The degradation of chelating agents and chemical ligands in soil
should be considered when chelate-assisted remediation is conducted.
The extent of contamination, soil properties, and metal
toxicity may all influence the degradation of the amendments.
Mineralisation of chelating agents and chemical ligands is not
always inhibited in the presence of Cd alone, but may be impeded
by co-contamination of Cd and Zn. In light of our results, we
conclude that rhamnolipid is more biodegradable than EDTA but
more stable in the soil than citric acid. Therefore, concerns related
to the resilience time of metal-complexing agents in soil may be smaller for rhamnolipid than for other ligands, such as EDTA.
However, further studies may be required to fully evaluate the
residual effects of high rhamnolipid rates applied in situ.