Bioturbation/bioirrigation effect on thallium released from reservoir sediment by different organism types

Copyright © 2015 Elsevier B.V. All rights reserved..

Bioturbation can remobilize heavy metal in the sediments and may pose a risk for aquatic biota. The effects of bioturbation/bioirrigation by three different riverine organism types (Tubificid, Chironomid larvae, and Loach) on thallium release from contaminated sediment (10.0 ± 1.1 mg Tl/kg sediment, dry wt.) were evaluated in this study. The bioturbation by the epibenthos clearly caused an increased turbidity in the overlying water, and the effect was in the order of Loach > Chironomid larvae > Tubificid. A significant release of Tl into the water column via the resuspended sediment particles was observed, especially for Loach. During the first few days, the leaching of dissolved Tl from sediment into water was fast, and the dissolved Tl under bioturbation/bioirrigation was much higher than the control group. However, after 14 days, the bioturbation/bioirrigation process seemed to suppress the release of Tl from the sediment particles to water, especially for sediment with Loach. This may partly be due to the sorption or coprecipitation of Tl simultaneous with the formation of iron and manganese hydrous oxides with increased pH values as a consequence of phytoplankton growth. Linear regression analysis confirmed that both the total and particulate Tl concentrations had good correlations with particulate Fe and Mn concentrations as well as turbidity in the overlying water. Additionally, planktonic bacteria may oxidize the Tl(I) to Tl(III), resulting in a reduced solubility of Tl by which Tl(OH)3 becomes the predominant form of Tl.

Medienart:

E-Artikel

Erscheinungsjahr:

2015

Erschienen:

2015

Enthalten in:

Zur Gesamtaufnahme - volume:532

Enthalten in:

The Science of the total environment - 532(2015) vom: 01. Nov., Seite 617-24

Sprache:

Englisch

Beteiligte Personen:

He, Yi [VerfasserIn]
Men, Bin [VerfasserIn]
Yang, Xiaofang [VerfasserIn]
Wang, Dongsheng [VerfasserIn]

Links:

Volltext

Themen:

AD84R52XLF
Bioturbation
Chironomid larvae
Journal Article
Loach
Research Support, Non-U.S. Gov't
Reservoir
Thallium
Tubificid
Water Pollutants, Chemical

Anmerkungen:

Date Completed 04.03.2016

Date Revised 28.08.2015

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.scitotenv.2015.06.075

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM250388243