A rapidly growing group of commercial treatment systems that use filters and/or multiple chemical agents (e.g. chlorine) for household-level or on-the-go use. Devices or products combine filtration or coagulation and disinfection ability, sometimes including (pre-)sedimentation. Key proponents include PUR, AquaEst, PureIt, WaterPurifier and Lifestraw.
Often imported products, with notable exceptions of China and India. Regularly replaced filters and additives may make it a costly, albeit safe option. Unit cost per treated m3 may be in the range of USD1-5. Device purchasing may require funding.
Large-scale introduction of more affordable products may offer a relatively safe household-level treatment method even for low-income households. Should be aided with awareness-raising and maintenance monitoring to ensure timely exchange or cleaning of filters (or whole product, where applicable).
Applicable especially for surface water sources where physical and biological contamination is not complemented by chemical purification needs (e.g. arsenic). Requires no alteration of the natural environment, and is often without treatment residuals. Spent filters require safe disposal.
The limited user involvement for a safe treatment makes this option one of the most reliable HWTS treatments. Unforeseen contaminations, regular cleaning or exchange of filters and safe storage remain the only risk factors in treatment efficiency.
An easy-to-use, but low-yield option for household-level water purification. Regardless of method, daily output is in the range of 15-20 L. When also considering the related costs, it is most suitable as an emergency or ‘drinking only’ water supply option.
No relevant remarks for Commercial multi-treatment units.