• Transactions of the Korean hydrogen and new energy society
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• v.25 no.5
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• pp.482-490
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• 2014

Gaseous sulfur compound such as $H_2S$ or COS in coal- or biomass-derived hot syngas can be purified by solid sorbents at high temperatures. In this study, we investigated the physical properties and reactivity of solid regenerable desulfurization sorbents with 37.2, 41.9, and 46.5wt% ZnO to look into the ZnO content effect. The sorbents were produced by spray-drying method to apply to a fluidized-bed process. Sulfidation and regeneration reaction were carried out using a thermogravimetric analyzer. Sorbent prepared with 46.5wt% ZnO had physical properties suitable for a fluidized-bed process applications such as spherical shape, sufficient mechanical strength and density, high porosity and surface area. It showed high sulfur sorption capacity of 10.4wt% (ZnO utilization of 57%) at reaction temperatures of 500 and $650^{\circ}C$ for sulfidation and regeneration, respectively. However, the sulfur sorption capacity and ZnO utilization were significantly reduced and dimple shape appeared when the ZnO content decreased to 37.2 and 41.9wt%. Sulfur sorption capacity and regenerability were improved as reaction temperature increased within the experimental temperatures used in this work. The reaction temperature zones of $1500{\sim}550^{\circ}C$ and $650{\sim}700^{\circ}C$ are recommended for sulfidation and regeneration, respectively, to lead best reaction performances of the ZnO-based spray-dried sorbents developed in this work.

• Journal of Environmental Health Sciences
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• v.42 no.6
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• pp.385-395
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• 2016

Objectives: The aim of this study was to assess exposure to VOCs and PAHs and the health effects on volunteers who participated in an oil spill cleanup in Yeosu. Methods: Atmospheric VOCs were evaluated in the vicinity of the accident site and questionnaire surveys were conducted to identify personal characteristics and acute health symptoms of clean-up workers seven days after the accident. The levels of metabolites of VOCs (t,t-MA, HA, PGA, MA, MHA) and PAHs (2-NAP, 1-OHP, 2-HF, 1-HPH), oxidative stress markers (TABARS, 8-OHdG) in the urine of workers were analyzed. Their correlation was determined by multiple regression analysis with SAS ver. 9.4. Results: Although the concentration of atmospheric VOCs in the residential areas were low at the time of survey, the levels of VOCs and PAHs metabolites in clean-up workers were higher than those in the control group after clean-up activities. The levels of urinary VOC and PAH metabolites were significantly increased after clean-up compared to those measured before participation. The thiobarbituric acid reactive substance (TBARS) concentrations were also increased and showed significant correlations with those of metabolites of benzene. Conclusion: This study shows that oil spill clean-up activities affect exposure to VOCs and PAHs and the health of clean-up workers. The results suggest the need for check-ups of participants in oil spill cleaning work.

• Journal of Preventive Medicine and Public Health
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• v.43 no.2
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• pp.166-173
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• 2010

Objectives: On December 7, 2007, the Hebei Spirit oil tanker spilled out 12,547 kl of crude oil on the Yellow Sea 10 km away from the cost of Taean Province, Korea. As the coastline has been contaminated, local residents have been exposed to crude oil. Because the residents were showing many symptoms, we investigated the acute health effects of this oil spill on them. Methods: We conducted a cross-sectional study consisting of the heavy and moderately oil soaked area in Taean and the lightly oil soaked area in Seocheon. Ten seashore villages were selected from each area, and 10 male and female adults were selected from each village. We interviewed the subjects using a structured questionnaire on the characteristics of residents, the cleanup activities, the perception of oil hazard, depression and anxiety, and the physical symptoms. The odds ratios and 95% confidence intervals were analyzed using logistic regression analysis. The logistic regression model was adjusted for age, gender, education, smoking, the perception of oil hazard and anxiousness. Results: The more highly contaminated the area, the more likely it was for residents to be engaged in cleanup activities and have a greater chance of exposure to oil. The indexes of anxiety and depression were higher in the heavy and moderately oil soaked areas. The increased risks of headache, nausea, dizziness, fatigue, tingling of limb, hot flushing, sore throat, cough, runny nose, shortness of breath, itchy skin, rash, and sore eyes were significant. Conclusions: The results suggest that exposure to crude oil is associated with various acute physical symptoms. Long-term investigation is required to monitor the residents' health.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.632-638
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• 2006

