• Applied Biological Chemistry
• /
• v.8
• /
• pp.101-111
• /
• 1967

Daily doses of phenylmercuric acetate arranged in $30{\gamma}\;(group\;I)$, 3{\gamma}\;(group\;II)$ and $0.3{\gamma}\;(group\;III)$ were administered respectively to rabbits for 90 days. The chief histopathological changes in the organs and the analytical data on mercury residues in the excretion and liver were as follows. 1. Kidney: In group I, severe degrees of vacuolization and cloudy swelling were occurred in the epithelial cells of proximal convoluted tubules and severe cloudy swelling and coagulative necrosis were observed in the proximal straight tubules. There were many hyaline casts in the collecting tubules. In group II, moderate degrees of vacuolization and cloudy swelling were observed in the epithelial cells of proximal convoluted tubules and moderate cloudy swelling and coagulative necrosis were encountered in the proximal straight tubules. A little numbers of hyaline casts were located in the lumen of collecting tubules. In group III, slight degree of cloudy swelling were observed in the epithelial cells of proximal convoluted and straight tubules. 2. Liver: In group I, cloudy swelling, fatty changes and coagulative necrosis were observed in the central zone of hepatic lobules. Dissociation of hepatic cell cords was encountered. Hyperplsia of hepatic cells were remarkable in group II. No Pathological changes were observed in group III. 3. Spleen: Deposition of hemosiderin pigment was prominant in group I and small amount of the pigment was observed in group II. There were no pathological changes in group III. 4. Adrenal, colon and heart: No pathological changes were detected in all 3 groups. 5. In an average about 76.5% of mercury was excreted from group I, 85.4% from group II and 79.8% from group III. 6. Mercury content in the liver was 0.0348 g in group I, 0.00378 g and 0.00066 g in group II and group III respectively. 7. In general, as to increased mercury doses the concentration of mercury accumulation in the liver became higher, how·ever, the accumulation quantity against a total amount of mercury doses showed an adverse trend. In other word, the quantity of mercury accumulation was not increased proportionately by higher dose of mercury.

• Clean Technology
• /
• v.4 no.1
• /
• pp.35-44
• /
• 1998

Photodecomposition behaviors of volatile organic compounds (VOCs ; benzene, toluene, ethylbenzene and xylenes) over UV irradiation and UV irradiation with $TiO_2$ powder catalyst were studied and the extent of degradation were also investigated under various reaction conditions. The reactions were conducted in a quartz annular reactor equipped with a medium pressure mercury lamp. As a result, the extents of degradation were 92% for toluene and ethylbenzene, 83% for benzene, and 82% for xylenes under UV irradiation. And they were 92% for toluene, 82% for xylene and ethylbenzene, and 53% for benzene under UV irradiation with $TiO_2$ powder. Analyses of reacted samples by FID-gas chromatograph with Purge & Trap concentrator and GC-MS indicated that the aromatics formed many intermediates.

• Journal of Environmental Health Sciences
• /
• v.19 no.1
• /
• pp.24-29
• /
• 1993

