Laboratory Efficacy of Locally Available Backwashing Methods at Removing Fouling in Hollow-Fiber Membrane Filters Used for Household Water Treatment
Laboratory Efficacy of Locally Available Backwashing Methods at Removing Fouling in Hollow-Fiber Membrane Filters Used for Household Water Treatment
Publication Year:
2021
Authors:
Heylen, Camille; Oliveira Aguiar, Alice; String, Gabrielle; Domini, Marta; Goff, Nathaniel; Murray, Anna; Asatekin, Ayse; Lantagne, Daniele.
Language:
English
Resource Type:
Journal Article
Summary:
This study tested the efficacy of different cleaning solutions in low- and middle-income countries and humanitarian contexts. The study also simulated the use of a water filtration system over a period of 10 days to test its effectiveness in removing E. coli and other contaminants.
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Resource Information
Abstract
Hollow-fiber membrane filters (HFMFs) for household water treatment (HWT) can efficaciously remove disease-causing organisms in laboratory settings. However, lower effectiveness in use in low- and middle-income countries (LMICs) and humanitarian contexts (HCs) has been observed and attributed to membrane fouling and the associated cleaning. In LMICs/HCs, it is not possible to prevent and control fouling using commonly known methods (e.g., testing influent water, maintenance regimes), and the literature on fouling/cleaning of HFMFs distributed in LMICs is scarce. As such, controlled laboratory experiments were conducted to determine the efficacy of locally available (in LMICs/HCs) backwashing solutions at removing fouling using different influent waters and HFMF types. Four commonly distributed HFMFs were selected; fouling layers were developed by filtering three influent water compositions, representing LMIC/HC waters, for 10-days, and bleach, water, or vinegar backwashing solutions were used for daily backwashing. Filter performance indicators included: fiber mechanical properties (strain at break, break force), water quantity performance (flow), water quality performance (turbidity, E. coli), and imaging. The study found fouling developed rapidly and altered mechanical properties and water quantity indicators within 200 h of filtration. Fouling did not decrease water quality indicators. Backwashing improved the filter’s mechanical properties and water quantity performance, but it did not fully recover the initial performance. Additionally, recovery differed between backwashing solutions, and no universal cleaning recommendation appropriate for HFMFs in LMICs/HCs was identified. Overall, fouling development and control depended on HFMF type, influent water quality, and backwashing solution type; thus, caution before distributing HFMFs for long-term use in LMICs/HCs is recommended.
Resource Type
Journal Article
Publication Year
2021
Author
Heylen, Camille; Oliveira Aguiar, Alice; String, Gabrielle; Domini, Marta; Goff, Nathaniel; Murray, Anna; Asatekin, Ayse; Lantagne, Daniele.
Language
English
Specific Contaminants
Bacteria, E. coli, Heavy Metals, Ca++, humic acid
University Affiliation
Tufts University
Business Connect Takeaways
The study tested the efficacy of three locally available cleaning solutions (bleach, vinegar, and clean water) in low- and middle-income countries and humanitarian contexts.
The study simulated the use of a water filtration system over a period of 10 days to test its effectiveness in removing E. coli and other contaminants. Four different commonly distributed HFMFs that met the minimum criteria for HWT filters were purchased and tested
The study highlights the need for future research on fouling in HFMF filters for HWT. Additional laboratory work should focus on expanding testing with other field-relevant influent water qualities but also to test additional cleaning solutions and backwashing solution combinations.