Release flux of heavy metals from river sediments at different flow rates

Abstract

This paper simulates sediment motion under different hydrodynamic conditions, aiming to investigate the release flux of heavy metals in river sediments. During the lab experiments, carried out in a circular rectangular flume device, water velocity in the flume was altered by controlling the gate switch, and the flow rate was controlled from 0 to 1 m/s. Sediment from the Le'an River and chlorine-removed tap water were used as experimental sediment and water, respectively. Through analyses of Cu, Zn, Cd, and Pb concentration in water at different flow rates, the relationship between the release flux (y) of Cu, Zn, Cd, and Pb and the flow rate (x) was established with a fitting error of less than 15%. In order to judge the reliability of the conclusions, experimental results were verified outdoors. The results showed when the sediment particle size is between 0 and 250 μm, within 1 hour, a quadratic polynomial correlation between the release flux of Cu, Cd, and Pb from river sediments and water velocity when the water pH is 5–9 and the flow rate is 0–65 cm/s; when the water pH is 5–9, the flow rate is 0–35 cm/s, the release flux of Zn from river sediments was shown to have a quadratic polynomial relationship with water velocity. The error between the calculated and measured values of heavy metals released from sediment in the Le'an River were within 5–30%. Our results can provide a theoretical reference for the control and treatment of heavy metal pollution in rivers and further improve corresponding water quality models.

Release of Selected Metals (Al, Cd, Cu, Mn, Ni, Fe, Zn) from River Bottom Sediments: An Experimental Study

“…Especially strong migration was observed there for copper compounds. Although the present study did not undertake this type of research and simulation under laboratory conditions, as presented in their study by Lu et al [19], it proves that this type of process can take place in studies of the Nysa Szalona, Bystrzyca and Strzegomka rivers.…”

“…The aim of this study was to determine the effect of changes (variation in environmental conditions) in water pH on the release of metals bound in bottom sediments into water, as this research problem has not been addressed in the area examined by us so far and has not been presented in the literature [18][19][20][21][22][23]. Although the study area does not record particularly high levels of heavy metals in environmental components, the catchment area of these three rivers is the source of drinking water for a sizable portion of the population of southwestern Poland.…”