• Journal of the Mineralogical Society of Korea
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• v.6 no.2
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• pp.122-144
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• 1993

The Kimhae napseok clay deposit was studied to characterize its mineralogy and genesis. Geology of the deposit is composed of Tertiary volcanic rocks and granodiorite. Tertiary volcanic rocks consist of andesitic tuff with minor interstratified tuffaceous shale, and rhyodacitic tuff. The main ore body of 2.4 to 4 m in thickness developed parallel to the bedding of andesitic tuff bed. Its strike and dip are $N70^{\circ}E-N85^{\circ}E$ and $16^{\circ}NW-32^{\circ}NW$, respectively. Two alteration zones; the propylitic zone of albite-epidote-chlorite-quartz assemblage and advanced argillic zone of pyrophyllite-dickite-alunite-diaspore assemblage are developed. Correlation of $SiO_2$ to $Al_2O_3$ shows no relation in propylitic zone, while a negative linear relation in advanced argillic zone. Chemical variation shows that $SiO_2$, $Al_2O_3$, MgO, CaO, $Na_2O$ and $K_2O$ were leached out during hydrothermal alteration. Pyrophyllite, the most abundant mineral in advanced argillic zone, occurs as low temperature 2M polytype. It is closely associated with dickite, diaspore and alunite. The Hinckley index of dickite is 0.83 showing moderate crystallinity. Na content is increasing in the M site with the increasing content of cations in the R-site. the mole percent of Na replacing K in alunite ranges from 53.2 to 71.6. It is also found that pyrophyllite grows in the dissolution site of diaspore. Plagioclase was albitized. Lowering of pH caused mainly by sulfide and sulfate decomposition resulted in preferential leaching of Si. It is inferred that aluminum released from plagioclase in the volcanic rocks as well as from the tuffaceous shale intercalated in andesitic tuff were the main sources of aluminum required for the formation of clay deposit. pH in hydrothermal fluid decreased from propylitic zone to advanced argillic zone with increasing degree of alteration. Based on experimental data reported in the literature and mineral assemblages, the formation temperature of the deposit ranges 270 to $320^{\circ}C$.

• Economic and Environmental Geology
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• v.55 no.1
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• pp.63-76
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• 2022

Dacitic tuffs, 97 to 118 m thick, were recovered from the lower part of the subsurface Seongdongri Formation, Janggi Basin, which was drilled to assess the potential for underground storage of carbon dioxide. The tuffs are divided into four depositional units(Unit 1 to 4) based on internal structures and particle componentry. Unit 1 and Units 3/4 are ignimbrites that accumulated in subaerial and subaqueous settings, respectively, whereas Unit 2 is braided-stream deposits that accumulated during a volcanic quiescence, and no dacitic tuff is observed. A series of analysis shows that mordenite and clinoptilolite mainly fill the vesicles of glass shards, suggesting their formation by replacement and dissolution of volcanic glass and precipitation from interstitial water during burial and diagenesis. Glass-replaced clinoptilolite has higher Si/Al ratios and Na contents than the vesicle-filling clinoptilolite in Units 3. However, the composition of clinoptilolite becomes identical in Unit 4, irrespective of the occurrence and location. This suggests that the Si/Al ratio and pH in the interstitial water increased with time because of the replacement and leaching of volcanic glass, and that the composition of interstitial water was different between the eastern and western parts of the basin during the formation of the clinoptilolite in Units 1 and 3. It is also inferred that the formation of the two zeolite minerals was sequential according to the depositional units, i.e., the clinoptilolite formed after the growth of mordenite. To summarize, during a volcanic quiescence after the deposition of Unit 1, pH was higher in the western part of the basin because of eastward tilting of the basin floor, and the zeolite ceased to grow because of the closure of the pore space as a result of the growth of smectite. On the other hand, clinoptilolite could grow in the eastern part of the basin in an open system affected by groundwater, where braided stream was developed. Afterwards, Units 3 and 4 were submerged under water because of the basin subsidence, and the alkali content of the interstitial water increased gradually, eventually becoming identical in the eastern and western parts of the basin. This study thus shows that volcanic deposits of similar composition can have variable distribution of zeolite mineral depending on the drainage and depositional environment of basins.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.734-744
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• 2011

