TY - JOUR
T1 - Gypsum soil amendment in metal-polluted soils—an added environmental hazard
AU - Dubrovina, Tatiana A.
AU - Losev, Artem A.
AU - Karpukhin, Mikhail M.
AU - Vorobeichik, Evgenii L.
AU - Dovletyarova, Elvira A.
AU - Brykov, Vasyl A.
AU - Brykova, Ramilla A.
AU - Ginocchio, Rosanna
AU - YAÑEZ PRIETO, CAROLINA ELVIRA
AU - NEAMAN, ALEXANDER
N1 - Funding Information:
Phytotoxicity experiments involving perennial ryegrass in soils polluted by a copper smelter were funded by the Russian Science Foundation , project number 17-77-200-46 . Article writing was supported by the FONDECYT 1200048 project, the RUDN University Strategic Academic Leadership Program, and the ANID PIA/BASAL FB0002 project (Center of Applied Ecology and Sustainability, CAPES ). The authors also wish to thank Ivan Smorkalov and Maxim Zolatarev for help with soil sampling, Tatiana Gabershtein for soil sample preparation for analysis, Michel Mench and Iván Selles for helpful comments, and Andrei Tchourakov for editing this article.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/10
Y1 - 2021/10
N2 - 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.
AB - 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.
KW - Calcium sulfate
KW - Environmental hazard
KW - Phytotoxicity
KW - Soil remediation
KW - Toxicity
UR - http://www.scopus.com/inward/record.url?scp=85106511306&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2021.130889
DO - 10.1016/j.chemosphere.2021.130889
M3 - Article
AN - SCOPUS:85106511306
VL - 281
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
M1 - 130889
ER -