Study of Adsorption and Flocculation Properties of Natural Clays to Remove Prorocentrum lima

Abstract

High accumulations of phytoplankton species that produce toxins are referred to as harmful algal blooms (HABs). HABs represent one of the most important sources of contamination in marine environments, as well as a serious threat to public health, fisheries, aquaculture-based industries, and tourism. Therefore, methods effectively controlling HABs with minimal impact on marine ecology are required. Marine dinoflagellates of the genera Dinophysis and Prorocentrum are representative producers of okadaic acid (OA) and dinophysistoxins responsible for the diarrhetic shellfish poisoning (DSP) which is a human intoxication caused by the consumption of shellfish that bioaccumulate those toxins. In this work we explore the use of natural clay for removing Prorocentrum lima. We evaluate the adsorption properties of clays in seawater containing the dinoflagellates. The experimental results confirmed the cell removal through the flocculation of algal and mineral particles leading to the formation of aggregates, which rapidly settle and further entrain cells during their descent. Moreover, the microscopy images of the samples enable one to observe the clays in aggregates of two or more cells where the mineral particles were bound to the outer membranes of the dinoflagellates. Therefore, this preliminary data offers promising results to use these clays for the mitigation of HABs.

Mechanism by Which MC Controls Harmful Algal Blooms Revealed by Cell Morphology of Aureococcus anophagefferens

“…In addition to particle size, shape (tube-shaped or spherical), surface electrical properties, and environmental pH, it has been reported that absorption sites play an important role in clay flocculation [28][29][30]. Recently, some properties of the particle surface, such as adhesion and rigidity, which also affect the flocculation efficiency, are also receiving much attention [31][32][33].…”

Occurrence of three dominant epibenthic dinoflagellates (Ostreopsis spp., Coolia monotis and Prorocentrum lima) in relation to biotic substrates and environmental factors in a highly dynamic ecosystem, the Strait of Gibraltar (Southwestern Mediterranean)

“…Direct contact with contaminated seawater or inhalation of aerosolized biotoxins can lead to intoxications considered a direct impact of HABs on human health (Berdalet et al, 2016 ; Durando et al, 2007 ). Many species belonging to the Ostreopsis and Prorocentrum genera are able to synthetize potent toxins such as palytoxins (PLTXs), ovatoxins (OVTXs) and okadaic acid (OA)/dinophysistoxins (DTXs) (Karafas et al, 2015 ; Lewis et al, 2018 ; Louzao et al, 2015 ; Nascimento et al, 2016 ; Scalco et al, 2012 ; Wakeman et al, 2015 ; Wang et al, 2015 ). Other toxins are synthesized by other dinoflagellates belonging to the Coolia and Amphidinium genera, but they have never been demonstrated as having caused human poisoning (Holmes et al, 1995 ; Pagliara & Caroppo, 2012 ; Rhodes & Thomas, 1997 ; Rhodes et al, 2014 ).…”

Radioactive Cobalt(II) Removal from Aqueous Solutions Using a Reusable Nanocomposite: Kinetic, Isotherms, and Mechanistic Study

“…Therefore, removal of Co(II) from industrial effluents is crucial. Several different methods exist to remove Co(II), including chemical precipitation, ion-exchange, coagulation, flocculation, and reverse osmosis [ 4 , 5 , 6 , 7 ]; unfortunately, most of these methods are expensive and/or environmentally unfriendly. Adsorption has been emerging as an effective technique for removing Co(II) and has many advantages, such as being high efficiency, environmentally friendly, and cost-effective [ 8 , 9 ].…”