• Journal of Environmental Science International
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• v.7 no.2
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• pp.149-156
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• 1998

Enoronmental problems caused by certain geologic conditions Include pollution of soil by heavy metal, acidization of souls , acid mine drainage, Pound-water pollution, and natural radioactivity, as well as zoo-logical hazards such as landslide and subsidence. The acrid mine drainage contains large amount of heavy metals nO, therefore. cause serious pollution onto the nearby drainage systems and soils. In spite of this prospective environmental danger, few studies have been done on the acid mine drainage derived from non-metallic ore deposits such as pyrophyllitefNapseok) deposits. The sudo-bearing pyrophyllite ores, alteration zones, and mine talllngs of pyrophylllte deposits produce acrid mine drainage by the okidation of weathering. Compared to the fresh host rocks, the ores and altered rocks of pyrophyllite deposits produce acidic solution which contain higher amount of heavy metals because of OeP lower buffering capacity to acrid solution. The pus of urine water and nearby stream water of pyrophyllite deposits are 2.1~3.7, which are strong- ly acidic and much lower than that (6.2~7.2) of upstream water and than that (6.8~7.6) of the stream water derived from the non-mineralized area. This study reveals that this acrid mine drainage can affect the downstream area which is 8km far from the pyrophyllite deposits, even though the drain Is diluted with abundant non-contaminated river water This suggmists that not only acid mine drainage but also the sulfide-bearing sediments originated from the pyrophyllite deposits move downstream and form acidic water through continuous oxidation reaction. The heavy metals such as Pb, Zn, Cu, Cd, Nl, Mn and Fe are enriched In the mine water of low pH, and their contents decrease as the pH of mine water Increases because of the Influx of fresh stream wainer. SoUs of the Pyrophyulte deposits are characterized by high contents of heavy metals. The stream sediments containing the yellowish brown precipitates formed by neutralization of acid mine drainage occur in all parts of the stream derived from the pyrophyllite deposits, and the sediments also contain high amounts of heavy metals. In summary, the acid mine drainage of the pyrophyllite deposits is located in the upstream part of Hoidong water reservoir in Pusan contains large amounts of heavy metals and flows into the Holdong water reservoir without any purification process. To protect the water of Holdong reservoir, the acid mine drainage should be treated with a proper purification process.

• Journal of Korean Neurosurgical Society
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• v.67 no.4
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• pp.467-476
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• 2024

Objective : To evaluate the usefulness of a cranial implantable chemoport, the H-port, as an alternative to the Ommaya reservoir for intraventricular chemotherapy/cerebrospinal fluid (CSF) access in patients with leptomeningeal metastasis (LM). Methods : One hundred fifty-two consecutive patients with a diagnosis of LM and who underwent H-port installation between 2015 and 2021 were evaluated. Adverse events associated with installation and intraventricular chemotherapy, and the rate of increased intracranial pressure (ICP) control via the port were evaluated for safety and efficacy. These indices were compared with published data of Ommaya (n=89), from our institution. Results : Time-to-install and installation-related complications of intracranial hemorrhage (n=2) and catheter malposition (n=5) were not significantly different between the two groups. Intraventricular chemotherapy-related complications of CSF leakage occurred more frequently in the Ommaya than in the H-port group (13/89 vs. 3/152, respectively, p<0.001). Intracranial hemorrhage during chemotherapy occurred only in the Ommaya group (n=4). The CSF infection rate was not statistically different between groups (14/152 vs. 12/89, respectively). The ICP control rate according to reservoir type revealed a significantly higher ICP control rate with the H-port (40/67), compared with the Ommaya result (12/58, p<0.001). Analyzing the ICP control rate based on the CSF drainage method, continuous extraventricular drainage (implemented only with the H-port), found a significantly higher ICP control rate than with intermittent CSF drainage (33/40 vs. 6/56, respectively, p<0.0001). Conclusion : The H-port for intraventricular chemotherapy in patients with LM was superior for ICP control; it had equal or lower complication rates than the Ommaya reservoir.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.206-212
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• 1999

