• Title/Summary/Keyword: Chlorine Control

Search Result 231, Processing Time 0.02 seconds

Evasive Behavior of the Red Flour Beetle, Tribolium castaneum, against Chlorine Dioxide and Its Suppression by Heat Treatment (이산화염소에 대한 거짓쌀도둑거저리의 회피행동과 이를 억제하는 열처리 효과)

  • Kim, Yonggyun;Kumar, Sunil;Rahman, M. Mahbubur;Kwon, Hyeok;Chun, Yongsik;Na, Jahyun;Kim, Wook
    • Korean journal of applied entomology
    • /
    • v.54 no.3
    • /
    • pp.151-158
    • /
    • 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.

Development of Automatic Decision System for Chlorination Demand in Water Treatment Plant (정수장내 염소요구량 자동결정시스템 개발)

  • Oh, Sueg-Young
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.26 no.6
    • /
    • pp.757-764
    • /
    • 2002
  • Chlorination dosage in water treatment plant of field is determined by chlorination demand experiment through two or three hours after raw water was sampled in inflow. It is impossible to continuously control for real time because the sampled water is adapted chlorination dosage after water treatment process had been proceeded. Therefore in this study, we will design informal chlorination demand system, this designed system will be experimented as to water quality and accuracy of control in various conditions. Throughout these experimental results, we will revise the system and the revised system is enable to optimal control of chlorination dosage. Finally, we have developed chlorination demand system, which can automatically determination of chlorination dosage to be determined according to variety of raw water quality inflow in water treatment plant.

Aqueous Chlorine Dioxide Treatment Decreases Microbial Contamination and Preserves Sensory Properties of Mackerel During Storage

  • Kim, Yun-Jung;Nam, Sa-Uk;Chae, Hyeon-Seok;Lee, Seoung-Gyu;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
    • /
    • v.12 no.3
    • /
    • pp.181-184
    • /
    • 2007
  • Effect of aqueous chlorine dioxide ($ClO_{2}$) treatment on quality change of mackerel during storage was examined. Mackerel treated with 0, 5, 10, and 50 ppm of $ClO_{2}$ solution, respectively was stored at $4^{\circ}C$. $ClO_{2}$ treatment decreased populations of aerobic bacteria in mackerel during storage. The number of total aerobic bacteria of mackerel treated with 50 ppm $ClO_{2}$ increased from 2.45 to 3.44 log CFU/g after 9 days of storage, while that of the control increased from 3.47 to 4.72 log CFU/g. The pH values of mackerel increased during storage, with no significant changes among treatments. Volatile basic nitrogen values of mackerel were decreased by $ClO_{2}$ treatment. Quality of mackerel treated with $ClO_{2}$ was better than that of the control during storage based on sensory evaluation. These results indicate that aqueous $ClO_{2}$ treatment could be useful for improving the microbial safety and qualities of mackerel.

Serial Changes in the Rate of Respiratory Metabolism of Olive Flounder, Paralichthys olivaceus Exposed to Intermittent Chlorination of Chlorine Dioxide ($CIO_2$) (이산화염소 (CIO2)의 간헐적 처리에 따른 넙치, Paralichthys olivaceus 호흡대사율의 경시적 변화)

  • Kim, Heung-Yun
    • Journal of fish pathology
    • /
    • v.16 no.2
    • /
    • pp.91-102
    • /
    • 2003
  • The present study was investigated the effects of chlorine dioxide ($CIO_2$) on the rcspimtory metabolism of olive flounder (Parolichlhys olivaceus) imtermittently exposed to seawater chlorinated by $CIO_2$:. Oxygen consumption of flounder before and after once or twice $CIO_2$-treatment with 12 hr- or/and 24 hr-interval were serially measured with automatic intenniteent-flow respirometer system (AIRS). The oxygen consumption rates of flowKier exposed to 0.10 and 0.20 ppm$CIO_2$, were not different from the control fish prior to the once or twice chlorinations . On the other hand, the respiratory metabolic rates of flounder exposed to 0.30 ppm$CIO_2$ were significantly increased 15% and 22 - 23% after the once and twice chlorinations compared to the control fish. respectively. The flounder exposed In 0.40 and 0.50 ppm$CIO_2$: died within 4 hr and I hr. respectively. The elevation( respiratory metabolism in flounder exposed toO.30 ppm$CIO_2$ and above is considered due to physiological stress caused by $CIO_2$ exposure.

