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Mitigating fish-killing algal blooms with PAC modified clays: efficacy for cell flocculation and ichthyotoxin adsorption
conference contribution
posted on 2023-05-23, 12:55 authored by Andreas SegerAndreas Seger, Gustaaf HallegraeffGustaaf HallegraeffFlocculation of harmful algal cells through treatment with modified clay minerals offers great promise in reducing clay loadings required for effective cell removal, yet the ichthyotoxin adsorptive properties of such modified clays have received little attention. We here compare Chattonella marina (raphidophyte) cell removal by conventional (kaolin, bentonite) and polyaluminium chloride (PAC) modified clays (bentonite and Korean loess), while newly exploring the capacity of PAC and PAC modified clays to mitigate C. marina and Alexandrium catenella (dinoflagellate) ichthyotoxicity (quantified with the RTgill-W1 cell line assay). Conventional clays proved ineffective in reducing C. marina cell numbers (14±5% removal at 0.5 g L-1), but treatment efficacy could be much improved through modification of bentonite and Korean loess with PAC (85±5% removal at 0.1 g L-1). Ichthyotoxin adsorption by PAC and PAC modified clays proved species specific. While both PAC (0.1 g L-1) and PAC modified clays (0.25 g L-1) could completely eliminate C. marina cytotoxicity, only bentonite clay proved effective in mitigating the negative impact of lysed A. catenella preparations on the gill cell line (69±10% gill cell viability). This work highlights how application of modified clays extends beyond improved cell flocculating properties to also include adsorption of selected ichthyotoxins.
Funding
Australian Research Council
History
Publication title
Proceedings of the 17th International Conference on Harmful Algae 2016Editors
LAO Proenca, GM HallegraeffPagination
154-157ISBN
9788799082766Department/School
Institute for Marine and Antarctic StudiesPublisher
International Society for the Study of Harmful Algae (ISSHA), Intergovernmental Oceanographic Commission of UNESCOPlace of publication
Copenhagen, DenmarkEvent title
17th International Conference on Harmful Algae 2016Event Venue
Florianopolis, BrazilDate of Event (Start Date)
2016-10-09Date of Event (End Date)
2016-10-14Rights statement
Copyright 2017 The International Society for the Study of Harmful Algae.Repository Status
- Restricted