Application of membrane filtration and photocatalysis in household river water purification system

Abstract

Providing safe drinking water is one of the first priorities during a disaster. This study developed a water treatment system to supply drinking water in emergencies without requirement of chemicals and electricity. The process consisted of two main units, including membrane filtration using human power and solar photocatalytic unit. Feed water was sampled from river in Vietnam and the samples’ characteristics were monitored. Results showed that membrane unit eliminated most of turbidity, resulted in the effluent from 0.19 to 0.81 NTU, and provided COD_Mn removal efficiency of 40%, with the output COD_Mn of 3.8±0.9 mg/L. In only some membrane treated samples,  E.coli and total coliform  was found at 1-7 CFU/100 mL, while in majority, they were not detected. Photocatalytic unit using nanomaterials (i.e. Ag-TiO₂-SiO₂) under solar irradiation was then employed to further treat the remaining dissolved organic and microorganism. With hydraulic retention time from 10 to 15 min, COD_Mn was reduced to the final concentration less than 2.0 mg/L, and total coliform and E.coli was totally removed.