Investigation of colloid water content with laser-induced breakdown detection during drinking water ourification
Wagner, T. / Bundschuh, T. / Schick, R. / Schwartz, T. / Köster, R. (2002)
Acta Hydrochim. Hydrobiol. 30, 5-6, 266-274
- Date: 2002
Wagner, T. / Bundschuh, T. / Schick, R. / Schwartz, T. / Köster, R. (2002): „Investigation of colloid water content with laser-induced breakdown detection during drinking water ourification“. In: Acta Hydrochim. Hydrobiol. 30 (2002), 5-6, 266-274
Colloids (diameter typically < ca. 1 μm) are present in all aquatic systems. They have a high surface to mass ratio and therefore a large sorption capacity for both pollutants and microbial water impurities. Also, microorganisms as such can be regarded as colloidal matter. For drinking water purification it is vitally important to effectively remove such particulate water contents.
The laser-induced breakdown detection (LIBD) was used as a powerful tool for the quantification of aquatic nano-particles in very low concentrations. The Fe(III)-assisted filtration used for purification of water from Lake Constance did not only remove suspended particles, but also colloids with a mean efficiency higher than 98 % (regarding the mass concentration). The number weighted mean particle diameter before filtration was typically several hundred nanometers, after filtration it was reduced to an average of 54 nm.
The average mass concentration before the filtration step was 57 μg/L, afterwards only 0.66 μg/L. In a separate experiment it could be shown that the LIBD technique is capable of detecting microorganisms in water.