• Title/Summary/Keyword: Free chlorine

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Model development for chlorine generation using electrolysis (전기분해에 의한 잔류염소 생성 예측 모델 개발)

  • Sohn, Jinsik;Lee, Sunjae;Shin, Chorong
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.3
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    • pp.331-337
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    • 2009
  • Electrolysis produces hypochlorous acid by using a small quantity of NaCl as electrolyte. This process maximizes the stabilization of drinking water through the control of chlorine residual concentration. This study investigated free chlorine generation by an electrolytic method using $Ti/IrO_2$ and stainless steel. The generation of free chlorine was increased with increasing hydraulic retention time, voltage, chlorine ion concentration and the number of electrodes. However, the change of pH did not affect the generation of free chlorine. There was no significant difference on the behavior of chlorine concentration between electrolytic method and NaOCl injection. In this study, the concentration of free chlorine predicted model based on power functional model was developed various under conditions. Electrolysis free chlorine generation model can be effective tool in the estimation of free chlorine generation.

Effectiveness of the Electrochemical Sensor for the Free Chlorine Measurement (잔류염소 측정용 전기화학센서의 유효성)

  • Kim, Hong-Won;Chung, Nam-Yong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.5
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    • pp.720-725
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    • 2012
  • Sodium hypochlorite is used worldwide as a water disinfectant and in bleaching agent. Sodium hypochlorite applied to water initially undergoes hydrolysis to form free chlorine consisting of hypochlorous acid(HOCl) and hypochlorite ion($OCl^-$). For free chlorine determination, an electrochemical method is simple due to the electroactivity of free chlorine; it measures current and is free of most reagents. Amperometric free chlorine sensor has been developed with gold (Au)-based electrode. The 3-electrode free chlorine sensor whose working and counter electrodes were Pt exhibited excellent response to HClO at +400mV vs. Ag/AgCl/sat. KCl. In addition, the use of a pH error correction algorithm provided a reliable measurement of residual free chlorine in water sample without any pretreatment in the normal pH range(pH 6~8) of municipal water supply. The free chlorine sensor installed in on-line monitoring system could be used to continually monitor the level of residual free chlorine in real samples.

The Seasonal Variation of Free Chlorine Residuals by Water Supply Distance in Daegu (대구 지역의 계절 변화에 따른 급수관내 잔류염소 농도 거동)

  • Lee, Tae-Gwan
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.3
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    • pp.363-369
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    • 2005
  • This paper presents the integrated technique of water quality analysis and Geographic Information System(GIS) for assessing the variation of free chlorine residuals by water temperature and supply distance in Sangri water supply system in Daegu. GIS was utilized for mapping projectmap, extraction of a pipeline route, and supply distance. Free chlorine residual is analyzed every month for appraising the seasonal variation. As a result, free chlorine residuals are affected both water temperature and water supply distance, and it becomes worse as water temperature and water supply distance is increased. To maintain 0.4mg/l of free chlorine residual, initial dose concentration should be over 1.85mg/l in summer.

Effect of Chlorine Treatment on the Lipid Composition of Wheat Flour (염소처리가 밀가루의 지방질 조성에 미치는 영향)

  • Han, Myung-Kyu;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
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    • v.24 no.2
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    • pp.132-136
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    • 1992
  • The effects of chlorine treatment on the lipid composition of wheat flour were studied by treating flour with different amounts (1, 2 and 4 ounces per 100 pounds of flour) of liquidized chlorine gas. The contents of free lipid increased slightly while those of the bound lipid decreased at all levels of chlorine used. The contents of neutral lipid in the free lipid decreased while those in the bound lipid increased as the level of chlorine increased. The contents of triglycerides in the free and bound lipids decreased as the level of chlorine increased. As the level of chlorine increased, digalactosyl diglycerides in the bound lipid decreased, whereas those in the free lipid increased within the range of 1 to 2 oz of chlorine. The phosphatidylcholine content in the free and bound lipids decreased while the lysophosphatidylcholine increased in both free and bound lipids as the level of chlorine increased. The content of saturated fatty acids increased while that of unsaturated ones decreased as the level of chlorine increased.

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Burnability and Mineral Properties of Clinker Added Chlorine (염소 함유 클링커의 소성성 및 광물특성에 관한 연구)

  • Kim, Tae-Yeon;Kim, Nam-Il;Chu, Yong-Sik
    • 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.

Models for Formation of Chloroform by Reaction of Linear Alkylbenzenesulfonate with Free Chlorine (LAS의 염소와 반응에 의한 클로로포름 생성 모델)

  • 김혜태;남상호
    • Environmental Analysis Health and Toxicology
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    • v.13 no.3_4
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    • pp.77-85
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    • 1998
  • It is very frequent that LAS meets the chlorine bleaches not only in the processes but also in the path from the sewages to the rivers. Therefore, it is not difficult to imagine that the harmful substances like DBPs are produced when LAs reacts with free chlorine. THMs are the major components of DBPs which are formed by reactions of organic substances with the chlorine oxidants. Among them, chloroform is the most noteworthy material. Since the major behavior observed was the formation of chloroform during reaction of LAS with free chlorine, the models were developed to grasp the tendency of chloroform formation depending on condition. According to these models, the effect of pH in the formation of chloroform is most grave.

