Household slow sand filters in continuous and intermittent flows and their efficiency in microorganism's removal from river water

This study aimed to evaluate the efficiency of four household slow sand filter (HSSF) models for the removal of microorganisms from river water throughout the development of their biological layers (schmutzdecke). Two models were designed to be operated continuously (HSSF-CC and HSSF-CT) and two int...

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Veröffentlicht in:Environmental technology. - 1993. - 43(2022), 10 vom: 08. Apr., Seite 1583-1592
1. Verfasser: Nasser Fava, Natália de Melo (VerfasserIn)
Weitere Verfasser: Terin, Ulisses Costa, Freitas, Bárbara Luíza Souza, Sabogal-Paz, Lyda Patricia, Fernandez-Ibañez, Pilar, Anthony Byrne, John
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2022
Zugriff auf das übergeordnete Werk:Environmental technology
Schlagworte:Journal Article biosand filter decentralized treatment drinking water microscopy schmutzdecke Silicon Dioxide 7631-86-9
Beschreibung
Zusammenfassung:This study aimed to evaluate the efficiency of four household slow sand filter (HSSF) models for the removal of microorganisms from river water throughout the development of their biological layers (schmutzdecke). Two models were designed to be operated continuously (HSSF-CC and HSSF-CT) and two intermittently (HSSF-ID and HSSF-IF). Filters were fed daily with 48 L pre-treated river water (24 h sedimentation followed by filtration through a non-woven synthetic blanket). Water samples were quantified by coliform group bacteria and analysed by bright field microscopy to visualize the microorganisms. Total coliform reduction was between 1.42 ± 0.59 log and 2.96 ± 0.58 log, with continuous models showing a better performance (p-values < 0.004). Escherichia coli reduction varied from 1.49 ± 0.58 log to 2.09 ± 0.66 log and HSSF-IF, HSSF-CC and HSSF-CT presented a similar performance (p-values > 0.06), slightly better than the one presented by HSSF-ID (p-value=0.04). Microorganisms, such as algae, protozoa and helminths were detected by microscopy in raw water and pre-treated water. Algae were the most significant group in these samples, although they were not visualized by bright field microscopy in the filtered water. Results showed the potential of HSSF in microbiological risk reduction from river water, which increases the range of point-of-use water treatments in rural communities. However, additional studies of the HSSF biological layer must be performed
Beschreibung:Date Completed 11.04.2022
Date Revised 11.04.2022
published: Print-Electronic
Citation Status MEDLINE
ISSN:1479-487X
DOI:10.1080/09593330.2020.1841834