Effect of amendments on soil Cd sorption and trophic transfer of Cd and mineral nutrition along the food chain

• Published in: Ecotoxicology and environmental safety 2020-02, Vol.189, p.110045, Article 110045
• Main Authors: Wang, Yi-min, Tang, Dou-dou, Yuan, Xu-yin, Uchimiya, Minori, Li, Ji-zhou, Li, Zhen-yu, Luo, Zi-cheng, Xu, Ze-wen, Sun, Shi-ge
• Format: Article
• Language: English
• Subjects: Animals; Bioaccumulation; Biochar; Cadmium; Cadmium - analysis; Cadmium - metabolism; Calcium - metabolism; Charcoal - chemistry; Food Chain; Lactuca - drug effects; Lactuca - metabolism; Micro-hydroxyapatite; Minerals - metabolism; Nutrient element; Silicon - metabolism; Snails - drug effects; Snails - metabolism; Soil - chemistry; Soil Pollutants - analysis; Soil Pollutants - metabolism; Trophic transfer
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2019.110045

Phytotoxicity of cadmium (Cd) and its trophic transfer along a terrestrial food chain have been extensively investigated. However, few studies focused on the role of amendments on the trophic transfer of Cd and related mineral nutrients. In a 60-day pot experiment, soil Cd availability, accumulation of Cd, mineral nutrients (Ca and Si) in lettuce, and subsequent trophic transfer along the lettuce-snail system were investigated with or without 3% (w/w) soil amendment (biochar or micro-hydroxyapatite, μHAP). Soil CaCl2 extractable Cd (CdCaCl2) contents decreased by both amendments. μHAP amended soil increased the Freundlich sorption capacity of Cd2+ to a greater extent (15.9 mmol/kg) than biochar (12.6 mmol/kg). Cd, Ca and Si accumulation in lettuce tissues (roots and shoots) varied with amendment species and soil Cd levels. Linear regression analysis showed that root Cd contents are negatively correlated with root Ca and Si contents (r2 = 0.96, p  0.05). After 15 days snail feeding, nearly 90% content of Cd was found in snail viscera, while nearly 95% content of Ca was found in snail shells. Contents of Si distributed equally in snail tissues. Biomagnification of Cd, Ca and Si (TF > 1) was found in lettuce shoot - snail viscera system. Opposite tendency of TF variation between Cd and nutrient elements (Ca and Si) from shoots to snail tissues indicated that μHAP, rather than biochar, amendment is applicable to remediate soil Cd contamination in our study. •μHAP amended soil had a higher adsorption capacity of Cd2+ than biochar amendment.•Root Cd content was negatively correlated with root Ca and Si contents (r2 = 0.96).•μHAP, rather than biochar, amendment decreased Cd TF but increased Ca and Si TFs.