J 2004

Dynamics of Cu, Zn, Cd, and Hg release from sediments at surface conditions

KOMÁREK, Martin and Josef ZEMAN

Basic information

Original name

Dynamics of Cu, Zn, Cd, and Hg release from sediments at surface conditions

Name in Czech

Dynamika uvolňování Cu, Zn, Cd a Hg ze sedimentů za povrchových podmínek

Authors

KOMÁREK, Martin (203 Czech Republic) and Josef ZEMAN (203 Czech Republic, guarantor)

Edition

Bulletin of Geosciences, Praha, Czech Geological Survey, 2004, 1214-1119

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

Geochemistry

Country of publisher

Czech Republic

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

RIV identification code

RIV/00216224:14310/04:00036716

Organization unit

Faculty of Science

Keywords (in Czech)

průtočný reaktor, interakce, geochemické modelování, dynamika uvolňování těžkých kovů, rozpouštění kalcitu

Keywords in English

flowthrough reactors sequential analysis system sediment-water interactions geochemical modeling dynamics of heavy metal release

Tags

International impact, Reviewed
Změněno: 30/9/2009 14:28, doc. RNDr. Josef Zeman, CSc.

Abstract

ORIG CZ

V originále

Sediments and soils have a high capacity for binding heavy metals from contaminated waters. However, these sediments become a potential source of water contamination by subsequently releasing the metals into the water when environmental conditions change. Samples of typical sediments from the Vienna Basin were collected for the experimental study of Cu, Cd, Zn, and Hg release from sediments to water. These sediments were characterized using chemical analysis, XRD analysis, the measurement of sediment sorption parameters, grain and pore analysis, and sequential analysis. Initially, a set of sediment samples was placed into batch reactors, each containing 0.1Msolution of CuSO4, CdSO4, ZnSO4, or HgCl2, and kept there for two months. These artificially contaminated sediments were subsequently leached by distilled water in flow-through reactors. Described experiments show that a significant proportion of the metal remains strongly bound to the sediment after the leaching process, suggesting that the reactions by which they are bound to the sediment are not completely reversed. The rate of metal release is significantly affected by sediment composition and bond type. Geochemical modeling and sequential analysis have confirmed that the metals are not only bound to sediments by sorption, but also by the precipitation of secondary minerals such as brochantite, tenorite (Cu2+), hydrozincite (Zn2+), and otavite (Cd2+). Significant quantities of the metals are releasable from the sediments only in extreme conditions (Cd, Zn, and Cu in strongly acidic reducing conditions, and Hg in acidic oxidizing conditions). The presence of calcite in the sediment decreases the rate of Hg, Zn and Cu release through pH buffering by calcite dissolution (in solutions with pH values ranging from 7 to 7.5). Under these conditions the metals are not released, and can remain bound to the sediment.

In Czech

Sedimenty a půdy mají vysokou kapacitu pro vazbu těžkých kovů z kontaminovaných vod. Vybrané sedimenty byly charakterizovány a podrobeny laboratorním sorpčním experimentům. V závislosti na složení sedimentu dochází k významnému záchytu těžkých kovů.