Title Zastupljenost koloidnih mineralnih faza u recentnim sedimentima Jadrana i njihova uloga u biogeokemijskom kruženju tvari Title (english) The occurrence of the colloidal mineral phases in the recent sediments of the Adriatic sea and their role in the biogeochemical processes Author Maja Ivanić Mentor Ivan Sondi (mentor)Committee member Neda Vdović (predsjednik povjerenstva)Committee member Srečo Škapin Committee member Mladen Juračić (član povjerenstva)Granter University of Zagreb Defense date and country 2015-05-22, Croatia Scientific / art field, NATURAL SCIENCES Universal decimal classificationUDC ) 55 - Geology. Meteorology. Hydrology Abstract U ovom radu istražen je mineralni sastav i zastupljenost mineralnih čestica koloidnih, a osobito nanometarskih dimenzija, u recentnim sedimentima iz različitih morskih okoliša jadranskog područja. Posebna pozornost posvećena je detaljnom istraživanju njihovih površinskih fizikalno-kemijskih, mineraloških, morfoloških i geokemijskih značajki. Također, istražen je utjecaj površinski vezanih organskih i anorganskih tvari na površinske fizikalno-kemijske značajke mineralnih čestica i njihova uloga u vezanju elemenata u tragovima. Dobiveni rezultati ukazali su da organska tvar uvjetuje stvaranje agregata s mineralnim česticama i njezinim uklanjanjem dolazi do porasta udjela glinovite komponente i smanjenja prosječne veličine čestica. Uklanjanje organske tvari uzrokovalo je porast SSA i CEC- a svih uzoraka, no istovremeno nije utjecalo na karakter naboja mineralnih čestica. Porast SSA i CEC-a sa smanjenjem veličine čestica posljedica je većeg udjela minerala glina i Fe i Mn oksida i oksihidroksida u sitnim frakcijama sedimenta, dok je intenzitet porasta SSA i CEC odraz zastupljenosti ovih mineralnih faza. Željezovi oksidi i oksihidroksid i, zbog velikih SSA, dodatno povećavaju ukupnu površinu uzorka. Ustanovljen je porast zastupljenosti metala asociranih s alumosilikatnom mineralnom fazom i Fe i Mn oksidima i oksihidroksidima prema sitnijim frakcijama. Uklanjanje Fe i Mn oksida i oksihidroksida ukazalo je na afinitet Co, Cu i Mo za Mn okside i oksihidrokside te As za Fe okside i oksihidrokside. Značajna zastupljenost karbonata u koloidnoj fazi utvrđena je u sedimentacijskom okolišu u kojem dolazi do njihovog autigenog formiranja. Nasuprot tome, u sedimentima u koje karbonati dolaze kao rezultat mehaničkog i kemijskog trošenja njihov udio u koloidnoj, a poglavito nanomineralnoj fazi je vrlo mali.
Abstract (english) The main objective of this study was to determine the mineral composition and the occurrence of the colloidal, and particularly nanosized, mineral phases in the recent marine sediments of different sedimentological environments of the Adriatic Sea. Particularly, detailed investigation of their surface physico-chemical, mineralogical, morphological and geochemical properties were preformed. The influence of organic and inorganic surface coatings on these properties was also investigated. The results obtained showed that the removal of organic matter caused disintegration of aggregates, increase in clay fraction and lowering of mean particle size. Also, an increase in SSA and CEC was observed in all investigated samples. The removal of organic matter had no effect on the charge of mineral particles. The increase in SSA and CEC with particle size diminishing to colloidal dimension was ascribed to the accumulation of clay minerals and Fe and Mn oxides and oxyhydroxides in finer sediment fractions, while the intensity of this increment was the result of different distribution of these mineral phases. Iron and manganese oxides and oxyhydroxides on the surfaces of mineral particles additiona lly increased their SSA. The results showed an increase in concentrations of metals associated with aluminosilicates and Fe and Mn oxides and oxyhydroxides with particle size lowering. The removal of Fe and Mn oxides and oxyhydroxides significantly affected the distribution of Co, Cu and Mo on account of their association with Mn oxides and oxyhydroxides and indicated the importance of Fe oxides and oxyhydroxides in cycling of As in the environment. The significant occurrence of carbonates in colloidal mineral phase was determined in the sedimentary environment where their presence was the result of authigenic formation. In sediments where carbonates were a product of mechanical and chemical weathering, their occurrence in colloidal mineral phase was very limited.
Keywords
recentni sedimenti
koloidna mineralna faza
površinske fizikalno-kemijske značajke
organska tvar
Fe oksidi i oksihidroksidi
elementi u tragovima
Keywords (english)
recent sediments
colloidal mineral phase
surface physico-chemical properties
organic matter
Fe oxides and oxyhydroxides
trace elements
Language croatian URN:NBN urn:nbn:hr:217:456220 Project Number: 195-0982934-2742 Project Number: IP-11-2013-2504 Study programme Title: Interdisciplinary doctoral study in Oceanology Type of resource Text Extent 190 str. ; 30 cm File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Public note Ovaj doktorski rad izrađen je u Laboratoriju za geokemiju koloida, Zavoda za istraživanje mora i okoliša, Instituta Ruđer Bošković. Istraživanja su provedena u okviru navedenih projekata. Created on 2017-02-15 14:45:44
