3D-Printing Technologies for Environmental and Water Applications

Three-dimensional (3D) printing, also termed additive manufacturing, is a versatile fabrication technique capable of constructing virtually any geometrically complex object. Due to their cost-effectiveness, rapid production, and precise control over target structures, 3D-printing technologies have gained widespread attention and have been extensively applied in various environmental and water-related applications, such as environmental detection, wastewater treatment, water splitting, oil–water separation, and desalination. In response to this trend, we are honored to publish this new special issue entitled “3D Printing Technologies for Environmental and Water Applications” in ACS ES&T Water showcasing the latest reviews, advancements, and challenges encountered in applying 3D-printing technologies to address environmental and water-related issues. This special issue includes two review papers, eight research articles, and a viewpoint article covering a wide spectrum of environmental and water-related topics: (1) water treatment via adsorption, photocatalysis, and advanced oxidation processes, (2) environmental detection, (3) design of environmental devices, and (4) membrane separation. Majooni et al. (1) presented a comprehensive overview of 3D-printed nanomaterials utilized in water treatment and highlighted the critical role of nanoenabled 3D-printed structures in improving conventional water treatment strategies. Meanwhile, Ibrahim and Hilal (2) summarized the positive aspects of surface patterning of membranes on their performances, indicating that upon overcoming the challenges of material compatibility, reproducibility, and limited resolution, 3D-printing technologies will hold great potential to enhance membrane performances in the domain of water treatment. In the work of Fung et al., (3) the microstreaming behaviors of air bubbles trapped in 3D-printed Helmholtz structures were explored, revealing that acoustically induced fluidic streaming can potentially be employed to mitigate membrane fouling, which constitutes the most significant problem in membrane processes. In their article, Wang et al. (4) emphasized that further research should prioritize advancements in 3D-printing software, innovation in the design of printable structures, the expansion of 3D-printable material options, and optimizing the efficiency of 3D printers. These endeavors are essential for facilitating the widespread application of 3D-printing technologies and accelerating their development in membrane-related research fields. Peroxymonosulfate (PMS)- and sulfite [S(IV)]-based advanced oxidation processes (AOPs) are effective strategies for addressing the issue of water pollution. Inspired by these approaches, Guo et al. (5) and Yang et al. (6) developed novel 3D hierarchical porous copper (3D-Cu) catalysts for degrading antibiotics through PMS and S(IV) activation, respectively. Notably, both catalysts can maintain high performance with respect to tetracycline hydrochloride (TC) even after 40 successive cycles. Meanwhile, titanium dioxide (TiO₂), commonly acknowledged as the most promising photocatalyst for wastewater treatment due to its wide availability, high chemical stability, and corrosion resistance, was selected as the basis of the works of Wei et al. (7) and Chen et al., (8) who utilized 3D printing to construct nanoporous-TiO₂-encapsulating microporous-double-gyroid-structure photocatalysts and diamond-structured TiO₂ reactors to degrade antibiotics and organic synthetic dyes, respectively. Both of the as-printed catalysts demonstrated remarkable durability and reusability, which can be attributed to their stable 3D structures. Beyond water treatment, 3D-printing technologies have also been implemented in contamination detection in aquatic environments. For example, Paré et al. (9) applied the direct ink writing (DIW) method to introduce single-walled carbon nanotube (SWCNT)/polylactic acid ink to graphite electrodes, resulting in their increased sensitivity and resistance to sulfur poisoning. Similarly, Liu et al. (10) designed a 3D-printed, smartphone-assisted acute toxicity detector capable of rapidly assessing the inhibition rate of luminescent bacteria, which offers an efficient and cost-effective approach for immediate acute toxicity evaluation. In addition, Monaghan (11) developed low-cost automatic sampler and data processing software using a 3D printer and the software Matlab. This system enables the automated and high-throughput analysis of tire-derived p-phenylenediamine quinones (PPDQs) in water through the implementation of online membrane sampling coupled with mass spectrometry technology. In summary, this special issue highlights the diverse applications of 3D-printing technologies in tackling environmental challenges, primarily within the expansive realm of water-related topics. As guest editors of this special issue, we extend our deep appreciation to Dr. Shane Snyder, Editor-in-Chief of ACS ES&T Water, and Dr. Ching-Hua Huang, Associate Editor of ACS ES&T Water, for their invaluable editorial support. We are also grateful to Dr. Margaret Mills, Managing Editor of ACS ES&T Water, for her meticulous handling of this special issue as well as all of the authors and reviewers for their sincere and significant contributions. We hope that this special issue will inspire a broader spectrum of researchers to embrace and integrate innovative 3D-printing technologies into water-related environmental fields and offer scientifically robust and technologically advanced solutions for the protection and/or detection of contaminants in aquatic environments, as well as the efficient utilization of water resources. Dr. Sheng Guo is a Professor of Environmental Engineering in the State Key Laboratory of New Textile Materials & Advanced Processing Technologies at Wuhan Textile University. He received his Ph.D. from Wuhan University of Technology in 2015 and served as a postdoctoral researcher at Nanyang Technological University from 2018 to 2020. His research focuses on the synthesis, characterization, and applications of fibers, metallic oxides, and 3D-printed materials. Dr. Yifu Ding is a professor in the Paul M. Rady Department of Mechanical Engineering at the University of Colorado Boulder. He received his B.S. degree in polymer science and engineering from Fudan University, followed by a Ph.D. from the University of Akron, with an emphasis on spectroscopic studies of polymer dynamics. After three years of postdoctoral research at the National Institute of Standards and Technology (NIST), Dr. Ding joined the University of Colorado Boulder in 2008. His research interests include surface and interfacial properties of polymers with applications in membrane technologies. Dr. Ding currently serves as the director for the University of Colorado Boulder site of the Membrane Application Science and Technology (MAST) center, a National Science Foundation Industry University Collaborative Research Center (IUCRC). Dr. Kun Zhou is a Professor of Mechanical Engineering in the School of Mechanical and Aerospace Engineering at Nanyang Technological University, Singapore. He currently serves as Programme Director (Marine & Offshore) of the Singapore Centre for 3D Printing. He received his B.Eng. and M.Eng. degrees from Tsinghua University, China, and his Ph.D. from Nanyang Technological University. He has been conducting multidisciplinary research at the crossroads of mechanics, additive manufacturing, materials science, and molecular physics. He is a Fellow of the European Academy of Sciences. This article references 11 other publications. This article has not yet been cited by other publications.