• Journal of Animal Environmental Science
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• v.18 no.sup
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• pp.1-6
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• 2012

This study was conducted to verify the effect of chlorine dioxide ($ClO_2$) on odor reduction at a commercial swine facility consisting of a compost ficility. Compost facility in $NH_3$ concentration was around 550 ppm and less than 78 ppm before and after the $ClO_2$ spraying, respectively, which was over 86% reduction. There was no H2S detection. $NH_3$ concentration was around 420 ppm and less than 35 ppm before and after the $ClO_2$ spraying, respectively, which was over 83% reduction. $H_2S$ concentration was around 210 ppb and less than 32 ppb before and after the $ClO_2$ spraying, respectively, which was over 85% reduction. Hence, $ClO_2$ spraying at windowless barns was compost facility decreased malodor such as $NH_3$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.955-959
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• 2006

Effects of chlorine dioxide ($ClO_2$) on weight loss, polyphenol oxidase activity, and microbial change of fresh mushrooms (Agricus bisporus Sing) were investigated. Mushrooms were treated with 5, 10, and 50 ppm of $ClO_2$ solution. Mushrooms were stored at room temperature and $4^{\circ}C$. Weight loss for $ClO_2$ treated mushrooms was smaller than that of the control group. Polyphenol oxidase activity of the $ClO_2-treated$ samples stored at room temperature increased until day 2 of storage and then decreased, and the activity of the samples stored bacteria, yeast and mold counts than the control during storage. Aerobic bacterial counts for 50 ppm of $ClO_2$ treatment at $4^{\circ}C$ increased from $1.62{\times}10^2\;CFU/g\;to\;1.66{\times}10^7\;CFU/g$ at day 10 of storage, while control groups were from $1.00{\times}10^3\;CFU/g\;to\;3.72{\times}10^8\;CFU/g$. These results indicate that $ClO_2$ treatment could be useful in improving the quality and microbial safety of mushrooms.

• Resources Recycling
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• v.29 no.6
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• pp.48-56
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• 2020

In this study, raw mix was mixed with CaCl2 for analyzing characteristics of clinker added chlorine and chlorine was added by 2,000ppm at high concentration condition. The raw mix added chlorine was burned at 1250℃~1350℃ and maintained during 10minutes at each maximum temperature. Clinker target modulus was LSF 92, SM 2.5 and IM 1.6 in this study. The burnability of clinker added chlorine was identified by free-CaO content. Free-CaO content decreased as chlorine content increased and free-CaO content of 1350℃-2000ppm clinker decreased by 1.5%. Optical microscope and XRD Analyses were used for identify mineral properties of clinker added chlorine. The mineral of clinker could not be observed at 1250℃ and the size of alite grew larger as chlorine content increased at 1350℃. It showed a good crystallizability as chlorine content increased. As chlorine content of clinker increased, clinker showed a good burnability and mineral property.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.916-927
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• 2010

In general water treatment process, the disinfection process by chlorine is used to prevent water borne disease and microbial regrowth in water distribution system. Because chlorines were reacted with organic matter, carcinogens such as disinfection by-products (DBPs) were produced in drinking water. Therefore, a suitable injection of chlorine is need to decrease DBPs. Rechlorination in water pipelines or reservoirs are recently increased to secure the residual chlorine in the end of water pipelines. EPANET 2.0 developed by the U.S. Environmental Protection Agency (EPA) is used to compute the optimal chlorine injection in water treatment plant and to predict the dosage of rechlorination into water distribution system. The bulk decay constant ($k_{bulk}$) was drawn by bottle test and the wall decay constant ($k_{wall}$) was derived from using systermatic analysis method for water quality modeling in target region. In order to predict water quality based on hydraulic analysis model, residual chlorine concentration was forecasted in water distribution system. The formation of DBPs such as trihalomethanes (THMs) was verified with chlorine dosage in lab-scale test. The bulk decay constant ($k_{bulk}$) was rapidly decreased with increasing temperature in the early time. In the case of 25 degrees celsius, the bulk decay constant ($k_{bulk}$) decreased over half after 25 hours later. In this study, there were able to calculate about optimal rechlorine dosage and select on profitable sites in the network map.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.419-424
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• 2007

