Posiva publishes Working Reports and Posiva Reports. From the year 2006 nearly all the reports have been published on our webpage and they can be found in the databank. In the databank you can also find our Annual Reviews and some other publications as well. You can also find print-quality pictures and useful links in the databank.

Recent publications

Workreport 2019-8



Follow-Up Study of the Humic Substances and Colloidal Material in Groundwater from ONKALO, Olkiluoto, 2017


Luste, S.



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The humic substances (HS) at groundwater from ONKALO®, Olkiluoto were studied in order to determine the apparent molecular size distribution and the amount of humic substances and to compare the results with the previous years’ results. Groundwater samples were taken from the groundwater stations ONK-PVA3, ONK-PVA5 and ONK-PVA10. Humic substances were isolated and molecular size distribution was determined using high resolution size exclusion chromatography (HPSEC) method optimized during previous years. The amount of humic substances was determined by total organic carbon analyser (TOC). In addition, metal content of initial and isolated humic fraction was studied. The results of both molecular size distribution and amount of humic substances were similar with previous studies.

In addition to HS also a study related to colloids was performed. The purpose of this study was to estimate the concentration of groundwater colloids and to compare the results with the previous ones. The water samples were collected from groundwater stations ONK-PVA5, ONK-PVA10 and ONK-PVA11.

The colloid concentrations were determined from scanning electron microscopy (SEM) micrographs taken from the filters in which the groundwater was run through. The particle calculations were performed with computer software ImageJ. The colloid concentration (Ø 0–1 µm) determined by the single particle analysis of SEM micrographs was somewhat higher in ONK-PVA5 and ONK-PVA10 compared to previous study. Colloids could not be evaluated from ONK-PVA11 since the filter used for sampling was blocked due to long sampling time.


DAX-8, colloids, fulvic acids, groundwater, humic acids, HPSEC, SEM


WR 2019-08_web (pdf) (1.3 MB)


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