Use of macadamia nut shell residues as magnetic nanosorbents

Wongcharee, Surachai and Aravinthan, Vasantha and Erdei, Laszlo and Sanongraj, Wipada (2017) Use of macadamia nut shell residues as magnetic nanosorbents. International Biodeterioration and Biodegradation, 124. pp. 1-12. ISSN 0964-8305


Nanosorbents have been increasingly used for targeted contaminant removal; however, handling and
separation of spent sorbents from treated water remains a challenge. To address these drawbacks, a
hybrid magnetic nanosorbent was prepared from waste macadamia nut shell and magnetite nanoparticles.
The novel nanosorbent had primarily meso- and macroporous structure with 70 m2 g-1 specific
surface area. Batch sorption tests using methylene blue model pollutant found sorption capacities
increasing from 33 to 42 mg g-1 with temperature in the 25 - 45 oC range. Nonlinear regression analyses
found that process kinetics was accurately described by a fractal-like pseudo first order model. The
isotherms showed excellent fits to the Langmuir model and implied monolayer adsorption mechanism.
The thermodynamic parameters confirmed that the process was spontaneous, endothermic, and
involved physisorption. The point of zero charge was 7.4, which is advantageous in the removal of anionic
aquatic pollutants. The ferrimagnetic sorbent had 48 emu g-1 saturation and 0.65 emu g-1 remanence
that allowed easy handling and rapid separation by magnetic field. Spent sorbents were effectively regenerated
by acidic wash for subsequent reuse over four cycles. The intrinsic characteristics of the
magnetite/carbon nanosorbent befit tailored water and wastewater treatment applications.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published online 17 April 2017. Permanent restricted access to ArticleFirst version, in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying
Date Deposited: 19 May 2017 04:47
Last Modified: 19 Apr 2018 01:57
Uncontrolled Keywords: magnetite, activated carbon, nanosorbent, adsorption, nonlinear regression
Fields of Research : 03 Chemical Sciences > 0303 Macromolecular and Materials Chemistry > 030301 Chemical Characterisation of Materials
05 Environmental Sciences > 0502 Environmental Science and Management > 050205 Environmental Management
Identification Number or DOI: 10.1016/j.ibiod.2017.04.004

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