Heavy metal uptake by wheat seedlings grown in fly ash-amended soils

A bioassay technique was used to investigate heavy metals uptake by wheat seedlings grown in fly ash-amended soils. No negative effect of fly ash on the growth of wheat seedlings was found. The addition of the fly ash generally decreased the heavy metal concentration in the wheat seedlings. The total accumulation largely depended on the soil characteristics. The variation in the soil pH induced by the fly ash treatment could be considered the most important parameter that influenced heavy metals uptake. In the soil with a higher increase of pH (2 units) total accumulation of heavy metals decreased with increasing fly ash addition. In the other soils where the pH variation was lower (0.4 units), total accumulation of some heavy metals increased. These obtained data provide useful information which is required before the agronomic use of fly ash can be recommended in Italian soils.