Clay minerals as a source of cadmium to estuaries.

ABSTRACT: Given the high surface reactivity of clay minerals, it is assumed that flocculation will lead to metal accumulation in marginal marine settings. However, the degree of metal sorption to clays is impacted by solution pH and ionic strength, and it remains unknown whether riverine clays indeed serve as a metal sink once they encounter seawater where pH and ionic strength markedly increase. Here, we conducted cadmium (Cd) adsorption experiments to three types of common clay minerals - kaolinite, illite and montmorillonite. We found that 20-30% of Cd from illite and montmorillonite surfaces were desorbed when transitioning from freshwater to seawater pH and ionic strength conditions, while kaolinite showed no discernible differences. Synchrotron X-ray adsorption spectroscopy confirmed that Cd r

SUBMITTER: Hao W 

PROVIDER: S-EPMC7320025 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature