Origin and transport of organic pollutants in intergranular aquifers

Organska onesnaževala kot posledica raznih antropogenih dejavnosti na površju vodonosnika vstopajo v podzemno vodo in s tem tudi v pitno vodo. Namen raziskav v sklopu doktorske disertacije je bil raziskati prisotnost, razgradnjo in dinamiko organskih onesnaževal v podzemni vodi ter določiti njihov antropogeni izvor. Posebno pozornost smo posvetili študiju transportnih procesov treh farmacevtskih učinkovin, propifenazona, kofeina in karbamazepina, v nenasičeni coni. Na podlagi kombiniranega sledilnega poskusa smo določili hidravlične lastnosti nenasičene cone prodnega vodonosnika ter parametre sorpcije (Kd) in degradacije (?,T1/2) propifenazona in kofeina. Krivulj prehoda za karbamazepin, advekcijsko – disperzijske enačbe ne opišejo, zato s programom Hydrus 1-D ni bilo možno določiti transpotnih parametrov, kar kaže na bolj zapletene mehanizme transporta pri omenjeni spojini. Ugotovili smo, da ima kofein najmanjšo sposobnost sorpcije (povprečen Kd = 0,027), vendar hitro razpade (največji T1/2 = 69,31 dni). Koeficient sorpcije propifenazona je večji, njegova degradacija v primerjavi s kofeinom pa počasnejša (najvišji T1/2 = 92,42 dni). Na Dravskem polju spojine, omenjene v doktorski raziskavi, niso bile zaznane nad mejo detekcije analitične metode. V triletnem obdobju raziskav v podzemni vodi Dravskega polja je bilo z metodo pasivnih vzorčevalnikov skupaj določenih 382 organskih spojin. Med spojinami je bil največji delež (29 %) neznanih spojin, 27 % je urbanih spojin, med katerimi so tudi ostanki zdravil, 19 % pesticidov, 7 % topil ter 19 % ostalih spojin, med katere uvrščamo tudi industrijske spojine. Metoda pasivnih vzorčevalnikov se je izkazala kot zelo uporabna za preliminarno določanje prisotnosti onesnaževal v podzemni vodi. Za posamezno vrsto onesnaženja smo določili značilne pokazatelje onesnaženja kmetijskega, urbanega in industrijskega vpliva na podzemno vodo. Povezave med pojavom onesnaževal, lastnostmi onesnaževal, virom onesnaženja ter hidrogeološkimi razmerami so prikazane na kartah, izdelanih na podlagi izračunov večkratne linearne regresije. S statistično obdelavo je bilo ugotovljeno, da na pojav posamezne vrste onesnaževal vplivajo smer toka podzemne vode, koeficient prepustnosti, debelina nenasičenega in nasičenega območja. Za pojav skupine kmetijskih onesnaževal so pomembne kmetijske površine, na skupino urbanih onesnaževal vplivajo kanalizacijsko omrežje, železnica, ceste ter kmetijske površine in gozd, na pojav industrijskih onesnaževal pa se poleg hidrogeoloških pogojev kaže še vpliv urbanega zaledja, cest ter železnice.Organic pollutants enter the groundwater as well as drinking water due to various anthropogenic activities on the surface of the aquifer. The purpose of the research within the framework of the doctoral dissertation was to investigate the presence, degradation and the dynamics of organic pollutants in groundwater and to determine their anthropogenic origin. Special attention was paid to the study of the dynamic processes of three pharmaceuticals, propyphenazone, caffeine and carbamazepine, in the unsaturated zone. On the basis of the combined tracking experiment, we determined the hydraulic properties of the unsaturated zone of the aquifer and the parameters of sorption (Kd) and degradation (?, T1/2 ) of propyphenazone and caffeine. The breakthrought curves for carbamazepine, with advection- disperzion eqations, could not be modelled with Hydrus 1-D program, which indicates more complex transport mechanisms for the compound. We found that caffeine has the lowest sorption capacity (average Kd = 0.027), but it decays rapidly (the highest T1/2 = 69.31 days). The coefficient of sorption of propyphenazone is higher, and its degradation compared to caffeine is slower (the highest T1/2 = 92.42 days). At the Dravsko polje aquifer, these three compounds were not detected above the detection limit of the analytical method. In the three- year research period, 382 organic compounds were found in the groundwater of the Dravsko polje aquifer with the passive sampling method. Among the compounds, the largest percentage was the unknown compounds (29 %), followed by 27 % of urban compounds, among which there were also pharmaceuticals, 19 % of pesticides, 7 % of solvents and 19 % of other compounds, including industrial compounds. The passive sampler method has proved to be a very useful tool for the preliminary determination of the presence of pollutants in groundwater. For each type of pollution, we have identified typical indicators of agricultural, urban and industrial impacts on groundwater. We showed the links between the appearance of pollutants, the properties of pollutants, pollution sources and hydrogeological conditions on maps, which were made on the basis of the multiple linear regression calculations. By statistical analysis, it was found that the occurrence of a particular type of pollutant is influenced by the direction of the groundwater flow, the coefficient of permeability, as well as the thickness of the unsaturated and saturated area. Agricultural areas are the most important areas for the presence of the agricultural pollutants groupwhile the sewerage network, railways, roads, agricultural land and forest influence the group of urban pollutants. In addition to hydrogeological conditions, the impact of the urban hinterland, roads and railways is also responsible for the presence of industrial pollutants in groundwater