Effect of Glauconite-Containing Wastes Obtained during Phosphorite Enrichment on Lead Mobility in Soils

• Published in: Biology bulletin of the Russian Academy of Sciences 2022-12, Vol.49 (10), p.2004-2008
• Main Authors: Syrchina, N. V., Pilip, L. V., Ashikhmina, T. Ya, Kantor, G. Ya
• Format: Article
• Language: English
• Subjects: Acidic soils; Biochemistry; Biomedical and Life Sciences; Cell Biology; Ecology; Heavy metals; Humus; Immobilization; Lead; Life Sciences; Mobility; Organic matter; Organic soils; Phosphorus; Rehabilitation; Soil contamination; Soil pollution; Zoology
• ISSN: 1062-3590; 1608-3059
• DOI: 10.1134/S1062359022100387

—Lead (plumbum, Pb) is a toxic element of the first hazard class. Global soil pollution with Pb leads to severe consequences for the environment and human health. Mobile Pb forms represent a special environmental danger. To immobilize Pb in soils, various materials (ameliorants) are used which can convert it into some form that is poorly soluble in water and weak acids. The search for safe natural materials for the rehabilitation of contaminated soils is of great practical importance. Glauconite-containing phosphorite tailings (PTs) are promising reclamation materials. The main component of PTs, glauconite, is a natural sorbent that is capable of binding heavy metals. The composition of PTs also includes small-fraction phosphorites, clay and calcareous components, and quartz. The effect of PTs on lead mobility in soil was studied in laboratory conditions. Four variants of loamy soil with various chemical structures were used. The lead content in different soil samples did not differ statistically significantly from each other. The effect of PTs on lead mobility was evaluated in comparison with limestone. The ameliorants were introduced in a dosage of 1 g/kg. The studies revealed that the use of PTs led to active Pb immobilization in acidic organic-depleted soils, while lime did so in neutral highly humus soils. Mathematical processing of our experimental results suggests that the formation of sedentary complexes with organic matter and adsorption of lead on glauconite serves as the predominant mechanism of binding Pb in soil when using lime and PTs, respectively. The introduction of PTs causes a decrease in the Pb mobility, as well as the enrichment of the soil with phosphorus, potassium, sulfur, calcium, and trace elements contained in this ameliorant. This is important for restoring the fertility of degraded lands.