• Journal of the Speleological Society of Korea
• /
• no.92
• /
• pp.9-18
• /
• 2009

A number of closed metal mines act as point sources of contamination on nearby streams, soils and plants in our country. The contamination of twelve decomposed samples had earned from nine closed metal mines had been evaluated by TEA-3000. The contents of heavy metal with ion fraction exchange and carbonate fraction forms had been showed that the speciation of heavy metals represented with easy solubility, mobility and bioavailable of plants, and in case of sulfide compounds and organic residuals forms are related with the speciation of metals which may be stable forms because of strong bindable capacity. Also heavy metals elements in mosts of mines got with relative stable within crystal lattice, but results of trace element analyser showed that, in the most of tailings from mine areas, large portions of concentration of heavy metals were explained as stable from, sulfides/ organics and residual. In tailing from Imchun mines, the concentrations extracted by water were relatively high as compared with other mine areas whose total concentrations were very high because of large quantities of exchangeable ions and carbonates and low soil pH. Danger Index (D.I.) suggested in this study was based on the cumulative concentrations of step 1 and 2 from the result of trace element analyser. When the soil pH was considered, this index became better indicator to determine the priority for the remediation of mine area.

• Journal of Energy Engineering
• /
• v.26 no.1
• /
• pp.76-83
• /
• 2017

In this paper, the carbon resources recycling of the overview of coffee waste generation in Vietnam. Since few years, there has been a significant research studies was done in the areas of coffee waste generation areas and also waste water generation from coffee production. The coffee residue (solid) and waste water (liquid) both are caused the underground water contamination and also soil contamination. These residues contain high organic matter and acid content leads to the severe threat to environment. In second stage of coffee production process, the major solid residue was generated. Various solid residues such as spent coffee grounds, defective coffee beans and coffee husks) pose several environmental concerns and specific problems associated with each type of residue. Due to the unlimited usage of coffee, the waste generation is high. At the same time, some researchers have been investigated the spent coffee wastes are the valuable sources for various valuable compounds. Biodiesel or biomass productions from coffee waste residues are the best available utilization method for preventing the landfill problems of coffee waste residues.

• Journal of Preventive Medicine and Public Health
• /
• v.22 no.4 s.28
• /
• pp.454-465
• /
• 1989

In a small island community with a population of less than 100 residents, nine persons died and five experienced severe illnesses during the period from November 1986 to May 1988. Their initial symptoms were sore throat and fever. Renal failure and hepatitis developed within one week after the onset. Oral mucosal ulcer developed in some cases. After one week, progressive respiratory failure and dyspnea developed evidently and severe respiratory distress and hypoxia preceded those fatal cases. Chest X-ray findings revealed bilateral diffuse multiple cystic lesion with occasional multiple large emphysematous bullae. Based on these features paraquat poisoning was diagnosed and route of poisoning was investigated. In three sources of drinking water, trace amount of paraquat was detected in November 1988, six months after the incidence of recent fatal case. In November 1988, soybean sauces and soybean pastes from 12 households were found contaminated with high concentration of paraquat, the cause could not be identified. The possibility of the contamination of drinking water as the cause of this mass poisoning has been suggested.

• Journal of Soil and Groundwater Environment
• /
• v.26 no.6
• /
• pp.82-94
• /
• 2021

Facilities for low impact development (LID) or groundwater recharge have the high potential spreading groundwater nitrate contamination because of the rapid infiltration. This study was initiated to remove nitrate from the waters using agricultural byproducts as organic sources for denitrification during infiltration. As the first step of this purpose, we experimentally tested the denitrifying efficiency of 4 organic materials (pine tree woodchips, cherry leaves, rice straws, and rice hulls) and tried to identify the key factors controlling the efficiency. For this study, we precisely investigated the change of chemical reactions during the experiment by analyzing various geochemical parameters. The result shows that the denitrification efficiency is not simply linked to the availability of the easily decomposable contents in the organic matter. It is found that avoiding the severe pH decrease due to the CO₂ generation is the essence to derive the efficient denitrifying conditions when organic matters were used.

