3D Printed, Self-Regeneratable Photocatalytic Filters as Hydroxyl Radical ManufacturerA Lab to Pilot Scale Approach

The importance to persistent organic pollutants (POPs) from nature has been
established with the Stockholm Convention on POPs in 2001. One challenge is that POPs survive in secondary and/or advanced treated wastewater contaminated with conventional wastewater treatment technologies persistent organic pollutants (POPs) is highly challenging. Ozonation is the most adapted
advanced oxidation process (AOP) to degrade wastewater's persistent organic pollutants (POPs). Recent studies at the Water Research Center at Tel Aviv University (Israel) suggested that ozonation (or) photocatalytic oxidation alone is ineffective in removing POPs because it transforms them into more persistent and toxic compounds instead of complete mineralization. In contrast, photocatalytic
ozonation (visible light/O3/catalyst) has more potential as a solar-powered decontamination technique (Next-AOP). This sustainable innovation was attributed to the synergy between ozone, sustainable (photo) catalyst, and visible light for generating highly active and nonselective OH radicals. Therefore,
the key to developing a highly efficient process for degradation and mineralization of POPs in wastewater is to rationally design a "next-generation AOP photocatalytic filter," which serves as an in situ •OH manufacturer to degrade POPs directly in wastewater treatment plants (WWTPs). To achieve
the approach will be taken in this project: (i) integration of edge functionalized, biocompatible and oxidized graphitic carbon nitride (Ox-gC3N4) chemically coordinated with a biopolymeric semiconductor, such as polypyrrole (PPy), perylene diimide (PDI) to create a (Z-scheme) heterojunction with strong
redox ability and a wide light response range, (ii) up-scale of the technology from the laboratory to pilot scale adapting 3D printing, i.e. Digital Light Processing (DLP) and Stereolithography (SLA) to obtain fractal as a photocatalytic filter (PCF) based on computer-aided design (CAD) virtual 3D models, and
(iii) specialization of PCF for self-regeneration and membrane processes to reduce fouling will be thoroughly investigated by the Membrane Group at Lund University (Sweden). In situ EPR spectroscopy, including spin trapping techniques, will quantify reactive charge carriers and identify active radical species formed during photocatalytic ozonation (PCO). UV-vis DRS spectroscopy and valence band XPS spectroscopy will be applied to determine the band structure of photocatalysts. Besides the degradation of POPs, the fate of the transformed products (TPs) formed after the treatment will be monitored by analytical techniques such as HPLC-MS, GC-MS, and NMR consisting of anticancer, antiseizure, antidepressant drugs, antibiotics and X-ray contrast agents simulating the wastewater effluents will be used for studying the photocatalytic ozonation of the synthesized catalysts. After the successful trial on a laboratory scale, the 3D printed PCF framework will be deployed on a (photo) catalytic membrane reactor in conjunction with ozone technology for oxidative degradation of POPs on an existing pilot-scale (Shafdan and Herzliya, Israel) and one in Sweden (Kälby WWTP) in Lund) to treat secondary or tertiary effluents. The project's outcome will be prominent to the scientific community in Israel and Sweden by paving the way toward next-generation decentralized wastewater
systems based on sustainable 3D printing technology and solar (photo) catalytic ozonation.