Impact of Salinity Change on Water Quality Variables from the Sediment of an Artificial Lake under Anaerobic Conditions

Abstract

Artificial reservoirs are created by dike construction in coastal areas to secure the agricultural water supply on the west coast of South Korea. These systems are found to retain brackish characteristics until total desalination is achieved. To evaluate the effects of salinity on the organic substances released from the sediment, a laboratory water-sediment column experiment was conducted to assess associated changes in water quality variables such as the sediment oxygen demand (SOD), chemical oxygen demand (COD), and concentrations of nitrogen (N) and phosphorus (P). Under high salinity conditions, the release of N from the sediment was promoted with the enhancement of SOD and COD. This trend was accounted for by the response of the microorganisms (cell breakdown of algae and suppression of metabolic activity). Our results suggest that chemicals (N, P, and COD) released from sediment and its overall impact on the water quality of a brackish lake should vary depending on the temporal and spatial dynamics of the salinity.

A Study on the Characteristics of Organic Matter and Nutrients Released from Sediments into Agricultural Reservoirs

“…However, physicochemical environmental changes that occur because of actual rainfall runoff, inflow and outflow of water, and biological environment changes from microbial activity could not be reflected accurately within the given experimental time frame. However, several other studies have obtained significant results by using the same experimental procedure, as that used for the release experiment in the current study [32,[36][37][38]. Several other studies have also yielded meaningful results.…”