According to increase of consumer's desire for clean tap water, advanced treatment processes include with membrane, ozone, and granular activated carbon(GAC) were introduced. In order to evaluate the effect of advanced treatment processes for residual chlorine decay and trihalomethane(THM) formation in water distribution system, dissolved organic matter(DOC) removal of each advanced treatment process was investigated. The residual chlorine decay and THM formation using bottle tests were also evaluated. $UV_{254}$ removal in all advanced treatment was better than DOC removal. Especially, DOC by ozone treated was removed as 4% in contrast with sand filtered water, but $UV_{254}$ was removed about 17%. This result might be due to convert from hydrophobic DOC to hydrophilic DOC by ozonation. Ozone/GAC process was most effective process for DOC removal. The residual chlorine decay constants in treated water by sand filtration, ozonation, GAC adsorption, and ozone/GAC processes were 0.0230, 0.0307, 0.0117 and 0.0098 $hr^{-1}$, respectively. The sand filtered water was produced 81.8 ${\mu}g/L$ of THM after 190 hours of reaction time, as the treated water by ozone, GAC, and Ozone/GAC was less produced 6.0, 26.2, 30.3% in contrast with sand filtered water, respectively. Consequently, the durability of residual chlorine and reduction of THM formation were improved by advanced treatment processes.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.29-34
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• 2009

In this study, a chloride ion probe as a direct measurement for perchlorate reduction was used to determine whether biological perchlorate reduction was inhibited by other electron acceptors ($O_2$ and ${NO_3}^-$) and to investigate competition of electron acceptors for using electron donors. Profiles of chloride production (= perchlorate reduction) in flasks containing perchlorate reducing populations were monitored by a chloride ion probe. Biological reduction of 2 mM perchlorate was inhibited by 2 mM nitrate that chloride production rate was decreased by 30% compared to perchlorate used as the only electron acceptor and chloride production rate was decreased by 70% when acetate was limited. Reduction of 2mM perchlorate was completely inhibited by oxygen at 7~8 mg/L, regardless of acetate excess / limitation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.221-228
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• 1974

산란직전의 남해산 참굴(Crassostrea gigas)을 산채로 구입하여 통상조건하에서 탈각하여 얻은 굴육질을 polyethylene laminated aluminium pouch (Al+PE : 0.03+0.03mm) 속에 밀봉하여 살균선량(0.2Mrad) 및 멸균선량(2.0Mrad)의 감마선으조 조사하고, 한편, 100ppm의 염소수에 굴육질을 2분간 침지한 후 탈수하여 같은 방법으로 포장하여 35일간의 빙장기간중 세균학적 및 화학적 변화를 대조 굴(조사치 않고 염소수 처리하지 않은)의 경우와 비교하였다. 굴육질의 시초의 총균수는 g당 700-800에 달했고, 0.2 Mrad의 감마선 조사는 빙장 10일째의 저장 기간중의 총 균수를 검측할 수 있는 선 이하로 감소시켰으며 2.0 Mrad 조사는 20일째까지 거의 무균상태를 가져왔다. 감마선 조사는 또한 세균활동을 표시하는 대사물질인 TMA와 TCA soluble nitrogen의 축적을 현저히 억제시켰으며 빙장 후기부터 번식하기 시작하여 총균수가 g당 100,000을 초과케 된 35일째까지도 대조굴의 동일한 총균수 시기에 비하여 이 대사물의 축적억제가 현저했음은 감마선 조사의 효과가 총균수의 양적인 감소뿐만 아니라 동시에 TMA를 생산하고 단백질을 분해할 능력이 있는 세균제거 내지는 번식의 억제라는 선택적인 양면을 가지고 있음을 보여 준다. 염소수 처리한 굴육질의 경우 총균수의 양적인 감소효과는 현저하지 않했는데도 불구하고 감마선 조사 경우처럼 세균대사물질 축적의 철저한 억제를 가져 왔음은 주목할만 하다. 굴육질의 glycogen 함량은 사후 저장 기간 중 쉽사리 감소되지 않했으며 PH 측정으로 본 생굴의 신선도와의 관련성은 희박하며 조사와 염소수 처리굴의 경우 더욱 그러했다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3292-3297
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• 2014

The vehicle wiper blade(W/B) to lower the friction coefficient of the rubber surface after the surface treatment with chlorine were investigated. IR spectrum from W/B was used to determine the extent of chlorination of the rubber surface. Coefficient of friction is significantly reduced by the treatment with chlorine. In particular, the more sensitive influence on the initial chlorination. Rubber surface properties with respect to the longitudinal direction of the cutting plane were obtained by EPMA line analysis results. Penetration depth by EPMA chlorine concentration($20.0{\ell}$ of water for 35.0% hydrochloric acid(HCl) $300m{\ell}$ with 5.25% sodium hypochlorite(NaOCl) $400m{\ell}$), the chlorine treatment for 5 minutes was conducted to find that after 1.2 ${\mu}m$.

