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PHOTOCATALYTIC DECOMPOSSITION OF METHANE AS A TECHNOLOGY FOR REDUCING EMISSIONS FROM LOWMETHANE MUNICIPAL WASTE LANDFILLS
No full textOdlagališta otpada predstavljaju ekološke, ekonomske i društvene izazove, prvenstveno zbog
onečišćenja nastalog od organskog otpada koji se raspada u samom odlagalištu. Razgradnjom
organskog otpada nastaje metan (CH4), staklenički plin koji doprinosi klimatskim promjenama.
Metan (CH4) se obično zbrinjava spaljivanjem čime ga se pretvara u ugljični dioksid (CO2) i
vodenu paru (H2O). Međutim, kada su razine metana ispod 20 %, spaljivanje na baklji postaje
neisplativo, što dovodi do njegovog izravnog ispuštanja u atmosferu.
U predmetnom istraživanju stoga je istražen potencijal fotokatalitičke oksidacije s ciljem samog
razvitka prikladne tehnologije za zaštitu zraka iznad odlagališta otpada. Ovaj proces koristi
Sunčevo zračenje i fotokatalizator, a pokazao se učinkovitim i isplativim za razgradnju
onečišćivala poput metana (CH₄) u odlagališnom plinu. Uz navedeno, razvijen je i matematički
model za računalnu simulaciju i dizajn budućih sustava za smanjenje emisija odlagališnih
plinova na samom izvoru.
Ispitivanje fotokatalitičke razgradnje na uzorku stvarnog metana (CH₄) s odlagališta neopasnog
otpada Totovec pokazalo je smanjenje metana (CH₄) za približno 20 %. Iako je smanjenje bilo
nešto niže od očekivanog, rezultati su potvrdili učinkovitost fotokatalitičke oksidacije, čak kada
je koncentracija metana nešto niža (< 10 %).
Matematički model otkrio je ključne čimbenike koji utječu na razgradnju metana (CH₄) u
prstenastom reaktoru, osobito važnost duljine cijevi. Iako je model bio učinkovit, upotreba alata
računalne dinamike fluida za simulaciju pokazala se izazovnom zbog potrebe za opsežnom
prilagodbom i stručnošću za ovu specifičnu primjenu.Landfills are places intended for the disposal of solid waste and, as such, carry numerous
ecological, economic, and social problems. The decomposition of organic waste at landfills
produces methane (CH4), a greenhouse gas that is 25 times more potent than carbon dioxide
(CO2) in terms of heat retention, according to the Intergovernmental Panel on Climate Change
(IPCC). Accordingly, landfills represent one of the largest sources of methane (CH4) resulting
from human activity.
To reduce methane (CH4) emissions at landfills, landfill gas collection systems are often
installed to "capture" methane (CH4) and other gases emitted during the decomposition of
organic waste and transport them to a centralized facility for disposal. The most common
method of methane (CH4) disposal at landfills is flaring, which converts methane into carbon
dioxide (CO2) and water vapor (H2O). This practice is typical when the methane (CH4) content
in the landfill gas is at least 20%. When concentrations are lower, flaring becomes economically
unfeasible, leading to the release of methane into the atmosphere.
For this reason, the potential of photocatalytic oxidation was explored in this study on a real
landfill gas sample with lower methane (CH4) content. The goal of the study was to develop an
effective air protection technology for use at the source of landfill gas emissions. Photocatalytic
oxidation is a process that uses light-activated photocatalysts to create redox reactions that
degrade pollutants such as volatile organic compounds (VOCs) into harmless substances like
water and carbon dioxide (CO2).
The expected scientific contribution of this research is to confirm the effectiveness of solar
photocatalysis and demonstrate that it is a suitable technology for air protection above landfills,
which could potentially be used at the source of landfill gas emissions. Additionally, the
development of a mathematical model for the photocatalytic degradation of air pollutants will
provide the foundation for scaling up the process and applying it in real systems.
For the purpose of the research, the following four hypotheses were proposed: (1) Methane
(CH4), whose content in landfill gas composition is variable, can oxidize to carbon dioxide
(CO2) with the available amount of oxygen at the outlet from the landfill body; (2) Hydrogen
sulphide (H₂S), a component of landfill gases, is separated by the adsorption process from the
gas stream and remains on the photocatalytic material; (3) Suitable photocatalytic materials
based on titanium dioxide (TiO2) can be used for extended periods and regenerated if necessary
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before reuse; (4) An annular-type photocatalytic reactor represents a model system for the
simple upgrade of gas wells within the landfill body.
The first phase of research included the selection of photocatalytic material based on previous
research on commercial photocatalysts. Research has shown that titanium dioxide (TiO2) has
the most effective photoactivity, the highest stability and the lowest costs, which is why it was
chosen as the photocatalyst for conducting research. In the research itself, the photocatalyst was
applied to a mesh of glass fibres.
The next step in the research was the assembly of a laboratory photocatalytic reactor.
Photocatalytic reactors for air treatment require appropriate design with the aim of achieving
high quantum yields for long operating times with minimal costs. In order to achieve the above,
it is necessary to choose the appropriate configuration of the reactor and the source of UV
radiation in addition to the photocatalyst. In the test, an annular type of reactor was used, which
consists of two glass, concentric cylinders, between which the reaction mixture flows. The light
source (UV lamp) is placed in the inner cylinder, parallel to the tube. To simulate solar
radiation, Narva BIO vital® LT T5 24W / 958, UV lamp with the length of 549 mm was used.
The lamp in question emits radiation with a characteristic part of the UV-A and UV-B spectrum
(λ > 315 – 400 nm).
As a final step, the photocatalytic reactor was modelled using Computational Fluid Dynamics
(CFD). The computer program COMSOL Multiphysics was used for data visualization. In
addition to visualization, the mentioned computer program also enabled the computer
simulation of methane (CH4) decomposition in the test reactor using the estimated kinetic
parameters. Computer simulations were performed for different cases in order to be able to
compare the results obtained by the research with those obtained in the computer simulation.
The purpose of the above was to check the accuracy of the computer simulation, which will
ultimately enable further optimization of the test system and the adaptation of future potential
air protection systems above the waste disposal site.
Regarding the results themselves, based on which the proposed hypotheses were confirmed, the
results of the photocatalytic oxidation of methane (CH4) on a real gas sample from the
"Totovec" non-hazardous waste landfill showed an average reduction in methane (CH4)
concentration of 19.91 % across three measurements, specifically 21.59 % in the first
measurement, 18.15 % in the second, and 20.00 % in the third measurement. The
aforementioned confirmed the effectiveness of photocatalytic oxidation as methane (CH4) was
X
oxidized to carbon monoxide (CO) and carbon dioxide (CO2). This was confirmed by observing
the decomposition products, evidenced by a 30 % increase in carbon monoxide (CO) levels, as
CO concentrations rose from 2 to 3 ppm in the first and second tests and from 3 ppm to 4 ppm
in the third test.
