Fe1-xS/biochar combined with thiobacillus enhancing lead phytoavailability in contaminated soil: Preparation of biochar, enrichment of thiobacillus and their function on soil lead. (December 2020)

• Record Type: Journal Article
• Authors: Ye, Junpei; Liao, Wenmin; Zhang, Panyue; Li, Juan; Nabi, Mohammad; Wang, Siqi; Cai, Yajing; Li, Fan
• Is Part Of: Environmental pollution. Volume 267(2020)
• Publication Date: 2020-12
• Subjects: Lead-contaminated soil -- Sulfur-iron modified biochar -- Thiobacillus -- Biooxidation -- Phytoavailability; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115447
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Properly increasing mobility of heavy metals could promote phytoremediation of contaminated soil. Fe1-x S/biochar was successfully prepared from sawdust with loading pyrrhotite (Fe1-x S) at a pyrolysis temperature of 550 °C. Thiobacillus were successfully adsorbed and enriched on the surface of Fe1-x S/biochar. Microbial growth for 36 d supported by bio-oxidization of Fe1-x S decreased the system pH from 4.32 to 3.50, increased the ORP from 298 to 487 mV, and the Fe 3+ release reached 25.48 mg/g, enhancing the oxidation and leaching of soil Pb. Finally, Fe1-x S/biochar and Thiobacillus were simultaneously applied into Pb-contaminated soil for 60 d, the soil pH decreased from 7.83 to 6.72, and the exchangeable fraction of soil Pb increased from 22.86% to 37.19%. Ryegrass planting for 60 d in Pb-contaminated soil with Fe1-x S/biochar and Thiobacillus showed that the Pb content in shoot and root of ryegrass increased by 55.65% and 73.43%, respectively, confirming an obvious increase of phytoavailability of soil Pb. The relative abundance of Thiobacillus in remediated soil significantly increased from 0.06% to 34.55% due to the addition of Fe1-x S/biochar and Thiobacillus . This study provides a novel approach for regulating the Pb phytoavailability for phytoremediation of Pb-contaminated soil. Graphical abstract: Image 1 Highlights: Fe1-x S/biochar was simply prepared for in-situ phytoremediation of soil Pb. Fe1-x S/biochar supported Thiobacillus growth and improved bioavailability of soil Pb. Fe1-x S/biochar with Thiobacillus worked as acidic spots in Pb-contaminated soil.