Related Experiment Videos
Development of a biosorbent for arsenite: structural modeling based on X-ray spectroscopy
Monica Cristina Teixeira1, Virginia S T Ciminelli
1Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, Belo Horizonte MG, Brazil.
Environmental Science & Technology
|March 11, 2005
Summary
Chicken feather waste effectively removes toxic As(III) arsenic from water. This biological method selectively adsorbs arsenic in its reduced form, offering a novel environmental remediation strategy.
Area of Science:
- Environmental Science
- Biotechnology
- Materials Science
Background:
- Arsenic(III) (As(III)) species are highly toxic and mobile in soil and water.
- Conventional arsenic removal methods often require prior oxidation of As(III).
- Waste biomass with high protein content is a potential low-cost adsorbent.
Purpose of the Study:
- To develop a biological route for direct As(III) sorption from aqueous solutions.
- To investigate the use of chicken feather waste as a selective adsorbent for As(III).
- To elucidate the mechanism of As(III) adsorption on modified biomass.
Main Methods:
- Modification of chicken feather biomass by reducing disulfide bridges with thioglycolate.
- Batch adsorption experiments to determine As(III) uptake capacity and pH dependency.
- Synchrotron-based X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) analyses to characterize adsorbed arsenic species and coordination environment.
Main Results:
- Chicken feather biomass selectively adsorbs As(III) with an uptake capacity of up to 270 micromol As(III)/g.
- Adsorption efficiency increases as pH decreases, unlike inorganic sorbents.
- XANES and EXAFS analyses confirmed that As(III) is adsorbed in its trivalent state, bound to three sulfur atoms.
Conclusions:
- Modified chicken feather biomass provides an effective biological route for direct As(III) removal.
- The adsorption mechanism involves direct binding of As(III) to sulfur atoms in the biomass.
- This approach offers a promising alternative for arsenic remediation without requiring prior oxidation.