Effects of biochar and activated carbon amendment on maize growth and the uptake and measured availability of polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs)

With the aim of investigating the effects of carbonaceous sorbent amendment on plant health and end point contaminant bioavailability, plant experiments were set up to grow maize (Zea mays) in soil contaminated with polycyclic aromatic hydrocarbons (PAHs) and metals. Maize and pine derived biochars, as well as a commercial grade activated carbon, were used as amendments. Plant growth characteristics, such as chlorophyll content and shoot to root biomass, improved with sorbent amendment to varying extents and contaminant uptake to shoots was consistently reduced in amended soils. By further defining the conditions in which sorbent amended soils successfully reduce contaminant bioavailability and improve plant growth, this work will inform field scale remediation efforts. •Carbonaceous sorbent amendment had a net positive effect on plant growth.•Biochar and activated carbon reduced Cu and As uptake to plants and extractability from soil.•Activated carbon was better at reducing PAHs in porewater than biochar but plant uptake was similar. Biochar and activated carbon reduce PAH and PTE uptake to maize plants to varying extents and improve plant growth.