This study focused on the evaluation of stability of mercury compounds in byproducts from industrial facilities. Stability testing was conducted using a 5-step sequential extraction procedure using six kinds of byproducts. The mercury compounds extracted were categorized as ion-exchangeable (F1), acid soluble (F2), organic matter-bound (F3), strong complex (F4), and residual (F5) mercury compounds. The amount of mercury in each step was calculated and compared with total mercury amount; a 51% to 92% recovery rate was estimated. Hg-extracted F1, F2, and F3 were easily released into environment. It is necessary to apply an appropriate method to handle byproducts that contain these portions of mercury. On the other hand, mercury in F4 and F5 fraction is relatively more stable. F4 fraction means strong complex and elemental mercury. Byproduct from metal production facility has a higher elemental mercury fraction. It was found that 89% and 65% of mercury were contained in F4 fractions from fly ash and sludge, respectively. The goal of this study is to investigate stability of Hg compounds in different byproducts to suggest appropriate treatment methods for each byproduct on its Hg compound characteristics.

This study provides an experimental result of thermal mercury reduction and condensation characteristics for inventing a mercury recovery technology from the waste sludge which contains high concentration of mercury. Thermal treatment was conducted in the temperature range of up to 900oC from 600oC with different residence time using a waste sludge from domestic industrial facility. Properties of powder material condensed after thermal treatment were analyzed to assess the effectiveness of thermal processing. Leaching characteristics of bottom ash and condensed powder material were analyzed by Korean Standard Leaching Test method (KSLT). Cold vapor atomic absorption spectroscopy (CVAAS) Hg analyzer was used for the analysis of mercury content in solid and liquid samples. We found that mercury contents was concentrated compared with waste sludge. However, the mercury concentration of leached solution from the condensed powder material was very low. The chemical characteristics of condensed powder material was estimated using experimental analysis and literature survey. In order to recover purified elemental mercury, the further researches of refining experiments would be required.

본 연구는 돌연변이원(mutagen)의 하나인 메틸수은(methylmercuric chloride, MMC)의 세포독성을 알아보기 위하여 배양 NIH3T3 섬유모세포를 재료로 메틸수은의 독성을 산화적 손상측 면에서 조사하였으며, 또한 메틸수은의 세포독성에 대한 꿀풀 (Prunella vulgaris L. var lilacina Nakai) 추출물의 영향을 세포 생존율을 비롯한 SOD-유사 활성(SOD-like activity) 및 지질과산 화(lipid peroxidation, LP) 저해능과 같은 항산화 측면에서 분석 하였다. 본 실험에서 배양 NIH3T3 섬유모세포에 15∼35uM의 메 틸수은을 처리한 결과 처리농도에 비례하여 세포생존율이 대조군 에 비하여 유의하게 감소하였으며, 또한 XTT50값이 34.2uM에서 나타나 고독성(highly-toxic)인 것으로 나타났다. 한편, 항산화제 인 vitamin E는 메틸수은에 의하여 감소된 세포생존율을 유의하게 증가시켰다. 메틸수은의 세포독성에 대한 꿀풀 추출물의 영향에 있 어서, 꿀풀 추출물은 메틸수은에 의하여 감소된 세포생존율을 유의 하게 증가시킴으로서 메틸수은의 세포독성을 방어하였으며, 동시 에, SOD-유사 활성 및 지질과산화 저해능을 보임으로서 항산화능 을 나타냈다. 위의 결과로 부터 메틸수은의 세포독성에 산화적 손 상이 관여하고 있으며, 동시에 꿀풀 추출물은 항산화능에 의하여 메틸수은의 산화적 손상을 효과적으로 방어하였다. 따라서, 꿀풀 추출물과 같은 천연물질은 메틸수은과 같이 산화적 손상과 관련된 중금속의 독성을 방어 내지는 치료하는데 있어 항산화 소재로서의 유효한 기능이 있음을 제시하고 있다.

