Performance Evaluation of In-Situ Iron Reactive Barriers at the Oak Ridge Y-12 Site

Watson, David B.

doi:10.2172/885783

Cited by 3 publications

(1 citation statement)

References 8 publications

(16 reference statements)

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“…Permeable reactive barriers (PRBs) and reaction zone (RZ) are technologies used for remediation of soil and contaminated groundwater [4]. Specific adsorption is one of the physicochemical processes used for toxic elements removal [5].…”

Section: Introductionmentioning

confidence: 99%

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

Chaves

Dockal

Souza

et al. 2009

Environmental Technology

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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. The surface area of the silica was measured by nitrogen adsorption/desorption analysis. Surface modification was measured by Fourier transform infrared spectroscopy. The degree of functionalization was obtained by elemental analysis. This work showed that biogenic modified silica can be produced in aqueous media from rice hull ash using a simple method, providing an alternative method for adsorbent preparation. Thermogravimetric analysis showed that the salen-modified silica is stable up to 209 degrees C. The modified silica displays appropriate structural characteristics for an adsorbent. The cylindrical pores, open at both ends, allow free diffusion of cadmium ions to the adsorption sites on the silica surface. The surface modification increases cadmium adsorption on the silica surface 100-fold. The salen-modified silica showed specific adsorption for Cd(2+) of 44.52 mg/g SiO2 at cadmium concentration of 100 mg/l.

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Section: Introductionmentioning

confidence: 99%