Regarding the second hypothesis, the presence of hydrogen sulphide (H2S) in the landfill gas
samples was low (< 100 ppm) due to the prior separation of food waste at the source (the
landfill), and no significant difference in methane (CH4) degradation efficiency was observed
between samples with and without hydrogen sulphide (H2S) during the testing.
The third hypothesis was confirmed by using a fiberglass mesh in the research. The fiberglass
mesh served as a carrier for the photocatalyst, titanium dioxide (TiO2), and enabled efficient
photocatalytic oxidation due to its large surface area and porous structure, as supported by the
results of the photocatalytic oxidation during the study. This mesh had previously proven to be
a very good solution, as it could be regenerated after use through thermal treatment, thereby
extending its usage time. Thermal regeneration of the fiberglass mesh was effective due to the
high thermal stability of titanium dioxide (TiO2), allowing the removal of organic pollutants
through thermal oxidation. This kept the surface clean and ready for the further adsorption of
pollutants for additional photocatalytic degradation.
Concerning the fourth hypothesis, the annular-type photocatalytic reactor represents a model
system for the simple upgrade of gas wells at landfills due to its efficient design. The ring shape
allows for a larger surface area for the photocatalyst, promoting effective interaction between
the landfill gases and the used catalyst, as demonstrated in the model simulation created in the
COMSOL Multiphysics software. This design, being of a ring type, facilitates integration into
existing landfill gas collection systems, which are cylindrical in shape and thus require minimal
modifications to the gas wells
ORGANSKA ONEČIŠĆIVALA OD RASTUĆEGA ZNAČAJA U KRŠKIM PODZEMNIM VODAMA U HRVATSKOJ
No full textNapredak analitičkih metoda i instrumenata omogućio je otkrivanje organskih onečišćivala od rastućega značaja (OORZ) u površinskim i podzemnih vodama u koncentracijama reda veličine ng/L do μg/L, a čija je prisutnost u okolišu rezultat kontinuiranoga, svakodnevnoga ispuštanja diljem svijeta. Istraživanje pojavnosti i ponašanja OORZ-a u krškim vodonosnicima je u začecima, što je razlog trenutnog nedostatka političkih mjera i zakonodavne kontrole za ove spojeve u podzemnim vodama. Vodonosnici dinarskog krša opskrbljuju pitkom vodom gotovo
polovicu teritorija Hrvatske, a odlikuje ih heterogenost i anizotropnost strukturnih i hidrauličkih značajki, intenzivna okršenost i znatna pukotinsko-kavernozna poroznost. Ove značajke rezultiraju brzim tokovima podzemne vode i izdašnim krškim izvorima, ali istovremeno čine krške vodonosnike izrazito ranjivima na onečišćenje te njihovo istraživanje složenim i izazovnim. Znanstveni radovi objavljeni kao dio ove doktorske disertacije po prvi puta u
Hrvatskoj identificiraju i kvantificiraju OORZ-ove u krškim vodonosnicima na regionalnoj (17
krških izvora i jedno jezero) i lokalnoj (izvori Jadro i Žrnovnica, bušotina Gizdavac i rijeka Cetina) razini. U dvije sveobuhvatne kampanje analizirano je 740 OORZ-a, od čega je utvrđena pojavnost 65 spojeva na regionalnoj razini, među kojima su najčešće detektirani farmaceutici
(n=26) i poljoprivredni spojevi (n=26). Industrijski spojevi i umjetna zaslađivala imala su
najviše koncentracije do 90 ng/L (TPPA) i 440 ng/L (sukraloza). Tijekom sedam kampanja uzorkovanja na lokalnoj razini slijeva izvora Jadra i Žrnovnice, identificirana su 22 OORZ-a u
koncentracijama koje su se kretale od 0.3 ng/L (opioidni analgetik tramadol) do 372 ng/L
(industrijski spoj 1H-benzotriazol). Repelent DEET bio je najčešće detektiran spoj prosječne koncentracije od 50 ng/L utvrđene u površinskoj vodi rijeke Cetine, izvorima i podzemnoj vodi.
Niže koncentracije i manja učestalost detekcije OORZ-a u hrvatskom kršu, za razliku od drugih krških područja, sugeriraju značajno razrjeđenje koje se pripisuje velikim protocima izvora “klasičnog krša” i relativno niskom intenzitetu poljoprivrednih i industrijskih aktivnosti u istraživanom području. Maksimalne koncentracije OORZ-a u izvorima Jadro i Žrnovnica
uočene su nakon jesenskih kiša, dok tijekom najviših protoka uslijed razrjeđenja nije zabilježena pojavnost spojeva iznad granica detekcije (LOD). Suprotno izvorima, u podzemnoj
vodi iz duboke bušotine Gizdavac, najveća ukupna koncentracija OORZ-a utvrđena je pri
uvjetima malih protoka što naglašava značajnu ranjivost krškog vodonosnika. Uz uvid u dinamiku krškog sustava, analiza hidrokemijskih značajki pokazala se korisnom za bolje razumijevanje funkcioniranja i ranjivosti hidrogeoloških sustava na OORZ-ove. Oštri skokovi uočeni na kemografovima izvora Jadra i Žrnovnice dokaz su značajne okršenosti i inherentne
ranjivosti sustava. Zastupljenost ponora, razvijene mreže krških kanala i pukotina mogu
pospješiti transport OORZ-a. Utvrđena je snažna, statistički značajna pozitivna korelacija između metformina i iona NO3
-, kao i koncentracije OORZ-a, broja detektiranih spojeva i iona
NO3
- u rijeci Cetini, što ukazuje na njihovo zajedničko porijeklo, vjerojatno otpadnu vodu.
