The Water Treatment Using Dual-Media Slow Sand Filter: Efficiency, Sustainability, and Water Security in the Brazilian Semiarid Region

Abstract

Water scarcity and unequal access to supply systems remain critical challenges in Brazil’s semiarid region, requiring sustainable and socially appropriate technological solutions. This study aims to analyze the efficiency of the dual-media slow sand filter as a decentralized water treatment alternative, based on a literature review and a case study conducted in the rural community of Pilar, municipality of Jaguarari, Bahia. The methodology combined a comprehensive bibliographic review of scientific databases and technical reports with empirical observation of a system built using anthracite and fine sand layers to optimize filtration and improve turbidity and microorganism removal. The results showed reductions above 99% in coliform concentrations and residual turbidity below 1.0 NTU, meeting the potability standards established by Ordinance GM/MS No. 888/2021. The technical performance, coupled with operational simplicity and community engagement, confirms the technology’s potential as a tool for water security and social inclusion. It is concluded that the dual-media slow sand filter constitutes an effective, replicable, and environmentally low-impact solution aligned with the principles of the United Nations 2030 Agenda for Sustainable Development, particularly SDG 6, which promotes universal access to safe and potable water.