• Journal of Environmental Science International
• /
• v.11 no.6
• /
• pp.569-576
• /
• 2002

Anaerobic/aerobic reactor system was used to treat a synthetic wastewater with glucose as carbon sources(0.38~2.29 kg COD/m3.day) and Acid Red 14(1.05 "24.00 g Acid Red 141m3.day, color degree of 570 ~ 1710). COD removal efficiency by the anaerobic stage in operation period were above 90 % organic loading rate of 0.38 ~ 2.29 kg COD/m3.day(except, adaptation period) and the removal efficiency of the whole system were above 96 %. The decolorization of the Acid Red 14 was through the alteration of the dye structure(or cleavage of the Azo bond) during the anaerobic treatment. In the A/A system, the anaerobic stage played an essential role in removing both color and COD. In addition it also improves biodegradability of dye f3r further aerobic treatment. After operation, average MLSS concentration of anaerobic sludge reactor, anaerobic fixed-bed reactor and aerobic fixed-bed reactor were 17100mg/L, 20000mg/L, and 10000mg/L, respectively.

• Korean Journal of Environmental Agriculture
• /
• v.13 no.3
• /
• pp.373-385
• /
• 1994

Resistance to paraquat (1,1'-dimethyl-4,4'-bipyridilium ion) has developed in 12 species of 8 genera to which paraquat has been applied 6 to 10 times per year for 5 or more years. In recent years, tolerance to paraquat has been found in Rehmannia glutinosa (Gaertn.) Liboch. ex Fisch. & Mey. which has never been applied with any herbicides involving paraquat. In this review, we differentiate the terms, resistance and tolerance, on the basis of the paraquat-exposure history. Five hypotheses have been evaluated in several species as potential mechanisms of paraquat resistance and/or tolerance. In a species, the mode of action may be due to 1) reduced quantities of paraquat absorbed through the leaf surface, 2) detoxification of paraquat caused by the enhanced paraquat-metabolic activity, 3) rapid sequestration reducing level of paraquat at the site of action in chloroplast, 4) alteration of site of action in photosystem I resulting in interruption of electron transport to paraquat, and 5) rapid enzymatic detoxification of superoxide and other toxic forms of oxygen.

• Economic and Environmental Geology
• /
• v.21 no.4
• /
• pp.349-358
• /
• 1988

K-Ar ages were determined on gangue and wall rock alteration minerals from twenty metallic mineral deposits in the Gyeonggi Massif. Beryl deposits give the age of 185 Ma, whereas tungsten - molybdenum deposits reveal two different age groups such as 172~156 Ma and 91~86Ma. Lead - zinc deposits and gold - silver deposits yield the ages of 160 Ma and 71~197 Ma, respectively. Mineralization ages for each genetic type of deposits in the Gyeonggi Massif can be summarized as follows; pegmatite deposits, 185 Ma; skarn deposits, 156~160 Ma; hydrothermal deposits, 71~197 Ma. Present results together with data previously reported reveal that rare earths, tungsten-molybdenum, base and precious metal deposits in the Gyeonggi Massif were formed in Jurassic and Cretaceous time with a genetic relationship to the Daebo and Bulguksa felsic igneous activity.

• Journal of Environmental Science International
• /
• v.5 no.4
• /
• pp.495-511
• /
• 1996

The quantitative study of the groundwater contamination in a porous media is a difficult task. For complex problems, numerical solutions are the most effective means to study the movement of contaminants in the groundwater, The solute transport model used in this study has proved to be an efficient tool to model contaminant transport for complex problems. The model demonstrates its effectiveness in reproducing the coniamination by ihlorides of the groundwater at the landfill site due to leachath from the wastes. It describes the two dimentional solute transport and alteration of the water quality and forecasts the contamination for different management alternatives of the landfill. The model also indicates how the groundwater contamination can be contained within the lower site if a barrier is constructed downstream of the disposed wastes.

• Environmental Analysis Health and Toxicology
• /
• v.19 no.2
• /
• pp.119-134
• /
• 2004

Human exposure to highly nickel-polluted environments, such as those associated with nickel refining, electroplating, and welding, has the potential to produce a variety of pathologic effects. Among them are skin allergies, lung fibrosis, and cancer of the respiratory tract. The exact mechanisms of nickel-induced carcinogenesis are not known and have been the subject of numerous epidemiologic and experimental investigations. This review provides the evidence of the current state for the genotoxic and mutagenic activity of Ni (II) particularly at high doses. Such doses are best delivered into the cells by phagocytosis of sparingly soluble nickel-containing dust particles. Ni (II) genotoxicity may be aggravated through the generation of DNA-damaging reactive oxygen species (ROS) and the inhibition of DNA repair by this metal. The epigenetic effects of nickel includes alteration in gene expression resulting from DNA hypermethylation and histone hypoacetylation, as well as activation some signaling pathways and subsequent transcrziption factors.

