Gypsum soil amendment in metal-polluted soils-an added environmental hazard

Dubrovina, Tatiana A.; Losev, Artem A.; Karpukhin, Mikhail M.; Vorobeichik, Evgenii L.; Dovletyarova, Elvira A.; Brykov, Vasyl A.; Brykova, Ramilla A.; Ginocchio, Rosanna; Yanez, Carolina; Neaman, Alexander

Abstract

Scientists around the world have long been searching for effective strategies to reduce the bioavailability of metals in contaminated soils. In case of metal-spiked soils, some studies have proposed gypsum as a soil amendment to alleviate metal phytotoxicity. However, for real field-collected soils, evidence on the efficacy of gypsum as a metal phytotoxicity amendment is limited. Therefore, the present study was designed to examine the effect of gypsum on plant growth in soils polluted by a copper smelter. We grew perennial ryegrass on untreated and gypsum-treated soils (at a dose of 3% by weight) under laboratory conditions. We found that gypsum had no effect on alleviating metal phytotoxicity in our soils. We also demonstrated - for the first time - that gypsum increased the concentrations of soluble metals in the soil, enhancing metal uptake by plants. The calcium ions from gypsum displace metals in the soil exchangeable complex; however, the metals do not get immobilized in soils because gypsum is a neutral salt. While our results contrast with the Terrestrial Biotic Ligand Model, that Model has never been tested on real industrially polluted soils but only on metal-spiked soils. Our main conclusion is that gypsum is ineffective in alleviating metal phytotoxicity in real industrially polluted soils and, moreover, its use is inappropriate as a soil remediation method, because it increases the environmental hazard rather than reducing it. Our study is the very first attempt to recognize that gypsum is a hazardous material when used to ameliorate soils polluted by metals.

Más información

Título según WOS: Gypsum soil amendment in metal-polluted soils—an added environmental hazard
Título de la Revista: CHEMOSPHERE
Volumen: 281
Editorial: PERGAMON-ELSEVIER SCIENCE LTD
Fecha de publicación: 2021
DOI:

10.1016/j.chemosphere.2021.130889

Notas: ISI