Primjena multielementne analize u istraživanjima prijenosa i raspodjele elemenata u slatkovodnim sustavima: područje Visovačkog jezera u ekosustavu rijeke Krke

doctoral thesis

• Title (english): Application of multielement analysis in research of transport and distribution of elements in freshwater systems: the area of Visovac lake in the ecosystem of the Krka river
• Author: Niko Bačić
• Mentor: Dario Omanović (mentor)
• Committee member: Sanda Rončević (predsjednik povjerenstva)
• Committee member: Irena Ciglenečki-Jušić (član povjerenstva)
• Committee member: Željka Fiket (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2022-06-10, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

Da bi se istražio transport, ponašanje i raspodjela elemenata u sustavu Visovačkoga jezera
analizirani su uzorci vode, sedimenata i tla koji su uzeti uzimajući u obzir geomorfološke
karakteristike sustava, te dinamiku sezona i promjene protoka. Multielementna analiza
napravljena je metodom spektrometrije masa visoke razlučivosti uz induktivno spregnutu plazmu.
Razvijena je metoda određivanja manje istraživanih tehnološki-kritičnih elemenata (Ga, Ge, Nb,
Te) u krutim okolišnim uzorcima (tla i sediment).
Multielementna analiza sedimenata prevladavajućim utjecajem rijeka Krke i Čikole
pokazala je značajne razlike u elementnom sastavu geoloških podloga tih rijeka. Procjenom
brzine sedimentacije rekonstruirani su antropogeni pritisci koji su sve događali u prošlosti.
Sedimenti u blizini nove tvornice vijaka i ispusta otpadnih komunalnih voda u Kninu pokazali su
da je to i dalje potencijalni izvor zagađenja rijeke Krke ekotoksičnim elementima, ponajviše Cd,
Cr i Zn, čije vrijednosti premašuju razine pri kojima se očekuje toksični učinak. Iako se rijekama
Krkom i Čikolom u jezero unose ekotoksični elementi, koncentracije elemenata u sedimentima
Visovačkoga jezera su općenito niske, te se taj vodeni sustav može okarakterizirati kao
nezagađen ili vrlo slabo zagađen.
Analizom prostornih i vremenskih raspodjela ukupnih i otopljenih elemenata u vodi
tijekom nekoliko godina utvrđeno je da se pri visokim protocima najviše unose elementi pretežito
vezani za čestice, dok pri niskim protocima u ljetnim mjesecima podzemne pritoke rijeke Krke
čine znatan udio unosa vode u jezero. Povećane koncentracije antropogenih elemenata (Cr, Cu,
Na, Pb, V) izmjerene na lokaciji gdje se Čikola ulijeva u Visovačko jezero ukazuju na
antropogeno onečišćenje koje dolazi iz komunalnih voda grada Drniša. Godišnji hidrološki
pronosi elemenata pokazali su da se u Visovačkom jezeru djelomično talože elementi vezani za
čestice, te da osim rijeka Krke i Čikole postoje dodatni izvori unosa elemenata u jezero.

Abstract (english)

The Krka River is a very clean karst water system characterised by a low level of trace
elements of natural origin, which makes this system particularly sensitive to anthropogenic
influences. In order to investigate the transport, behaviour and distribution of elements in the
Visovac Lake system, sediment, soil and water samples were analysed, taking into account its
geomorphological characteristics and the dynamics of seasonal and river flow changes.
Multielement analysis was performed by high resolution inductively coupled plasma mass
spectrometry technique and a method was developed for the analysis of the less studied
technologically critical elements in solid samples.
Sediment and water analyses identified the main anthropogenic sources and the main
transport pathways of elements into this water system. The history of anthropogenic pollution by
metals was reconstructed by analysing dated sediment cores. Although the input of some ecotoxic
elements through the Krka and Čikola rivers was identified, their concentrations in the sediments
of the Visovac Lake were generally low, so this water system can be classified as unpolluted or
low-polluted with respect to metals.
The analysis of the spatial and temporal distribution of total and dissolved elements in the
water over a period of several years showed that the high discharges bring mainly elements bound
to the particles, while during the low discharges in summer the underground tributaries of the
Krka (characterised by a different elemental composition) account for a significant proportion of
the water entering the lake. Increased concentrations of anthropogenic elements (Cr, Cu, Na, Pb,
V) measured at the location where Čikola flows into Visovačko Lake indicate anthropogenic
pollution originating from the municipal waters of the town of Drniš. The analysis of the annual
hydrological fluxes of elements has shown that elements bound to particles are partially retained
in the lake and that there are other sources of elements in Lake Visovac besides the Krka and
Čikola rivers.

• Keywords: antropogeni utjecaj; ICP-MS; multielementna analiza; rijeka Krka; TCE
• Keywords (english): anthropogenic impact; ICP-MS; Krka river; multielement analysis; TCE
• Language: croatian
• URN:NBN: urn:nbn:hr:217:331811
• Promotion: 2022
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 156 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-06-15 11:54:27