Making Waves: Principles for the Design of Sustainable Household Water Treatment.

Household water treatment (HWT) represents a key engineering intervention for billions of people's daily and emergency water needs. However, established HWT practices experience different challenges to achieve sustainability. Here, five essential principles are identified and discussed for the design of sustainable HWT, including treatment capability, environmental friendliness, user experience, economic viability, and social acceptance. A well-implemented HWT, with a consideration of energy resilience, relies heavily on advanced materials, innovative technologies, and/or creative designs capable of reliably abating both traditional and emerging contaminants, while minimizing undesirable chemical leaching and the formation of harmful disinfection byproducts. Environmental friendliness can be pursued by appreciably reducing environmental and energy footprints and properly managing HWT residuals. Meanwhile, a user-centered design approach and economic consideration need to be integrated into the HWT development to improve end users' willingness to use and pay, respectively. Finally, social acceptance should be intertwined by fostering public acceptance and market adoption for strengthening commercial viability of new-generation HWT products. Given that these principles span across different domains, multidisciplinary collaboration is required throughout different stages of the HWT technology innovation.