Method for soil remediation and engineering

Abstract

An electrokinetic method for groundwater protection, soil remediation and engineering which comprises applying an electric field across an area of soil, sediment or slurry so as to generate a pH and Eh gradient and thereby promote the in situ precipitation of a stable iron-rich band. The method may be performed for the purpose of stabilisation and / or strategic dewatering / rewatering of soils, sediment and / or slurries, the improvement of the physical properties of soils and sediments for engineering purposes, the forced and directed migration of contaminated leachates, and / or electro-osmotic purging of non-polar contaminants.

Description

FIELD OF THE INVENTION [0001] This invention relates to an electrokinetic method for groundwater protection, soil remediation and engineering, and, more particularly, to such a method which involves the strategic electrokinetic placing of an iron-rich barrier in soils, sediments and slurries. BACKGROUND [0002] Contaminated soils and groundwater at industrial, waste disposal and spill sites are serious environmental problems. Although clays and silts tend to sequester large quantities of heavy metals, radionuclides, and selected organic polluants (Kovalick 1995), they are relatively resistant to remediation with traditional technologies (e. g. pump and treat, soil washing) because of their low hydraulic conductivities. This has stimulated a considerable amount of research into cost-effective, in situ techniques that can be used to remediate low-permeability, high clay content soils. One emerging technology that has received much attention is electrokinetic remediation. Electrokinetic...

AI Technical Summary

Benefits of technology

[0010] It is an object of the present invention to provide an improved electrokinetic method for groundwater protection, soil remediation and engineering which is low cost, efficient and flexible in its application. The method involves:—

[0011] the strategic and remote electrokinetic placement of an iron-rich barrier to a required geometry, which provides a physical and / or chemical barrier to contaminants, and improves the engineering properties of soils and sediments (contaminated or otherwise);

Problems solved by technology

Contaminated soils and groundwater at industrial, waste disposal and spill sites are serious environmental problems.

It also causes electrophoresis, which results in the migration of colloidal fractions.

However, most contaminated sites contain mixtures of wastes rather than single contaminants and which makes remediation more complicated.

At present there is no standardised universal soil / sediment remediation approach.

Many of these technologies are technically complex and energy intensive, and geared toward the removal of 90% or more of specific contaminants, under very specific field or laboratory-based conditions.

Images