Pojavnost postojanih OORZ-a u izvorima i podzemnoj vodi pri uvjetima niskih voda i pozitivna
statistički značajna korelacija DEET-a s Ca2+ ionom, ukazuje na potencijalno skladištenje postojanih OORZ-a u pukotinsko-poroznoj epikrškoj zoni vodonosnika. Uočena sezonalnost i
sveprisutnost u slijevu indikatora onečišćenja otpadnom vodom, spojeva DEET i 1Hbenzotriazola, ukazuje na ograničenu atenuaciju postojanih i mobilnih spojeva unutar krškog vodonosnika. Kako na regionalnoj, tako i na lokalnoj razini, većina otkrivenih spojeva ocijenjena je kao potencijalno postojana, mobilna i toksična ili kao vrlo postojana i vrlo
mobilna, ukazujući na njihov potencijalno negativan utjecaj na ekosustav podzemnih voda. Analizom utjecaja na ljudsko zdravlje utvrđeno je kako izmjerene koncentracije OORZ-a u
ng/L u krškim izvorima koji se koriste u vodoopskrbi, trenutno ne predstavljaju značajan rizik za zdravu populaciju, no preporuka je da se budućim istraživanja analiziraju potencijalni učinci
dugotrajne izloženosti koktelu različitih OORZ-a. Važno je uspostaviti protokole redovitog praćenja OORZ-a koji su prioritizirani ovom disertacijom na temelju analize njihove postojanosti, bioakumulativnosti, mobilnosti i toksičnosti, uz razmatranje mogućnosti provedbe Dobrovoljnog popisa praćenja OORZ-a u podzemnim vodama, prilagođenog karakteristikama dinarskog krša. Radi utvrđivanja potencijalnih pozadinskih koncentracija OORZ-a i njihovog
ponašanja pri različitim hidrološkim uvjetima, fokus budućih istraživanja treba usmjeriti na analize događaja na razini pojedinih sljevova. Za slijev izvora Jadra i Žrnovnice predlaže se praćenje spojeva DEET-a, 1H-benzotriazola i metformina. Također, ističe se prednost usporedne analize hidrokemijskih markera i OORZ-a kao novih trasera koji će rasvijetliti zamršeno međudjelovanje čimbenika koji utječu na transport unutar krških vodonosnika i uvjetuju kemiju podzemnih voda podložnih različitim antropogenim pritiscima. Takva
istraživanja pružit će uvide ključne za smanjenje rizika, posebice u svjetlu očekivanog porasta opterećenja onečišćenjem u nadolazećim godinama i utjecaja klimatskih promjena na količine vode.Owing to considerable advancement in analytical techniques and instrumentation, emerging
organic contaminants (EOCs) are being detected in both surface water and groundwater at
concentrations ranging from ng/L to μg/L, where they have been introduced by ongoing, global
daily emissions. Research on the occurrence and behaviour of EOCs in karst aquifers is in its early stages, leading to a dearth of policy measures and legislative controls for these compounds in groundwater. The Dinaric karst aquifers, which provide drinking water to nearly half of Croatia's territory, exhibit heterogeneous, anisotropic structural and hydraulic characteristics, intense karstification, and high fracture-cavernous porosity. These features result in rapid
groundwater flow and large karst springs, yet they also render the aquifers highly vulnerable to contamination and their investigation intricate and challenging. The scientific papers published
as part of this PhD thesis were the first to identify and quantify EOCs within Croatian karst
aquifers at regional (17 karst springs and 1 karst lake) and local (4 locations within Jadro and Žrnovnica catchment) scales. Through two comprehensive campaigns encompassing analysis of 740 EOCs, 65 compounds were detected at the regional level, with pharmaceuticals (n=26)
and agrochemicals (n=26) being predominant. Industrials and artificial sweeteners exhibited
the highest concentrations up to 90 and 440 ng/L, respectively. At local scale, 22 EOCs were identified in the karst catchment of Jadro and Žrnovnica springs during seven sampling campaigns, with concentrations reaching up to 372 ng/L. The comparatively lower
concentrations and detection frequency of EOCs in the Croatian karst, as opposed to other karst
regions, suggest significant dilution attributed to substantial discharge of “classical karst” springs and relatively low intensity of agricultural and industrial activities in the area. At both
regional and local scales, the majority of compounds were assessed as potentially persistent,
mobile and toxic or very persistent and very mobile, unraveling their potential negative impact
on (ground)water ecosystem. While current concentrations of EOCs in ng/L in karst drinking
water are not expected to pose a significant risk to healthy populations, future research should
analyse the potential effects of long-term exposure to EOCs mixtures, particularly for
vulnerable or at-risk groups. The importance of establishing regular monitoring protocols for EOCs prioritized with this thesis is underscored, with due consideration given to the
implementation of a Voluntary Groundwater Watch List tailored to Dinaric karst
characteristics. Future in-depth event analysis at catchment levels is recommended, to elucidate
potential background EOCs levels and their behaviour under varying hydrological conditions.
Such research will offer crucial insights for risk mitigation, in light of the expected increase in
contamination mass loads in the coming years and the ongoing impact of climate changes on water quantities
The analysis of smart readines indicatior (SRI) implementation
No full textNekontroliranim i neodgovornim ispuštanjem velikih količina stakleničkih plinova antropogenog podrijetla povećava se utjecaj na klimatske promjene koje predstavljaju sve veću prijetnju društvu i gospodarstvu. Donošenjem raznih međunarodnih klimatskih i energetskih inicijativa želi se postići smanjenje negativnog utjecaja na klimatske promjene, što je u sektoru zgradarstva, između niza direktiva koje su utjecale na smanjenje potrošnje energije, rezultiralo nastankom pokazatelja pripremljenosti zgrada za pametne tehnologije. Svrha navedenog indikatora jest ocjenjivanje „pametnosti zgrade“, odnosno primjena digitalnih tehnologija. Kroz rad je opisan razvoj Direktive o energetskim svojstvima zgrada koja utječe na buduće uvođenje analize spremnosti zgrada za pametne tehnologije. Pametne zgrade u konačnici pomažu u ostvarivanju cilja dekarbonizacije sektora zgradarstva kroz bolji nadzor, upravljanje i integraciju termotehničkih i svih ostalih energetskih sustava u zgradama. Dodatno se postiže povećanje energetske učinkovitosti postojećih sustava, integraciju obnovljivih izvora energije, poboljšanje kvalitete zraka i udobnosti te poticanje inovacija i ulaganja.
U ovom se radu nastoji detaljno opisati pokazatelj pripremljenosti za pametne tehnologije te su dana dva primjera analize i primjene u višestambenim zgradama i obiteljskim kućama u europskim zemljama. Dodatno je napravljena preliminarna analiza dva scenarija tehničkih sustava u zgradi Geotehničkog fakulteta. Tehnički su sustavi zgrade dodatno opisani kako bi se prikazale njihove karakteristike. Provedenom analizom utvrđeno je kako sustavi oba scenarija ne postižu ni približno zadovoljavajuću ocjenu „pametnosti“. Nadalje, napravljena je i dodatna analiza sa svrhom procjene starosti i životnog vijeka tehničkih sustava. Rezultati analize ukazuju na zastarjelost tehničkih sustava za koje se procjenjuje da se ne isplate nadograđivati pametnim tehnologijama. Takvi rezultati dodatno su potvrdili ocjene „pametnosti“ dobivene analizom scenarija.
