Helder Gomes

Polytechnic Institute of Braganca, Portugal

Title: Sustainable materials applied in wastewater treatment

---

Biography

Helder Gomes is Associate Professor at the Polytechnic Institute of Bragança (IPB), Portugal, and Coordinator of the Research Group "Sustainable Products and Processes" of the Mountain Research Center (CIMO). He graduated in Chemical Engineering from the Faculty of Engineering of the University of Porto (FEUP), Portugal in July 1997, obtaining the PhD degree in Chemical Engineering in June 2002 (FEUP). He joined the Department of Chemical and Biological Technology of IPB, in 2001, being Chair between 2019 and 2025. Between 2016 and 2018 he was President of the Catalysis and Porous Materials Division of the Portuguese Chemical Society and, since 2024, he is President of the Iberoamerican Federation of Catalysis Societies. His main research interests focus the synthesis and characterization of heterogeneous carbon-based materials for environmental applications, the valorization of industrial and agro-industrial wastes into materials, and the development of water/wastewater treatment solutions based on advanced oxidation processes.

Abstract

Water worldwide is becoming an increasingly valuable and vulnerable resource due to its depletion and contamination by human activities. Both untreated and treated municipal wastewater is commonly released to surface water bodies, including streams and reservoirs, representing a source of contamination that may end up compromising water quality. Contaminants of emerging concern (CECs), such as pharmaceuticals, personal care products, antibiotics and their metabolites, are commonly found in municipal wastewater effluents, due to their persistent nature in conventional biological treatment processes. Present disposal of wastewater effluents in structures built on sandy high permeability soils presents an opportunity to develop treatment solutions to remove CECs from these effluents by installation of horizontal permeable reactive barriers. These structures are barriers through which the effluent waters should flow, constituted by materials (fillers) that passively capture the contaminants, removing or degrading them by adsorption, precipitation, or chemical reaction, releasing uncontaminated water with quality to be reused. The selection of proper materials, as adsorbents and catalysts, is thus crucial in the development of permeable reactive barriers as solutions for the removal of CECs from effluents of wastewater treatment plants.

In this work low-cost and sustainable materials were developed, as biochar and activated carbon prepared from agro-industrial wastes, with their physico-chemical properties tuned to be used as reactive fillers in permeable reactive barriers, integrated as environmental treatment solutions. Experiments included the synthesis and characterization of biochar and activated carbon using biomass agro-industrial wastes, by pyrolysis and activation procedures, the monitorization of targeted CECs and assessment of the quality of the waters collected at the exit of the barriers to ensure that water is of sufficient quality to be used for irrigation. Results obtained show that permeable reactive barriers can be constructed and used as cost-effective and sustainable water treatment solutions, especially when considering materials derived from wastes.