In a mercury leaching test for waste using the Korean Standard Method (ES 06404.1), the pre-treatment process of an eluate is very complicated with a high possibility of contamination and low mercury recovery rate. It is also difficult to analyze multiple samples in a short time and the process generates experimental wastes. Accordingly, a direct mercury analyzer (DMA) applying thermal decomposition gold-amalgamation analysis has been recently used. The method shows a relatively high recovery rate for solid samples without complicated pre-treatment and it can be applied to both liquid and solid samples as the EPA method 7473 does. In order to use the auto-sampler in DMA for analyzing many elution samples from waste, this study checked recovery rates depending on acid solutions and additives during continuous analysis. The result showed a significant drop in recovery and precision except for an L-cysteine added sample. Considering commonly used acid-treatment of wastes, three types of acid solutions (nitrate, hydrochloric acid and sulfate) were chosen for analysis, and precision and accuracy were relatively high in nitric acid solution. It has been determined that accuracy and precision improved when 0.01% L-cysteine was added as an additive and this reduced the impact of continuous measurement. Therefore, during analysis of liquid samples or eluted samples using DMA continuously, introducing suitable additives is necessary depending on pre-treatment method in order to improve accuracy and precision in the analysis of mercury.

Mercury distribution and hazardous characteristics of major components from SCFLs (Spent compact fluorescent lamps)for 3 lamp manufactures (A, B, C) are estimated by the analysis of mercury concentration and leaching tests such asKorean Extraction Test (KET) and Toxicity Characteristic Leaching Procedure (TCLP). SCFLs can be separated into glasstube, phosphor powder, metals, ballast, plastics, and binder. Through the analysis of mercury in major components forSCFL, mercury concentration in phosphor powder is much higher than that in other components regardless manufacturesof lamp. Also, mercury concentration in phosphor powder is dependent of the manufactures of lamp. From the leachingtests, all components except phosphor powder from 3 lamp manufactures are verified to be non-hazardous waste becauseall leaching concentrations are below the regulatory level. However, the leaching concentration of mercury in phosphorpowder of SCFLs is higher than the regulatory level in both KET and TCLP regardless manufactures of lamp. Hence,phosphor powder should be managed as a hazardous waste and should be separately managed to control mercury.

This study provides a result of thermal mercury reduction for inventing a mercury recovery technology from the sludgewhich contains high concentration of mercury. Physical, chemical and thermal properties of the sludge were analyzed andmercury degradation at elevated temperatures was investigated to find out the optimum temperature range for thermalrecovery of mercury from the sludge generated from an industrial facility, which contained high concentration of mercury.The study was carried out in the temperature range of up to 650oC from 200oC, and 500~710µm particle size of wastesludge samples were selected from such industries. As primary thermal tests the sludge was heated up to observe weightdegradation at a continuous weight measurable thermogravimetric analyzer and a muffle furnace and the degradationcurves from both devices were found to be well matched. Mercury conversion to gaseous form was investigated fromthe analyzed data of mercury concentrations sampled every 25oC from a muffle furnace. Cold vapor atomic absorptionspectroscopy (CVAAS) Hg analyzer was used for the analysis of mercury content in solid and liquid samples. Most ofmercury was degraded and released as gas phase at the temperature range from 300oC to 550oC, which could be theoptimum temperature of mercury recovery by thermal method for the sludge containing high concentration of mercury.Based on these thermal mercury reduction studies, degradation kinetics study of mercury was conducted to provide thereaction kinetics data for further reactor design to recover mercury using a thermal method.

Ocean dumping of sewage sludge has been prohibited since 2012. Therefore, various methods to recycle sewage sludgeare studied And the adsorption is used to remove mercury released to the atmosphere. Chlorine and Iodine impregnatedadsorbent is used to remove mercury in the flue gas. In our study, we studied the method to recycle sewage sludge andbrewers grain as an adsorbent to remove mercury. Thermal treating time and temperature, and mixing ratio of sewage sludgeand brewers grain are discussed for the preparation of adsorbent. According to the results, the optimal condition oftemperature, time and mixing ratio was 400oC, 45min and 7:3 of sewage sludge/brewers grain, respectively. Theimpregnation of I is needed to keep the concentration of KI above 7%. I and Cl are dispersed uniformly in prepared adsorbent.