Preporučena je zamjena svih sustava osim fotonaponskih kolektora za koje se preporučuje nadogradnja jer su instalirani tijekom 2023. godine. Također, preporučuje se analiza raznih kombinacija tehničkih sustava s kojima bi se ubuduće zgrada Geotehničkog fakulteta mogla nadograditi kako bi se unaprijed analizirala mogućnost povezivanja sustava i njihovo zajedničko upravljanje pomoću čega bi dijelovi svih sustava koji se ugrađuju mogli međusobno komunicirati, te u svrhu smanjenja potrošnje energije provjerilo stanje „pametnosti“ zgrade za takve scenarije i dala njihova ocjena.The uncontrolled and irresponsible release of large amounts of greenhouse gases of anthropogenic origin increases the negative impact of climate change, which represents an ever-increasing threat to society and the economy. The aim of various international climate and energy initiatives is to reduce the negative impact of climate change, which, among a series of directives that have influenced energy consumption reduction, has resulted in the emergence of the smart readiness indicator in the building sector. The purpose of the indicator is to rate the smart readiness of buildings, i.e., the application of digital technologies. This paper discusses the development of the Energy Performance of Buildings Directive, which affects the future introduction of smart readiness analysis for buildings. Ultimately, smart buildings help achieve the goal of decarbonizing the sector through better monitoring, management, and integration of thermal and all other energy systems in buildings. Additionally, this increases the energy efficiency of existing systems, integrates renewable energy sources, improves air quality and comfort, and encourages innovation and investments.
In this paper, the smart readiness indicator is described in detail along with two examples of analysis and application in multi-family residential buildings and single-family homes in European countries. A preliminary analysis of two scenarios of technical systems in the Geotechnical Faculty building is also conducted. The technical systems of the building are further described to present their characteristics. The analysis shows that the systems in both scenarios achieve the smart readiness indicator rating which is far from satisfactory. Based on this, an additional analysis was made for the purpose of determining the age and lifespan of technical systems. The results of the analysis show that technical systems are outdated and they are not worth upgrading with smart technologies. Such results further confirm the smart readiness indicator ratings obtained from the scenario analysis.
The replacement of all systems is recommended except for the photovoltaic collectors installed in 2023, for which an upgrade is recommended. It is also recommended to analyze various combinations of technical systems with which the Geotechnical faculty building could be upgraded in the future. This analysis would pre-assess the possibility of system integration and joint management, enabling parts of all installed systems to communicate with each other. The goal is to evaluate the building's "smartness" for such scenarios, aiming to reduce energy consumption and provide a smart readiness rating
BIOMONITORING OF METALS IN ENVIRONMENT AND HONEY BEE COLONIES (Apis mellifera L.)
No full textOvo znanstveno istraživanje obuhvaća ispitivanje specifičnih pokazatelja onečišćenja, konkretno teških i toksičnih metala i metaloida, prisutnih u sastavnicama okoliša (u vodi i tlu) te njihovu prisutnost u biljnom materijalu kao i u pčelinjim zajednicama Apis mellifera L. (u odraslim pčelama i medu). Medonosne pčele su vrlo osjetljivi organizmi i pouzdani bioindikatori onečišćenja. Uzorci su uzimani s 20 lokacija na području triju regija Republike Hrvatske, u kontinentalnom nizinskom dijelu, primorskom dijelu i gorskom dijelu. Lokacije su vezane uz intenzivnu poljoprivrednu proizvodnju, urbano područje i prometnu gustoću, industrijsko područje te šumsko područje i područje uz more. Određivani su metali i metaloidi: As, Cd, Co, Cr, Cu, Hg, Fe, Mn, Ni, Pb, Se i Zn. Navedeni elementi analizirani su na atomskom apsorpcijskom spektrometru (AAS) odnosno induktivno spregnutom plazmom s masenom spektrometrijom (ICP-MS). Dobiveni rezultati uspoređeni su s postojećim propisima o kvaliteti vode, tla i meda, a izrađena je i korelacijska analiza prisutnih onečišćivala u okolišu i pčelinjim zajednicama. Antropogeni otisak odnosno pritisak na okoliš i pčele izražen je u vidu faktora bioakumulacije, indeksa kvalitete i ukupnog pokazatelja antropogenog utjecaja.This scientific research includes analysis of specific indicators of contamination, heavy and toxic metals and metalloids, present in the components of the environment (water and soil) and their presence in plant material as well as in honey bee colonies Apis mellifera L. (in adult honey bees and honey). Honey bees are very sensitive organisms and reliable bioindicators of environmental contamination. Samples were taken from 20 locations in three regions of the Republic of Croatia, in the continental lowland region, the coastal region and the mountain region. The locations are related to intensive agricultural production, urban area and transport activity, industrial area, forest area and near the sea coast. The following metals and metalloids were determined: As, Cd, Co, Cr, Cu, Hg, Fe, Mn, Ni, Pb, Se and Zn. These elements were analysed on atomic absorption spectrometer (AAS) and inductively coupled plasma with mass spectrometry (ICP-MS). A correlation analysis of the present contaminants in the environment and honey bee colonies was made. The obtained results were compared with the existing regulations on the quality of water, soil and honey, and a correlation analysis of the contaminants present in the environment and honey bee colonies was made. The anthropogenic footprint, i.e. anthropogenic pressure on the environment and honey bees, is expressed in the form of bioaccumulation factors, quality index and total indicator of anthropogenic impact
INFLUENCE OF THE SHAPE, SIZE AND DECOMPOSITION OF THE SAMPLE ON THE COEFFICIENT OF PERMEABILITY OF BIODRIED WASTE MEASURED BY DIRECT AND INDIRECT METHODS
No full textPrema aktualnom Planu gospodarenja otpadom Republike Hrvatske (RH) za razdoblje 2023. -
2028. godine (NN 84/2023), u RH su u pogonu tri od ukupno jedanaest predviđenih centara za
gospodarenje miješanim krutim komunalnim i ostalim otpadom kojeg nije moguće izravno
reciklirati (CGO). Od postojećih centara, CGO Kaštijun i CGO Marišćina primjenjuju tehnologiju
biološko-mehaničke obrade (BMO) dok se u sklopu CGO Bikarac primjenjuje tehnologija
mehaničko-biološke obrade (MBO) otpada. Obje primijenjene tehnologije kombiniraju i
mehaničke i biološke postupke obrade komunalnog otpada. Tijekom BMO komunalni otpad se
podvrgava procesu biosušenja pri čemu je jedan od produkata obrade dijelom bio-stabilizirana
sitnozrnata frakcija, tzv. „metanogena frakcija“, pogodna za odlaganje na bioreaktorsko odlagalište
(BO) u sklopu CGO. U BO se uvođenjem tekućine (najčešće odlagališnog filtrata - eluata) u tijelo
odlagališta potiču procesi biološke razgradnje odloženog otpada. Mikrobiološki procesi razgradnje,
potaknuti vlaženjem, odvijaju se u anaerobnim uvjetima. Produkt anaerobne razgradnje je
odlagališni plin - metan, koji se koristi za energetske potrebe tj. za proizvodnju električne energije.
