Chlorate-induced Inhibition of Nitrate Uptake Mediated by Enterobacter amnigenus GG0461

( Hee Sung Wang ),( Min Woo Han ),( Young Kee Kim ) 한국응용생명화학회 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.2

Enterobacter amnigenus GG0461, isolated and identified from greenhouse soils, has a high activity of nitrate uptake in the Pseudomonas agar factor medium. Although nitrate is not essential for the growth of this microorganism, it increases the growth rate. To characterize the microbial nitrate uptake, we measured the effect of chlorate on the uptake, since chlorate is an inhibitor of plant nitrate uptake. In the absence of nitrate, the growth of E. amnigenus was inhibited by chlorate at concentrations higher than 1 mM. In the presence of 50 mM nitrate, nitrate uptake was completely inhibited by 30 mM of chlorate, and growth was suppressed by chlorate at concentrations above 10 mM. In the presence of chlorate, the growth and nitrate uptake gradually improved when nitrate concentration increased. To overcome the inhibitory effect of chlorate, the nitrate concentration was required to be 2.5 times higher than that of chlorate, suggesting that there exists competition between chlorate and nitrate for the binding site of the nitrate transporter. Chlorate-induced inhibitions of bacterial nitrate uptake and growth seemed to have different mechanisms: a competitive inhibition in the former case and the formation of chlorite, a toxic reduced metabolite of chlorate, in the latter case.

Chlorate-induced Inhibition of Nitrate Uptake Mediated by Enterobacter amnigenus GG0461

Wang, Hee-Sung,Han, Min-Woo,Kim, Young-Kee The Korean Society for Applied Biological Chemistr 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.2

Enterobacter amnigenus GG0461, isolated and identified from greenhouse soils, has a high activity of nitrate uptake in the Pseudomonas agar factor medium. Although nitrate is not essential for the growth of this microorganism, it increases the growth rate. To characterize the microbial nitrate uptake, we measured the effect of chlorate on the uptake, since chlorate is an inhibitor of plant nitrate uptake. In the absence of nitrate, the growth of E. amnigenus was inhibited by chlorate at concentrations higher than 1 mM. In the presence of 50 mM nitrate, nitrate uptake was completely inhibited by 30 mM of chlorate, and growth was suppressed by chlorate at concentrations above 10 mM. In the presence of chlorate, the growth and nitrate uptake gradually improved when nitrate concentration increased. To overcome the inhibitory effect of chlorate, the nitrate concentration was required to be 2.5 times higher than that of chlorate, suggesting that there exists competition between chlorate and nitrate for the binding site of the nitrate transporter. Chlorate-induced inhibitions of bacterial nitrate uptake and growth seemed to have different mechanisms: a competitive inhibition in the former case and the formation of chlorite, a toxic reduced metabolite of chlorate, in the latter case.

전기화학적 공정에 의한 클로레이트의 생성메커니즘

백고운(Ko Woon Baek),정연정(Yeon Jung Jung),강준원(Joon Wun Kang),오병수(Byung Soo Oh) 大韓環境工學會 2009 대한환경공학회지 Vol.31 No.8

본 연구는 염화 이온 (Cl-)을 전해질로 이용하는 전기화학적 공정에서 생성되는 염소산화부산물인 클로레이트(ClO₃-, 염소산염)의 생성 메커니즘을 알아보기 위해 수행되었다. 우선, pH 및 초기농도에 따른 생성 특성을 살펴보았으며, 유리염소 생성과의 관련성 및 오존, OH 라디칼 등의 혼합산화제의 영향을 간접 평가하여 클로레이트의 생성 메커니즘을 구체화하였다. 그 결과, 클로레이트의 생성은 유리염소 (HOCl/OCl)의 전기화학적 반응을 주된 반응으로 하며, 염화 이온의 직접 양극산화 반응 및 OH 라디칼에 의한 경로가 있음을 확인하였다. 이어서 생성된 클로레이트가 퍼클로레이트로 산화되는 반응도 볼 수 있었다. 또한, 전극 간격에 따른 생성 농도를 유리염소 생성과 함께 평가하여, 유리염소 생성 효율은 극대화 시키되 클로레이트의 발생을 최소화 할 수 있는 최적조건을 찾는 방안을 제시하였다. This study was done to find out the formation mechanism of chlorate by electrochemical process using chloride ion (Cl-) as an electrolyte. Firstly, the effective factors such as pH and initial chloride concentration were figured out to see the formation property of chlorate during electrolysis. And the relation of free chlorine, and mixed oxidants such as OH radical and ozone with chlorate were estimated to concretize the formation mechanism. As a result, it was found that the major reaction of chlorate formation would be electrochemical reaction with free chlorine, and also the direct oxidation of chloride ion and the reaction by OH radical were participated in the formation of chlorate. Moreover, it was observed that formed chlorate was oxidized to perchlorate. Lastly, the optimum condition was recommended by comparing free chlorine with chlorate concentration during the electrochemical process with the different electrode separation.

