Background and objectives:

Nowadays, the Army uses disinfectant tablets to purify water. Recently, it was hinted the possibility of including in our combatants’ equipment a special kind of bottle with a new filtering system, the NKD POD+ The main objective of this research is to analyse the efficacy of this bottle filtering system in order to assess its possible use by Spanish Army so as to allow the filtering of any type of water which, once drunk, implies no health risk. In order to do so, the Laboratorio de Análisis de Aguas (Water Analysis Lab) of the Instituto de Toxicología de la Defensa (Defence Toxicology Institute) performed chemical and microbiological tests on different water samples to assess the degree of efficacy of the filter in order to eliminate heavy metals, pesticides, nitrates and water microorganisms.

Materials and method:

In order to conduct the tests, different samples with distilled water and certified patron solutions of the contaminants were used. Later, these samples were filtered through the bottle. The samples were analyses prior and after the filtering process. The analysis of the nitrites was conducted with visible ultraviolet spectroscopy (UV-Vis), heavy metals through inductive coupling plasma, coupled to mass spectrometry (ICP-MS), and pesticides through coupling gas chromatography to mass spectrometry (CG/MS).

Results:

It was proved that the water filter had hardly eliminated heavy metals. Pesticides in concentration of 1 µg/L were properly filtered by the bottle but to a lesser extent for concentrations of 10 µg/L. Regarding nitrites, it was observed an increase with respect to the original concentration in the filtered sample. In the microbiological test, the filtering system only retained those particles bigger than 0.45 µm, being totally ineffective with the tiniest ones such as enterococcus.

Conclusions:

The Nkd POD+ bottle generates a false feeling of safety as it does not meet the necessary requirements and compromises the combatants’ health.