A Study on the Dosage ate Control of the Pre-Chorine in Water Purification using Fuzzy Inference Technique (퍼지 론기법 정수공정의 전염소주입율 제어에 관한 연구)

  • 이상석;소명옥;이준탁
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.2 no.1
    • /
    • pp.89-95
    • /
    • 1996
  • This paper describes a fuzzy controlled pre-chlorination technique for purifying the pulluted raw water in water purification lants. For the purpose of obtaining the high quality water, the appropriate pre-chlorine dosage rate has to be continuously adjusted according to a change in quality of a intake raw water, weather, solar nergy mount, temperature and etc. Therefore, the method of expressing an expert's empirical knowledge cumulated from his past carrier by fuzzy reasoning and the fuzzy controller design technique is necessary.In this paper fuzzy membership functions and rules accordingto emprircal knowledge and experimental field data were obtained, And also fuzzy cintriller design using four feedforward components for the determination of pre-chlorine dosage rate and four feedback ones for the compensation of its dosage rate with residual chlorine and its change rate, was executed.

  • PDF

A Study on the Microbiological Quality of Vegetables in Relation to the Sanitization Method Used and Vegetable Types (채소군별 미생물학적 안전성 확보를 위한 적정 소독방법)

  • Kim, Heh-Young;Lee, Yun-Hee
    • Korean journal of food and cookery science
    • /
    • v.25 no.5
    • /
    • pp.632-642
    • /
    • 2009
  • In this study the microbiological quality of vegetables was evaluated in relation to the sanitization methods used and vegetable types which consisted of raw food ingredients used in foodservice operations. We analyzed the microbial quantities on lettuce and spinach, which were used as leaf vegetables and cucumber and tomato, which were used as fruit vegetables according to various disinfection methods using different chlorine concentration(50 ppm, 100 ppm, 200 ppm) and exposure time(5 min, 10 min) over 5 days. When the effects of the disinfection methods on microbial qualities and sensory evaluation were analyzed, the following results were obtained. First, in the leaf vegetables, disinfection with a chlorine concentration of 200 ppm for a 5 minutes exposure time was needed to control microbial growth. Second, fruit vegetables sterilized with tap water had reduced microbial qualities after an extended amount of time relative to chlorine disinfection, that is, disinfection with a chlorine concentration of 50 ppm for 5 minutes exposure time was desirable.

The Influence of Chlorine Application on Corrosion and Bacterial Growth in Home Plumbing Systems (급수관내 염소 주입이 미생물의 증식과 부식에 미치는 영향)

  • Kim, Tae-Hyun;Lee, Yoon-Jin;Lim, Seung-Joo
    • Journal of Environmental Health Sciences
    • /
    • v.32 no.5 s.92
    • /
    • pp.431-439
    • /
    • 2006
  • This research was conducted using a model home plumbing system composed of copper, stainless steel, galvanized iron, carbon steel, and PVC (polyvinyl chloride) pipe. The number of bacteria present in stainless steel pipe and PVC was higher than other pipes. High turbidity and zinc release were found in galvanized iron pipe material and detected during the first 6 months. Conversely, there was a decrease in turbidity and zinc release after 6 months resulting in levels similar to other pipes. Copper concentration decreased as operation times increased. In this experiment, the number of bacteria detected in biofilm for a copper pipe continued to increase. Pipe material influenced bacterial numbers in biofilm and water. This showed that elevated chlorine could not control bacterial growth in biofilm for galvanized iron and stainless steel systems. It also suggested that the dosing of chlorine might not be available for all kinds of pipes. Therefore, another complementary method should be introduced to manage biofilm effectively in water distribution systems.