Compact fluorescent lamps are strongly encouraged to manage separately in Korea because Compact fluorescent lamps contain mercury. Compact fluorescent lamps have managed as household waste in Korea, however, even though Compact fluorescent lamps contains hazardous material such as mercury. The aim of management of Compact fluorescent lamps separately is to reduce the release of mercury from Compact fluorescent lamp lamps into the environment and to reuse of the glass, metals and other components of Compact fluorescent lamps. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In the crushing process, CFL(compact fluorescent lamp) is separated into glass, plastic, ballast, phosphor powder and vapor. Using the crushing technique, concentration of mercury vapor emission from CFL is evaluated. Through the experiments, the efficiency of the crushing and separation for the unit is estimated by measuring the volume of CFL. In this study, the concentration of mercury is analyzed by MVI(Mercury Vapor Indicator) method for vapor in CFL. From the results of mercury distribution for 3 companies, the concentration of mercury in compact fluorescent lamp is less than that in the other type lamps. And phosphor powder has greater than 99% of total mercury amount in CFL and the mercury concentration in phosphor powder is measured between 1,008ppm and 1,349ppm. The mercury concentration in phosphor powder can be changed by the type of company and period of usage. KET and TCLP are carried out for phosphor powder, glass, plastic, ballast and base cap to estimate the hazardous characteristic. From the results of KET and TCLP test for CFL, phosphor powder from CFL should be controlled separately by stabilization or other methods to reuse as a renewable material because the phosphor powder is determined as a hazardous waste. From the results of characteristics of CFL, the carbonization system of CFL should be carried out in the temperature of less than 350℃. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of Compact fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In Korea, demonstration for recycling of U type lamps had once begun in the area of Seoul Metropolitan, 2000. In 2004, U type lamps was included as an item in EPR(Extended Producer Responsibility) system. According to Korea Lighting Recycling Association, approximately 38 million Compact fluorescent lamps were recycled in Korea, 2011 because 3 recycling facilities for Compact fluorescent lamps are operated in Korea. Recycling rate of Compact fluorescent lamps in Korea is about 31.0% but about 70% of Compact fluorescent lamps may not manage properly. Hence, discarded lamps release approximately 2 to 3 tons of mercury per year into the environment[6]. In USA, Compact fluorescent lamps has controlled by Universal Waste Rule and merchandises containing mercury prohibited to produce. Also, MEBA(Mercury Export Ban Act) is activated in USA from 2013. According to Association of Lighting and Mercury Recycler, member companies accomplish about 85% of the lamp recycling done each year. In Germany, best available technology (BAT) system for recycling of Compact fluorescent lamps is established and about 20 companies are involved in recycling of Compact fluorescent lamps. In 1994, approximately 70-80% of total Compact fluorescent lamps are recycled in 1994 and Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 1996. In Sweden, MRT System, which was developed by Lumalampan, separated mercury from Compact fluorescent lamps by distillation operation, 1979. Reverse route collection system is active to improve the collection of Compact fluorescent lamps. Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 2001. In Austria, about 40 companies are involved in recycling of Compact fluorescent lamps to recycle glass and ferrous metals. And wastes containing mercury are treated in landfill site by using special container [7,8]. In this study, Compact fluorescent lamps is cut by a end-cutting unit with a cam crusher and base-cap is separated from glass part. In the end-cutting unit, a vacuum system is operating to collect mercury vapor to prevent leaking from the end-cutting unit. First of all, characteristics and major composition of Compact fluorescent lamps are estimated. Through the experiments, it is measured mercury concentration in the parts of Compact fluorescent lamps such as glass tube, phosphor powder, and base cap after separation in the end-cutting unit. Also, it is evaluated mercury emission from Compact fluorescent lamps by measuring the concentration of effluent gas in the end-cutting unit with changing flow rate. Finally, Korea Extraction Method (KET) and TCLP(Toxicity Characteristic Leaching Procedure) test are applied to phosphor powder to verify that phosphor powder is a hazardous waste [9].