• Membrane and Water Treatment
• /
• v.14 no.2
• /
• pp.95-106
• /
• 2023

In the developing country like India, groundwater is the main sources for household, irrigation and industrial use. Its contamination poses hydro-geological and environmental concern. The hazardous waste sites such as landfills can lead to contamination of ground water. The contaminants existing at such sites can eventually find ingress down through the soil and into the groundwater in case of leakage. It is necessary to understand the process of migration of pollutants through sub-surface porous medium for avoiding health risks. On this backdrop, the present paper investigates the behavior of pollutants' migration through porous media. The laboratory experiments were carried out on a soil-column model that represents porous media. Two different types of soils (standard sand and red soil) were considered as the media. Further, two different solutes, i.e., non-reactive and reactive, were used. The experimental results are simulated through numerical modeling. The percentage variation in the experimental and numerical results is found to be in the range of 0.75- 11.23 % and 0.84 - 1.26% in case of standard sand and red soil, respectively. While a close agreement is observed in most of the breakthrough curves obtained experimentally and numerically, good agreement is seen in either result in one case.

• Advances in environmental research
• /
• v.12 no.2
• /
• pp.77-93
• /
• 2023

The water can be contaminated by natural sources or by industrial effluents. One such contaminant is fluoride. Fluoride contamination in the water environment due to natural and artificial activities has been recognized as one of the major problems worldwide. Among the commonly used treatment technologies applied for fluoride removal, the adsorption technique has been explored widely and offers a highly efficient simple and low-cost process for fluoride removal from water. This review paper the recent developments in fluoride removal from surface water by adsorption methods. Studies on fluoride removal from aqueous solutions using various carbon materials are reviewed. Various adsorbents with high fluoride removal capacity have been developed, however, there is still an urgent need to transfer the removal process to an industrial scale. Regeneration studies need to be performed to more extent to recover the adsorbent in field conditions, enhancing the economic feasibility of the process. Based on the review, technical strategies of the adsorption method including the Nano-surface effect, structural memory effect, anti-competitive adsorption and ionic sieve effect can be proposed. The design of adsorbents through these strategies can greatly improve the removal efficiency of fluoride in water and guide the development of new efficient methods for fluoride removal in the future. This paper describes brief discussions on various low-cost adsorbents used for the effective removal of fluoride from water.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.6
• /
• pp.930-940
• /
• 2013

We evaluated contamination with organic matter and trace metals by analyzing grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Ni, Cr, Mn, Hg, and As) in surface sediments at 28 stations around the Geum River estuary in July 2008. The surface sediments in the estuary were mainly composed of coarse sediment (sand and muddy sand), with mean grain size (Mz) ranging between $2-4{\O}$. The high concentrations of IL, COD, and trace metals were mainly found at stations in front of the Gusan outer port and industrial complex, and near the Seocheon coast with relatively fine sediments. In addition, the concentrations of IL and all trace metals, except Pb and As, showed good positive correlations with Mz, indicating that the concentrations of organic matter and trace metals were mainly dependent on sediment grain size. The concentrations of COD, AVS, and trace metals in most sediments did not exceed the sediment quality guideline (SQGs). Although the sediments in the study region are not polluted with organic matter and trace metals, there are many point sources of pollutants, such as Gusan port and industrial complex, Janghang refinery, and a thermoelectric power plant around the Geum River estuary. Thus, the management of coastal environments through periodic monitoring of organic matter and trace metals is required in the future.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2003.11a
• /
• pp.544-547
• /
• 2003

