Using biochar as an amendment to control the mobility of heavy metals in contaminated soils

Frederic Rees, Researcher and PhD student at the University of Lorraine in Nancy, France, will give this seminar titled "Using biochar as an amendment to control the mobility of heavy metals in contaminated soils" at the James Hutton Institute in Aberdeen.

Abstract

Biochar, the solid product obtained from the pyrolysis of biomass, has gained attention over recent years as a providential soil amendment, mainly in relation to storing carbon; high carbon content, low bio-physical degradability etc. In organo-mineral soils biochar has also been used as a soil improver, for example, for soil water retention etc. Its porous nature and chemical properties (high cation-exchange capacity) have also resulted in several favourable remediation effects, in particular regarding the immobilisation of heavy metals in available/leachable forms.

In this seminar, after a brief overview of all the potential benefits and risks that have been suggested for biochar, we will focus on the influence of biochar on the mobility of potentially toxic cations such as Pb, Cu, Cd, Zn and Ni in contaminated soils, by differentiating between:

• 1) the direct retention of these elements on biochar surfaces 
• 2) their indirectly increased retention on soil particles, using batch sorption experiments and specific column leaching tests.

We will then examine, with the help of plant growth experiments in pots and rhizoboxes, how biochar can affect the uptake of metals by the plants by modifying the development of roots in the soil and the local pH variations within the rhizosphere.

Biography

Frederic is a researcher and PhD student from University of Lorraine in Nancy, France and part of a team studying organic and mineral matrices in the context of environmental remediation, especially of heavy metal contaminated substrates. Frederic has recently published two papers highlighting the actual influence of biochar on trace element mobility in soil-plant systems, to identify the processes behind such effects and to enable the long-term prediction of heavy metals immobilisation in polluted soils after applying biochar.

This seminar will be hosted by Dr Luke Beesley, Environmental and Biochemical Sciences.