Optimalno funkcioniranje BO podrazumijeva upravljanje procesom sakupljanja, ekstrakcije i
recirkulacije filtrata u tijelu BO. Recirkulacijom se ubrzava biološka razgradnja organske
komponente otpada i povećava proizvodnja odlagališnog plina. Nužan preduvjet recirkulacije,
odnosno stalni kontinuitet u tekućoj fazi, realizira se na način da su donji dijelovi BO trajno
zasićeni filtratom.
Vodopropusnost je hidrauličko svojstvo koje uvjetuje mogućnost kontinuiranog kretanja fluida
unutar poroznog medija, odnosno u kontekstu BO, omogućuje nesmetan protok filtrata unutar tijela
odlagališta. Cilj istraživanja provedenog u sklopu ove doktorske disertacije je utvrđivanje
hidrauličkih svojstava BMO otpada u zasićenom stanju kroz utvrđivanje koeficijenta
vodopropusnosti navedenog materijala. Provedeno istraživanje može se podijeliti u tri faze,
detaljnije opisane u nastavku.
Prva faza istraživanja uključuje preliminarnu karakterizaciju BMO otpada određivanjem njegovih
osnovnih fizikalnih i geotehničkih parametara. U tu su svrhu provedena laboratorijska ispitivanja
za određivanje: udjela vlage, udjela organske tvari, sastava po komponentama, sastava prema
obliku čestica, granulometrijskog sastava i gustoće čvrstih čestica. Provedenim ispitivanjima je
utvrđeno da je BMO otpad dobro graduirani materijal sa širokim rasponom veličina zrna te je u
tom pogledu usporediv s krupnozrnatim tlom. Visoka utvrđena vrijednost udjela organske tvari od
38,39 % kao i niska inicijalna vrijednost udjela vlage koji iznosi 13,93 % (u odnosu na suhu masu),
potvrđuje prikladnost ispitanog BMO otpada za ugradnju u BO te proizvodnju metana.
U drugoj fazi istraživanja provedena je modernizacija nestandardnog hidrauličkog edometra
Laboratorija za inženjerstvo okoliša na Geotehničkom fakultetu. Riječ je o edometru velikih
dimenzija s ćelijom promjera 500 mm i visine 200 mm. Uređaj je konstruiran za potrebe ispitivanja
krupnozrnatih materijala poput obrađenog komunalnog otpada. Osim nestandardnih dimenzija,
specifičnost tzv. „velikog edometra“ je i njegov sustav za opterećivanje koji se sastoji od
hidrauličkog agregata s tlačnim cilindrom te torusne gumene membrane ispunjene vodom.
Modernizacija velikog edometra uključivala je implementaciju dvaju značajnih poboljšanja, a to
su ugradnja potpuno novog sustava za opterećivanje i mjerenje vertikalnih pomaka te ugradnja
potopnog mjerila sile.
Novi sustav opterećivanja bazira se na električnom aktuatoru sile GDSFA, proizvođača GDS
Instruments Ltd. Sustav je pomoću novoizrađene noseće konstrukcije montiran na gornju ploču
velikog edometra. Izvedenom nadogradnjom omogućeno je potpuno automatizirano provođenje
ispitivanja te znatno preciznije mjerenje parametara ispitivanja: vertikalnih opterećenja i
vertikalnih pomaka, uz maksimalni iznos naprezanja na uzorak koji iznosi 254,78 kPa.
Potopno mjerilo sile Omega LSHD-50K-60FT koje je kablom povezano s digitalnim mjeračem
Omega DP41-S-230, ugrađeno je na dno edometarske ćelije s ciljem mjerenja sile trenja koja se
javlja između oboda uzorka i unutarnje stjenke ćelije. Utjecaj trenja na rezultate ispitivanja
analiziran je uzimajući u obzir otklon osi djelovanja glavnih naprezanja od horizontalne ravnine.
U trećoj fazi istraživanja provedena su laboratorijska ispitivanja za utvrđivanje koeficijenta
vodopropusnosti BMO otpada u zasićenom stanju. Ispitivanja uključuju: izravno određivanje
koeficijenta vodopropusnosti u standardnom hidrauličkom edometru tipa Rowe & Barden, zatim
neizravno određivanje koeficijenta vodopropusnosti na temelju rezultata troosnih ispitivanja te
neizravno određivanje koeficijenta vodopropusnosti na temelju rezultata ispitivanja provedenih u
velikom edometru.
U standardnom hidrauličkom edometru su ispitana 3 uzroka svježeg BMO otpada i 3 uzorka
razgrađenog BMO otpada. Predmetni materijal je prosijan kroz sito od 3 mm te ugrađen u uzorke
promjera 63,69 mm i visine 19,11 mm s početnom vrijednosti suhe gustoće od 380,23 kg/m3.
Koeficijenti vodopropusnosti određeni su izravnim mjerenjem vertikalnog protoka vode kroz
uzorak, induciranog nametnutim gradijentom pritiska, pri vrijednostima konsolidacijskog pritiska
od 50, 100, 200 i 400 kPa, te pri rasterećenju na vrijednost od 200 kPa.
Troosna ispitivanju su provedena na svježim uzorcima BMO otpada s početnom srednjom
vrijednosti suhe gustoće od 378,65 kg/m3 te 487,64 kg/m3. Srednje vrijednosti promjera i visine
manje zbijenih uzoraka iznose 100,26 mm odnosno 100,00 mm dok srednje vrijednosti promjera i
visine zbijenijih uzoraka iznose 100,51 mm odnosno 100,00 mm. Ispitano je 8 manje zbijenih i 7
zbijenijih uzoraka koji su bili podvrgnuti konsolidacijskim pritiscima od 45 do 304 kPa odnosno
od 18 do 203 kPa. Koeficijenti vodopropusnosti određeni su neizravno, na temelju rezultata
ispitivanja provedenih u uvjetima izotropne konsolidacije.
