Factors affecting metal exchange between sediment and water in an estuarine reservoir: a spatial and seasonal observation.
Water quality response in a reservoir has often been assessed using relatively restricted datasets that cannot provide sufficient information, thereby giving rise to a dramatic over- or underestimate of actual figures. In this paper we discuss how the levels of metallic elements between the sediment and overlying water in an estuarine reservoir can be influenced by aquatic parameters in response to spatial and seasonal conditions. To better elucidate the interfacial exchange between sediment and water, statistical analyses are employed to intensive data sets collected from the Yeongsan Reservoir (YSR), Korea, which has undergone widespread deterioration in water quality due to the continuous growth of anthropogenic sources. During three seasonal sampling campaigns, we found that oxygen deficiency at the bottom water layer promotes Fe and Ni accumulation in sediment, likely due to the formation of sulfide and oxide complexes under anoxic and suboxic environments, respectively. In addition, salinity levels as high as 11 per thousand in the bottom water layer during autumn substantially increase the release of Mn, restricting the use of YSR as a primary source of agricultural irrigation water. Although most dissolved metals are at acceptable levels for sustaining aquatic life, it is recommended that for long-term planning the elevated Fe and Mn levels in sediment should be controlled with oxygen deficiency during dry weather to ensure a sustainable water supply or, at a minimum, better coordinated operation of YSR.
Kang
Joo-Hyon
JH
Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Korea.
Lee
Young Geun
YG
Lee
Keun-Young
KY
Cha
Sung Min
SM
Cho
Kyung Hwa
KH
Lee
Yun Seok
YS
Ki
Seo Jin
SJ
Yoon
In-Ho
IH
Kim
Kyoung-Woong
KW
Kim
Joon Ha
JH
D000693:Anaerobiosis; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D007723:Korea; D008345:Manganese / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D012621:Seasons; D012995:Solubility; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D014881:Water Supply / Q000592:standards*
D014874:Water Pollutants, Chemical; D008345:Manganese; D007501:Iron; D010100:Oxygen