Tailoring 3D-Printed Inorganic Polymers for Enhanced Removal of Emerging Water Pollutants

Description

Sources of clean, potable water are rapidly declining worldwide, posing a critical threat to human survival. Addressing this crisis is essential to ensuring a sustainable future for humankind. Emerging pollutants (EPs) from our daily activities such as pharmaceuticals, personal care products, per- and polyfluorinated substances, pesticides and dyes, among others, are poorly removed by conventional wastewater treatment plants (WWTPs) which act as the main source of EPs to the environment.(Alexander et al., 2020) Besides the harmful impact on aquatic life, a huge potential risk for humans arises from the food chain through processes of bioaccumulation and biomagnification, and their presence in our drinking water. The integration of the water management approach, in which treated wastewater (WW) represents an alternative source for irrigation has been proposed as an important solution to increase the water supply and cope with water scarcity. Recently, the EU approved minimum requirements for reclaimed water (i.e., treated WW) to be safely used for agricultural purposes. In Portugal only 1% of reclaimed water is currently used. Thus, there is an urgent need for effective, economical, and eco-friendly technologies for the post-treatment of conventional WWTPs effluents.Semiconductor photocatalysts have shown remarkable efficacy in degrading pollutants in water. Despite their proven potential, the current limitation of using photocatalysis in suspension form prevents widespread industrial adoption due to challenges in reusability and the potential for secondary pollution from the catalysts themselves. To address this, efforts are required to enhance existing photocatalysts and create cost-effective immobilization strategies for high reusability and minimal environmental risks.Inorganic polymers (IPs), commonly referred to as geopolymers, have emerged as one of the most promising materials for environmental applications. Leveraging their zeolitic-like structures, intrinsic porosity, and inherent ion-exchange capabilities have been explored for environmental applications, namely as metal sorbents from polluted waters. Recently, the preparation these ceramic-like materials trough additive manufacturing (AM), also known as 3D printing, demonstrated the potential to obtain IPs with controlled design, porosity and interconnectivity between pores which maximizes their effectiveness for environmental application.The combination of photocatalysts with IPs can advance their suitability for real scale applications for water pollutants removal. This synergy increases the surface area for pollutant adsorption, facilitates electron transfer, and enhances the photocatalyst’s stability over repeated cycles. Surprisingly, the use of AM to enhance the potential of semiconductor photocatalysts combined with inorganic polymers remains unexplored.PRIME project aims to enhance wastewater treatment efficiency at a lower cost by developing photoactive membranes, through additive manufacturing, that can be applied as a post-treatment process after the conventional WWTPs. It will decrease the knowledge gap concerning functionality of photocatalyst/IPs and beyond the state-of-the-art by exploring AM technique to creating photoactive membranes with complex channels, microfluidic designs, and efficient shapes, which can improve light absorption and pollutant contact. This will be achieved by: i) producing new highly active and stable photoactive catalysts; ii) developing 3D printed photoactive membranes either by incorporating the catalyst into printable compositions and post printing surface functionalization; iii) exploring their effectiveness for emerging water pollutants removal.Activities will be supported by a multidisciplinary team with complementary expertise in photocatalysis, additive manufacturing and inorganic polymers.