• Korean journal of applied entomology
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• v.55 no.1
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• pp.27-33
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• 2016

Chlorine dioxide has been used as a disinfectant against microbial pathogens. Recently, its insecticidal activity has been known against stored insect pests by oxidative stress. However, any molecular target of the oxidative stress induced by chlorine dioxide has been not known in insects. This study assessed an enzyme activity of acetylcholinesterase (AChE) as a molecular target of chlorine dioxide in the Indianmeal moth, Plodia interpunctella. AChE activities were varied among developmental stages of P. interpunctella. Injection of chlorine dioxide with lethality-causing doses significantly increased AChE activity of the fifth instar larvae of P. interpunctella. Exposure of the larvae to chlorine dioxide fumigant also significantly increased AChE activity. The fifth instar larvae of P. interpunctella exhibited a negative phototaxis. However, chlorine dioxide treatment significantly interrupted the innate behavior. These results suggest that AChE is one of molecular targets of oxidative stress due to chlorine dioxide in P. interpunctella.

• Environmental Analysis Health and Toxicology
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• v.19 no.2
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• pp.207-216
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• 2004

유기염소계 농약은 화학적으로 안정하고, 지용성이 크며 체내 대사에 대해 저항성을 가지고 있어서 인체 및 생태계의 생물체 중 축적성이 매우 크다. 또한 대부분 내분비계 장애물질로 분류되어 있어 관심의 대상이 되고 있다. 유기염소계 농약은 잔류성으로 인하여 사용이 금지되었음에도 불구하고 인체에서 검출되고 있으며 한국인의 지방조직을 분석한 결과 9종의 유기염소계 농약이 주로 축적되어 있음이 보고된 바 있다. 본 연구에서는 이들 유기염소계 농약의 에스트로겐 활성을 MCF-7 BUS cell을 이용한 E-screen assay competitive binding assay 및 pS$_2$ gene experession assay에 의해 조사하였다. o,p'-DDT,p, p'-DDT,p,p'-DDD,p,p'-DDE등 4종의 유기염소계 농약은 에스트로겐 수용체에 대한 ligand의존적인 작용기전에 의해 에스트로겐 활성을 가지며, $\alpha$-, $\beta$-, ${\gamma}$-, $\delta$-BHC, dieldrin등 5종의 유기염소계 농약은 lingand-비의존적 작용기전에 의해 에스트로겐 활성을 보였다. 또한 이들 유기염소계 농약을 혼합 투여하여 에스트로겐 활성을 관찰한 결과 DDT류의 경우에는 단독투여시 보다 그 대사체와 혼합 투여할 때 에스트로겐 활성에 상승적 효과가 나타났으며 o,p'-와 p,p'-DDT의 두 이성질체를 혼합 투여할 경우가 단독 투여시 보다 상승적 효과가 나타났다. 따라서 지방조직에서 검출되는 유기염소계농약은 상호작용에 의해 개별 물질이 나타내는 내분비계장애작용 보다 실제로는 강한 효과를 나타낼 것으로 추정되었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.344-349
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• 2001

The removal of chlorine from aqueous solutions on dried Chlorella vulgaris(DCV) and green tea powder(GTP) were investigated as a function of contact time, pH and initial chlorine concentration. Removal by DCV and GTP reached equilibrium after 3hrs and 0.5hr, respectively. Optimum removal pH values of DCV and GTP were determined as above 10. Both Langmuir and Freundlich adsorption models were suitable for describing the short-term removal of chlorine by DCV and GTP. According to Langmuir adsorption isotherms the maximum removal capacity of DCV (2.75mg $Cl_2/mg$) was nearly two times greater than those of GTP (1.53mg $Cl_2/mg$) and activated carbon (1.47mg $Cl_2/mg$). These results suggested that Chlorella vulgaris biomass might potentially be used as an alternative to traditional water treatment materials for removal of residual chlorine in drinking water or process waste-water.

• The monthly packaging world
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• s.350
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• pp.67-71
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• 2022

• Water for future
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• v.23 no.3
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• pp.363-371
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• 1990

Foundational experiments are conducted to examine the applicability of redox control in brak-point chlorination of ammonia on drinking water purification. Through the research, the behauial affects by ph and temperature to a chloromine forming reactions are evaluated. The possibility of redox control in breakpoint chlorination is recoguized by drawing up the titration curve in terms of redox potential and $C{\ell}_2$/N ratios.

• Journal of the Korean Electrochemical Society
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• v.15 no.4
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• pp.242-248
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• 2012

The measurement of residual chlorine as a disinfectant is very important to ensure the safety against the pathogenic microbes and to suppress injection. The portable free chlorine sensor was fabricated with a disposable strip format by a screen printing method. The strip sensors prepared with a carbon-Ag/AgCl(cathode-anode) combination exhibited less interfering responses towards combined chlorine species(especially $NHCl_2$) and oxygen than the sensors prepared with other metals(i.e., gold and platinum). Free chlorine was determined chronoamperometrically with carbon-based electrodes at an applied potential of -0.3 V(vs. Ag/AgCl). A channel was built on the strip-type electrode for easy sampling, and the resulting strip sensors were employed to determine the concentrations of residual free chlorine.