The objective of this study is to investigate the contamination levels and dispersion patterns of arsenic and heavy metals and to estimate the bioaccessible fraction of the metals in soil and plant samples in the vicinity of the abandoned Songcheon Au-Ag mine. Tailings, soils, plants (Chinese cabbage, red pepper, soybean, radish, sesame leaves, green onion, lettuce, potato leaves, angelica and groundsel) and waters were collected around the mine site. After appropriate preparation, all samples were analyzed for As, Cd, Cu, Pb and Zn by ICP-AES and ICP-MS. Elevated levels of As and heavy metals were found in tailings. Mean concentrations of As in agricultural soils were higher than the permissible level. Especially, maximum level of As in farmland soil was 513 mg/kg. The highest concentrations of As and Zn were found in Chinese cabbage (6.7 mg/kg and 359 mg/kg, respectively). Concentrations of As, Cd, and Zn in most stream waters which are used for drinking water around this mine area were higher than the permissible levels regulated in Korea. Maximum levels of As, Cd and Zn in stream waters were 0.78 mg/L, 0.19 mg/L and 5.4 mg/L, respectively. These results indicate that mine tailings can be the main contamination sources of As and heavy metals in the soil-water system in the mine area. The average of estimated bioaccessible fraction of As in farmland soils were $3.7\%$ (in simulated stomach) and $10.8\%$ (in simulated small intestine). The highest value of bioaccessible fraction of metal in farmland soils was $46.5\%$ for Cd.

• Journal of Korean Society on Water Environment
• /
• v.21 no.4
• /
• pp.403-409
• /
• 2005

Methyl tert-butyl ether (MTBE) contamination in groundwater often coexists with benzene, toluene, ethylbenzene, and xylene (BTEX) near the source of the plume. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by BTEX and MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc. In oil-contaminated environments, anaerobic biodegradation of BTEX and MTBE depended on the concentration and distribution of terminal electron acceptor. In this study, effect of electron acceptor on the anaerobic biodegradation for BTEX and MTBE-contaminated soil was investigated. This study showed the anaerobic biodegradation of BTEX and MTBE in two different soils by using nitrate reduction, ferric iron reduction and sulfate reduction. The soil samples from the two fields were enriched for 65 days by providing BTEX and MTBE as a sole carbon source and nitrate, sulfate or iron as a terminal electron acceptor. This study clearly shows that degradation rate of BTEX and MTBE with electron acceptors is higher than that without electron acceptors. Degradation rate of Ethylbenzene and Xylene is higher than that of Benxene, Toluene, and MTBE. In case of Benzene, Ethylbenzene, and MTBE, nitrate has more activation. In case of Toluene and Xylene, sulfate has more activation.

• Journal of Korean Society on Water Environment
• /
• v.23 no.6
• /
• pp.822-828
• /
• 2007

Perchlorate is an unregulated contaminant but recently many cases of perchlorate contamination have been reported in the US. In Japan, also, a couple of contamination incidents caused by perchlorate occurred. Against this backdrop, investigation on perchlorate was urgent for Korea. Accordingly, perchlorate investigation in tap water and river water was conducted one time a week for seven consecutive weeks at major water sources of Korea including Han River, Guem River, Yeong-san River, and Nak-dong River. Perchlorate was not found at Han River, Guem River, and Yeong-san River. However, all the 4 tap water samples in Nak-dong River recorded high level of perchlorate. Among others, NT1 located at Daegu posted the highest value of $22.3{\mu}g/L$. This level is lower than $24.5{\mu}g/L$, the threshold recommended by US EPA. Still, perchlorate contamination in drinking water can deal a heavy blow to nerve development of infants and children by causing iodine deficiency. At the 1st and 2nd investigations, perchlorate concentration reached $18.7{\sim}95.6{\mu}g/L$ and $4.0{\sim}25.6{\mu}g/L$ respectively, both of which are relatively higher. The high perchlorate concentration in Nak-dong River was possible because of the waste water discharged from LCD manufacturing factory which was located at NS3 in Gumi, Korea. Perchlorate concentration of waste water from the factory was $730{\sim}1,858{\mu}g/L$.