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PCB류 노출에 따른 파밤나방 (Spodoptera exigua)의 세대간 발육억제 효과 평가
박상순,정철의,유건상,김용균 7개 국립대학교 환경연구 논문집 공동발행 위원회 2004 공업기술연구 Vol.4 No.-
Polychlorinated biphenyls (PCBs) are persistent, bioaccumulative, toxic and widely distributed environmental chemicals. A previous report indicates that exposure to PCBs causes substantial hazard for survival and development of beet armyworm, Spodoptera exigua, which is a non-target insect species in the environment. This study was focused to evaluate the effect of PCBs on persistent and bioaccumulative toxic action using the susceptible species. For this purpose, PCBs were treated to parent generation and the following progency development was evaluated. PCB-treated female adults showed significant decrease of fecundity (number of oviposition) in dose-dependent manner. The laid eggs differed in successfully hatched larvae, development to pupal stage was also affected by the PCB concentrations exposed during previous parent stage. A life table analysis suggests that the PCB exposure during previous generation can give substantial reduction in population growth of following generation. Thus, the PCB exposure during previous generation would have additive hazard effect on the action of PCBs to S. exigua in the following generation.
손춘옥,유건상,김태동 7개 국립대학교 환경연구 논문집 공동발행 위원회 2001 환경연구논문집 Vol.1 No.1
Although chlorine has been widely used as one of the disinfectants in the water treatment process, it is often unfavorable since it produces not only the toxic materials like THMs, but also has the strong resistance in some microorganisms including viruses. Recently, ozonation has been paid much attention as the new disinfectant technology because it is very effective in inactivating the pathogenic microorganisms including viruses. The present study was directed toward the efficiencies of the ozonation technology. To assess the effect of inactivation of viruses and E. coli., the poliovirus and E. coli. KCCM 11234 were used as the model microorganisms, and the efficiencies of inactivation with the concentration of ozone, the concentration of initial microorganisms, and the pH were examined. The results showed that, at the higher concentration of ozone, the inactivation efficiencies of virus and E. coli. were significantly higher. On the other side, under the circumstances of lower pH and concentration of virus and E. coli., the efficiencies of inactivation were more effective.
임우택,정용식,유건상,김종현,김영훈 7개 국립대학교 환경연구논문집 공동발행 위원회 2005 공업기술연구 Vol.5 No.-
Cr(VI) is a known toxic heavy metal which is found frequently in many industrial sites. Contaminates soil and ground water with Cr(VI) is a big enviromental concern due to the high toxicity. Permeable Reactive Barrier(PRB)is an innovative remedial technology intensively studied and developed recenty. The most popular PRB material is zero-valent iron which is environmentally favorable and cheap. Scrapped steels and precleaned scrapped steels were tested in this study for Cr(VI). Scrapped steels were precleaned wuth detergent, acetone, hexane.The precleaned scrapped steel showed relatively high reactivity for Cr(VI). The results indicate that the scrapped steel could be used as PRB material after proper pretreatments.
김태동,나미정,유건상 안동대학교 환경연구소 2001 환경연구 Vol.1 No.-
It is well known that biological treatments are not able to remove all organic compounds, especially if they are toxic and refractory in the environment, from the contaminated water. Thus, they accumulate in the effluent water, causing an increase in pollution of our natural environment. The present study is directed towards the removal of non-biodegradable organics like parathion and THMs using ozone that are noticeable recently in the third treatment of contaminated water. In order to evaluate performance of ozone treatment, such parameters as the concentration of ozone, reaction time, the concentration of organics of interest, and the change in pH were examined. At the same time, the removal efficiency of above-mentioned organics by hybrid O_(3)/activated carbon treatment was also investigated, comparing with O_(3) treatment alone. In conclusion, the removal efficiency of parathion and THMs by O_(3) treatment alone was approximately 70% and less than 10%, respectively. Whereas, O_(3)/activated carbon treatment represented higher efficiency, showing almost 100% and 95%. It proves that hybrid O_(3)/activated carbon treatment for the removal of organics that are resistant to the environment is superior to ozone treatment alone.
