Behaviour of Sediments in Water Structures

Abstract

Bottom sediments are a natural part of aquatic ecosystems. They are increasingly contributing to the deterioration of watercourses and reservoirs and are an undesirable material that causes various serious environmental and technical problems. The most significant problems include the instability of riverbeds, the transport of chemicals, nutrients and organic compounds, the supply of sediments to water reservoirs. Bottom sediments have the ability to bind to their surface various predominantly harmful substances such as heavy metals, radionuclides, nutrients and organic substances. Such sediments pose a risk to the water system in terms of possible remobilization of pollutants into the water.This paper is focused on the study of behavior of sediments in the Hervartov small water reservoir located in the east of Slovakia and their ability to adsorb phosphorus at the sediment-water interface. The results show that the efficiency of sorption of phosphorus from the aqueous environment by fine and coarse-grained sediments is the highest at the lowest input concentrations of phosphorus in solution, or at low concentrations in surface water above the sediment. At these concentrations, the amount of sorbed phosphorus by fine-grained sediments was up to almost 99%. The coarse-grained sediments sorbed phosphorus at a level of up to 84%. Increasing the concentration of phosphorus in the solution leads to a decrease in the sorption efficiency of the sediment, while at high concentrations of the sorbate, the sorption process is significantly stabilized due to reaching the maximum sorption capacity of bottom sediments.