Ispitivanja u moderniziranom velikom edometru provedena su na 3 svježa uzorka BMO otpada
promjera 500 mm i visine 95 mm te početne vrijednosti suhe gustoće od 379,75 kg/m3. Uzorci su
ispitani pri inkrementima naprezanja u rasponu od 4,74 do 124,74 kPa te dekrementima naprezanja
od 64,76 i 4,74 kPa. Koeficijenti vodopropusnosti određeni su neizravno, na osnovu primjene
Terzaghi-jeve teorije jednodimenzionalne konsolidacije. Postupci određivanja koeficijenta
konsolidacije uključuju standardno korištenu Taylor-ovu i Casagrande-ovu metodu te
nestandardnu metodu nelinearne optimizacije uz ograničenja (Bardet, 1997). Utvrđene su značajne
razlike u rezultatima primijenjenih metoda te je potvrđena visoka pouzdanost metode nelinearne
optimizacije pri određivanju koeficijenta konsolidacije. Ugrađenim potopnim mjerilom sile
izmjereno je trenje koje se javlja na kontaktu oboda uzorka i unutarnje stjenke ćelije edometra te
je analiziran njegov utjecaj na rezultate ispitivanja.
Na kraju je provedena detaljna analiza rezultata ispitivanja vodopropusnosti. Utvrđen je utjecaj
različitih metoda određivanja, različitih parametara ispitivanja i fizikalnih odnosno geotehničkih
karakteristika kao i veličine i starosti ispitanih uzoraka na vrijednost koeficijenta vodopropusnosti.
Za pojedine relacije između analiziranih parametara određene su funkcijske zavisnosti.According to the current Waste Management Plan of the Republic of Croatia for the period 2023 -
2028 (NN 84/2023), three out of a total of eleven planned centers for the management of mixed
solid municipal and other waste that cannot be directly recycled are in operation in the Republic of
Croatia (WMC). Of the existing centers, WMC Kaštijun and WMC Marišćina apply the technology
of biological-mechanical treatment (BMT), while WMC Bikarac applies the technology of
mechanical-biological treatment (MBT) of waste. Both applied technologies combine both
mechanical and biological processes of municipal waste treatment. During BMT, municipal waste
is subjected to a biodrying process, where one of the processing products is a partially bio-stabilized
fine-grained fraction, the so-called "methanogenic fraction", suitable for disposal at the bioreactor
landfill (BL) within the WMC. In BL, by introducing a liquid (most often landfill filtrate - eluate)
into the body of the landfill, the processes of biological decomposition of the disposed waste are
stimulated. Microbiological decomposition processes, stimulated by moistening, take place in
anaerobic conditions. The product of anaerobic decomposition is landfill gas - methane, which is
used for energy needs, i.e. for the production of electricity. Optimal functioning of the BL implies
management of the process of collection, extraction and recirculation of filtrate in the body of the
BL. Recirculation accelerates the biological decomposition of the organic component of the waste
and increases the production of landfill gas. The necessary prerequisite for recirculation, i.e.
constant continuity in the liquid phase, is realized in such a way that the lower parts of the BL are
permanently saturated with filtrate.
Permeability is a hydraulic property that conditions the possibility of continuous fluid movement
within the porous medium, that is, in the context of BL, it enables the unimpeded flow of filtrate
within the body of the landfill. The aim of the research carried out as part of this doctoral
dissertation is to determine the hydraulic properties of BMT waste in a saturated state by
determining the coefficient of permeability of the material. The conducted research can be divided
into three phases, described in more detail below.
The first phase of the research includes the preliminary characterization of BMT waste by
determining its basic physical and geotechnical parameters. For this purpose, laboratory tests were
carried out to determine: moisture content, organic matter content, composition by components,
composition by particle shape, grain size analysis and particle density. The conducted tests
established that BMT waste is a well-graded material with a wide range of grain sizes, and in this
respect is comparable to coarse-grained soil. The high determined value of the share of organic
matter of 38.39%, as well as the low initial value of the share of moisture, which is 13.93% (in
relation to the dry mass), confirms the suitability of the tested BMT waste for incorporation into
BL and methane production.
In the second phase of the research, the modernization of the non-standard hydraulic oedometer of
the Environmental Engineering Laboratory at the Geotechnical Faculty was carried out. It is a
large-sized oedometer with a cell diameter of 500 mm and height of 200 mm. The device is
designed for testing large-grained materials such as processed municipal waste. In addition to nonstandard
dimensions, the specificity of the so-called "large oedometer" is also its loading system,
which consists of a hydraulic aggregate with a pressure cylinder and a torus rubber membrane filled
with water. The modernization of the large oedometer included the implementation of two
significant improvements, namely the installation of a completely new system for loading and
measuring vertical displacements and the installation of a submersible force gauge.
The new loading system is based on the electric force actuator GDSFA, manufactured by GDS
Instruments Ltd. The system is mounted on the upper plate of the large oedometer using a newly
designed support structure. The upgrade made it possible to carry out a fully automated test and
significantly more precisely measure the test parameters: vertical loads and vertical displacements,
with the maximum amount of stress on the sample being 254.78 kPa.
Submersible force gauge Omega LSHD-50K-60FT, which is connected by a cable to the digital
gauge Omega DP41-S-230, is installed at the bottom of the oedometer cell with the aim of
measuring the friction force that occurs between the sample rim and the inner wall of the cell. The
influence of friction on the test results was analyzed taking into account the deviation of the axis
of action of the main stresses from the horizontal plane.
In the third phase of the research, laboratory tests were conducted to determine the water
permeability coefficient of BMT waste in a saturated state. The tests include: direct determination
of the coefficient of water permeability in a standard Rowe & Barden type hydraulic oedometer,
then indirect determination of the coefficient of water permeability based on the results of triaxial
tests and indirect determination of the coefficient of water permeability based on the results of tests
carried out in a large oedometer.
In the standard hydraulic oedometer, 3 samples of fresh BMT waste and 3 samples of decomposed
BMT waste were tested. The subject material was sieved through a 3 mm sieve and incorporated
into samples with a diameter of 63.69 mm and a height of 19.11 mm with an initial dry density
value of 380.23 kg/m3. The coefficients of permeability were determined by direct measurement
of the vertical water flow through the sample, induced by an imposed pressure gradient, at
consolidation pressure values of 50, 100, 200 and 400 kPa, and after unloading to a value of 200
kPa.
Triaxial tests were performed on fresh samples of BMT waste with an initial mean value of dry
density of 378.65 kg/m3 and 487.64 kg/m3. The mean values of the diameter and height of the less
compacted samples are 100.26 mm and 100.00 mm, respectively, while the mean values of the
diameter and height of the more compacted samples are 100.51 mm and 100.00 mm, respectively.
