Investigation of fouling mechanisms in membranes for water and effluent treatment

• Grant number: 24/18292-2
• Support Opportunities: Scholarships in Brazil - Program to Stimulate Scientific Vocations
• Start date: January 14, 2025
• End date: March 01, 2025
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Míriam Cristina Santos Amaral
• Grantee: Maria Eduarda de Oliveira Crist
• Host Institution: ESC ENGENHARIA/UFMG

Abstract

Access to clean water, proper sanitation, and hygiene is one of the most fundamental human needs for health and well-being. Membrane technologies are recognized for their robustness and ability to provide safe drinking water, and/or produce reuse water from wastewater. Membranes act as selective barriers, allowing certain substances to pass through based on properties like size or charge, while restricting others. The main membrane technologies applied in water and wastewater treatment are pressure-driven processes, including microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO). MF membranes are effective in removing suspended particles. UF, with its smaller pore size, can also remove microorganisms and macromolecules. NF is particularly suitable for treating water containing inorganic compounds, such as multivalent ions, as well as organic substances. For desalination, RO is typically the technology of choice. However, membrane fouling is a critical challenge that leads to reduced membrane selectivity, permeability, and overall lifespan. Understanding and mitigating fouling mechanisms are therefore essential to improving membrane performance. Fouling can be classified into several types: biofouling (managed by biocides), inorganic fouling (controlled with scale inhibitors), and organic fouling (which requires effective pretreatment). Direct observation techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR) can be employed to study fouling mechanisms. In recent years, machine learning (ML) has been successfully applied to predict membrane fouling and permeate characteristics, enabling more efficient management of membrane systems. The Research Group on Study and Application of Membrane Separation Processes (GEAPS Membranas), led by the Proponent, has been investigating the use of membranes for water and wastewater treatment since 2010, with a particular focus on water reuse and byproduct recovery. The Candidate, Maria Christ, has been developing research at CNPEM involving computer simulations of material properties, including thin films. Thus, this project aims to integrate the membrane technology expertise of GEAPS Membranas with the Candidate's experience in computer simulation to investigate membrane fouling mechanisms in water and wastewater treatment and establish strategies for effective fouling control. Maria will be integrated into the research group and supported by a multidisciplinary team, including professors, doctoral, master's, and undergraduate students from the Graduate Program in Sanitation, Environment, and Water Resources. The work will be divided into two stages. In the first stage, Maria will monitor membrane system operations for water and wastewater treatment under the supervision of her advisor and master's and doctoral students. Samples of fouled membranes will be collected for analysis at the UFMG Microscopy Center and other university laboratories. These samples will be characterized using SEM, AFM, zeta potential analysis, energy-dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FTIR). In parallel, data on permeate flux, pressure, temperature, and the physical-chemical properties of feed and permeate will be collected. In the second stage, the results will be analyzed, and predictive models will be developed to forecast membrane performance based on fouling and the adopted control strategies. The summer internship at UFMG is expected to provide Maria with an environment that fosters scientific thinking, creativity, and critical analysis, driven by the challenges inherent to research. Moreover, this experience will strengthen her multidisciplinary training by exposing her to a new field while allowing her to apply her prior knowledge in a meaningful way. Overall, this internship will significantly contribute to her academic and scientific development.