Abstract
Abstract The project “Cyanotoxins oxidation by atmospheric plasma, a green technology for water decontamination (PLASMADETOX)” proposes to develop a new powerful advanced oxidation process (AOP) activated by air atmospheric plasma to tackle and mitigate the global challenge of harmful cyanobacterial blooms and released cyanotoxins in surface water intended for human use (e.g. drinking, recreational). Air atmospheric plasma is weakly ionized air at room temperature and pressure containing, among others, free electrons, excited neutrals and ions, O atoms, ozone and OH radicals. When air plasma is in contact with water these reactive species diffuse into or react with water and activate very efficient AOPs leading to the degradation of organic contaminants present therein. Air plasma-based AOPs are green processes only needing electricity and no added chemicals, heat or cooling, pressure or vacuum, and are easily and quickly switched on and off. PLASMADETOX has the aim to test air plasma sources on spiked solutions containing cyanotoxins and toxic Cyanobacteria cultures and identify the best system and optimal experimental conditions for these targets. Next, research will proceed in parallel to characterize the mechanisms of toxins oxidation and Cyanobacteria inactivation induced by atmospheric plasma and to evaluate the treatment efficacy on Cyanobacteria-contaminated real water samples. The knowledge acquired could be exploited to design a scaled-up apparatus or a floating and moving platform to be proposed to companies dealing with potabilization or water decontamination of recreational ponds/lakes. Methodologies to carry out this research plan rely on the expertise in plasma chemistry, advanced mass spectrometry and Cyanobacteria isolation and cultivation of the research units. Expected results include the advancement of fundamental knowledge on novel plasma induced AOPs, on cyanotoxins degradation and underlying mechanisms and on Cyanobacteria inactivation; the achievement of sufficient know-how to arouse interest and engage potential stakeholders into the development of this approach into a technology; the establishment of a new network of researchers with complementary backgrounds which could usefully lead to continuing collaboration; the high level training of young researchers.
Results achieved
The PLASMADETOX project aimed to assess the potential of atmospheric plasma as a green and scalable technology for the treatment of cyanobacteria-contaminated waters. The project successfully generated new experimental evidence on both cyanobacterial inactivation and cyanotoxin degradation, while identifying the most effective plasma configurations and operational conditions. A comprehensive set of cyanobacteria, including both strains from international culture collections and environmental isolates originating from Italy, was established and characterized from taxonomic and toxicological perspectives. This activity enabled the selection of representative bloom-forming species with different morphologies and cyanometabolites’ profiles, providing a robust biological platform for subsequent plasma treatments. Notably, the study highlighted the occurrence of bioactive secondary metabolites beyond common cyanotoxins, contributing to a broader understanding of cyanobacterial chemical diversity. Different plasma reactor configurations for the treatment of cyanobacteria were investigated, demonstrating that air atmospheric plasma effectively impairs cyanobacterial photosynthetic efficiency; these results were consistent across all tested conditions, indicating rapid plasma-mediated physiological inactivation of cells within few minutes of continuous treatment. Microscopy-based investigations, including environmental scanning electron microscopy (eSEM), confirmed that air atmospheric plasma led to structural damage of cyanobacterial cells, and, in the case of filamentous cyanobacteria, to fragmentation of trichomes. The project provided clear evidence of the ability of air atmospheric plasma to degrade cyanotoxins and other cyanometabolites. Complete removal of intra- and extracellular toxins was achieved under optimized conditions, with fast kinetics observed strongly depending on the reactor and configuration. The effectiveness of the optimized plasma treatment was investigated on mixed cyanobacterial cultures and on environmental bloom samples, overall demonstrating the capability of plasma to simultaneously act on multiple and different cyanobacterial species under complex natural conditions. The project also aimed to elucidate how environmental conditions could influence treatment efficacy, including physico-chemical parameters of water, cyanobacteria cell density and morphology, contributing to defining preliminary operational guidelines for plasma-based treatment of waters contaminated by cyanobacteria under environmentally relevant conditions. Beyond experimental results, PLASMADETOX contributed to the consolidation of interdisciplinary collaboration among research units and stakeholders. The project outcomes were disseminated through national and international conferences, and new partnerships were established with local authorities managing water bodies affected by cyanobacterial blooms. Overall, the project demonstrates that air atmospheric plasma is a versatile and promising green technology for the mitigation of cyanobacterial contamination, providing the basis for further technological development and scale-up.Project details
Unibo Team Leader: Marina Antonia Colangelo
Unibo involved Department/s:
Dipartimento di Scienze Biologiche, Geologiche e Ambientali
Coordinator:
Università degli Studi di PADOVA(Italy)
Total Unibo Contribution: Euro (EUR) 65.000,00
Project Duration in months: 24
Start Date:
16/10/2023
End Date:
28/02/2026
