In-Situ-Immobilization of Arsenic Compounds in the Water-Saturated Zone. 
Joint Venture Project: "Development of Remediation Technologies for Inorganic Contaminants in Soils"
(Arsen)

Formerly, arsenic compounds were widely used in the tannery process, and arsenic waste was disposed either by burying or spray irrigation. Consequently, those soils are contaminated with arsenic and need to be remediated.
In order to develop soil remediation technologies, the Engler-Bunte-Institut, the Umweltwirtschaft GmbH (Stuttgart), and the Institut für Wasserbau at the University of Stuttgart cooperate in the joint venture project "Development of remediation technologies for inorganic contaminants in soils".
The research focuses in a first phase of the project on the analysis of a contaminated soil containing "naturally" immobilized arsenic in order to develop an in-situ soil remediation technology by immobilization of arsenic. After physical characterization, leaching and mobility tests, sequential extraction techniques will be performed to monitor the distribution of arsenic between different fractions. The determination of different arsenic species (arsenites, arsenates and methylated organic arsenic species) will be carried out using HPLC-ICP/MS.
After the investigation of the mechanisms and chemical conditions causing the immobilization of arsenic in the analyzed soil, the results will be used in immobilization studies using artificially contaminated soils.
In cooperation with the project partners, the results obtained in the laboratory studies will be transferred on a model soil contaminated with arsenic. This second phase of the project will take place in the Pilot Plant for Groundwater and Soil Remediation Technologies (VEGAS) which is situated at the University of Stuttgart.

Supported by the Umweltbundesamt (Federal Environmental Agency)