I. 서론 : 식생활은 인간의 가장 원초적인 욕구이며 생존을 위한 기본조건입니다. 그러므로 식생활의 기본이 되는 식품은 사람에게 가식성, 영양성, 안전성을 충족시켜야 하며 여기에 생산자의 입장에서는 높은 생산성이 요구되고 있습니다. 이러한 식품의 구비조건은 과거 자급자족의 농경시대에는 생산자가 바로 소비자로서 커다란 문제를 제기하지 않았으나 도시화, 산업화된 현대사회에서는 생산자와 소비자가 다르며 식품은 상품으로서 판매되므로 소비자는 고품질의 안전한 식품을 요구하고 생산자는 수익성이 높은 고생산성의 식품을 상품으로서 생산하기에 이르렀습니다. 축산식품이 상품으로 생산되면서 생산자들은 더 높은 생산성을 요구하게 되었고 이러한 요구에 따라 축산분야에서는 가축 품종의 육종 개량과 함께 생산성을 저해하는 각종 질병의 예방과 치료약제 및 성장촉진과 사료효율을 개산할 수 있는 물질들을 사료첨가제로 개발하여 사용하게 되었습니다. 그러나 이러나 의도적으로 사용한 물질들은 대부분 항생제물질이나 화학적 합성품들로서 가축자체는 물론 생산물에 잔류되어 그 축산물을 이용하는 사람에게 유해작용의 우려를 갖게 하였습니다(의도적 오염). 또한 농작물의 생산성을 높이기 위하여 사용되는 농약들은 경우에 따라서는 샤료곡물에 잔류되어 사료를 통한 오염원ㅇ니이 될 수도 있고 목초지에 산포한 잔류성 농약이 목초를 오염시켜 뜻하지 않게 가축과 축산물을 오염시킬 수도 있습니다. 축산분야에서 잘 알려진 아플라톡신 같은 곰팡이 독소류는 오염된 사료원료에 의하여 가축에 피해를 일으킬 수 있으며 또 우유나 축산물을 통하여 사람에 피해를 줄 수 있습니다. 과학기술의 발달은 많은 공해요인들을 유발시켰으며 산업체에서 요구하는 고순도의 중금속류(수은, 납, 카드뮴 등)는 각종의 과학기계를 제작하는데 필수소재로써 우리의 생활을 윤택하게 하였지만 그 폐기물들은 우리의 생활주변을 오염시켜 그 환경에서 자라는 식물과 동물을 오염시키고 사람의 생활환경도 위태롭게 하고 있습니다.

• Korean Journal of Mineralogy and Petrology
• /
• v.33 no.4
• /
• pp.377-389
• /
• 2020

In this study, pollution characteristics were investigated for the Andong Dam sediments in the Nakdong River. Sediment samples were collected from the middle, left, and right points of the lake up to 40km upstream of the Andong Dam at intervals of about 5km by stratification and turnover period. In the case of nutrients and total organics such as loss of ignition, total nitrogen, and phosphorus, the degree of contamination is low, but heavy metals of arsenic and cadmium is very high. The contamination level of sediments in the dam area is higher than that of the branch of river and the control group, and concentration of chromium, copper, and lead are higher in the stratification period, and that of zinc is higher in turnover period. Arsenic, cadmium, manganese, and zinc showed contamination variation between upstream and downstream but chromium, copper, mercury, iron and lead didn't show the variation.

• Journal of the Korean Chemical Society
• /
• v.35 no.2
• /
• pp.158-164
• /
• 1991

The reduction mechanism at a mercury electrode of o-cresolphthalexon(OCP) in strongly alkaline supporting electrolytes has been investigated by several electrochemical techniques. The radical formed after first one electron reduction uptake, dimerizes. The result of cyclic voltammetric investigation demonstrated the reversible nature of the electron transfer and standard rate constant was $3.27{\times}10^{-2}$ cm/sec. The apparent irreversible behavior of the second wave is a result of the existence of a fast protonation following the second electron transfer. At low concentration of OCP(< $1{\times}10^{-4}$M), cathodic current were remarkably adsorptive properties. Prolonged electrolysis was carried out at controlled potential of -1.85V, original violet color of the solution becames progressively weaker, and then colorless solution. The final product of an exhaustive electrolysis is electro-inactive. The appearence of four steps may be explained by the fact that the reduction of OCP elucidated ECEC mechanism.

