The implications of 3D-printed membranes for water and wastewater treatment and resource recovery

It is widely acknowledged that three-dimensional (3D) printing or additive manufacturing will revolutionize many industries. However, the broad implications of 3D printing on water treatment membranes are not appreciated. 3D printing will transform the traditional membrane fabrication methods, reducing costs and industrial waste from manufacturing processes, with substantial benefits to treatment performance. In particular, 3D printing provides a high potential for radical decentralization. Remote communities, hospitality resorts, military bases, and oil and gas extraction operations could significantly benefit from the on-site fabrication of membrane units tunable to their specific wastewater challenges. Acute drinking water contamination events, like those associated with toxic by-products from algal blooms, chemical spills, forest fires, and extreme weather, cause adverse health effects on humans and shutdowns of piped water supply. 3D printing of customized membranes provides an opportunity for a fast response to such disastrous events. These membranes could be ready for installation within hours, with the vendor's role more akin to a software company installing a patch than the traditional approach, with major considerations for hardware availability, timeline, and supply chain. Despite these clear and potentially transformative advantages, 3D printing of membranes is not a panacea; countless aspects need to be taken into consideration for the successful implementation of this emerging technology. The full deployment of 3D-printed membranes in water and wastewater treatment can be achieved by extending the variety of printable materials, improving the speed and resolution of printing, creating nanoscale pores, reducing the fabrication costs, and improving the mechanical properties of the resulting membranes.