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This study critically appraises employing chitosan as a composite with bentonite, biochar, or both materials as an alternative to conventional barrier materials. A comprehensive literature review was conducted to identify the studies reporting chitosan-bentonite composite (CBC), chitosan amended biochar (CAB), and chitosan-bentonite-biochar composite (CBBC) for effective removal of various contaminants. The study aims to review the synthesis of these composites, identify fundamental properties affecting their adsorption capacities, and examine how these properties affect or enhance the removal abilities of other materials within the composite. Notably, CBC composites have the advantage of adsorbing both cationic and anionic species, such as heavy metals and dyes, due to the cationic nature of chitosan and the anionic nature of montmorillonite, along with the increased accessible surface area due to the clay. CAB composites have the unique advantage of being low-cost sorbents with high specific surface area, affinity for a wide range of contaminants owing to the high surface area and microporosity of biochar, and abundant available functional groups from the chitosan. Limited studies have reported the utilization of CBBC composites to remove various contaminants. These composites can be prepared by combining the steps employed in preparing CBC and CAB composites. They can benefit from the favorable adsorption properties of all three materials while also satisfying the mechanical requirements of a barrier material. This study serves as a knowledge base for future research to develop novel composite barrier materials by incorporating chitosan and biochar as amendments to bentonite.
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Development of fluorine-intercalated biochar material for radiation shielding
Biochar is a sustainable, carbon rich material that can be utilized for several applications including ionizing radiation protection. In this work, a high electron dense fluorine-doped biochar-based carbon material was developed by treating biochar with fluorine-based catalysts. Its application as a composite additive created several radiation protection materials was explored and compared to industry standards. It was found that the biochar composites were able to compete with the industry standards in both alpha radiation and gamma radiation, showing no significant difference between the materials and industry standards (p-value >.99), effectively performing as well as the industry standards. Lead was the most effective material at blocking beta radiation due to its high area density (about 1200 mg/cm2), but the biochar composites were able to reduce beta radiation by over 80 % in some composites, performing exceptionally well relative to their lower area densities (less than 200 mg/cm2). In general, the results indicated that the newly developed biochar composite materials have excellent shielding performance and can be used as an effective replacement for the industry standards ranging from lead to concrete.
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- Award ID(s):
- 1736173
- PAR ID:
- 10317127
- Date Published:
- Journal Name:
- Journal of analytical and applied pyrolysis
- Volume:
- 155
- ISSN:
- 0165-2370
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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