In order to evaluate the applicability of steel mill slag as a AMD (Acid Mine Drainage) neutralizer and to compare capacity of slag with that of limestone lab scale experiments were conducted. The fixed treatment experiments of AMD with slag and limestone separately for 24 hours under the stagnant condition showed that slag has higher capacity of pH increase and removal of Fe. Al and other trace elements. During the 10 days continuous step experiment the pH has been maintained and any decrease in the removal capacity of Fe and Al has not bun observed. In the trace element removal experiment slag showed higher capacity for removal of Ni, Co. Cu and Zn than limestone. The removal of trace element was more effective in AMD than in distilled water that the pH was adjusted to the same level of AMD (synthetic acid solution). It means that Fe and Al in AMD adsorbed trace elements during or after precipitation as oxide forms. In the size effect experiment, the slag of the smaller size with larger specific surface area exhibited higher capacity of pH increase and removal efficiencies of Fe. Al and other trace elements.

• Proceedings of the KSEEG Conference
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• 2004.12a
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• pp.9-28
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• 2004

Concern about arsenic is increasing throughout the world, including areas of the United States. Elevated levels of arsenic above current drinking-water regulations in ground and surface water can be the result of purely natural phenomena, but often are due to anthropogenic activities, such as mining and agriculture. The current study correlates arsenic speciation in acid mine drainage and mining influenced water with the important water-chemistry properties Eh, pH, and iron(III) concentration. The results show that arsenic speciation is generally in equilibrium with iron chemistry in low pH AMD, which is often not the case in other natural-water matrices. High pH mine waters and groundwater do not 짐ways hold to the redox predictions as well as low pH AMD samples. The oxidation and precipitation of oxyhydroxides depletes iron from some systems, and this also affects arsenite and arsenate concentrations differently through sorption processes.

• Journal of Environmental Science International
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• v.18 no.2
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• pp.239-244
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• 2009

In this study, to stabilize the heavy metal in the contaminated soils, the column leaching test based on rainfall and pH value was performed by using coal mine drainage sludge(CMDS): which was generated during electrical purification of abandoned coal mine wastewater. Four types of testing column were used in this study. That were the CMDS and the heavy metal contaminated soils well mixed in 0 wt%, 1 wt%, 3 wt% and 3 wt% layered column. According to the investigation, when the influent pH was $5.5{\sim}6.2$, there were no heavy metal elution at all conditions, and when the influent pH was $3{\sim}3.3$, the order of Cu, Zn, Pb, Cr elution concentration was 3 wt% M(mixed)<3 wt% S(separation)<1 wt% M<0 wt% and the average elution concentration was quite low, the value was 0.005 mg/L. Therefore, CMDS can used as new stabilizer of the heavy metal in the contaminated soils.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.57-62
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• 2008

The application of constructed subsurface-flow wetlands for treatment of wastewater from abandoned mines is being increased. Crushed limestone, oak chips, and mushroom composites are often employed in a bulk form, as the substrates in the bed media. Efficiency of the subsurface-flow treatment system drops with time as the hydraulic conductivity of the wetland soil decreases significantly, presumably due to chemical reactions with the wastewater. The purpose of this study is to investigate the applicability of immobilized beads carrying sulfate reducing bacteria for acid mine drainage treatment system. The ingredients of immobilized beads are organic materials such as mushroom composite and oak chips, limestone powder for a pH buffer, mixed with a modified Coleville Synthetic Brine. It was found that immobilized beads are more efficient than the bulk form for pH recovery, sulfate and heavy metal removal.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.3
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• pp.116-121
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• 1997

Pilot wetland reactor systems to test acid mine drainage treatment efficiencies for metals were designed and operated at the Dalsung mine and surveyed the operating problems. pH and Eh (redox potential) were measured in situ and anayses of Cd, Pb, As, Zn, Cu, Fe, Al and Mn were carried out in the laboratory. Maximum metal removal efficiencies of the reactor containing the rice stalks, the cow manure and limestones were that Cu, Zn, Fe, Cd, Al, Mn and Pb were lowered by 98%, 100%, 99%, 100%, 97%, 61% and 100%, respectively and at that time the pH and Eh of the effluents from the reactor were 6 and about -300 mV. However, the redox potential was raised and removal of metal elements except aluminium was decreased with operation time. It suggests that the reduced condition is very important for the metal removal. During the operation, problems such as scaling in pipes and volume change of the substrate within the reactor occurred, which were preventing the flow of main drainage in pipes and reactor.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.68-76
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• 2002

