Brief description of the project
Quest. The equilibrium of aquatic ecosystems in estuarine and coastal environments is particularly sensitive to the presence of micropollutants (such as pharmaceuticals, PFAS, surfactants, plastic and rubber additives), that easily escape the traditional wastewater treatments and, even at very low concentrations, have adverse effects on the ecological environment. Indeed, wastewaters are the main source of micropollutants and, once they reach the oceans, the possibility of successfully detecting and removing undesired elements drastically drops. Nowadays, the most effective strategy to remove the micropollutants is based on the activated carbons that, due to their negative charge, allow us to attract polarised compounds. However, such techniques are expensive and the increasingly restrictive limits of micropollutant concentration imposed on urban wastewaters by European “zero pollution action plan” (Green Deal) impose more sustainable processes to be identified.
Aims. The present project aims to deliver a high-efficiency treatment solution with minimal environmental impact, specifically designed to protect and restore sensitive aquatic ecosystems. The project explores the possibility to exploit the physical and chemical properties of micro/nanobubbles, eventually combined with other electrochemical approaches, to separate (by floatation) and remove targeted micropollutants (e.g., PFAS, pharmaceuticals). The removal can be obtained by adsorption or by oxidation (e.g. by using ozone micro/nanobubbles). The effects of the salinity characterising the estuarine and coastal areas will be also considered.
Objectives and Methodology. The objectives of the project are (i) identifying experimentally the micro/nanobubble-based treatment process to aggregate and separate the targeted micropollutants, and (ii) modelling the evolution and the interaction between micropollutant and micro/nanobubble dispersions, using the Population Balance Equations. The values of the model parameters will be possibly quantified by means of the direct numerical simulation of the micro/nanobubble-micropollutant interactions when the ambient flow is turbulent. (iii) Moreover, focus will be also directed toward optimizing system performance, evaluating environmental sustainability through Life Cycle Assessment (LCA) methodology, and assessing scalability for broader application in water management. Finally, the project will benefit from the collaboration with the company COGEDE that is specialised in the design and manufacture of wastewater and slurry treatment plants. Therefore, field experiences are also planned.