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Uticaj promene fizičko-hemijskih uslova i odabranih tretmana na mobilnost metala u sistemu sediment/voda / The impact of changes in physical-chemical conditions and selected treatments on the mobility of metals in sediment / water systems

<p>U radu je ispitana distribucija metala u sistemu sediment/voda na najugroženijim vodotocima u<br />AP Vojvodini. Na osnovu dobivenih podataka urađena je procena rizika na osnovu analize<br />porne vode, kiselog volatilnog sulfida i simultano ekstrahovanih metala i sekvencijalne<br />ekstrakcione procedure. Procena mobilnosti metala u sistemu sediment/voda određena je<br />promenom fizičko-hemijskih uslova u realnom sistemu (vodotok) i u laboratorijskim uslovima.<br />Ispitana je efikasnost in-situ (aeracijom sistema sediment/voda) i ex-situ remedijacije<br />sedimenta metodama termičkog tretmana i solidifikacije/stabilizacije.<br />Rezultati su ukazali da u svakom vodotoku i za&scaron;tićenoj zoni postoji lokacija u kojoj je sediment<br />barem po jednom metalu klasifikovan (holandski sistem klasifikacije sedimenata) kao zagađen<br />(klasa 3) ili izuzetno zagađen sediment (klasa 4). Generalno, kvalitet sedimenta manjih<br />vodotoka (Krivaja, Nadela, Kudo&scaron;, Veliki Bački kanal i Begej) je lo&scaron;iji u odnosu na ostale<br />ispitivane vodotoke.<br />Procena dostupnosti metala u sedimentu Velikog Bačkog kanala ukazala je da na svakom<br />ispitivanom profilu postoji minimum jedan metal i jedna metoda koja defini&scaron;e sediment kao<br />visoko rizičan. Takođe je zaključeno da je sediment na delu od 2+000 do 4+900 km zagađeniji,<br />jer postoji veći broj metala i metoda koji ga defini&scaron;u kao visoko rizičnim. Ovako dobijeni<br />rezultati ukazuju da nije dovoljan jednostavan i samo jedan pristup u oceni kvaliteta sedimenta<br />i proceni rizika koji metali mogu da ispolje u akvatičnom ekosistemu.<br />Ukazano je da pomeranje sedimenta (npr. otvaranja ustave), dovodi do promene fizičkohemijskih<br />uslova u sistemu sediment/voda, resuspenzije i transporta sedimenta. Usled ovih<br />promena povećava se dostupnost metala i dolazi do povećanja njihove koncentracije u vodenoj<br />fazi čime se znatno povećava rizik i mogućnost ispoljavanja negativnih efekata na akvatični<br />ekosistem.<br />U slučaju resuspenzije sedimenta u sistemu sediment/voda pronađena je zavisnost između<br />koncentracije metala u suspendovanim materijama i vodi od sadržaja određenih frakcija u<br />suspendovanim materijama (sadržaj organskih materija i frakcije do 63 &mu;m).<br />Remedijacione tehnike često su ekonomski neprihvatljive zbog velike zapremine zagađenog<br />sedimenta. Ukazano je da primena in-situ aeracije, omogućava smanjenje količine sedimenta<br />(čime se smanjuju tro&scaron;kovi eventualno naknadnog tretmana sedimenta), a da je tretman<br />solidifikacije/stabilizacije sedimenta sa glinom i termičke remedijacije zadovoljavjući sa<br />aspekta izluživanja metala. Dobijeni rezultati izvedenih testova izluživanja ukazali su na<br />moguću primenu ovih tretmana u pogledu re&scaron;avanja problema sedimenta koji je zagađen<br />metalima, bilo u pogledu sigurnog odlaganja na deponiju ili u smislu njegove upotrebe kao<br />dodatka pri proizvodnji građevinskog materijala (opeke), osnove za puteve, uređenje obale<br />(nasipa) itd. Na taj način mogu se znatno umanjiti tro&scaron;kovi izmuljivanja i manipulacije<br />kontaminiranog sedimenta, a sama remedijacija učiniti mnogo prihvatljivijom</p> / <p> This work investigates the distribution of metals in the sediment / water systems of the most<br /> endangered rivers in Vojvodina. Utilizing the data obtained, risk assessments are carried out<br /> based on analysis of pore water, acidic volatile sulphides and simultaneously extracted metals<br /> and sequential extraction procedure. The assessment of metal mobility in the sediment / water<br /> system is determined by the changing physical and chemical conditions in real systems<br /> (waterways) and under laboratory conditions. The effectiveness of in-situ (aeration of sediment<br /> / water) and ex-situ remediation of sediment by thermal treatment methods and solidification /<br /> stabilization are investigated.<br /> The results show that in each waterbody and protected area, certain locations have sediment<br /> which for at least one metal, is classified (by the Dutch system of sediment classification ) as<br /> polluted (class 3) or highly polluted (class 4). In general, the quality of sediment in smaller<br /> rivers (Krivaja, Nadela, Kudo&scaron;, Veliki Bački canal and Begej) is inferior to the other rivers<br /> studied.<br /> Assessment of the metals availability in the sediments of the Veliki Bački canal indicates that<br /> in each profile examined, at least one metal and one method defines the sediment as very<br /> hazardous. It is also shown that the sediment at the section from 2 +000 to 4 +900 km is the<br /> most polluted, with a number of metals and methods that define it as a high risk. The results<br /> indicate that it is inadequate to have a simple singular approach to sediment quality assessment<br /> and the assessment of the risks posed by metals detected in aquatic ecosystems.<br /> This work shows that sediment movement (e.g. from opening a sluice gate) leads to changes in<br /> the physical-chemical conditions of the sediment / water system, with resuspension and<br /> sediment transport. These changes increase metals availability and increase their<br /> concentrations in the aqueous phase, significantly increasing the posed risk and the possibility<br /> of adverse effects on aquatic ecosystems.<br /> In the case of sediment resuspension in the sediment / water system, a relationship was found<br /> between the concentration of metals in suspended matter and the concentration in the water for<br /> certain fractions of suspended matter (organic matter content and the fraction up to 63 &mu;m).<br /> Remediation techniques are often not economically viable due to the large volume of<br /> contaminated sediments involved. It is shown that the implementation of in-situ aeration<br /> reduces the amount of sediment (which reduces the costs of subsequent sediment treatment),<br /> and that solidification / stabilization treatment with clay and thermal remediation results in<br /> satisfactory remediation with respect to metals leaching. Leaching test results show the<br /> potential of these treatments to solve the problem of sediments which are contaminated with<br /> metals, either in terms of safe disposal in landfill or in terms of its use as a supplement in the<br /> production of building materials (brick), as road foundation, or for river bank reinforcement<br /> (dams), etc.. Thus, the costs of dredging and manipulating contaminated sediments can be<br /> significantly reduced, making remediation itself much more applicable.</p>

Identiferoai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)23652
Date08 October 2010
CreatorsKrčmar Dejan
ContributorsDalmacija Božo, Tamaš Zagorka, Klašnja Mile, Petrović Olga, Karlović Elvira
PublisherUniverzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, University of Novi Sad, Faculty of Sciences at Novi Sad
Source SetsUniversity of Novi Sad
LanguageSerbian
Detected LanguageEnglish
TypePhD thesis
Formatapplication/pdf

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