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

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. © 2021 Elsevier Ltd

Dubrovina T.A. 1 , Losev A.A. 1 , Karpukhin M.M.2 , Vorobeichik E.L.3 , Dovletyarova E.A. 1 , Brykov V.A. 4 , Brykova R.A. 1 , Ginocchio R.5, 6 , Yáñez C.7 , Neaman A. 8
Elsevier Ltd
  • 1 Department of Landscape Design and Sustainable Ecosystems, Peoples Friendship University of Russia (RUDN University), Moscow, Russian Federation
  • 2 Faculty of Soil Science, Lomonosov Moscow State University, Moscow, Russian Federation
  • 3 Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russian Federation
  • 4 Institute of Botany, National Academy of Sciences of Ukraine, Kiev, Ukraine
  • 5 Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
  • 6 Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile
  • 7 Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
  • 8 Instituto de Ingeniería Agraria y Suelos, Facultad de Ciencias Agrarias y Alimentarias, Universidad Austral de Chile, Valdivia, Chile
Calcium sulfate; Environmental hazard; Phytotoxicity; Soil remediation; Toxicity
Date of creation
Date of change
Short link

Other records