A soil stabilization method is an effective and practical remediation alternative for arsenic (As) and heavy metal contaminated farmland soils nearby abandoned metal mine in Korea. This method is a technique whereby amendments are incorporated and mixed with a contaminated soil. Toxic metal bind to the amendments, which reduce their mobility in soil, so the successful stabilization of multi-element contaminated soil depends on the combination of critical elements in the soil and the type of amendments. The objective of this study is to investigate the treatment effects and applicability of limestone (LS) and steel refining slag (SRS) as the amendment for farmland soil contaminated with As and heavy metals, and a lab-column test was conducted for achieving this purpose. The result showed that soil treated with LS and SRS maintained pH buffer capacity and, as a result, the heavy metal leaching concentration was quite low below the water quality standard compared to untreated soil which leachate exceeding the water quality standard was observed, however, the arsenic concentration rather increased with increasing mixture ratio of SRS. This was believed to be related to phosphorus (P) contained in SRS, and dominancy in the competitive adsorption relation between As and P binding strongly to iron might be different according to soil characteristic. We suggested that LS is a effective amendment for reducing heavy metals in soil, and SRS should be used after investigating its applicability based on the adsorption selectivity of arsenic and phosphorus in selected soil.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.39-50
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• 2015

Stabilization of heavy metals such as Pb, Cd, Zn, and Cu was evaluated in contaminated soil treated with poultry manure (PM) as well as its biochars pyrolyzed at $300^{\circ}C$ (PBC300) and $700^{\circ}C$ (PBC700) at the application rates of 2.5, 5.0, and 10.0 wt% along with the control, prior to 21-days incubation. After incubation, soil pH was increased from 6.94 (control) to 7.51, 7.24, and 7.88 in soils treated with PM 10 wt%, PBC300 10 wt%, and PBC700 10 wt% treatments, respectively, mainly due to alkalinity of treatments. In the soil treated with PM, the concentrations of the toxicity characteristic leaching procedure (TCLP)-extractable Pb, Cd, Zn, and Cu were increased by up to 408, 77, 24, and 955%, respectively, compared to the control. These increases may possibly be associated with an increased dissolved organic carbon concentration by the PM addition. However, in the soil treated with PBC700, TCLP-extractable Pb, Cd, Zn, and Cu concentrations were reduced by up to 23, 38, 52, and 36%, respectively, compared to the control. Thermodynamic modelling using the visual MINTEQ was done to predict the precipitations of $Pb(OH)_2$, $Cu(OH)_2$ and P-containing minerals, such as chloropyromorphite [$Pb_5(PO_4)_3Cl$] and hydroxypyromorphite [$Pb_5(PO_4)_3OH$], in the PBC700 10 wt% treated soil. The SEM-elemental dot mapping analysis further confirmed the presence of Pb-phosphate species via dot mapping of PBC700 treated soil. These results indicate that the reduction of Pb concentration in the PBC700 treated soil is related to the formations of chloropyromorphite and hydroxypyromorphite which have very low solubility.

• Resources Recycling
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• v.29 no.2
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• pp.69-77
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• 2020

With rapid increasing production and installation, recycling of photovoltaic modules has become the main issue. According to the research, the accumulation of waste modules will reach to 8600 tons in 2030. Moreover, Crystalline-silicon (c-Si) Photovoltaic modules account for more than 90% of the waste. C-Si PV modules contain 1.3% of weight of photovoltaic ribbon inside which contains the most of lead, tin and copper in the PV modules, which would cause environmental and humility problem. This study provided a valuable metal separation process for PV ribbons. Ribbons content 82.1% of Cu, 8.9% of Sn, 5.2% of Pb, and 3.1% of Ag. All of them were leached by 3M of hydrochloric acid in the optimal condition. Ag was halogenated to AgCl and precipitated. Cu ion was extracted and separated from Pb and Sn by Lix984N then stripped by 3M H2SO4. The effect of the optimal parameters of extraction was also studied in this essay. The maximum extraction efficiency of Cu ion was 99.64%. The separation condition of Pb and Sn were obtained by adjusting the pH value to 4 thought ammonia to precipitate and separate Pb and Sn. The recovery of Pb and Sn can reach 99%.

