Membrane-based decentralized water supply systems for rural population: A critical review

The rural population has often lagged behind the urban population in accessing safe drinking water, and this gap directly hinders the progress in achieving Sustainable Development Goal 6. With the escalating concerns over emerging contaminants and climate change, decentralized water supply system is becoming a key solution to sustainable provision of safe drinking water in rural areas. In the past decade, field implementation of decentralized membrane systems (DMS) has been accelerated because they can be flexibly adopted based on water usage scale, source water characteristics and economic conditions of rural communities. Thus, the purpose of this article is to provide a critical review of the current application status, main challenges and development trends of DMS for rural population. Currently, this technology has been implemented in some remote and resource-constrained areas, and commercially available products such as household equipment are also gaining popularity. However, the field performance of DMS is retarded by a combination of technical and practical factors, including economic levels, social acceptance, and local resource availability. In response, recent technological advancements have focused on novel membrane materials and integrated filtration processes, for easy equipment maintenance, low-carbon operation, and cost-effective contaminant removal. Assessment of these efforts identifies three key directions for future research and development, i.e., preparation of rural-friendly membrane materials, harness of alternative water sources, and integration of renewable energies. These findings offer practical references and development ideas to improve the applicability and sustainability of DMS for rural water supply.