What is the nature of goudrons?
Goudrons are acidic resin and sludge generated primarily as by – products of the refining of petroleum. During the refining goudron absorbs sulphuric acid and hydrocarbons, such as resins, organic sulphuric acids, asphaltenes and unseparated part of raffinate. Gudrons are characterized by high toxicity, mutagenicity, teratogenicity and carcinogenicity. The risk results from emergency of leachate escape, which can degrade surface and ground water, soil, human health and health of all species present in the area.
When did they appear in DNV?
A big dump of these environmentally dangerous particles has been created more than 50 years ago in quarry near the residential area of Devínska Nová Ves in Bratislava, where about 30,000 cubic metres of the toxic waste, mostly from the former oil refinery Apollo, were allocated. This waste was diplaced in 1960s from the refinery in liquidation – Apollo and presented major threat and potential catastrophy for the local flora and fauna of the biodiversity hotspot of Devínska Kobyla.
In 1963, the authorities assumed that the alcaline environment of the former limestone quarry would neutralize the acidic waste thus this location would be suitable as a dumping place for goudrons – acidic resin. Ten years later, the surface of the dumping site was coated by the layer of the clay soil with thickness of up to 5 metres. The density of goudrons, which is 1,3 g/cm3 is lower than the density of the clay (12,6 g/cm3 ) and over time, the clay began to sink in the goudrons, pressing out the goudrons into the top layer of the dumping site. The site was covered with goudrons that were melting during the hot, sunny days.
What were the possibilities?
Considering the solutions for this specific dumping site, several possibilities appeared. The cheapest, but the least green and safe way was adding a new cover, new top layer to an existing dumping site. The other possibility was to dig up all the goudrons, constructing a concrete site that would protect the environment and insulate the goudrons from it and then return the goudrons and close them in this concrete „box“. This would be relatively safe, but the inhabitans, same as the authorities of the adjacent residential area demanded the final solution that would liberate this locality from this enviromental burden.
The most expensive, but green way was chosen. The goudrons were to be removed from the quarry and destroyed.
The waste was decided to be excavated and transported by the trucks away from the limestone quarry. This realisation did not evade the criticism too. Despite the fact that the transportation was planned for the winter months to prevent the goudrons melting and leaking the material and smell to the residential area, the inhabitans feared that the uncovered trucks under their windows would present a threat to their health.
In the past, almost the only affordable way of getting rid of the goudrons was the dumping site, even though the hermetic box was within the possibilities of that time. Nowadays, we are able to use some alternative ways. Amongst the possibilities is using them as fuel in the heating plant or cement factory. The other possibility is to chemically neutralize the waste and either dump it in a hermetical box or use it in road construction (as used in Hungary).
The removal of the goudrons from the quarry was realised thanks to the funds from the European union and cost 12 millions euro.
In the present, with the technologies emerging, the oil processing changed to create less of the toxic waste and the waste that is created is directly neutralized and processed. However, the dumping site of the Devínska Nová Ves is not the only burden of the past that threatens the nature and the mankind. In Slovakia alone we are aware of at least one more goudron dumping site near the village of Predajná. The goudrons in their liquid form were dumped there by the refinery Dubová during the Slovak War State. It is up to us and our offsprings to employ the new technologies to deal with the problems created by our ancestors.