• Resources Recycling
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• v.31 no.3
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• pp.53-60
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• 2022

The physical properties of chlorine-containing cement were analyzed to optimize the operational conditions when waste resources containing chlorine were used in the cement manufacturing process. Cement with clinker to gypsum weight ratios of 95:5 and 93:7 were manufactured. In addition, the iron modulus (IM) of clinker was set to 1.3, 1.5, and 1.7 to evaluate the burnability and physical properties of clinker. With constant chlorine content, increasing gypsum content resulted in a decrease in the 3 day-compressive strength, whereas the 28 day-compressive strength increased. In addition, flow and setting time also increased with increasing gypsum content. As the IM decreased, burnability was improved, free-CaO content decreased, alite and ferrite content increased, and compressive strength increased In particular, the compressive strength of IM 1.3 was approximately 14% greater than that of IM 1.7.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.428-432
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• 2008

대수층의 저유량이 풍부한 강변여과수 개발 예정지역의 충적충(지표면하 25$\sim$35 m 구간)에서 수리전도도와 증분산지수의 규모종속효과를 규명하기 위해 양수시험과 수렴흐름 추적자시험이 수행되었다. 양수시험과 추적자시험의 규모는 2 m 와 5 m 이었으며 양수시험은 5개 공, 추적자시험은 3개 공을 이용하여 수행되었다. 양수시험은 일정한 양수율(2,500 m$^3$/day)로 수행되었으며, 양수 시작 후 경과시간에 따른 수위변화 자료를 AQTESOLV 3.5 프로그램에 입력하여 해석하였다. 시험대수층의 수리전도도는 양수정에서 1.745$\times$10$^{-3}$ m/sec, 양수정에서 이격거리가 2 m 구간에서는 2.161$\times$10$^{-3}$ m/sec와 2.270$\times$10$^{-3}$ m/sec 이었으며, 이격거리가 5 m 구간에서는 2.452$\times$10$^{-3}$ m/sec와 2.591$\times$10$^{-3}$ m/sec로 산정되었다. 그리고, 양수정에서 회복시험 시 Theis(Recovery) 방법에 의해 해석된 수리전도도는 1.603$\times$10$^{-3}$ m/sec이었다. 양수정에서 관측정의 이격거리(d)에 따른 수리전도도(K) 증가함수는 log K = 0.0693logd-2.071와 log K = 0.08171og d-2.655로 추정되었으며, 결정계수는 각각 0.965와 0.979로서 매우 높게 나타났다. 따라서 양수정에서의 이격거리가 멀수록 수리전도도가 증가하는 규모종속을 확인하였으며, 또한 시험대수층의 수리전도도가 방사상으로 유사하게 분포하고 있음을 알 수 있었다. 수렴흐름 추적자시험의 양수율은 2,500 m$^3$/day 이었으며, 2개의 주입정에 염소이온 5 kg을 순간 주입하였다. 염소이온의 농도이력곡선을 작성하여 초기도달시간과 최고농도의 차이를 분석하였으며, 누적질량회수곡선을 통해 양수 후 경과시간에 따른 염소이온의 질량회수율을 분석하였다. 그리고, 염소이온농도 대 누적질량회수율의 이력그래프를 작성하여 누적질량회수율에 따른 염소이온농도의 증가와 감소 변화를 분석하였다. 또한, 염소이온농도의 증가/감소 구간에 대한 선형회귀분석을 수행하여 농도 증가율과 감소율의 변화를 파악하였다. 양수정에서 관측된 경과시간별 염소이온농도 자료를 CATTI 코드의 "Converging Radial Flow With Instantaneous Injection" 해석법에 적용하여 종분산지수를 추정하였다. 양수정에서 이격거리가 2 m인 경우의 종분산지수는 0.4152 m, 이격거리가 5 m인 경우의 종분산지수는 3.2665 m 이었다. 따라서 양수정에서 이격거리가 멀수록 종분산지수가 증가하는 규모종속효과를 확인하였으며, 또한 이격거리에 대한 종분산지수의 비는 각각 0.21과 0.65 정도로서 증가하였다.