Inactivation of White Spot Baculovirus(WSBV) by Chlorine, Iodine, Sunlight Exposure, Drying and Fresh Water (염소, 요오드, 일광, 건조 및 담수처리에 의한 White Spot Baculovirus(WSBV)의 불활성화)

  • Heo, Moon-Soo;Sohn, Sang-Gyu
    • Journal of fish pathology
    • /
    • v.13 no.2
    • /
    • pp.97-102
    • /
    • 2000
  • In order to investigate the effect of chlorine disinfectant against white spot baculovirus (WSBV), 5, 10, or 30 ppm of sodium hypochlorite (NaOCl) was treated to the WSBV-infected shrimp, Penaeus chinensis. In contrast with the non-treated control, no shrimp was dead after of sodium hypochlorite treatment. This result indicated that WSBV was inactivated by chlorine treatment. No inactivation of WSBV was observed by 10, 20, 30 ppm of povidon-iodine treatment. WSBV was also inactivated by 2, 4 hr sunlight exposure and by 1, 2, 3 hr drying. WSBV was inactivated very effectively by addition of fresh water on sea water.

  • PDF

Post-Chlorination Process Control based on Flow Prediction by Time Series Neural Network in Water Treatment Plant

  • Lee, HoHyun;Shin, GangWook;Hong, SungTaek;Choi, JongWoong;Chun, MyungGeun
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.16 no.3
    • /
    • pp.197-207
    • /
    • 2016
  • It is very important to maintain a constant chlorine concentration in the post chlorination process, which is the final step in the water treatment process (hereafter WTP) before servicing water to citizens. Even though a flow meter between the filtration basin and clear well must be installed for the post chlorination process, it is not easy to install owing to poor installation conditions. In such a case, a raw water flow meter has been used as an alternative and has led to dosage errors due to detention time. Therefore, the inlet flow to the clear well is estimated by a time series neural network for the plant without a measurement value, a new residual chlorine meter is installed in the inlet of the clear well to decrease the control period, and the proposed modeling and controller to analyze the chlorine concentration change in the well is a neuro fuzzy algorithm and cascade method. The proposed algorithm led to post chlorination and chlorination improvements of 1.75 times and 1.96 times respectively when it was applied to an operating WTP. As a result, a hygienically safer drinking water is supplied with preemptive response for the time delay and inherent characteristics of the disinfection process.

Effect of Aqueous Chlorine Dioxide and Citric Acid Treatment on Microbial Safety and Quality Control of Minimally Processed and Refrigerated (MPR) Salad (이산화염소 및 citric acid 처리가 minimally processed and refrigerated (MPR) salad의 미생물학적 안전성 및 품질에 미치는 영향)

  • Youm, Hyoung-Jun;Ko, Jong-Kwan;Kim, Mee-Ree;Cho, Yong-Sik;Chun, Hye-Kyung;Song, Kyung-Bin
    • Korean Journal of Food Science and Technology
    • /
    • v.37 no.1
    • /
    • pp.129-133
    • /
    • 2005
  • Aqueous chlorine dioxide and citric acid treatment was introduced to insure microbial safety of minimally processed and refrigerated (MPR) salad. Salad samples were treated with 50 ppm chlorine dioxide and 1% citric acid. Chemical treatment decreased total aerobic bacteria, yeast and molds, E. coli, and Listeria by 3.75, 3.47, 3.41, and 3.38 log cycles, respectively, and polyphenoloxidase activity of MPR salad by 49.73%. Plain water washing of salads did not effectively decrease microbial growth. These results indicate appropriate chemical treatment provides microbial safety and quality control in MPR salad during marketing.