소독방법에 따른 실내수영장 수질 특성 -브롬산염, 클로레이트, 염소이온을 중심으로-

조광운 ( Gwang Un Jo ),이세행 ( Se Haeng Lee ),위환 ( Whan Wi ),윤상훈 ( Sang Hoon Yoon ),김난희 ( Nan Hee Kim ),안상수 ( Sang Soo An ),정숙경 ( Suk Kyeong Jung ),김동수 ( Dong Su Kim ),조영관 ( Young Gwan Cho ) 한국환경분석학회 2015 환경분석과 독성보건 Vol.18 No.2

This study was carried out to investigate the characteristics of water quality parameters in the indoor swimming pool water according to the type of disinfection. The method of disinfection has a on-site oxidant generation, sodium hypochlorite and artificial seawater electrolysis that the salt was put in the pool directly. The on-site oxidant generation and sodium hypochlorite in the disinfectant contain high concentrations of bromate and chlorate. The bromate and chlorate containing the disinfectant is the cause of detection in a swimming pool. Maximum concentration of bromate in swimming pool waters was 1.365 mg/L at on-site oxidant generation and maximum concentration of chlorate was 36.00 mg/L at sodium hypochlorite. Therefore, to reduce the concentration of bromate and chlorate in swimming pool water, it is necessary to use the disinfectant containing the less quantity of bromate and chlorate and to exchange of swimming pool water frequently.

수산물에 이산화염소(ClO₂) 처리에 따른 변이원성 및 Chlorate와 Chlorite ion의 결정

김정목 木浦大學校 工業技術硏究所 2000 工業技術硏究誌 Vol.10 No.-

The use of chlorine dioxide (CIO2) as a potential substitute for aqueous chlorine to improve the quality of seafood products has not been approved by regulatory agencies due to health concerns related to the production of chlorite (CIO2-) and chlorate (CIO3-) as well as possible mutagenic/ carcinogenic reaction products. Cubes of Atlantic salmon (Salmo salar) and red grouper (Epinephelus morio) were treated with 20 or 200 ppm aqueous chlorine or CIO2 solutions for 5 min, and extracts of the treated fish cubes and test solutions were checked for mutagenicity using the Ames Salmonella/microsome assay. No mutagenic activity was detected in the treated fish samples or test solutions with CIO2. Only the sample treated with 200 ppm chlorine showed weak mutagenic activity towards S. typhimurium TA 100. No chlorite residue was detected in sea scallops, maxi-mahi, or shrimp treated with CIO2 at 3.9 - 34.9 ppm. However, low levels of chlorate residues were detected in some of the treated samples. In most cases, the increase in chlorate in treated seafood was time- and dose-related.

휴대용 염소발생장치에서 발생하는 총 염소 생성량 및 소독부산물 생성 특성

김효현(Hyohyeon Kim),김지예(Jiye Kim),윤제용(Jeyong Yoon),이호일(Hoil Lee),박현종(Hyunjong Park),강경석(Kyungseok Kang) 적정기술학회 2015 적정기술학회지(Journal of Appropriate Technology) Vol.1 No.1

