The role of interface interaction between iron/sulfate-reducing bacteria (ISRB) and goethite in sulfur (S) redox cycling couple with Cd immobilization.

Abstract

Microbial sulfate reduction leads to the formation of various chalcophile trace metal sulfides, thereby immobilizing chalcophile trace metals in sediments. Iron/sulfate-reducing bacteria (ISRB) are ubiquitous in soils and sediments, its ability to reduce Fe(III) (oxyhydr)oxides and biogeochemical significance have attracted much attention. This research investigated the effect of the goethite and ISRB induced S cycle on cadmium mobility. The experiment demonstrated that the removal of Cd(II) in coexistence of ISRB19 and goethite was more efficiently than their individual components. Combined with X-ray absorption spectroscopy (XAS), transmission electron microscopy (TEM), Raman spectra and X-ray photoelectron spectroscopy (XPS), conclusions can be drawn that goethite enhanced Cd(II) retention by ISRB, which was attributed to the formation of metabolism product during interaction between ISRB19 (Enterobacter chengduensis) and goethite. Our results revealed the interaction of goethite and ISRB in S cycling under anaerobic conditions with its implications for Cd(II) remediation.