There are numerous approaches available to cleanup a contaminated surface and subsurface ground currently in use, however, these methods all classify the decontamination after the contamination has penetrated into the soil masses and is costly. Unlike these approaches, in this study, utilization of soil's self-decontamination ability by rearranging and preplanning of the topographical features and surface and subsurface drainage systems for the potential contamination sites before or during contamination process has been considered as an another cleanup method. Step by step explanations on why and how to develop the self-decontamination procedure is proposed in detail. Two examples are presented including contaminated saltwater intrusion along a coastal region and control or prevention of radioactive toxic radon gas ($^{222}Rn$) in residential areas. The effectiveness of the proposed systems to these two examples using the soil's self-decontamination ability is well illustrated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.11a
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• pp.39-49
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• 1996

Hundreds of contaminated sites have been generated due to the past mismagement of toxic substances, the lack of adequate environmental controls and ignorance of the potential environmental impacts of general activities in Canada. The general public, industry and governments have been addressing the contaminated sites with a number of cleanup responses. Environmental protection and remediation have become top priorities for the public and private sectors alike in Canada. Between the late 1980s and the early 1990s, the Canadian Environmental Protection Act and Canada's Green Plan were followed by provincial and territorial laws and policies to regulate contaminated sites. The National Contaminated Site Remediation Program(NCSRP) was initiated in 1989. It has been administered through bilateral agreements between the federal and participating provincial/territorial governments. They have committed a total of $250 million toward orphan site cleanup and technology development/demonstration over a five year period. The federal government has committed an additional $25 million to assess contaminated sites on federal crown land. Over 40 orphan high-risk contaminated sites, over 230 federal sites and over 35 technology development/demonstration projects have been addressed. The Canadian Council of Ministers of the Environment has developed a series of guidance documents to ensure a consistent and successful implementation of the Program. The management/regulation scheme of contaminated sites generally consists of： 1) identifying and investigating sites, 2) determining site contamination, 3) recognizing responsibility and liability, 4) assessing priority for remediation, 5) activation, evaluation and implementing remediation options, and 6) documenting remediation completion. The NCSRP supported the successful development/demonstration of a wide range of innovative remedial technologies. They are related to stabilization/solidification, thermal washing/flushing, advanced oxidation, sonics, and groundwater contaminated with hydrocarbons, PAHS, PCBs, heavy metals, and other hazardous pollutants in a variety of site environments.

• Mass Spectrometry Letters
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• v.2 no.2
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• pp.33-36
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• 2011

The misuse of anabolic androgenic steroids is of particular concern in sports and society. Thus, it is of great importance to discriminate endogenous steroids such as testosterone or testosterone prohormones from their chemically identical synthetic copies. In this study, gas chromatography-combustion/isotope ratio mass spectrometric (GC-C/IRMS) method has been developed and validated for discriminating the origin of anabolic androgenic steroids. The method involves the solid-phase extraction, enzymatic hydrolysis with ${\beta}$-glucuronidase, HPLC-fractionation for the cleanup and analysis by GC-C/IRMS. The difference(${\Delta}^{13}C$) of urinary ${\delta}^{13}C$ values between synthetic analogues and endogenous reference compounds (ERC) by GC-C/IRMS was used to elucidate the origin of steroids, and intra- and inter-day precision, specificity and isotope fractionation were evaluated. The present GC-C/IRMS method combined with HPLC cleanup was accurate and reproducible enough to be successfully applied to the test of urine sample from suspected anabolic steroid abusers.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.75.1-75.1
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• 2011

