Integration of rapid filters for the provision of drinking water at rural home level

Abstract

Centralized drinking water systems benefit many households, but do not reach the most disadvantaged populations such as rural communities. Therefore, initiatives for providing universal access to drinking water must focus on the implementation of simple and easy-to-implement technologies. The purpose of this study was to evaluate a multi-stage high-rate filtration (MSHRF) system as a decentralized strategy for household drinking water supply in developing areas. For which, a MSHRF was implemented in the field consisting of five PVC columns with a diameter of 110 mm and height of 2 m, whose filter media were gravel (GF), quartz (QF), coarse sand (CSF), fine sand (FSF), and anthracite (AF). The tests were divided into two phases: (a) filtration without prior coagulation and (b) filtration with prior coagulation using Poly Aluminum Chloride (PAC). In turn, different turbidities of raw water were tested in each phase, as well as different filtration rates (FR); likewise, the filtration runs and the optimal washing time of each filter were evaluated. For evaluating the efficiency of this system, the removal of turbidity, colour, and fecal coliforms were measured in each one of the stages. The results indicated the following: (a) when coagulation is not performed prior to filtration, it is necessary the operation of the five columns for obtaining turbidities less than 5 NTU and (b) when prior coagulation is used, it is sufficient to implement the GF and QF columns for obtaining turbidities less than 5 NTU, complying with Ecuadorian standards and the recommendations of the World Health Organization. The MSHRF maintained its ability for treating raw water with high turbidity and filtration rate, providing a significant amount of water for one family. This system represents a potential novel and effective solution for treating drinking water in homes and communities without access to drinking water.