri and Gyewhado. These are dissmilar to external feature in each other. The results of this study may be summarized as followed; As the results of particle analysis, Eueunri tidal flat fediment located in Keum river estuary consists of 98.98% as silt & clay, Chunjangdae tidal flat sediment located in SeocheonGun consists of 97.99% as sand. And Gyewhado tidal flat sediment located in Saemankeum in Saemankeum area consists area consists of 32.81% as silt & clay and 67.19% as sand. The concentration of organic pollutants(I.L., COD, POC, PON) in Eueunri tidal flat sediment which highly content of silt & clay were 3~4 times higher than others. The concentration of organic pollutants at each layer were slightly increase goes with deepen layer. The linear correlation between I.L. and COD, POC, PON were obtained. Correlation coefficients were in range of 0.821~0.940. Also the correlation between pH and COD, POC, PON were high(>r=0.9). Filteration rate in Chunjangdae tidal flat sediment was 0.01584cm/s as mean value, but the other were almost nothing filtered off.