In this study, we have investigated the geochemical behavior and fate of heavy metals in acid rock drainage (ARD). The ARD was collected from the area of the former Dongrae pyrophyllite mine. The Dongrae Creek waters were strongly acidic (pH : 2.3~4.2) and contained high concentrations of $SO_4$, Al, Fe, Mn, Pb, Cu, Zn, and Cd, due to the influence of ARD generated from weathering of pyrite-rich pyrophyllite ores. However, the water quality gradually improved as the water flows downstream. In view of the change of mole fractions of dissolved Fe, Al and Mn, the generated ARD was initially both Fe- and AA-ich but progressively evolved to more Al-rich toward the confluence with the uncontaminated Suyoung River. As the AR3 (pH 2.3) mixed with the uncontaminated waters (pH 6.5), the pH increased up to 4.2, which caused precipitation of $SO_4$-rich Fe hydroxysulfate as a red-colored, massive ferricrete precipitate throughout the Dongrae Creek. Accompanying the precipitation of ferricrete, the Dongrae Creek water progressively changed to more Al-rich toward downstream sites. At the mouth of the Dongrae Creek, it (pH 3.4) mixed with the Suyoung River (pH 6.9), where pH increased to 5.7, causing precipitation of Al hydroxysulfate (white precipitates). Neutralization of the ARD-contaminated waters in the laboratory caused the successive formation of Fe precipitates at pH<3.5 and Al precipitates at higher pH (4~6). Manganese compounds were precipitated at pH>6. The removal of trace metals was dependent on the precipitation of these compounds, which acted as sorbents. The pHs for 50% sorption ($pH_{50}$) in Fe-rich and Al-rich waters were respectively 3.2 and 4.5 for Pb, 4.5 and 5.8 for Cu, 5.2 and 7.4 for Cd, and 5.8 and 7.0 for Zn. This indicates that the trace metals were sorbed preferentially with increasing pH in the general order of Pb, Cu, Cd, and Zn and that the sorption of trace metals in Al-rich water occurred at higher pH than those in Fe-rich water. The results of this study demonstrated that the partitioning of trace metals in ARD is not only a function of pH, but also depends on the chemical composition of the water.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.21-27
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• 2012

The characteristics of floc formation of the iron(Fe) ions contained in the acid mine drainage was studied for developing the process treating the acid mine drainage. The iron(Fe) ions were formed into flocs by the acid-base reaction with the added $Ca(OH)_2$. The molal ratio of iron(Fe) vs $Ca(OH)_2$ was one of major control variables in treatment; pH change, iron(Fe) ions concentration in treated drainage, DO (dissolved oxygen content). In addition, the air gave much effect on the color of the $iron(Fe)-Ca(OH)_2$ flocs and the attachment to magnet. The attaching to the magnet of the flocs formed in the air was much less than the case without air.

• Journal of Korea Soil Environment Society
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• v.2 no.3
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• pp.31-38
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• 1997

Temporal and spatial comparisons of acid mine drainage contaminated waters are difficult because of the complex physico-chemical nature of the pollutant. In the present study, an acid mine drainage index has been developed and evaluated for the assessment of surface waters. AMD index is calculated using a modified arithmetic weighted index using seven parameters which are most indicative of AMD contamination, i. e. pH value, sulphate, iron, zinc, aluminum, copper and manganese. Weighting is used to express the relative indicator value of each parameter. The proposed AMD index is used to quantify contamination from acid mine drainage over ten different old mine sites and assess the degree of impact on surface on surface waters. As a result of AMD evaluation, the Sukbong Mine located near the Moonkyung province showed lowest AMD value indicating the worst acid mine drainage quality. In overall, Youngdong mine sites showed higher contaimination compared to the other mine sites including Youngsuh, Choongbu, Suhbu and Nambu area.