• Title, Summary, Keyword: Disinfection by-products

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Disinfection effect and formation characteristics of disinfection by-product at the Electrolyzed Water (전기분해수 살균효과 및 소독부산물 생성 특성 평가)

  • Cho, Youngman
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.5
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    • pp.547-554
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    • 2013
  • Chlorine has strong oxidizing power, also it is many advantages over other disinfectants such as the residual characteristic and economic feasibility. However, chlorine also has disadvantages such as creating disinfection by-products of chlorine as THMs. In particular, the most deadly disadvantage of chlorine is that it is extremely poisonous toxins about all alive lives. Disinfection with electrolysis water can be a very useful way Because you do not have to worry about chlorine's dangerous. In this study, we evaluated the potential as a disinfectant, across the evaluating disinfection effect and generating characteristic of by-products. The electrolyzed water could be obtained removal efficiencies of over 99.9 % the coliform by operating condition such as residence time, current density (voltage), the electrode gap. The residual chlorine be generated 10,000 mg/L in current density $1.0A/dm^2$ and residence time of 10 minutes. The residual chlorine concentration was possible to maintain a stable. The by-products generated by high concentration residual chlorine in the reactor such as trihalomethanes, haloaceticacid, chloralhydrate, haloacetonitrile were detected in less than a water quality standards. At the concentration of less than residual chlorine of 1 ppm, the chlorine disinfection by-products be generated most below the detection limit.

Assessment of Disinfection By-Products in Drinking Water in Korea (음용수 중 소독부산물 발생현황에 관한 연구)

  • Shin, Dong-Chun;Chung, Yong;Choi, Yoon-Ho;kim, Jun-Sung;Park, Yeon-Sin;Kum, Hee-Jung;Jeon, Hee-Kyoung
    • Environmental Analysis Health and Toxicology
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    • v.16 no.1
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    • pp.1-8
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    • 2001
  • The main purpose of applying the chlorination process during water treatment is for disinfection. Research results, however, indicate that disinfection by-products including trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, and chloropicrin can be produced by chlorination process. Some of these disinfection by-products are known to be potential human carcinogens. This three-year project is designed to establish a standard analysis procedure for disinfection by-products in drinking water and investigate the distribution and sources of specific disinfection by-products. The occurrence level of DBPs in drinking water was below 50$\mu\textrm{g}$/L in most cases. THMs in plant effluent accounted for 48% of all DBPs measured, whereas HAAs accounted for 24%, HANs 14%, haloketones 5%, chloral hydrate 7%, and chloropicrin 2%. Chloroform was found to be the major THMs compound (71%), followed by bromodichloromethane (21%), dibro-mochloromethane (7%), and bromoform (3%), The concentration of DBPs formed in distribution systems increased from those detected in plant effluent. Results would play an important role in exposure assessment as a part of the risk assessment process, and would give basic information for establishment of disinfection by-products reduction and management procedures.

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Development of Transport Parameters affecting on the Removal of Micro Organic Compounds such as Disinfection By-Products and Pharmaceutically Active Compounds by Low-Pressure Nanofiltration

  • Oh, Jeong-Ik;Yamamoto, Kazuo
    • Environmental Engineering Research
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    • v.14 no.2
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    • pp.126-133
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    • 2009
  • This study investigated the removal characteristics of various micro organic compounds by low-pressure nanofiltration membranes comprised of disinfection by products and pharmaceutically active compounds. The experimental removal of micro organic compounds by low-pressure nanofiltration membranes was compared with the transport model calculations, which consist of diffusion and convection terms including steric hindrance factor. The selected molecule from the disinfection byproducts and pharmaceutical active compounds showed a much lower removal than polysac-charides with a similar molecular size. However,the difference between model calculation and experimental removal of disinfection by-products and pharmaceutically active compounds could be corrected. The correlation of Ks with solute radius was further considered to clarity transport phenomena of micro organic solutes through nanofiltration membranes.