8 less compacted and 7 more compacted samples were tested, which were subjected to
consolidation pressures from 45 to 304 kPa and from 18 to 203 kPa, respectively. Coefficients of
permeability were determined indirectly, based on the results of tests conducted under isotropic
consolidation conditions.
Tests in a modernized large oedometer were performed on 3 fresh samples of BMT waste with a
diameter of 500 mm and a height of 95 mm and an initial dry density value of 379.75 kg/m3. The
samples were tested at stress increments ranging from 4.74 to 124.74 kPa and stress decrements of
64.76 and 4.74 kPa. Water permeability coefficients were determined indirectly, based on the
application of Terzaghi's theory of one-dimensional consolidation. Procedures for determining the
consolidation coefficient include the standard Taylor and Casagrande methods and the nonstandard
method of nonlinear optimization with constraints. Significant differences in the results
of the applied methods were determined, and the high reliability of the nonlinear optimization
method in determining the consolidation coefficient was confirmed. The friction occurring at the
contact between the sample rim and the inner wall of the oedometer cell was measured with a builtin
submersible force gauge, and its influence on the test results was analyzed.
Finally, a detailed analysis of the results of the permeability test was carried out. The influence of
different determination methods, different test parameters and physical or geotechnical
characteristics as well as the size and age of the tested samples on the value of the coefficient of
permeability was determined. Functional dependencies were determined for certain relations
between the analyzed parameters
Determination of TOC, KMnO4 and BOD5 in surface waters
No full textPovršinske vode obuhvaćaju rijeke, jezera, potoke i druge vodene tokove koji su izloženi različitim izvorima onečišćenja, uključuju i otpadne vode, poljoprivredne aktivnosti i
atmosferske padaline. Kakvoća vode ima značajan utjecaj na zdravlje, životne uvjete i op u kvalitetu života ljudi te također potiče socioekonomski razvoj zajednice. S ciljem osiguravanja zdravstveno ispravne vode za vodoopskrbu, industrijske potrebe i
poljoprivredu, kakvo a vode procjenjuje se pomoću fizikalno-kemijskih, bioloških i
mikrobioloških pokazatelja. Uzorkovanje površinskih voda za potrebe ovog diplomskog
rada provedeno je od travnja 2023. do oujka 2024. godine na 5 lokacija u Varaždinskoj
županiji (Lonja, Presećno, Ljubelj, Ljuba voda i Korušak) te su određeni sljedeći
pokazatelji: ukupni organski ugljik (TOC), utrošak kalijeva permanganata (KMnO4) i
biokemijska potrošnja kisika nakon 5 dana (BPK5). Rezultati analiza s pet lokacija u
Varaždinskoj županiji pokazali su sezonsku varijabilnost pokazatelja kakvo e voda.
Vrijednosti TOC-a bile su najviše na lokacijama Ljuba voda i Korušak, posebno u
ljetnim mjesecima, dok je BPK¥ bio značajno veći na lokacijama Korušak i Ljubelj, što
upućuje na prisutnost organske tvari. Potrošnja KMnO¤ također je varirala, s povišenim
vrijednostima u toplijim razdobljima, što ukazuje na povećano organsko onečišćenje u
tim razdobljima.Surface water includes rivers, lakes, streams, and other watercourses that are exposed to
various pollution sources such as wastewater, agricultural activities, and atmospheric
precipitation. Water quality has a significant impact on human health, living conditions,
and overall life quality and it also promotes the socioeconomic development of
communities. Water quality is assessed using physical-chemical, biological, and
microbiological indicators in order to ensure its safety for human consumption,,
industrial needs, and agriculture. Surface water sampling which was used for the purpose
of this master thesis was conducted from April 2023 to March 2024 at five locations in
Varazdin County (Lonja, Presecno, Ljubelj, Ljuba voda, and Koruscak), and the
following indicators were measured: total organic carbon (TOC), potassium
permanganate consumption (KMnO¤), and biochemical oxygen demand after 5 days
(BOD5). The results of the analyses from five locations in Varazdin County showed
seasonal variability in water quality indicators. The highest values of TOC were recorded
at the Ljuba voda and Koruscak locations, particularly in the summer months, while
BOD¥ was significantly higher at the Koruscak and Ljubelj locations, indicating the
presence of organic matter. KMnO¤ consumption also varied, with elevated values during
warmer periods, suggesting increased organic pollution during these times
Microplastics in surface waters
No full textPlastika se zahvaljujući svojoj rasprostranjenosti može smatrati materijalom današnjice što opravdava činjenicu da velika njezina količina završava u vodenom okolišu, točnije površinskim vodotocima. Njezinim raspadom nastaju sitniji dijelovi (mikrovlakna, fragmenti...) veličine od 1 μm do 5 mm koji se nazivaju sekundarnom mikroplastikom. Primarnu mikroplastiku čine sve čestice (mikrozrna...) koje se nalaze u potrošačkim i komercijalnim proizvodima poput kozmetike. Razlikuju se brojni potencijalni izvori, a najčešće se navode plastični proizvodi, industrija, otpadne vode te uređaji za njihovo pročišćavanje. Mikroplastika je prema dosadašnjim istraživanjima pronađena u nekim od najvećih europskih rijeka poput Rajne i Elbe te u ostalim rijekama diljem svijeta. S obzirom na kemijski sastav i vrstu adsorbiranih tvari, ostavlja posljedice po vodeni ekosustav (bioakumulacija, smanjenje populacija), ali i zdravlje ljudi. Kako bi se smanjilo i spriječilo onečišćenje, donose se mjere od strane političkih organizacija.Thanks to its prevalence, plastics can be considered the most widely used material, which justifies the fact that a large amount of it ends up in the environment, particularly in surface waters. Its disintegration results in smaller parts (microfibers, fragments) with a size of 1 μm to 5 mm, known as secondary microplastics. Primary microplastics are all particles (such as microbeads) found in consumer and commercial products like cosmetics. There are many potential sources, with the most frequently mentioned being plastic products, industry, wastewater, and wastewater treatment plants. According to previous research, microplastics have been found in some of the largest European rivers, such as the Rhine and the Elbe, as well as in other rivers around the world. Considering their chemical composition and type of adsorbed substances, microplastics have effects on aquatic ecosystems (such as bioaccumulation and population reduction) and also on human health. Political organizations have taken measures to reduce and prevent pollution
The recycling of urine-polluted water by photocatalytic and ultrasound-based processes - proof of concept
No full textOvaj diplomski rad istražuje recikliranje urinom onečišćene vode koristeći tehnologije fotokatalize i ultrazvuka. Urin je značajan izvor onečišćenja u otpadnim vodama zbog spojeva poput uree koji mogu štetno utjecati na okoliš. S obzirom na rastuće ekološke izazove, nužne su učinkovite metode za obradu i recikliranje ovih voda.