• Resources Recycling
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• v.30 no.2
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• pp.39-45
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• 2021

Spent photovoltaic module is one of the important resource of silver, while related research concerning silver recovery remains limited. In our previous research, HNO3 was utilized to dissolve Ag(I) and Al(III) from the spent silicon solar cells. In order to recover Ag(I) from the leachate of a silicon solar cell, the present study made use of a nitrate solution containing Ag(I) and Al(III), which was subjected to a solvent extraction process with 5,8-diethyl-7-hydroxydodecan-6-oxime (LIX63). Ag(I) was selectively extracted with LIX63 over Al(III) from the nitrate leach solution. Subsequently, quantitative stripping of Ag(I) from the loaded LIX63 was performed by using 20% ammonia water. The McCabe-Thiele plots for the extraction and stripping isotherms of Ag(I) were also constructed. Extraction and stripping simulation tests confirmed an Ag(I) extraction and stripping efficiency of >99.99% and 98.9%, respectively with high purity Ag (99.998%) and Al (99.99%) solution. A process flow sheet for Ag(I) recovery from the nitrate leach solution was proposed.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.12-21
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• 1999

This study was carried out to improve the cultivation method of paddy rice when the application amount of nitrogen decreased. We investigated the growth and the yield of paddy rice, the changes of nutrients in the soil solution, soil and paddy rice. The results are as follows. The yield at the N4 plot(N $73kg\;ha^{-1}$) was higher than that of control(N $110kg\;ha^{-1}$). N1(N $55kg\;ha^{-1}$), N2(N $55kg\;ha^{-1}$), and N3(N $73kg\;ha^{-1}$). The number of panicle per square meter at the N4 plot was larger than that of control plot. The increase in yield at the N4 plot was due to increased number of panicle where planting density was two times higher compared to the control plot. The availability of nitrogen at the N4 plot also was two times higher than that of control plot. The pH in soil solution was around 7 and did not change largely. The $K^+$ concentration in soil solution at all plots decreased gradually. The $Ca^{2+}$ concentration in soil solutions increased gradually, and decreased at the later stage slightly. The P concentration in soil solution decreased gradually, increased after the heading stage, and then decreased due to decrease of soil temperature. Leaching of $Ca^{2+}$ was higher, while that of $K^+$ and P was lower compared to other ions. Total content of nutrients in soil after harvest decreased. Contents of total N, total P, and O.M. at the N4 plot were higher than those of the other plots. The content of total N and O.M. was correlated to yield. Contents of N, P and K in rice straw and grain at the N4 plot were the highest among all plots. In conclusion, to decrease N application amount in paddy rice cultivation as well as to maintain yield, planting density should be twice of control and the amount of application of N fertilizer should be two-third of control where N fertilizer should be applied mainly at 20 and 10 day before heading.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1615-1634
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• 2004

A review was undertaken to obtain information on the sustainability of pig free-range production systems including the management, performance and health of pigs in the system. Modern outdoor rearing systems requires simple portable and flexible housing with low cost fencing. Local pig breeds and outdoor-adapted breeds for certain environment are generally more suitable for free-range systems. Free-range farms should be located in a low rainfall area and paddocks should be relatively flat, with light topsoil overlying free-draining subsoil with the absence of sharp stones that can cause foot damage. Huts or shelters are crucial for protecting pigs from direct sun burn and heat stress, especially when shade from trees and other facilities is not available. Pigs commonly graze on strip pastures and are rotated between paddocks. The zones of thermal comfort for the sow and piglet differ markedly; between 12-22$^{\circ}C$ for the sow and 30-37$^{\circ}C$ for piglets. Offering wallows for free-range pigs meets their behavioural requirements, and also overcomes the effects of high ambient temperatures on feed intake. Pigs can increase their evaporative heat loss via an increase in the proportion of wet skin by using a wallow, or through water drips and spray. Mud from wallows can also coat the skin of pigs, preventing sunburn. Under grazing conditions, it is difficult to control the fibre intake of pigs although a high energy, low fibre diet can be used. In some countries outdoor sows are fitted with nose rings to prevent them from uprooting the grass. This reduces nutrient leaching of the land due to less rooting. In general, free-range pigs have a higher mortality compared to intensively housed pigs. Many factors can contribute to the death of the piglet including crushing, disease, heat stress and poor nutrition. With successful management, free-range pigs can have similar production to door pigs, although the growth rate of the litters is affected by season. Piglets grow quicker indoors during the cold season compared to outdoor systems. Pigs reared outdoors show calmer behaviour. Aggressive interactions during feeding are lower compared to indoor pigs while outdoor sows are more active than indoor sows. Outdoor pigs have a higher parasite burden, which increases the nutrient requirement for maintenance and reduces their feed utilization efficiency. Parasite infections in free-range pigs also risks the image of free-range pork as a clean and safe product. Diseases can be controlled to a certain degree by grazing management. Frequent rotation is required although most farmers are keeping their pigs for a longer period before rotating. The concept of using pasture species to minimise nematode infections in grazing pigs looks promising. Plants that can be grown locally and used as part of the normal feeding regime are most likely to be acceptable to farmers, particularly organic farmers. However, one of the key concerns from the public for free-range pig production system is the impact on the environment. In the past, the pigs were held in the same paddock at a high stocking rate, which resulted in damage to the vegetation, nutrient loading in the soil, nitrate leaching and gas emission. To avoid this, outdoor pigs should be integrated in the cropping pasture system, the stock should be mobile and stocking rate related to the amount of feed given to the animals.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.289-302
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• 2023

