An electrical- and chemical-free approach using microfilter and Ag-based catalysts for emergency drinking water treatment

ABSTRACT

In emergency cases such as disasters, supplying enough safe drinking water is one of the most urgent needs for human life. This research aimed to develop a chemical- and electricity-free drinking water treatment system based on microfiltration and catalysts of Ag and Ag-TiO₂-SiO₂ coated on glass spheres in both dark and sunlight conditions. The system was applied to treat raw water samples taken from five rivers in Vietnam, simulated floodwater samples with high turbidity and E. coli concentration, and real flooding water samples. The results showed the filtration unit fed with simulated floodwater generated lower fluxes and shorter working durations before chemical cleaning than that fed with normal river water. However, filtrate quality was not significantly different for these five water samples with very low values of turbidity (0–0.66 NTU), total coliform (5–19 CFU (100 mL)⁻¹), and E. coli (0–17 CFU (100 mL)⁻¹). The catalyst units using glass spheres coated with either Ag in dark and sunlight or Ag-TiO₂-SiO₂ under sunlight can completely remove E. coli and coliform as well as additionally mitigate natural organic matters. This study hence suggests the combination of microfiltration and Ag-based catalytic treatment for safe drinking water supply in emergencies, especially for flooding conditions.

GRAPHICAL ABSTRACT

KEYWORDS:

• Drinking water
• floods
• membrane filtration
• photocatalyst
• river water

Acknowledgements

The authors appreciated Le Van Dung, Nguyen Thi Ngoc Huyen, and Nguyen Huynh Thuy Tien for their support in sampling. We thank Green Tech Environmental Joint Stock Company for their donation of membrane fibres.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials. Other data are available from the corresponding author, NNH, upon reasonable request.

Additional information

Funding

This research is funded by Centre of Science and Technology Development for Youth, HCM city, Vietnam, under grant number 12/2018/HĐ-KHCN-VƯ; and Ho Chi Minh City University of Food Industry, Vietnam, under grant number 108/HĐ-DCT.