Abstract
In this work, the viability of bioaccumulation and bioextraction processes for arsenic removal from contaminated waters, as well as the recycling of arsenate-treated amorphous ferric oxyhydroxide adsorbent (FeOOH) were evaluated using the common soil microscopic filamentous fungus Aspergillus niger. After treating the contaminated arsenate solution (100 mg As L−1) with FeOOH, the remaining solution was exposed to the growing fungus during a static 19-day cultivation period to further decrease the arsenic concentration. Our data indicated that although the FeOOH adsorbent is suitable for arsenate removal with up to 84% removal efficiency, the fungus was capable of accumulating only up to 13.2% of the remaining arsenic from the culture media. This shows that the fungus A. niger, although highly praised for its application in environmental biotechnology research, was insufficient for decreasing the arsenic contamination to an environmentally acceptable level. However, the bioextraction of arsenic from arsenate-treated FeOOH proved relatively effective for reuse of the adsorbent. Due to its production of acidic metabolites, which decreased pH below 2.7, the fungal strain was capable of removing of up to 98.2% of arsenic from the arsenate-treated FeOOH adsorbent.
Highlights
The release and mobilization of arsenic in complex geological substrates is a result of various chemical and biological processes that take place on the arsenic-bearing minerals’ surfaces [1]
Our results indicated limited applicability of the filamentous fungus, A. niger, for remediation of arsenate-contaminated water as a post-treatment method to further decrease the arsenic concentration to an acceptable level
84% removal efficiency was achieved with 10.8 mg g−1 FeOOH sorption capacity for arsenic
Summary
The release and mobilization of arsenic in complex geological substrates is a result of various chemical and biological processes that take place on the arsenic-bearing minerals’ surfaces [1]. Bioextraction can be applied on adsorbents when considering their regeneration after usage in heavy metal removal from contaminated waters. This has been demonstrated by Adams et al [8], who desorbed zinc from zinc-spiked charcoal using chelating extracellular metabolites of the filamentous fungal strains of Trichoderma harzianum, T. reesei and Coriolus versicolor. We believe that the biologically driven extraction can be applied for regeneration of arsenic loaded iron-based adsorbents when their maximum adsorption capacity has been reached
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
