Journal of Korean Society of Agricultural Engineers ISSN:1738-3692(Print) 2093-7709(Online) 한국농공학회논문집

Sediment pollutants have been considered an important source for the eutrophication of estuarine reservoir. In this study, the effects of pollutants released from bottom sediment to water column were investigated. Sediment samples were collected each two station from Namyang and Sukmoon estuarine reservoirs in August 2013. The fractionation result of sediment phosphorus indicated that Adsorbed-P (36.7±8.84 %) and Nonapatite-P (29.3±12.50 %) are the two dominant phosphorus groups in the sediments. For sediment release test, eight sets of acrylic chamber (0.3 m diameter×1 m high, with 0.15 m sediment depth) were used with aerobic and anaerobic environment. Under anaerobic conditions, rates of NH4-N release from the sediments were highly variable, with final concentrations of NH₄-N in the overlying water varying from between about 0.69～1.04 in Namyang and 2.58～4.23 mg/L in Sukmoon reservoir. The NH₄-N release was active at the upstream around the confluence of tributary compared to downstream near the embankment. The PO₄-P release was more obvious than NH₄-N in anaerobic condition. The final PO₄-P concentrations were approximately from two-fold to eight-fold higher than initial concentration. In terms of reservoir water quality management, not only tributary pollutants but also sediment nutrient loading is necessary to consider the water quality contribution.