Bioremediation in Samtskhe-Javakheti Region

Within the framework of “Keep Georgia Tidy” Project, which is financed by the Government of Sweden, Georgian Society of Nature Explorers “Orchis” team carried out a field visit in December 2019 in Samtskhe-Javakheti Region, where some dumpsites were selected (in Akhaltsikhe City – Rustaveli and Tamar Mepe Streets, Arali village – Adigeni Municipality, Aspindza, Ninotsminda and Vardgineti village – Borjomi Municipality) and soil was sampled for analysis. The soil samples were tested for the content of some heavy metals (Pb, Cu, Zn, Cd, Hg) to assess pollution level.

The following was found in Samtskhe-Javakheti Region: soil sampled adjacent to the dumpsite located in Rustaveli Avenue, Akhaltsikhe City (in the city centre) was contaminated by lead (1.6 MPC (maximum permissible concentration)). Surroundings of the dumpsites studied in Tamar Mepe Street, Akhaltsikhe City and Aspindza were polluted by lead and zinc, though insignificantly (34.8 mg/kg and 240.67 mg/kg respectively).

The soil sampled at the dumpsites in Adigeni and Vardgineti village (Borjomi Municipality) did not contain the studied elements in concentrations exceeding their permissible limits.

It should be also stated that the concentration of cadmium did not exceed the permissible limit in any of the tested samples. And, mercury was not detected at all in any of the tested samples.

Treatment of some dumpsite areas with Georgian zeolite to improve soil quality (Samtskhe-Javakheti Region).

Since 2020, the working group of GSNE “Orchis”, in parallel to the inventory of dumpsites, have started treating the areas of dumpsites with Georgian sorbent – zeolite, which contains 60-80% clinoptilolite. It is known from the literature that it is a quite useful and cheap raw material for soil improvement. Considering this, we treated the territories of dumpsites with Georgian zeolite, or clinoptilolite in order to reduce the pollution level at these sites (i.e. remediate soil).

The related activities involved, first of all, cleaning up a dumpsite area (that is, removal of waste from the territory), then taking analytical soil samples (the first round of chemical analysis), applying Georgian sorbent (zeolite) to the cleaned area followed by soil re-sampling from the same dumpsite areas in a while (2-4 months) (the second round of chemical analysis). The results of the comparative analysis showed a dynamic of changing (decreasing) the content of some toxic heavy metals (Pb, Cu, Zn, Cd, Hg) in soil.

The first region where such study was conducted in July 2020 is the Samtskhe-Javakheti Region (for two dumpsites in Akhaltsikhe and one dumpsite in Aspindza). The chemical analysis of the first round was carried out in July 2020, when the soil pollution level was assessed for the dumpsites, and the second round of the survey was carried out in November of the same year, when analytical samples were taken after treating the areas with sorbent.

It should be mentioned that the treatment with Georgian sorbent partly changed soil composition at the dumpsites. In particular, the comparative analysis clearly showed that in 2 cases (Akhaltsikhe, Aspindza) out of 3 the copper content decreased by 21 and 79%, while the zinc content decreased in all three cases, by 33, 56 and 66%. The lead concentration decreased only in 1 case (Aspindza dumpsite) by 78%, while the lead content remained the same in other cases, that is in the analytical samples from Akhaltsikhe dumpsites.

It could be said that the obtained results are impressive (although not in all cases) and therefore, in our opinion, such surveys should continue in the future in other regions of Georgia as well. It would be recommended if the described methodology would be used by relevant organizations.

It should be stated that under such conditions, the remediation process of dumpsites depends on a number of meteorological phenomena (rainfall, air temperature, wind speed, etc.) as well as on the soil type and the amount of sorbent applied.