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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Adaptive Cropping Systems Laboratory » Research » Publications at this Location » Publication #309415
Title: Potential of chitosan (chemically-modified chitin) for extraction of lead-arsenate contaminated soils

Author
item Codling, Eton
item PADILLA-RODRIGUEZ, ABIGAIL - University Of Puerto Rico

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/27/2016
Publication Date: 7/20/2016
Citation: Codling, E.E., Padilla-Rodriguez, A. 2016. Potential of chitosan (chemically-modified chitin) for extraction of lead-arsenate contaminated soils. Communications in Soil Science and Plant Analysis. 47(13-14):1650-1663. doi:10-1080/00103624.2016.1206123.

Interpretive Summary: Arsenic, phosphorous, and lead contamination in soils represents a health risk to humans and the environment. Chitosan (poly-N-acetyl glucosamine) is a non-toxic and inexpensive food industry byproduct derived from chitin that has been used as an adsorbent of heavy metals. The objectives of this study were: 1) to evaluate the effectiveness of chitosan solution for the extraction of Arsenic, phosphorous, and lead from soil contaminated with lead-arsenate, and, 2) to evaluate the effectiveness of protonated chitosan flakes and ferric hydroxide chitosan beads for the removal of As from those same soils. Soils were collected from orchards with a history of lead-arsenate use. Percent Arsenic, lead, and phosphorous removed by chitosan ranged from 0.96 to 17%, from 1.8 to 31%, and from 0.66 to 11%, respectively. Percent removal of As by PCF and by Fe(III)-CB ranged from 12 to 47% and from 36 to 77%, respectively. The amount of arsenic removed by Fe(III)-CB equals that of the standard soil extractant Mehlich III. This data indicate potential for the use of chitosan in remediation of lead-arsenate contaminated soils.

Technical Abstract: Arsenic (As), phosphorous (P), and lead (Pb) contamination in soils represents a health risk to humans and the environment. Chitosan (poly-N-acetyl glucosamine) is a non-toxic and inexpensive food industry byproduct derived from chitin that has been used as an adsorbent of heavy metals. The objectives of this research were: 1) to evaluate the effectiveness of chitosan solution for the extraction of As, Pb, and P from seven lead-arsenate contaminated soils, and, 2) to evaluate the effectiveness of protonated chitosan flakes (PCF) and ferric hydroxide chitosan beads (Fe(III)-CB) for the removal of As from those same soils. Soils were collected from Maryland, New York, Michigan, and Washington. A Montana soil was used as a reference soil. Percent removal of As, Pb, and P from soil by chitosan solution ranged from 0.96 to 17%, from 1.8 to 31%, and from 0.66 to 11%, respectively, for the seven soils. Percent removal of As by PCF and by Fe(III)-CB ranged from 12 to 47% and from 36 to 77%, respectively. Averaged over soils, Fe(III)-CB removed slightly more As (42 mg kg-1) than did the standard soil extractant Mehlich III (40 mg kg-1). This data indicate potential for the use of chitosan in remediation of lead-arsenate contaminated soils.