Coal gasification is considered as one of the most prospective technologies in energy field since it can be utilized for various products such as electricity, SNG (Synthetic Natural Gas or Substitute Natural Gas) and other chemical products. Among those products from coal gasification, SNG is emerging as a very lucrative product due to the rising prices of oil and natural gas, especially in Asian countries. The process of SNG production is very similar to the conventional IGCC in that the overall process is highly dependent on the type of gasifier and coal rank. However, there are some differences between SNG production and IGCC, which is that SNG plant requires higher oxygen purity from oxygen plant and more complex gas cleanup processes including water-gas shift reaction and methanation. Water-gas shift reaction is one of the main process in SNG plant because it is a starting point for the latter gas cleanup processes. For the methanation process, syngas is required to have a composition of $H_2$/CO = 3. This study reviewed various considerations for water-gas shift process in a conceptual design on an early stage like a feasibility study for a real project. The factors that affect the design parameters of water-gas shift reaction include the coal properties, the type of gasifier, the overall thermal efficiency of the plant and so on. Water-gas shift reaction is a relatively proven technology compared to the other processes in SNG plant so that it can reduce technological variability when designing a SNG project.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.66-74
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• 1992

A method for the multiresidual simultaneous analysis of 11 thiocarbamates was studied using HPLC. Thiocarbamate in Chinese cabbage was analyzed in the order of extraction, partition, and cleanup in their optimum condition. Acetone was chosen as an extracting solvent. As a partitioning solvent, the mixture of 50% methylene chloride and petroleum ether containing extremely small water content showed good recoveries of thiocarbamate from the water layer. Partition efficiency was affected by pH of the water layer; it remained almost constant under the acidic and neutral condition while decreasing under the basic condition. The comparison done in cleanup step showed that the column chromatographic method is superior to the treatment of coagulating reagent. As an absorbent, the mixture of charcoal, magnesia, and celite with the ratio of 1 : 2 : 4 gave better recoveries and also effectively removed chlorophyll. Over the total procedure, the average recoveries for thiocarbamates in Chinese cabbage were 91% at about 2 ppm fortification level within the relative standard deviation of 8%, and the minimum detection limit (MDL) was 2.2${\sim}$9.3 ng.

• Journal of Soil and Groundwater Environment
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• v.24 no.1
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• pp.17-23
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• 2019

Clean soil environment is of crucial importance to sustain lives of ecosystem and humans. With rapid industrialization, there has been a great increase of soil contamination by accidental releases of petroleum products. In general, soil remediation is an expensive and time-consuming process as compared to cleanup of water and air. Moreover, determining the source and responsible parties of soil pollution often turns into legal conflicts and that further delay the cleanup process of contaminated sites. In practice, total petroleum hydrocarbon (TPH) analysis has been employed to determine the petroleum species and to track down the responsible polluters. However, this approach often suffers from differentiating similar TPH species. In this study, we analyzed TPH chromatogram patterns of 24 domestic petroleum products in specific carbon ranges (${\sim}C_{10}$, $C_{10}-C_{12}$, $C_{12}-C_{36}$, and $C_{36}{\sim}$) and the fractional changes of THP ratio in the mixture products of gasoline, kerosene and diesel. The proposed TPH analysis method in this study could serve as a useful tool to better analyze the petroleum species in soils contaminated with complex oil mixtures, and ultimately be used to identify the polluters of soil.

• Journal of Environmental Impact Assessment
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• v.30 no.2
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• pp.61-74
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• 2021

In this study, we used marine environment assessment indices to evaluate impacts of various development projects on the marine environment. TheWaterQuality Index (WQI) was applied in the field of marine water quality and the Cleanup Index of Harmful Chemicals (CIHC), the Cleanup Index of Eutrophication (CIET), the Enrichment Factor(EF) were used in the field of marine sediment. In the field of marine benthic organisms, the Benthic Health Index (BHI) and the Benthic Pollution Index (BPI) were utilized. Each assessment index was calculated using the data observed in the development project, and its characteristics and usefulness were evaluated. The assessment method and criteria were clearly defined for WQI, CIHC, and BHI. Furthermore, through these indices, an integrated environment impact analysis was possible. Apart from the indices presented in this study, there are various indices that can be used for evaluating the marine environment. Therefore, it is important to utilize appropriate indices according to the characteristics of each project.