Fouling in hollow fiber membrane microfilters used for household water treatment

2015 ◽  
Vol 5 (2) ◽  
pp. 220-228 ◽  
Author(s):  
Anna Murray ◽  
Mario Goeb ◽  
Barbara Stewart ◽  
Catherine Hopper ◽  
Jamin Peck ◽  
...  
Keyword(s):  
Water Treatment ◽  
Hollow Fiber ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Hollow Fiber Membrane ◽  
Sterile Water ◽  
Fiber Membrane ◽  
Chemical Cleaning ◽  
Household Water Treatment ◽  
Household Water

The Sawyer PointOne hollow fiber membrane microfilter is promoted for household water treatment in developing countries. Critical limitations of membrane filtration are reversible and irreversible membrane fouling, managed by backwashing and chemical cleaning, respectively. The PointOne advertised lifespan is 10 years; users are instructed to backwash as maintenance. Owing to reduced turbidity and bacterial removal efficiencies, six PointOnes were removed from Honduran homes after 23 months of use. In the laboratory, we tested sterile water filtrate for turbidity and bacterial presence before and after backwashing and chemical cleaning. Sterile water filtrate from uncleaned filters had turbidity of 144–200 NTU and bacteria counts of 13–200 CFU. Cleaned filter effluent was positive for total coliforms. On one new and one used, cleaned filter, we imaged membranes with scanning electron microscopy and characterized surface elemental compositions with spectroscopy. Images and spectroscopy of the used, cleaned membrane revealed a dense, cake fouling layer consisting of inorganic metal oxides, organic material, and biofouling. Burst fibers were visually observed. This PointOne was thus irreversibly fouled and non-functional after <2 years of use. Further research is recommended to determine: impacts of source water quality on PointOne performance, a cleaning regimen to manage fouling, and an appropriate filter lifespan.

scholarly journals Laboratory efficacy and field effectiveness of hollow fiber membrane microfilters used for household water treatment in Honduras

2017 ◽  
Vol 7 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Anna L. Murray ◽  
Barbara Stewart ◽  
Catherine Hopper ◽  
Ellen Tobin ◽  
Jimmy Rivera ◽  
...  
Keyword(s):  
Water Treatment ◽  
Surface Waters ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Geometric Mean ◽  
International Standards ◽  
Fiber Membrane ◽  
Household Water Treatment ◽  
E Coli ◽  
Household Water

The Sawyer PointONE™ hollow fiber membrane filter is increasingly promoted for long-term household water treatment in developing countries. Limited data demonstrate PointONE™ microbiological laboratory efficacy and short-term diarrheal disease reduction among users, but household microbiological data is lacking. To compare laboratory and household PointONE™ filter microbiological performance, we enumerated Escherichia coli (E. coli) and total coliforms in source and filtrate water from: (1) one new filter with E. coli-spiked water (107–109 CFU/100 mL) in the laboratory, (2) one new filter with natural Maine and Honduran surface waters, and (3) 50 filters used in Honduran homes for 1–3 years. In laboratory tests, all filtrate samples had <1 CFU/100 mL E. coli (>99.99999% reduction). In natural surface waters, all filtrate samples had ≤1 MPN/100 mL E. coli (≥99.5% reduction). In households, filtrate samples had geometric mean 5.1 MPN/100 mL E. coli (90% reduction), with only 30% of filtrate samples complying with international standards of undetectable E. coli. Total coliform presence in natural water filtrate varied for both new and household filters. The discrepancy between laboratory and household results and premature filter failure are not well understood. Further research is recommended to understand this performance disparity and determine filter failure mechanisms in households.

Gas field produced/process water treatment using forward osmosis hollow fiber membrane: Membrane fouling and chemical cleaning

Desalination ◽  
2017 ◽  
Vol 402 ◽  
pp. 143-151 ◽  
Author(s):  
Shanshan Zhao ◽  
Joel Minier-Matar ◽  
Shuren Chou ◽  
Rong Wang ◽  
Anthony Gordon Fane ◽  
...  
Keyword(s):  
Water Treatment ◽  
Hollow Fiber ◽  
Membrane Fouling ◽  
Hollow Fiber Membrane ◽  
Forward Osmosis ◽  
Process Water ◽  
Fiber Membrane ◽  
Chemical Cleaning ◽  
Gas Field

scholarly journals The Effect of Ca and Mg Ions on the Filtration Profile of Sodium Alginate Solution in a Polyethersulfone-2-(methacryloyloxy) Ethyl Phosphorylchloline Membrane

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1207 ◽  
Author(s):  
Nasrul Arahman ◽  
Suffriandy Satria ◽  
Fachrul Razi ◽  
M. Bilad
Keyword(s):  
Sodium Alginate ◽  
Relative Permeability ◽  
Hollow Fiber ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Hollow Fiber Membrane ◽  
Pure Water ◽  
Fiber Membrane ◽  
Cake Layer ◽  
The Stability

The efforts to improve the stability of membrane filtration in applications for wastewater treatment or the purification of drinking water still dominate the research in the field of membrane technology. Various factors that cause membrane fouling have been explored to find the solution for improving the stability of the filtration and prolong membrane lifetime. The present work explains the filtration performance of a hollow fiber membrane that is fabricated from polyethersulfone-2-(methacryloyloxy) ethyl phosphorylchloline while using a sodium alginate (SA) feed solution. The filtration process is designed in a pressure driven cross-flow module using a single piece hollow fiber membrane in a flow of outside-inside We investigate the effect of Ca and Mg ions in SA solution on the relative permeability, membrane resistance, cake resistance, and cake formation on the membrane surface. Furthermore, the performance of membrane filtration is predicted while using mathematical models that were developed based on Darcy’s law. Results show that the presence of Ca ions in SA solution has the most prominent effect on the formation of a cake layer. The formed cake layer has a significant effect in lowering relative permeability. The developed models have a good fit with the experimental data for pure water filtration with R2 values between 0.9200 and 0.9999. When treating SA solutions, the developed models fit well with experimental with the best model (Model I) shows R2 of 0.9998, 0.9999, and 0.9994 for SA, SA + Ca, and SA + Mg feeds, respectively.

Sign in / Sign up

Export Citation Format

Share Document