전세계적으로, 특히, 개발도상국 국가들에서는 아직도 수많은 사람들이 안전하지 않은 먹는 물 문제로 고통 받고 있으며 그로 인해 사망하는 인구가 매년 150만 명을 넘는다. 특히 콜레라, 장티푸스, 이질 등과 같은 수인성 질병이 주로 문제가 되며, 이 경우 먹는 물 소독이 철저하지 않은데 기인한다. 본 연구에서는 이런 문제 해결에 도움을 주고자 마을 단위 또는 가정 단위에서 간편하게 사용할 수 있는 전기화학적 염소 발생 원리를 기반으로 한 포터블 염소 발생장치를 개발하였다. 본 연구에서는 포터블 염소발생장치에서의 염소 발생 특성과 염소 발생 반응과정에서 생성될 수 있는 염소계 소독부산물(chlorite(ClO 2 − ), chlorate(ClO 3 − ), perchlorate(ClO 4 − ))의 생성 특성을 조사하였다. 주요 결과로, 500 L 물탱크의 물을 소독하는데 필요로 하는 염소량(300 mg 가정)은 10 g 정도의 소금으로 8분 작동 시 생성되며, 이러한 조건에서 소독부산물의 경우 chlorite는 측정되지 않았고, chlorate는 먹는 물 기준 40분의 1, perchlorate는 5분의 1 수준이 었다(먹는 물에서의 소독부산물 chlorite와 chlorate 농도는 700 µg/L, perchlorate는 15 µg/L 이하로 제한된다). 따라서 본연구에서 개발된 포터블 염소발생장치는 마을단위 또는 가정단위의 작은 물탱크 소독에 필요로 하는 염소생산량 생산에 적절하게 사용될 수 있으며 이 경우 생성되는 염소계 소독부산물은 우려할 수준이 아니라는 사실을 알 수 있었다. Many people in the world, especially in developing countries, suffer from an unsafe drinking water and every year, over 1.5 million deaths occur from water-borne diseases. Water-borne diseases, such as cholera, typhoid, dysentery, are mainly caused by inexhaustive disinfection of drinking water. To help solving these problems, we developed a Portable Electrochemically Generated Chlorine Disinfection Device, based on the principle of electrochemical chlorine generation, which can be conveniently used in village or home unit. In this study, we investigated the characteristics of formation of chlorine and disinfection by-products (DBPs, chlorite (ClO 2 − ), chlorate (ClO 3 − ), perchlorate (ClO 4 − )) which could be produced during the chlorine generation process. The experimental results show that amount of chlorine (assumed as ~300 mg) suitable for disinfecting 500 L of water can be generated by operating the portable electrochemically generated chlorine disinfection device for 8 minutes with 10 g of salt. At this condition, in the case of DBPs generation, chlorite was not detected, concentrations of chlorate and perchlorate were one-fortieth and one-fifth of drinking water guideline values, respectively. (The drinking water guideline values are: less than 700 µg/L for chlorite and chlorate, and less than 15 µg/ L for perchlorate) Therefore, we confirmed that the portable electrochemically generated chlorine disinfection device is applicable as disinfecting device for village or home unit, and its level of DBPs was not an issue of concern.

The Use of Sodium Chlorate/Hydrochloric Acid Mixtures as a Novel and Selective Chlorination Agent

문병석,Han Young Choi,지대윤,고훈영 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

Sodium chlorate/hydrochloric acid mixtures were used to chlorinate activated arenes and the α-position of ketones.This chlorination method was used to produce selectively mono-, di-, and trichlorinated compounds by controlling the molarity of sodium chlorate. This reagent proved to be much more efficient and easier to handle than chlorine gas.

Variation in ClO₂/Cl₂ Ratio in the Chloride-Chlorate Process under Different Conditions

Deshwal, Bal Raj,Lee, Hyung-Keun 한국공업화학회 2004 Journal of Industrial and Engineering Chemistry Vol.10 No.4

The chloride-chlorate process is a highly efficient, easy to operate, and cost effective tool for generating ClO₂, wherein the theoretical ClO₂/Cl₂(η) ratio is 2. The present study attempts to investigate the optimal conditions for the best reaction yield in terms of chlorine dioxide production and minimal contamination of chlorine. The effects of the molar concentration of sulfuric acid, the temperature, and the chlorate/chloride (φ) ratio on the ClO₂/Cl₂(η) ratio is examined. The experimental η-value ranged from 0.46 to as high as 3.4 under different conditions. A reaction mechanism compatible with the experimental observations is proposed, and the role that side reactions have on influencing the ClO₂/Cl₂ ratio is highlighted. A general equation is derived to express the ClO₂/Cl₂ ratio.

The Use of Sodium Chlorate/Hydrochloric Acid Mixtures as a Novel and Selective Chlorination Agent

Moon, Byung-Seok,Choi, Han-Young,Koh, Hun-Yeong,Chi, Dae-Yoon Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

Sodium chlorate/hydrochloric acid mixtures were used to chlorinate activated arenes and the $\alpha$-position of ketones. This chlorination method was used to produce selectively mono-, di-, and trichlorinated compounds by controlling the molarity of sodium chlorate. This reagent proved to be much more efficient and easier to handle than chlorine gas.

Chlorate-induced Inhibition of Nitrate Uptake Mediated by Enterobacter amnigenus GG0461

Hee Sung Wang,Min Woo Han,Young Kee Kim 한국응용생명화학회 2010 Journal of Applied Biological Chemistry (J. Appl. Vol.53 No.2