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CLPP of Biofilm in Free Chlorine Residual and Monochloramine (유리잔류염소와 모노클로라민에서의 생물막의 CLPP)

  • Lee Dong-Geun
    • Journal of Environmental Health Sciences
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    • v.31 no.2 s.83
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    • pp.147-151
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    • 2005
  • The disinfection effect of free residual chlorine and monochloramine on biofilm communities were investigated by CLPP (community level physiology profile) using Biolog GN plates. Low concentration of disinfectant, $0.5\;mg/\iota$ free chlorine and $1.0\;mg/\iota$ monochloramine, stimulated the growth of bacteria rather than disinfection. Bacterial concentrations were decreased at more than $1.0\;mg/\iota$ of disinfectants. CLPP was different with the type and concentration of disinfectant and sampling time. Common and different carbon sources were actively used with similar bacterial concentration in free chlorine and monochloramine. This represents the differences of bacterial communities with tap water contact times and disinfectant.

Rechlorination for residual chlorine concentration equalization in distribution system (급배수시스템에서 잔류염소 농도 균등화를 위한 재염소 처리)

  • Kim, Jinkeun;Han, Ji-An
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.1
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    • pp.91-101
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    • 2014
  • Three water treatment plants(WTPs) in Jeju island whose source water have different characteristics from those of the mainland of Korea were investigated. Coefficients of bulk water decay($k_b$) of free chlorine at $5^{\circ}C$ for ES, GJ, NW WTPs were $-0.003hr^{-1}$, $-0.002hr^{-1}$ and $-0.001hr^{-1}$ respectively based on bottle tests. To simulate the free chlorine variations in the distribution system using EPANET, ES WTP was chosen. Free chlorine concentrations of several sites were less than the drinking water quality standards(i.e., 0.1 mg/L); E5(0.03 mg/L), E6(0.02 mg/L), W21(0.02 mg/L) and W25(0.03 mg/L). To maintain more than 0.1 mg/L of free chlorine in the distribution system, at least 1.9 mg/L of chlorine was needed at the WTP, which suggested rechlorination was needed to supply palatable tap water to customers. Two sites, one that diverged into E5 and E6 in the east-line and another located before E21 in the west-line were selected for the appropriate rechlorination locations. The recommended rechlorination dosages were 0.42 mg/L for the east and 0.27 mg/L for the west. The simulated results indicated that the free chlorine could be reduced to 0.4 mg/L at the WTP with rechlorination, and taps with excessive free chlorine could be more stabilized(i.e., 0.1~0.4 mg/L).

Behaviors of LAS in Reactions with Free Chlorine (鹽素와 反應에서 LAS의 擧動에 관한 연구)

  • Kim, Hea-tae;Lee, Hwan;Lee, Yoon-jin;Nam, Sang-ho
    • Journal of Environmental Health Sciences
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    • v.23 no.2
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    • pp.106-114
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    • 1997
  • When surfactants meet chlorine bleaches not only in the washing drums but also through the whole path from the stream to the river, it is not difficult to expect that they produce the harmful substances like DBPs. Furthermore considering wastewater that is contaminated by surfactants is used to discharge into drinking water sources via sewer system, it also can be imagined that residual surfactants would contribute to the some extent of DBPs' formation during chlorine disinfection in water treatment plants. Although the main behavior observed was the formation of chloroform during the reaction of LAS with free chlorine, the other manifest behaviors like the trends of pH, MBAS, free chlorine, the mole concentration of benzene ring and etc. were also investigated.

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Relationship between Bacterial Regrowth and Free chlorine Residuals in Water Distribution System

  • Lee, Yoon-Jin;Yoon, Tae-Ho;Jun, Byong-Ho;Oh, Kyoung-Doo;Nam, Sang-Ho
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2003.06a
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    • pp.136-139
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    • 2003
  • This study is to observe the occurrence of heterotrophic bacteria in terms of free chlorine residuals in two different water distribution system which belongs to both K and Y water treatment plant of S city of Korea. The data analyzing in distribution systems (DS) shows that the free chlorine residuals decrease from 0.10 to 0.56 mgmg/L for K, and 0.51 to 0.78 mg/L for Y. The decay of free chlorine is clearly higher in both March and August than those of in January. The HPC in DS are ranged from 0 to 40 CFU/mL for K, 0 to 270 CFU/mL for Y, on R2A medium. In particular, its level is relatively high at consumers ground storage tanks, taps and point-of-end area of Y. The predominant genera is studied in distribution systems are Acinetobacter, Sphingomonas (branch of Pseudomonas), Micrococcus, Bacillus, Staphylococcus. The diversity of heterotrophic bacteria increase in the end-point area. Most of them are either encapsulated cells or cocci of gram-positve. In conclusion, the point-of-end area in distribution systems shows the longer flow distance from water treatment plants, the greater diversity and higher level of heterotrophic bacteria due to the significant decay of free chlorine residuals.

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