대부분의 국가에서는 수은이 함유된 제품이나 각종 산업공정에서 사용되는 수은은 단계적으로 제거해 나가고 있으며 특히 선진국에서는 수은의 독성, 생물농축 및 환경에의 유해성으로 인하여 수은이 함유된 제품이나 수은을 사용하는 산업공정을 대체하기 위하여 노력하고 있다. 그러나 여전히 수은이나 수은을 함유한 제품은 특정 공정이나 오래된 공정에서 사용되고 있으며 지금까지는 수은 함유 폐기물을 재활용하거나 처리하는 것은 폐기물 관리 분야에서 주요 관심사가 아니었다. 수은의 국제적 규약 및 관리 동향이 1차적으로는 대기배출 수은에 치중되어 왔으나 배출원에서의 제어 및 회수된 수은이 부산물과 폐수 중에 남게 되면서 선진국에서는 이를 안정화하며 회수 저장하는 문제와 수은의 매체 간 통합적인 관리로의 접근이 시도되고 있어 우리나라도 이에 대한 방안 마련이 필요한 상황이다. 2013년 2월 제5차 INC (Intergovernmental Nagotiating Committee)의 결정에 따라 국제수은협약의 주요 조항으로 수은함유 폐기물의 관리 강화 및 환경친화적 수은 저장 능력 증대가 포함됨에 따라 향후 국제적인 규제 조치 시행이 예상되고 있다. EU는 수은화합물 수출 금지 및 수은 저장 의무화 규제 시행 (‘11.3.15 발효, Regulation (EC) No 1102/2008, 22 Oct. 2008)하여 원자재 수은을 폐기물로 규정하고, 클로랄-알칼리 분야, 비철금속 채광 및 제련, 천연가스 정제 및 금채광시설의 수은 회수 및 저장을 의무화하였다. 미국 또한 금속 수은 및 특정 수은화합물의 수출금지 법안을 발표하였으며, 미국 DNSC (Defense National Stockpile Center)는 1970년대 부터 4,400 톤 이상의 원자재용 수은을 보관해왔으며, 이를 영구저장시설로의 이전 사업이 추진 중이다. US EPA에서는 LDR 기준을 통해 수은 함유 폐기물 중 260 ppm 이상의 폐기물의 경우 일반 매립지로 갈 수 없으며 특수 설계 매립지를 통해 매립을 하거나 수은 저감 처리방법을 통해 수은 함유 농도 저감을 해야 한다고 규정하였다. 따라서 본 연구에서는 실험실 규모의 반응기를 구축하여 국내 고수은함유 폐기물을 대상으로 열적처리를 통한 수은 감량 특성을 연구하였다. 이는 TG 분석 결과를 바탕으로 온도범위를 700 ~ 800 ℃로 설정하여 각 온도조건에서 체류시간에 따를 수은 감량 특성을 평가하였으며, 각 조건 별로 수은 증기를 냉각시켜 수은 회수율을 평가하였다.

The response of the freshwater microalga Chlorella vulgaris to mercuric ion (Hg2+) stress was examined using chlorophyll a fluorescence image analysis and O-J-I-P analysis as a way to monitor the toxic effects of mercury on water ecosystems. The levels of photosynthetic pigments, such as chlorophyll a and b and carotenoids, decreased with increasing Hg2+ concentration. The maximum photochemical efficiency of photosystem Ⅱ(Fv/Fm) changed remarkably with increasing Hg2+ concentration and treatment time. In particular, above 200 μM Hg2+, considerable mercury toxicity was seen within 2 h. The chlorophyll a fluorescence transient O-J-I-P was also remarkably affected by Hg2+; the fluorescence emission decreased considerably in steps J, I, and P with an increase in Hg2+ concentration when treated for 4 h. Subsequently, the JIP-test parameters (Fm, Fv/Fo, RC/CS, TRo/CS, ETo/CS, ΦPO, ΨO and ΦEO) decreased with increasing Hg2+ concentration, while N, Sm, ABS/RC, DIo/RC and DIo/CS increased. Therefore, a useful biomarker for investigating mercury stress in water ecosystems, and the parameters Fm, ΦPO, ΨO, and RC/CS can be used to monitor the environmental stress in water ecosystems quantitatively.