Comparison of Evaluation Methods for Disinfection Efficacy of Contact Lens Care Products (콘택트렌즈 관리용품의 살균력 효능 검사법 비교)

  • Sung, Hyung Kyung;Byun, Hyun Young;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.1
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    • pp.59-67
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    • 2014
  • Purpose: The present study was aimed to compare the results of disinfection efficacy tested by membrane filtration method with dilution-neutralization method to develop the standard methods for evaluating disinfection efficacy of contact lens care products and to provide the result of disinfection efficacy of commercially available contact lens care products in domestic market. Methods: The results of disinfection efficacy against Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Candida albicans evaluated by membrane filtration method as a FDA standard and dilution-neutralization method as newly being a KFDA standard were compared and the disinfection efficacy of 16 multi-purpose solutions was further evaluated. Results: The disinfectants and contact lens care products having strong disinfection efficacy showed same results in both membrane filtration method and dilution-neutralization method. In case of contact lens care products having weak disinfection efficacy, the number of micro-organisms was not able to count since the colony was aggregated when evaluated by membrane filtration method. However, the number of micro-organisms was able to exactly count when evaluated by dilution-neutralization method. In addition, some commercially available contact lens care products did not meet disinfection standard and especially, their disinfection effect was often weak against Serratia marcescen and Candida albicans. Conclusions: It is concluded that dilution-neutralization method will be useful to evaluate disinfection efficacy since it is possible to count micro-organisms more precisely even with small amount of sample and check the results faster compared with membrane filtration method.

A Study on Removal of Natural Organic Matter (NOM) and Application of Advanced Water Treatment Processes for Controlling Disinfection By-Products (소독부산물 제어를 위한 자연유기물(NOM) 제거와 고도정수처리공정 적용에 관한 연구)

  • Kim, Hyun Gu;Eom, Han Ki;Lee, Dong Ho;Joo, Hyun Jong
    • Journal of Korean Society on Water Environment
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    • v.31 no.5
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    • pp.563-568
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    • 2015
  • Natural Organic Matter (NOM) is a precursor of disinfection by products. Recently, with the increase in NOM concentration caused by a large amount of algae, the creation of disinfection by-products is becoming a big issue. Therefore, in this study, PAC+Membrane+F/A hybrid process was organized to control disinfection by-products in small-scale water treatment plants. The optimal dosage of PAC was set at 20 mg/L through Lab. scale test. Also, it is judged that NOM concentration must be less than 1.0 mg/L to meet the recommended criteria of drinking water quality monitoring items of disinfection by-products during chlorination. The existing conventional water treatment process was compared to the independent F/A process and the PAC+Membrane+F/A hybrid process through pilot plant operation, and the result showed that there is a need to apply an advanced water treatment process to remove not only NOMs but also Geosmin caused by algae. Accordingly, it is considered that applying the PAC+Membrane+F/A process will help in controling a clogged filter caused by a large amount of algae and disinfection by-products created by chlorination and can be used as an advanced water treatment process to meet the recommended criteria of drinking water quality monitoring items.

A Study on Control Disinfection By-products in High Sodium Hypochlorite Generation (고농도 차아염소산나트륨 발생장치의 소독부산물 제어에 관한 연구)

  • Cho, Haejin;Shin, Hyunsoo;Ko, Sungho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.3
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    • pp.183-189
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    • 2017
  • Sodium hypochlorite used in water disinfection processes is generally in the production of chlorine to 0.8%. As the dose of chlorine increases, disinfection by-products (Chlorate) also increase simultaneously and exceed water quality standards. In this study, the electrolytic cell of a sodium hypochlorite generator (12% chlorine) was adjusted to control the production of the disinfection by-products. As a result, it was possible to reduce Chlorate concentrations by more than 95% by adjusting the pH of the electrolytic cell from 1.53 to 4.2 (normal pH of the electrolytic cell). As a low current is required to obtain these results, a 15% improvement in the efficiency of the positive electrode is also observed. For the development of High Sodium Hypochlorite Generation can be used in a safe sodium hypochlorite solution, which is expected to contribute to improvement in the safety of the disinfection process.

Variations of Disinfection By-products in a Chlorinated Drinking Water Distribution System

  • Lee, Soo-Hyung;Park, Jeong-Kun;Lee, Hyung-Jun;Kim, He-Kap
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.4 no.2
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    • pp.71-78
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    • 2000
  • The chlorination of municipal drinking water supplies leads to the formation of so-called disinfection by-products(DBPs), many of which have been reported to cause harmful health effects based on animal studies. This study was conducted: 1) to observe seasonal changes in the major DBPs at four sampling sites on a drinking water distribution system located in Chunchon, Kangwon Do; and 2) to examine the effects of major water quality parameters on the formation of DBPs. During the field sampling, the water temperature, pH, and total and free chlorine residuals were all measured. The water samples were then analyzed for total organic carbon(TOC) and eight disinfection by-products in the laboratory. Chloroform, dichloroacetic acid, and trichloroacetic acid were the major constituents of the measured DBPs. The concentrations of the total DBPs were highest in fall, particularly in October, and lowest in summer. The concentrations of the total DBPs increased with increasing TOC concentrations. Multiple regression analyses showed that the concentrations of chloroform, bromodichloromethane, and chloral hydrate were linearly correlated with the pH. Other water parameters were not included in the regression equations. Accordingly, these results suggest that TOC and pH are both important factors in the formation of DBPs.

