Characteristics on Water Quality of Rainwater Harvesting System in Gwangju

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Research article

Journal of the Korean Society for Environmental Analysis 2016;19(2):63-71.

광주지역 빗물이용시설의 수질특성에 관한 연구

안상수¹, 위환², 윤상훈², 장서은³, 정숙경³, 조영관², 김은선²

¹광주광역시보건환경연구원
²광주광역시 보건환경연구원
³광주시보건환경연구원

Abstract

To investigate the characteristics of rainwater quality as pH, color, turbidity, EC (electronic conductivity) and heavy metals in Gwangju area, 43 samples were collected at initial rainfall amounts over 3 mm/day during March to October in 2015. For 32 samples over 5 mm/day rainfall amount, pH was 4.8~6.5, and turbidity, color and NH3-N were 0.77~97.88 NTU, 4~16 degree, 0.6~12.0 mg/L, respectively, which are exceeding the drinking water standard. Heavy metals (except for Fe, Zn and Cu), volatile organic compounds and pesticides were not detected. Concentrations of color and turbidity in rainwater were decreased contrarily to the lapsed time at the storage, whereas the concentration of Zn was not so much changed compare to the initial state. Particulate matter (PM10) in air has the negative correlation with pH and positive correlations with turbidity, color and EC in rainwater. Seasonal variation showed that pH, DO, turbidity, color and EC in spring was lower than in summer with the influence of rainfall frequency and amount. Rainwater quality of pH, color and turbidity was lowered depending on the lapsed time for 10 days. pH was a little higher at concrete storage tank than at FRP storage tank because alkaline compound as CaCO3 flow out of the concrete surface, whereas turbidity was a little higher at FRP storage tank than at concrete storage tank.

Key Words: Rainwater harvesting system, Turbidity, Color, Concrete storage tank, FRP storage tank