Linear type SFL (spent fluorescent lamp) can be classified by 3-banded lamp and general lamp. Linear type SFL is separated by the end-cutting technique to examine the distribution of mercury in the major components such as base cap, glass part and phosphor powder. In this study, the concentration of mercury is analyzed by DMA (Direct Mercury Analysis) method for major components in linear type SFL. From the results of mercury distribution for 3 companies, the concentration of mercury in 3-banded lamp is less than that in general lamp. And phosphor powder has greater than 80% of total mercury amount in SFL and the mercury concentration in phosphor powder is measured between 1,250 ppm and 1,740 ppm. The mercury concentration in phosphor powder can be changed by the type of lamp, company, and period of usage. KET and TCLP are carried out for phosphor powder, glass, and base cap to estimate the hazardous characteristic. From the results of KET and TCLP test for general lamp and 3-banded lamp, phosphor powder from general lamp and 3-banded lamp should be controlled separately by stabilization or other methods to reuse as a renewable material because the phosphor powder is determined as a hazardous waste.

The objectives of this study were to measure ambient total gaseous mercury (TGM) concentrations in Seoul, to analyze the characteristics of TGM concentration, and to identify of possible source areas for TGM using back-trajectory based hybrid receptor models like PSCF (Potential Source Contribution Function) and RTWC (Residence Time Weighted Concentration). Ambient TGM concentrations were measured at the roof of Graduate School of Public Health building in Seoul for a period of January to October 2004. Average TGM concentration was 3.43±1.17 ng/㎥. TGM had no notable pattern according to season and meteorological phenomena such as rainfall, Asian dust, relative humidity and so on. Hybrid receptor models incorporating backward trajectories including potential source contribution function (PSCF) and residence time weighted concentration (RTWC) were performed to identify source areas of TGM. Before hybrid receptor models were applied for TGM, we analysed sensitivities of starting height for HYSPLIT model and critical value for PSCF. According to result of sensitivity analysis, trajectories were calculated an arrival height of 1000 m was used at the receptor location and PSCF was applied using average concentration as criterion value for TGM. Using PSCF and RTWC, central and eastern Chinese industrial areas and the west coast of Korea were determined as important source areas. Statistical analysis between TGM and GEIA grided emission bolsters the evidence that these models could be effective tools to identify possible source area and source contribution.

Removal of elemental mercury (Hg0) with the reactive species produced from dielectric barrier discharge (DBD) was studied. We investigated the effect of operating parameters such as the applied voltage, residence time, initial concentration and co-existence of other pollutants. The removal of Hg0 was significantly promoted by an increase in the applied voltage of the DBD reactor system. It is important to note that at the same input power, the removal efficiency of Hg0 was much higher than that of NO gas. These results imply that if the DBD system is used as a NOx treatment facility, it is capable of removing Hg0 simultaneously with NOx.

This experiment was carried out to investigate the effects of mercury and arsenic on the growth of Arabidopsis thaliana when treated with three different concentrations. When treated with mercury, there was no noticeable difference in the growth of the plant between the group treated with 0.5 ㎍/L (the effluent standard established by the Ministry of Environment) and the group treated with the concentration 100 times higher. They both showed almost the same level of growth as that of the normal plant. But the group of the concentration 10 times higher showed significantly 10% more growth compared with the normal plant. When treated with arsenic, the three different groups all showed a little more growth compared with the normal plant. Interestingly, the group of the concentration 10 times higher than the official standard concentration of arsenic (50 ㎍/L) showed the highest level of growth, significantly 20% more than the normal plant. These results show that some amount of mercury and arsenic in the soil do not have much effect on the growth of Arabidopsis thaliana, and that optimum concentrations of mercury and arsenic can even stimulate the growth of the plant.