In-situ metal precipitation immobilizes a mobile (heavy) metal contamination in the soil through the introduction of substrates into the aquifer. The contamination can be precipitated by both chemical and biological processes.
In situ metal precipitation is used for heavy metals such as zinc, nickel, chromium and cadmium. ISMP is applied in the saturated zone. The soil should be moderately to well permeable. The binding capacity of the soil is important and depends on the composition of the soil (organic matter, clay and iron- and aluminum oxides) and pH. This situation must be stable to prevent solution of precipitated metals. The technique can only be applied to the plume. In situ metal precipitation can be combined with pump and treat to prevent the spreading of the contamination in the plume and to control the spread of the substrate by stimulation of the contaminated soil. Another application is the precipitation through a reactive barrier.
The duration of this technique is entirely dependent on the extent of contamination and whether the source is still present or not. The duration varies from several months to many years. The disturbance of the site is low.
Related cases and HIP-pilots