• Membrane Journal
• /
• v.31 no.4
• /
• pp.241-252
• /
• 2021

Rapid industrialization with growing population leads to environmental water pollution. Demand in generation of clean water from waste water is ever increasing by scarcity of rain water due to change in weather pattern. Colorimetric detection of heavy metal present in clean water is very simple and effective technique. In this review membrane based colorimetric detection of mercury (II) ions are discussed in details. Membrane such as cellulose, polycaprolactone, chitosan, polysulfone etc., are used as support for metal ion detection. Nanofiber based materials have wide range of applications in energy, environment and biomedical research. Membranes made up of nanofiber consist up plenty of functional groups available in the polymer along with large surface area and high porosity. As a result, it is easy for surface modification and grafting of ligand on the fiber surface enhanced nanoparticles attachment.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.19 no.1
• /
• pp.128-138
• /
• 2015

Carbonation is one of the most critical deterioration phenomena to concrete structures exposed to high $CO_2$ concentration, sheltered from rain. Lots of researches have been performed on evaluation of carbonation depth and changes in hydrate compositions, however carbonation modeling is limitedly carried out due to complicated carbonic reaction and diffusion coefficient. This study presents a simplified carbonation model considering diffusion coefficient, solubility of $Ca(OH)_2$, porosity reduction, and carbonic reaction rate for low concentration. For verification, accelerated carbonation test with varying temperature and MIP (Mercury Intrusion Porosimetry) test are carried out, and carbonation depths are compared with those from the previous and the proposed model. Field data with low $CO_2$ concentration is compared with those from the proposed model. The proposed model shows very reasonable results like carbonation depth and consuming $Ca(OH)_2$ through reduced diffusion coefficient and porosity compared with the previous model.

• Journal of the Korea Concrete Institute
• /
• v.21 no.5
• /
• pp.639-647
• /
• 2009

In order to evaluate the durability of reinforced concrete structures under chloride attack from sea water and frost damage, it is important to analyze both the microstructural characteristics of concrete and its diffusion resistance of concrete against chloride ingress. In this study, a relation between micro-pore structures of concrete obtained by the Mercury Intrusion Porosimetry and accelerated chloride diffusivity as well as long term chloride diffusivity were studied for ground granulated blast furnace slag(GGBS) concrete. Different water-cement ratio of 40, 45, 50% and different unit cement concrete of 300, 350, 400 or 450 kg/$m^3$ of the GGBS concrete along with OPC concrete were used and freeze and thawing, and the change in diffusivity and microstructure were observed for both GGBS concrete and damaged GGBS concrete due to rapid freezing and thawing.

• Journal of Korean Society on Water Environment
• /
• v.20 no.3
• /
• pp.265-268
• /
• 2004

Larva of Carassius auratus and Pungtungia herzi were exposed to mercury ($HgCl_2$), lead ($PbCl_2$) and copper ($CuSO_4$) to determine acute toxicity. The toxicity tests were conducted triplicate and the $LC_{50}$ values (24, 48, 72 and 96 hours) were determined for two species. Data obtained from the toxicity tests were evaluated using the probit analysis. Although sensitivities of two species to mercury were relatively similar, C. auratus was more susceptible than P. herzi to the exposure of lead but P. herzi was more sensitive than C. auratus on copper. The sensitivity on three metals tested may be ranked in the following order from highest to lowest toxicity on larval stage of these fish: mercury > copper > lead. It is suggested that acute toxic test at the larval stage of C. auratus and P. herzi, indigenous species in Asia area, is an important part of the ecotoxicological assessment of some heavy metals.

• Journal of the Korean Chemical Society
• /
• v.24 no.1
• /
• pp.34-43
• /
• 1980

The reaction of thianthrene cation radical perchlorate with thioxanthene in acetonitrile gave thianthrene and dark reddish thioxanthylium ion instead of thioxanthene cation radical. Addition of aromatic nucleophiles such as anisole, aniline, N,N-diethylaniline, catechol, ethylbenzene, to the above mixture yielded the corresponding thioxanthenes with substituent at 9 position. Reactions with dibenzo-18-crown-6-ether, diphenylmercury, and triphenylphosphine gave similar products. However, reactions with aromatics with electron-withdrawing group were either too slow or inert to such a reaction.