Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
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Assessment of temperature-dependent water quality reaction coefficients and monthly variability of residual chlorine in water distribution networks

수온 변화에 따른 상수관망 내 수질반응계수 추정 및 월별 잔류염소농도 분포 변화 분석

  • Jeong, Gimoon (Water & Wastewater Research Center, K-water Research Institute) ;
  • Choi, Taeho (Water & Wastewater Research Center, K-water Research Institute) ;
  • Kang, Doosun (Department of Civil Engineering, Kyung Hee University) ;
  • Lee, Juwon (Korea Institute of Civil Engineering and Building Technology) ;
  • Hwang, Taemun (Korea Institute of Civil Engineering and Building Technology)
  • 정기문 (K-water 연구원 상하수도연구소) ;
  • 최태호 (K-water 연구원 상하수도연구소) ;
  • 강두선 (경희대학교 사회기반시스템공학과) ;
  • 이주원 (한국건설기술연구원 환경연구본부) ;
  • 황태문 (한국건설기술연구원 환경연구본부)
  • Received : 2023.09.25
  • Accepted : 2023.10.19
  • Published : 2023.11.30
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Abstract

In South Korea, ongoing incidents related to drinking water quality have eroded consumer trust. Specifically, beyond quality incidents, there have been complaints about taste, odor, and other issues stemming from the presence of chlorine. To address this, water service operators are employing various management strategies from both temporal (scheduling) and spatial (rechlorination) perspectives to ensure uniform and safe distribution of chlorine residuals. In this study, we focus on the optimal monthly management of chlorine residuals, based on water distribution network analysis. Water quality reaction coefficients, including bulk fluid and wall reaction coefficients, were estimated through lab-scale tests and EPANET water quality simulations, respectively, accounting for temperature variations in a large-scale water distribution network. Utilizing these estimated coefficients, we examined the monthly variations in chlorine residual distribution under different chlorine injection conditions. The results indicate that the efficient concentration for chlorine injection, which satisfies the residual chlorine limit range, varies with temperature changes. Consequently, it is imperative to establish a specific and quantitative chlorine injection plan that considers the accurate spatial distribution of monthly chlorine residuals.

국내에서는 지속적인 상수도 수질사고 발생으로 인해 수돗물 수질에 대한 이용자 불신이 확산되고 있다. 특히, 수질사고 외에도 수돗물에 포함된 염소 성분 등으로 인해 맛, 냄새 등에 대한 이용자들의 수질민원 또한 지속적으로 발생하고 있다. 따라서 상수도 사업자들은 이용자에게 공급되는 잔류염소농도가 충분히 잔류하면서도 과도하게 유지되지 않도록, 시간적(Scheduling) 및 공간적(Rechlorination) 관점에서 상수관망 내 잔류염소농도가 균등하게 분포하도록 다양한 방법을 검토 및 적용하고 있다. 본 연구에서는 상수관망 해석을 통한 월별 잔류염소농도 최적 관리 방법의 일환으로, 대규모 상수관망시스템을 대상으로 Lab-scale 실험을 통한 수체반응계수, EPANET 수질해석을 통한 관체반응계수 등 관망 수질반응계 수를 온도별로 추정하고, 온도별 수질반응계수를 바탕으로 염소투입농도 조건에 따른 월별 잔류염소농도 분포 현황을 분석하였다. 분석 결과, 온도 조건이 달라짐에 따라 잔류염소농도 하한 및 상한기준을 만족시킬 수 있는 효율적인 염소투입농도 조건 또한 달라지므로, 월별 잔류염소농도의 공간적 분포를 고려하여 구체적이고 정량적인 염소투입 계획 수립이 필요한 것으로 판단된다.

Keywords

Acknowledgement

본 연구는 1) 과학기술정보통신부 한국연구재단(과제번호: NRF-2020R1A2C2009517)의 지원과 2) 환경부 한국환경산업기술원의 상하수도 혁신 기술개발사업(과제번호: 2020002700004)의 지원으로 수행되었습니다. 이에 감사드립니다.

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