Mercury uptake by biogenic silica modified with L-cysteine.

Contaminated sediments provide the main source of mercury for methylation by bacteria in lakes and waterways. In situ capping has been used to remediate these sediments, but traditional reactive materials have very low affinity for Hg(II). This study investigated the mercury uptake by biogenic silica modified with L-cysteine, as a potential material to be used for in situ remediation technologies.

Biogenic modified silica as a sorbent of cadmium ions: preparation and characterization.

This work describes the preparation and characterization of biogenic modified silica from rice hull ash and its use as a sorbent of cadmium ions. Thus, an agro-industrial residue has been used to produce a new adsorbent product which is able to remove toxic elements. Mesoporous biogenic silica was obtained by alkaline extraction of sodium silicate by hydrolysis with the sol-gel process, and it was modified with salen using 1,2-dichloroethane as a spacer.