Taking advantage of the invasive bivalve Corbicula fluminea: potential as a remediator of olive oil mill wastewaters

• Autor(a) principal: Domingues, Ana Filipa Silva
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/25391
• topic: Corbicula fluminea; Olive oil mill wastewaters; Biorremediation; Biofiltration; Biosorption; Phenolic compounds

Olive oil is considered one of the main food ingredients in the Mediterranean countries, and its worldwide production is predominant in this region. Despite its paramount economic and gastronomic importance, the olive oil industry poses some environmental concerns due to olive oil mill wastewaters (OOMW) produced as a result of the extraction process. OOMW are composed by complex mixtures of organic compounds, including polyphenols. The recognized toxicity of these compounds, the high volumes of wastewaters generated in short periods of time due to the seasonality of the process, and, at last, the inexistence of an effective treatment to these wastewaters renders OOMW an actual and current environmental issue. Through the years, several chemical and biological treatments have been developed to reduce both the colour and toxicity of these effluents, however, a solution that completely meets these criteria has not been found yet. Therefore, it is relevant to test new treatment approaches, and the opportunity of using the filtration and accumulation capabilities of some bivalves has been raised as the rational for the present studies. Thus, the main objective of the present dissertation was to explore the viability of the Asian clam, Corbicula fluminea as a remediation agent of OOMW through the characterisation of its potential as a filter-feeder, and the potential of its shells as a biosorbent biomaterial. C. fluminea is a recognized freshwater invasive bivalve worldwide outside its native range in Eastern Asia. Despite its high dispersion and consequent negative environmental impacts, its capacity of filtering, tolerate and bioaccumulate some contaminants may render the Asian clam an interesting option as a bioremediation agent. Results show that living C. fluminea were able of significantly removing a fraction of organic contaminants of this wastewater, significantly reducing its environmental toxicity according to the results of bioassays performed with indicator species. This removal inversely corresponded to changes in the molecular composition of the soft body and the shells, the results suggesting further that a relevant part of the removed compounds may have been deposited through the production of pseudofaeces. When applied per se, the clam shells do not appear to have significant capacity to remove compounds from OOMW. The bioremediation potential of this bivalve would be further valued as its industrial use compensates, to a certain extent, the deleterious effects and economic losses associated with both its invasive nature in freshwater ecosystems and its biofouling activity in waterdependent industries.