Portable water treatment compared

Which portable method suits my trip or journey?

Filters, UV devices and chemical agents cover different pathogen groups and have their own weaknesses. No portable method reliably removes chemicals or salt, and mechanical filtering alone is not complete drinking-water treatment. ‘Yes’ means when used correctly according to the manufacturer, not under all circumstances.

Starting situation

Legend
Method	Bacteria	Viruses	Protozoa (Giardia, Cryptosporidium)	Chemicals	Needs clear water	Larger volumes for groups	Needs battery or power	Residual protection in storage	Cold and frost
Hollow-fibre and membrane filters	Yes	No	Yes	No	Partly	Partly	No	No	No
Gravity filters for camps and groups	Yes	No	Yes	Depends	Partly	Yes	No	No	Depends
Using a pump filter correctly	Yes	No	Yes	Depends	Partly	Partly	No	No	Depends
Ceramic filters	Yes	No	Yes	Depends	Partly	Partly	No	No	Depends
Using a UV-C pen correctly	Yes	Yes	Yes	No	Yes	No	Yes	No	Partly
Disinfection with chlorine	Yes	Yes	Partly	No	Yes	Yes	No	Yes	Partly
Disinfection with chlorine dioxide	Yes	Yes	Depends	No	Yes	Yes	No	Depends	Partly
Disinfection with iodine	Yes	Yes	Partly	No	Yes	Partly	No	Depends	Partly

Legend:● Yes◐ Partly◇ Depends○ No* = note available

Hollow-fibre and membrane filters

Effort:: Low
Needs:: Intact, never-frozen filter; additional disinfection if viruses are a risk

BacteriaYes
VirusesNo
Common elements no; only models with an explicit virus rating.
Protozoa (Giardia, Cryptosporidium)Yes
Including Giardia and Cryptosporidium.
ChemicalsNo
Does not remove dissolved chemicals.
Needs clear waterPartly
Works with cloudy water but clogs.
Larger volumes for groupsPartly
Squeeze filters suit individuals; more as a gravity set.
Needs battery or powerNo
No power or battery needed.
Residual protection in storageNo
No protection against recontamination.
Cold and frostNo
Frost can damage the fibres unnoticed.

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Gravity filters for camps and groups

Effort:: Low; hanging point needed
Needs:: Gravity kit, separate raw and clean sides; disinfection if viruses are a risk

BacteriaYes
Depending on the element.
VirusesNo
Common elements no; only models with an explicit virus rating.
Protozoa (Giardia, Cryptosporidium)Yes
Depending on the element.
ChemicalsDepends
Only elements with activated carbon reduce some organic substances.
Needs clear waterPartly
Cloudy water slows and clogs.
Larger volumes for groupsYes
Several litres without pumping.
Needs battery or powerNo
No power or battery needed.
Residual protection in storageNo
No protection against recontamination.
Cold and frostDepends
Frost sensitivity depends on the element; follow the manufacturer.

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Using a pump filter correctly

Effort:: Moderate; pumping and cleaning
Needs:: Undamaged element, pre-filter; disinfection if viruses are a risk

BacteriaYes
Depending on the element.
VirusesNo
Common elements no; only models with an explicit virus rating.
Protozoa (Giardia, Cryptosporidium)Yes
Depending on the element.
ChemicalsDepends
Models with activated carbon reduce some organic substances.
Needs clear waterPartly
A pre-filter on the hose helps; cloudy water clogs.
Larger volumes for groupsPartly
Several litres possible, but pumping effort.
Needs battery or powerNo
No power or battery needed.
Residual protection in storageNo
No protection against recontamination.
Cold and frostDepends
Frost-sensitive depending on element; follow the manufacturer.

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Ceramic filters

Effort:: Moderate
Needs:: Crack-free element; disinfection if viruses are a risk

BacteriaYes
Depending on pore size and product quality.
VirusesNo
No reliable virus retention.
Protozoa (Giardia, Cryptosporidium)Yes
ChemicalsDepends
Partly only with an activated-carbon core.
Needs clear waterPartly
Cloudy water slows the flow.
Larger volumes for groupsPartly
Slow flow.
Needs battery or powerNo
No power or battery needed.
Residual protection in storageNo
No protection against recontamination.
Cold and frostDepends
Fragile; frost behaviour per manufacturer.

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Using a UV-C pen correctly

Effort:: Low
Needs:: Clear water, charged battery, suitable container

BacteriaYes
Only in clear water.
VirusesYes
Per manufacturer, only in clear water.
Protozoa (Giardia, Cryptosporidium)Yes
Per manufacturer, only in clear water.
ChemicalsNo
Does not remove dissolved chemicals.
Needs clear waterYes
Yes – turbidity shields pathogens (drawback).
Larger volumes for groupsNo
Small volumes per cycle.
Needs battery or powerYes
Yes – battery (drawback).
Residual protection in storageNo
No protection against recontamination.
Cold and frostPartly
Cold shortens battery performance.

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Disinfection with chlorine

Effort:: Low; precise dosing
Needs:: Approved tablets, known volume

BacteriaYes
VirusesYes
With correct dose and contact time.
Protozoa (Giardia, Cryptosporidium)Partly
Giardia only partly; Cryptosporidium practically not.
ChemicalsNo
Does not remove dissolved chemicals.
Needs clear waterYes
Yes – turbidity weakens the effect (drawback).
Larger volumes for groupsYes
Large volumes easily treated.
Needs battery or powerNo
No power or battery needed.
Residual protection in storageYes
Residual chlorine protects stored water.
Cold and frostPartly
Works, but needs a longer contact time.

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Disinfection with chlorine dioxide

Effort:: Low; waiting time
Needs:: Approved tablets or drops, known volume

BacteriaYes
VirusesYes
With correct dose and contact time.
Protozoa (Giardia, Cryptosporidium)Depends
Only with the long contact time stated by the manufacturer.
ChemicalsNo
Does not remove dissolved chemicals.
Needs clear waterYes
Yes – turbidity weakens the effect (drawback).
Larger volumes for groupsYes
Volumes depend on product.
Needs battery or powerNo
No power or battery needed.
Residual protection in storageDepends
Do not plan on it as reliable residual protection; follow the manufacturer.
Cold and frostPartly
Works, but needs a longer contact time.

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Disinfection with iodine

Effort:: Low
Needs:: Approved product; no contraindications (pregnancy, thyroid, allergy)

BacteriaYes
VirusesYes
With correct dose and contact time.
Protozoa (Giardia, Cryptosporidium)Partly
Giardia only with long contact time; Cryptosporidium not reliably.
ChemicalsNo
Does not remove dissolved chemicals.
Needs clear waterYes
Yes – turbidity weakens the effect (drawback).
Larger volumes for groupsPartly
Possible, but not for long-term use.
Needs battery or powerNo
No power or battery needed.
Residual protection in storageDepends
Do not plan on it as reliable residual protection.
Cold and frostPartly
Works, but needs a longer contact time.

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