The use of spent mushroom compost to enhance the ability of Atriplex halimus to phytoremediate contaminated mine soils

ABSTRACT

The mushroom cultivation industry produces a huge amount of spent mushroom compost (SMC), a wide world agricultural organic waste which causes serious environmental problems. However, this cheap organic waste could be useful in the remediation of contaminated soils. The aim of this work was to assess the potential of SMC in combination with the native shrub Atriplex halimus, to phytoremediate two mine soils contaminated with Cd, Pb and Cu. Firstly, to minimize metal availability in the soil, the optimal doses of SMC were determined. Secondly, a phytoremediation assay in greenhouse conditions was carried out to test the effects of A. halimus in combination with SMC at different doses. The results showed the ability of SMC to reduce soil acidity, the mobility of the metals and the enhancement of A. halimus growth. SMC promoted metal immobilization in the root of A. halimus and decreased the translocation from the roots to the shoots. The combination of SMC amendment and A. halimus produced phytostabilization of the metals in the mine soils assayed. In conclusion, SMC represents an adequate organic solid waste which in combination with A. halimus can reduce the adverse impact caused by the high mobility of metals in acid mine soils.

KEYWORDS:

• Heavy metals
• phytostabilization
• agricultural waste
• immobilization
• pollution

Acknowledgements

The authors thank Recomsa for providing the spent mushroom compost.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCiD

Carlos García-Delgado http://orcid.org/0000-0001-9358-361X

Victoria Cala http://orcid.org/0000-0002-8598-8470

Agustin Gárate http://orcid.org/0000-0003-3034-7067

Enrique Eymar http://orcid.org/0000-0003-4982-1216

Additional information

Funding

This work has been economically supported by Ministry of Economy and Competitiveness of Spain [CTM2013-47874-C2-2-R].