• Environmental Analysis Health and Toxicology
• /
• v.7 no.3_4
• /
• pp.57-67
• /
• 1992

BPMC (2-Sec-butylphenyl N-methylcarbamate) was treated at the level of 100mg/kg/day in oral administration for 12th days in rat. It was investigated not only that the hematogram and the serological parameters, but also the content of cytochrome P-450, the activity of TBA, glucose-6-phosphatase, cholinesterase and carboxylesterase in rat. The results were as follows: The hematogram was not found any alteration but the value of AST, ALT, LDH and the content of glucose in serum were significantly increased compare with that of control group. The content of cytochrome P-450 in liver was increased significantly on the contrary cytochrome P-450 in kideny and NADPH-cytochrome c reductase in liver and Kidney were not significantly increased. After the final 12th day, the value of TBA and the activity of glucose-6-phosphatase appeared to the tendency of increasement in the liver. The activity of cholinesterase and carboxylesterase both in serum and liver were decreased. Especially the activity of cholinesterase was more significantly decreased. It was conclusion that the function of this insectivide should be due th the inhibition of cholinesterase activity.

• Environmental Analysis Health and Toxicology
• /
• v.8 no.1_2
• /
• pp.1-10
• /
• 1993

This study was done to determine the toxic effect of fthalide in rats which have oral administration at levels of 100 mg/kg/day for twelve days. It was examined the hematogram and serological parameters, and also the content of cytochrome P-450, the activity of NADPH-cytochrome c reductase, glucose-6-phosphatase, cholinesterase and carboxylesterase in liver. Any significant alteration of hematogram was not found but the value of AST, LDH and content of glucose in serum were statistically increased. The content of cytochrome P-450, the activty of NADPH-cytochrome c reductase were increased but glucose-6-phosphatase were slightly decreased compare with that of control group. The activity of cholinesterase was decreased slightly and on the contrary the activity of carboxylesterase was found to be the tendeny of increase in both of liver and serum.

• Environmental Analysis Health and Toxicology
• /
• v.18 no.1
• /
• pp.15-19
• /
• 2003

Metallothionein gene expression activity of cadmium was investigated in a human lung epithelial cell line. Cells, grown to near confluence, were exposed to 0∼10 ${\mu}$M Cd metal for 6 hours. Cadmium did not cause morphological alteration in lung epithelial cells that are characteristic of cell damages such as cell shrinkage, detachment of the cell from its neighbors, cytoplasmic and chromatic condensation. However, metallothionein genes of MT-1 and MT-2 were rapidly induced in the treated cell measured by RT-PCR. Regarding the induction pattern of motallothionein mRNA, MT-1 mRNA was induced in a dependent manner. MT-2 mRNA induction, which was measured using oligo primers based on cDNA of human reticulocytes, seemed to be slightly increased in low doses but decreased at high concentration used in the experiment.

• Journal of Environmental Health Sciences
• /
• v.14 no.1
• /
• pp.87-101
• /
• 1988

The effect of hepatic injury produced by CCL, was studied on rats receiving a low protein-high carbohydrate (7% casein), standard protein (20% casein) and a high protein diet (30% casein). The rats fed low protein diet are resistant to CCl$_4$ in its effects on the liver as judged by histology, serum enzymes(guanase, ALT) and the content of hepatic protein. On the other hand, the pretreatment of hydrocortisone before injection of CCl$_4$ to the rats fed a standard diet, slightly decreased both serum ALT and guanase activities. In the pretreatment of actinomycin D, the liver and serum guanase activities were significantly decreased. It indicates that the cause of increasing serum guanase is based on the alteration of membrane permeability and the result of accelerated enzyme synthesis in liver cells of CCl$_4$ intoxicated rats.

• Journal of Environmental Science International
• /
• v.9 no.3
• /
• pp.193-199
• /
• 2000

This study is carried out the analysis of the runoff characteristics for the design of the interior drainage systems by SWMM in urbanization basin. The basin analyzed in this study is Bumuh-chun basin which is located in Susung-gu of Taegu city. Huff method is used for rainfall distribution analysis. The optimal rainfall duration in Bumuh-chun basin is analyzed as about 90 minutes decided from comparison of arrival time and critical duration. Flood flow variation pattern is proposed through the comparison of the results of peak flow and peak time analyzed by SWMM about pre-urbanization and post-urbanization of Bumuh-chun basin. It is known that the variation of arrival time caused by the rapid increase of pavement rate in the upper area shows about 20∼25 minutes faster than pre- urbanization. Therefore, the management of surface water for design of water supply and drainage, and channel alteration has to considered the variation of geological factors according to urbanization.