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Operating Conditions for Minimization of DBPs (Disinfection by-Products) in Drinking Water Supply System (소독부산물 최소화를 위한 운영조건 연구)

  • Shin, Hyung-Soon;Choi, Phil-Kweon;Kim, Jong-Su;Choi, Ill-Woo;Kim, Sang-Hoon;Kim, Tae-Hyun;Lee, Kyung-Hee;Lee, Soo-Moon;Jang, Eun-Ah;Jung, Yeon-Hoon;Kim, Jung-Yeol
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.3
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    • pp.330-337
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    • 2005
  • This study was carried out to propose the managemental improvement of the purification plants and the distribution facilities which can minimize the formation of disinfection by-products in drinking water distribution system. The disinfection by-products were highly created in the water treatment plant that the organic matters were high and the chlorine dosage was excessive. The concentration of DSPs was shown the highest value in August and the lowest value in December, because of temperature and pre-chlorine dosage effect. From the result of tracer test, the travel time from the treatment plant to the end of pipeline was around 3-4 days in summer, 5-6 days in winter, respectively, and the DSPs concentration of the reservoir(end of pipe) was 2-3 times higher than that of the beginning point. The improvement of the chlorination process and structural reformation of distribution facility was demanded to minimize the DSPs increase from purification plant to the end of pipe.

Study on disinfection by-products formation according to kind of salt in on-site production (정수장 현장제조염소의 브로메이트와 클로레이트의 생성 특성연구)

  • Min, Byungdae;Chung, Hyenmi;Kim, Taewook;Park, Juhyun
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.5
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    • pp.575-581
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    • 2015
  • Although disinfection in drinking water treatment plants provides a safer water supply by inactivating pathogenic microorganisms, harmful disinfection by-products may be formed. In this study, the disinfectant, chlorine, was produced on-site from the electrolysis of salt (NaCl), and the by-products of the disinfection process, bromate and chlorate, were analyzed. The provisional guideline levels for bromate and chlorate in drinking water are $10{\mu}g/L$ and $700{\mu}g/L$, in Korea, respectively. Bromide salt was detected at concentrations ranging from 6.0 ~ 622 mg/kg. Bromate and chlorate were detected at concentrations ranging from non-detect (ND) ~ 45.3mg/L and 40.5 ~ 1,202 mg/L, respectively. When comparing the bromide concentration in the salt to the bromate concentration in the chlorine produced by salt electrolysis, the correlation of bromide to bromate concentration was 0.870 (active chlorine concentration from on-site production: 0.6-0.8%, n=40). The correlation of bromate concentration in the chlorine produced to that in the treated water was 0.866.

Formation Characteristics of Disinfection By-Products using Chlorine Disinfection in Sewage Effluent (하수 염소 소독시 소독부산물 발생 특성)

  • Beck, Young-Seog;Song, Min-Hyung;Jung, Kyung-Hun;Kwon, Dong-Sik;Lee, Gi-Gong
    • Journal of Korean Society on Water Environment
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    • v.20 no.3
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    • pp.275-280
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    • 2004
  • This study was performed to investigate the disinfection efficiency and the formation characteristics of disinfection by-products(DBPs) by chlorination in the sewage effluent. The effluent was sampled from the sewage treatment plants operated in the activated sludge process and the advanced sewage process. The type of DBPs investigated were Trihalomethanes(THMs), Dichloroacetonitrile(DCAN), Chloral hydrate(CH), Dichloroacetic acid(DCAA), Trichloroacetic acid(TCAA). Major findings are as follows. First, the optimum injection concentration for chlorination in sewage effluent were found to be in the range $0.5{\sim}1.0mg\;cl_2/L$. Also, It was found that the chlorine dosage in the effluent of activated sludge process was higher than in the effluent of advanced sewage process. Second, the maximum formation concentration of THMs were $12.7{\mu}g/L$. The THMs formation reaction was finished in a short time of several seconds and chloroform was mainly formed. Also, it was found that the concentration of ammonium nitrogen is higher, the concentration of THMs is lower. Third, it was found that DCAA and TCAA were mainly formed as DBPs by disinfection.