Teorijski dio analizira kemijski sastav urina, izvore onečišćenja urinom i njegov utjecaj na okoliš. Razmatra se recikliranje urina kao gnojiva, njegova primjena u svemirskim postajama i uklanjanje uree iz vode. Fokus je na tehnologijama fotokatalize i ultrazvuka, koje nude inovativne pristupe razgradnji onečišćujućih tvari u vodi.
Eksperimentalni dio obuhvaća testiranje metoda na modelnim otopinama uree. Istraženi su postavi s ultrazvukom, fotokatalizom i kombinacijom oba procesa (sonofotokataliza). Korišteni su različiti fotokatalizatori, kao što su titan dioksid (TiO2) i TiO2/CNT (nanokompozit TiO2 i ugljikovih nanocjevčica), u suspenziji i imobiliziranom obliku. Analitička metoda tekućinske kromatografije spregnute s masenom spektrometrijom vremena leta (LC/MS QTOF korištena je za precizno mjerenje učinkovitosti svake metode.
Rezultati istraživanja ukazuju na prednosti i izazove primjene ovih tehnologija, te nude smjernice za razvoj održivih metoda obrade otpadnih voda. Rad doprinosi razumijevanju inovativnih pristupa u zaštiti okoliša i upravljanju vodnim resursima.The topic of this master thesis is the recycling of urine-polluted water using photocatalysis and ultrasound technologies. Urine is a significant pollutant in wastewater due to compounds like urea, which can adversely affect the environment. Given the growing ecological challenges, effective methods for treating and recycling this water is necessary.
The theoretical part analyses the chemical composition of urine, the sources of urine contamination, and its environmental impact. It explores recycling urine as fertilizer, its application in space stations, and the removal of urea from water. The focus of this thesis is on photocatalysis and ultrasound technologies, which offer innovative methods for degrading pollutants in water.
The experimental section involves testing methods on model urea solutions. Various setups are investigated, including those with ultrasound, photocatalysis, and a combination of both processes, known as Sono photocatalysis. Different photocatalysts, such as titanium dioxide (TiO2) and TiO2/CNT (nanocomposite of TiO2 and carbon nanotubes), are used in suspended and immobilized forms. The LC/MS QTOF (liquid chromatography coupled with mass spectrometry quadrupole time of flight) analytical method is used for the precise measurement of the effectiveness of each method.
The results highlight the advantages and challenges of applying these technologies, providing guidelines for the development of sustainable wastewater treatment methods. The research presented in this mater contributes to the understanding of innovative approaches in environmental protection and water resource management
The application of a reinforced concrete diaphragm wall for ensuring denivelation in the urban environment - TEŽ Zagreb
No full textProblem građevnih jama, koje predstavljaju privremeni prostor namijenjen izvođenju
temelja ili dijela podzemne građevine, posebno je izrađen u gradskim sredinama. Cilj
ovog rada je prikazati zada e osiguranja dubokih građenih jama u urbanoj sredini, te u
konačnici opisati primjer osiguranja denivelacije za stambeno-poslovni kompleks TE}-
Zagreb. Neke od metoda osiguranja građevnih jama su armiranobetonska dijafragma,
pilotska stijena, talpe, geotehnička sidra, top-down metoda i berlinsko ziđe. U ovom radu
posebno je istaknuta tehnologija izvedbe armiranobetonske dijafragme. Osiguranje
građevne jame za stambeno-poslovni kompleks TE}-Zagreb izvedeno je pomoću
armiranobetonske dijafragme i geotehničkih sidara. Osim tehničkog rješenja u radu su prikazani geotehnički podaci o sastavu tla, statički proračuni te opis radovaThe problem of construction pits,, which are temporary spaces intended for the
construction of a foundation or a part of an underground structure, affects urban areas in
particular. The aim of this master thesis is to present the tasks of securing deep
construction pits in an urban environment, and eventually to describe an example of
unevenness securing for the TE}-Zagreb housing and business complex.. Some of the
methods of securing construction pits involve reinforced concrete diaphragm, pilot rock,
piles, geotechnical anchors, top-down method and Berlin wall. In this master thesis
special attention is paid to the construction technology of a reinforced concrete
diaphragm.. The process of securing the construction pit for the TE}-Zagreb housing and
business complex involved using a reinforced concrete diaphragm and geotechnical
anchors. In addition to the technical solution, the master thesis presents geotechnical data
on soil composition, static calculations, and a description of the work
Type B measurement uncertainty in the geotechnical laboratory
No full textU ovome radu opisuje se postupak izračuna mjerne nesigurnosti za ispitivanja u
geotehničkom laboratoriju s ciljem poboljšanja kvalitete i pouzdanosti dobivenih
rezultata.
Za procjenu mjerne nesigurnosti odabrana je GUM metoda (engl. Guide to the
expression of uncertainty in measurement), koja omogućuje izračun mjerne
nesigurnosti prema tipu A i tipu B. Određivanje mjerne nesigurnosti tipa A temelji se
na statisti kim metodama iz niza opažanja, dok tip B koristi apriorne distribucije koje
se određuju iz iskustva. Prikazani su primjeri izra una mjerne nesigurnosti prema
tipu B i kombinacijom tipa A i B pomo u ispitivanja vla~nosti tla. Za tip B provedena
je analiza i utjecaj dominantnih faktora nesigurnosti na konačan rezultat mjerne
nesigurnosti. Zbog specifičnosti tla kao ispitnog materijala, tip B pokazao se kao
bolja opcija izračuna mjerne nesigurnosti u geotehničkom laboratoriju.This paper describes the procedure for calculating measurement uncertainty for
tests in a geotechnical laboratory with the aim of improving the quality and reliability
of the obtained results.
The GUM method (Guide to the expression of uncertainty in measurement) was
chosen for the assessment of measurement uncertainty, which enables the
calculation of measurement uncertainty according to type A and type B. The
determination of measurement uncertainty of type A is based on statistical methods
from a series of observations, while type B uses a priori distributions that are
determined from experience. Examples of measurement uncertainty calculation
according to type B and a combination of type A and B using soil moisture testing
are presented. For type B, the analysis and influence of dominant uncertainty factors
on the result of measurement uncertainty was carried out. Due to the specificity of
soil as a test material, type B proved to be a better option for calculating
measurement uncertainty in a geotechnical laboratory