Remediation of arsenic-spiked soil by biochar-loaded nanoscale zero-valent iron: Performance, mechanism, and microbial response. (20th December 2022)

• Record Type: Journal Article
• Authors: Song, Peipei; Xu, Haiyin; Sun, Saiwu; Xiong, Weiping; Yang, Zhaohui
• Is Part Of: Journal of cleaner production. Volume 380:Part 1(2022)
• Publication Date: 2022-12-20
• Subjects: nZVI@BC -- Arsenic -- Soil -- Remediation mechanism -- Bacterial community; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.134985
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Given the increasingly serious problem of arsenic-contaminated soil, biochar-loaded nanoscale zero-valent iron (nZVI@BC) was prepared in this study for remediation of arsenic-contaminated soil. Characterization analysis showed that nZVI was evenly dispersed on the biochar, the characteristic functional groups of biochar, including –CH, –OH, CO, C–O–C, –OH, etc., were enriched and strengthened, and a relatively stable Fe–OH was formed. The effects of various factors (different materials, nZVI loading ratio, and remediation time) on arsenic fractionation, pH, and CEC in soil were comprehensively investigated. The results demonstrated that arsenic stabilization was positively correlated with the dosage, nZVI loading ratio, and remediation time. 5% nZVI@BC (3:1) exhibited the best immobilization performance, significantly promoted the transformation from labile arsenic to iron-aluminum oxide binding state and residue state, and improved the available iron, pH, and CEC of the soil. The remediation mechanism was revealed, involving electrostatic attraction, surface adsorption, redox, complexation and co-precipitation. In addition, the bacterial community abundance, diversity, and species composition displayed discrepancies with various treatments, especially with 5% nZVI@BC (3:1). Sixty-six biomarker species were screened, mainly belonging to Actinobacteria and Gemmatimonadetes with biochar treatment as well as Firmicutes, Acidobacteria, and Chloroflexi with nZVI@BC treatment . This study will provide the essential theoretical basis and extensive application value for nZVI@BC remediation of arsenic-contaminated soil. Graphical abstract: Image 1 Highlights: The effects of various factors on arsenic immobilization were investigated. 5% nZVI@BC (3:1) exhibited better arsenic immobilization performance. The remediation mechanism was deeply explored. The application of biochar and nZVI@BC changed the soil bacterial community. Sixty-six biomarkers were screened.