• Korean journal of applied entomology
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• v.54 no.3
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• pp.151-158
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• 2015

Chlorine dioxide ($ClO_2$) can be used as a fumigant to kill insects. However, some insects can exhibit an evasive behavior from chlorine dioxide. This evasive behavior decreases the efficiency of the insecticidal activity of chlorine dioxide. This study tested a hypothesis that heat treatment suppresses the evasive behavior and synergizes the control efficacy of chlorine dioxide. Chlorine dioxide fumigation killed the red flour beetle, Tribolium castaneum, under direct exposure condition to the chemical for 12 h with median lethal concentrations of 383.67 ppm (153.63 - 955.78 ppm: 95% confidence interval) for larvae and 397.75 ppm (354.46 - 446.13 ppm: 95% confidence interval) for adults. However, when they were treated with enough diet flour, they exhibited an evasive behavior by entering the diet, which significantly decreased the control efficacy of the fumigant. To clarify the evasive behavior, the choice test of the adults were performed in Y tube arena. The test adults significantly avoided the diet treated with chlorine dioxide, while the antennatectomized adults lost the avoidance behavior. Heat treatment using $46^{\circ}C$ for 6 h killed only 10% or less of T. castaneum. Interestingly, most adults were observed to come out of the diet under the heat treatment. Chlorine dioxide treatment even at 400 ppm for 6 h did not kill any T. castaneum. However, the combined treatment of chlorine dioxide with the heat treatment for 6 h resulted in 95% mortality. These results indicated that heat treatment suppressed the evasive behavior of T. castaneum and synergized the control efficacy of the chlorine dioxide fumigant.

• Nuclear Engineering and Technology
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• v.12 no.2
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• pp.99-105
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• 1980

The distribution of $^{55}$ Mn and $^{38}$ Cl recoil species following radiative neutron capture in permanganates, chlorates and perchlorates has been investigated by using ion-exchange chromatography method. The whole of the $^{55}$ Mn radioactivity in permanganates appeared in two valence states, the $^{38}$ Cl radioactivity in chlorates in two valence states and also the $^{38}$ Cl radioactivity in perchlorates in three valence states. Recoil energy was calculated. The internal conversion of $^{38}$ Cl isomer transition affects the retention value. The greater the radii of the cation, the higher is the probability of the recoil atom breaking through the secondary cage. In ammonium salt, the ammonium ion behaves as a reducing agent. Crystal structures with their greater free space have shown low retention.

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.451-463
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• 1992

A selective chlorination of titaniferrous magnetite in a fluidized bed reactor was investigated to find the optimum condition for selective removal of Fe component from low grade titaniferrours magnetite ore and to produce a rutile substitute from titaniferrous magnetite ore. The optimum chlorination condition was determined to be a temperaure of $950^{\circ}C$, 2hr of reaction time, reducting agent(petroleum coke) to titaniferrous magnetite weight ratio of 0.12, and $Cl_2$ gas velocity of 5cm/sec. Under the above mentioned condition, 99% of Fe in titaniferrous magnetite was removed and the reaction residue which became rutile substitute was identified as rutile by x-ray diffraction and was found to contain 70% $TiO_2$.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.490-490
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• 2021

상수도 관망은 대표적인 사회기반시설로 수원으로부터 수용가에게 수질적으로 안전한 물을 안정하게 공급하는 것을 목표로 한다. 초기의 상수도 관망의 최적 설계는 비용만을 고려함으로써 미래의 불확실한 상황에 대한 대처가 매우 취약하고, 사용자의 다양한 요구를 충족시키지 못하였다. 또한, 유량과 안정적인 수질 공급을 고려하는 설계는 몇몇 비선형적 요소를 포함하고 있으며, 특히 사용자의 수요 패턴에 따른 잔류 염소 농도가 설계 기준에 부합하지 못하는 문제가 되는 경우 사용자의 심미적, 심리적 불편을 초래할 수 있다. 이는, 수질의 안전성과 직결되는 문제이다. 따라서 본 연구에서는 상수도 관망의 설계에 대하여 수질과 수리학적 특성을 고려한 상수도 관망 다목적 최적 설계를 수행하였다. 상수도 관망은 수질적인 측면을 고려하기 위해 수원에서 수용가까지 용수를 공급하는 과정에서 병원성 미생물을 소독하기 위하여 염소를 주입한다. 또한, 유리 잔류 염소의 평상시 기준을 (1.0-4.0mg/L) 유지하도록 규정하였다 (수도법 시행규칙 제22조의2). 하지만 사용자의 사용패턴, 체류 시간에 따라 잔류염소량이 달라진다. 따라서, 본 연구에서는 상수도 관망의 설계 비용과 염소 주입량을 동시에 설계 인자로서 고려하기 위해 Multi-objective Harmony Search를 적용하고, 그 결과를 분석하였다. 이러한 상수도 관망의 수질 인자와 설계 비용을 고려한 최적 설계안은 경제적 측면 뿐만 아니라 사용자의 수질 측면의 안전성을 충족하는 방안을 제시할 수 있다.