Einsatz von Magnetit-immobilisierten Chelatoren zur Extraktion von Schwermetallen aus Boden und Wasser

The aim of this work was to investigate the feasibility of applying functionalized magnetic beads to extract the heavy metals from soil and water for analyzing heavy metals in soil and water and decontaminating the environment polluted by heavy metals. This study was carried out with the as received carboxylated magnetic beads (C12 and C22) provided by the manufacturer (Chemagen), and self-modified magnetic beads (Ep and Bu). First of all, to investigate the applicability of the magnetic beads to soil analysis, Cd and Pb were extracted from various soil samples with carboxylated beads (C12 and C22) and IDA-immobilized beads (Ep and Bu). The highest extraction efficiency (Cd: 56 %, Pb: 71 %) was achieved with the carboxylated C12-beads. Under the experimental conditions, mobile heavy metals were only extracted from the soil samples since magnetic beads, soil and water were simply involved in this extraction process. Significantly higher extraction efficiency was achieved with the C12-magnetic beads for the soil at Stolberg, which are heavily contaminated by Cd and Pb, in comparison with the EDTA-extraction method, which is the most well established method to determine the mobile heavy metal fraction in soil. This indicates that the extraction of the mobile heavy metals, i.e. absorbable heavy metals, in plants cannot be satisfactorily achieved with the EDTA-extraction method. On the contrary, for the loamy and silty soils, the extraction efficiency was lower with magnetic beads than with EDTA. Therefore, the magnetic beads/EDTA combined extraction method is proposed to determine the mobile heavy metals in various soils effectively. Secondly, decontamination of heavy metals from soils and wastewater with magnetic beads was tested. As mentioned previously, relatively high extraction efficiencies of Cd and Pb were achieved with C12- and C22-beads for sandy soil at Stolberg. From the economic viewpoint, reuse of magnetic beads is necessary. Several methods were investigated. First, the used magnetic beads were regenerated by diluted HCl or mixture of HCl/citric acid, and recycled for extracting heavy metals from soil. The extraction capacity was found to be 70 % - 100 % of the fresh beads. In addition, the applicability of magnetic beads to wastewater analysis was investigated. Heavy metals were combined with magnetic beads in order to separate from wastewater and then analyzed by dissolving the magnetic beads. To do so, heavy metals (Cd, Pb, Cu, Ni, Cr) in various concentrations (10 ppb – 10 ppm) were extracted with 4 types of magnetic beads (beads with carboxyl group: C12, C22 and beads with IDA-group: Ep, Bu) from the solution. For the 10 ppm heavy metal solution, a very high extraction efficiency of over 95 % could be achieved in short time of less than 1 min. with all types of beads. However, for the ppb range of solutions, the extraction efficiency was poor for all types of beads. When standard mixture was used, the extraction of each metal was not hindered by competitive heavy metal ions. On the contrary, addition such as salts (NaCl, Phosphate) or chelate (EDTA) clearly decreased the effect of the combination of all the metals investigated by the magnetic beads.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2003

Author dc:creator

• So, Hyungsuk

Contributors dc:contributor

• Schäffer, Andreas

• info:eu-repo/classification/ddc/540
• Trägerfixiertes Reagenz
• Chelatbildner
• Magnetit
• Trägersubstanz
• Schwermetall
• Extraktion
• Bodenverschmutzung
• Wasserverschmutzung
• Chemie
• Schwermetallanalytik
• Magnetbeads

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-120709%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:58882