Destruction and Removal of PCBs in Waste Transformer Oil by a Chemical Dechlorination Process
Ryoo, Keon-Sang,Byun, Sang-Hyuk,Choi, Jong-Ha,Hong, Yong-Pyo,Ryu, Young-Tae,Song, Jae-Seol,Lee, Dong-Suk,Lee, Hwa-Sung Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.4
A practical and efficient disposal of PCBs (polychlorinated biphenyls) in waste transformer oil by a chemical dechlorination process has been reported. The transformer oil containing commercial PCB mixtures (Aroclor 1242, 1254 and 1260) was treated by the required amounts of PEG 600 (polyethylene glycol 600), potassium hydroxide (KOH) and aluminum (Al), along with different reaction temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. The relative efficiencies of PCB treatment process were assessed in terms of destruction and removal efficiency (DRE, %). Under the experimental conditions of PEG600/KOH/Al/100 oC/2hr, average DRE of PCBs was approximately 78%, showing completely removal of PCBs containing 7-9 chlorines on two rings of biphenyl which appear later than PCB no. 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to 150 oC and 240 min, average DRE of PCBs including the most toxic PCBs (PCB no. 77, 105, 118, 123 and 169) in PCB family reached 99.99% or better, with the exception of PCB no. 5 and 8 (2,3-diCB and 2,4'-diCB). In studying the reaction of PEG with PCBs, it confirmed that the process led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines. The process also permits complete recovery of treated transformer oil through simple segregating procedures.
Comparative Study on Adsorptive Characteristics of Diazinon in Water by Various Adsorbents
Ryoo, Keon Sang,Jung, Sun Young,Sim, Hun,Choi, Jong-Ha Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.9
The aim of the present study is to explore the possibility of utilizing fly ash and loess, as alternative to activated carbon, for the adsorption of diazinon in water. Batch adsorption experiment was performed to evaluate the influences of various factors like initial concentration, contact time and temperature on the adsorption of diazinon. The adsorption data shows that fly ash is not effective for the adsorption of diazinon. The equilibrium data for both activated carbon and loess were fitted well to the Freundlich isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher $R^2$ compared to the pseudo-first-order kinetic model. The thermodynamic parameters such as free energy (${\Delta}G$), the enthalpy (${\Delta}H$) and the entropy (${\Delta}S$) were calculated. Contrary to loess, the ${\Delta}G$ values of activated carbon were negative at the studied temperatures. It indicates that the adsorption of diazinon by activated carbon is a favorable and spontaneous process. The positive ${\Delta}H$ values of activated carbon and loess suggest that the diazinon adsorption process is endothermic in nature. In addition, the positive ${\Delta}S$ values show that increased randomness occurs at the solid/solution surface during the adsorption of diazinon.
Ryoo, Keon-Sang,Ko, Seong-Oon,Hong, Yong-Pyo,Choi, Jong-Ha,Kim, Yong-gyun,Lee, Won-Kyoung Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.5
The proposed head-space supercritical fluid extraction (SFE) methodology as an alternative to an existing conventional procedure was explored for the determination of organochlorine compounds in aqueous matrix. In this study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were utilized as target analytes. To enhance the recovery efficiency, the factors such as the $CO _2$ density, the extraction time, and the extraction mode were investigated. Furthermore, the analytical procedures and the results obtained were compared with those provided by the conventional method (the U.S. EPA method 8080). Under the optimized conditions, i.e., a combination of static with dynamic SFE mode at 2,000 psi and 40 ${^{\circ}C}$, the head-space SFE methodology gave equivalent or better to the conventional method in recovery efficiencies with clear advantages such as simple sample treatment and fast analysis time as well as reduced solvent and reagent consumption.