The study area was Gangnim-myeon, Hoengseong-gun, Gangwon-do, composed of the Chiaksan gneiss complex, and it was revealed that the concentrations of uranium (U) and thorium (Th) within the groundwater of the study area exceeded their water quality standards. Hence, artificial weathering experiments were conducted to elucidate mineralogically the mechanisms of their leaching using drilling cores obtained from the corresponding groundwater aquifers. First of all, the mineralogical compositions of core samples were observed, and the results indicated that the content of clinochlore, a member of the chlorite group of minerals that can form through low- and intermediate-temperature metamorphisms, was relatively higher. In addition, the Th concentration was measured ten times higher than that of U. The results of artificial weathering experiments suggested that the Th concentrations gradually increased through the dissolution of radioactive-element-bearing minerals up to the first day, and then they tended to decrease. It could be attributed to the fact that Th was leached with the dissolution of thorite, which might be a secondary mineral, and then dissolved Th was re-precipitated as the various forms of salt, such as sulfate. Even though the U content was lower than that of Th in the core samples, the U concentration was one hundred times higher than that of Th after the weathering experiments. It is likely caused by the gradual dissolution and desorption of U included in intensively weathered thorite or adsorbed as a form of UO₂²⁺ on the mineral surface. In addition, the leaching tendency of U and Th was positively correlated with the bicarbonate concentration. However, the concentrations between U and Th in groundwater exhibited a relatively lower correlation, which might result from the fact that they occurred from different sources, as aforementioned. Among various kinetic models, the parabolic diffusion and pseudo-second-order kinetic models were confirmed to best fit the dissolution kinetics of both elements. The period that would be taken for the U concentration to exceed its drinking-water standard was inferred using the regressed parameters of the best-fitted models, and the duration of 29.4 years was predicted in the neutral-pH aquifers with relatively higher concentrations of HCO₃, indicating that U could be relatively quickly leached out into groundwater.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.219-228
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• 2009

The construction procedures and artificial turf maintenance program on golf course definitely influence on the distortion of its environment. Soil microbial communities in soil profile were affected directly by those practises on turf areas. In Jeju island, the environmental impact assessment has been required to apply the first quality class granular activated carbon(GAC), which has a high absorbent character to agricultural chemicals, on the soil profiles of golf green system to reduce the pesticide leaching to ground water. This research was carried out to analyze the changes of microbial communities and chemical properties on soil profiles where GAC had been applied at the construction stage at two golf courses in Jeju. The changes of soil microbial population and chemical properties associated with construction methods of soil profile and agrochemical management program were analyzed by monthly at the surface and sub-soil profiles during April through October, 2007. The total numbers of bacteria and fungi, soil moisture content, soil physio-chemical properties were measured on greens and fairways of the both golf courses with different GAC treatment on the green and fairway soil profiles. The results showed that GAC had positive effects on the water holding capacity, pH and EC, however, it did not improved the holding capacity of available nutrients ${NO_3}^-,{NH_4}^+$, and phosphorus by its sorption phenomenon. In microbial count test, the total numbers of bacteria and fungi showed a great variation during sampling dates. That may directly relate to the agrochemical application, however, the ratio of total bacterial number versus total fungus number showed a constant value on a sub-soil of 15~30cm depth. Thus, the construction method of GAC in soil profile, and application of fertilizer and pesticide, both impacted on the changes of microbial population. It's means that the construction method of soil profile and turf management using agro-materials might greatly affect on the turfgrass culture and the environment of golf course.