Ocjena stanja kakvoće podzemnih voda u južnoj Istri

Ocjena stanja kakvoće podzemne vode za cjelinu podzemne vode (CPV) Južna Istra je provođena analizom kemijskih parametara devet vodnih objekata, odabranih prema Okvirnoj direktivi o vodama (ODV, 2000) i Direktivi o podzemnim vodama (DPV, 2006), temeljem nadzornoga monitoringa definiranim Državnom mrežom opažanja Hrvatskih voda. Početni korak kod ocjene stanja podzemnih voda je određivanje pozadinskih (BL) i graničnih vrijednosti (TV) ispitivanih parametara, a za potrebe ovoga rada su preuzete iz Plana upravljanja vodnim područjima za razdoblje od 2016. do 2021. godine. One su utvrđivane na točkama opažanja Tivoli, Rizzi, Valdragon (3), Campanož, Fojbon, Škatari, Šišan, Ševe i Jadreški za sljedeće parametre: otopljeni kisik, pH vrijednost, električnu vodljivost, nitrate, amonij, pesticide, arsen, olovo, živu, kadmij, kloride, sulfate, ortofosfate, te sumu trikloretena i tetrakloretena. Možebitno prekoračenje graničnih vrijednosti (TV) propisanih parametara je ispitivano inicijalnim testom te ukoliko su se prosječne vrijednosti tih parametara pokazale veće od najstrožih TV, pristupano je provedbi klasifikacijskih testova (Generalna procjena kakvoće, Zaslanjenje i druge intruzije te Zone sanitarne zaštite) na osnovu kojih je ocijenjeno stanje CPV Južna Istra. Prema dobivenim rezultatima testa Zaslanjenje i druge intruzije vrijednosti električnih vodljivosti ne prekoračuju TV vrijednosti te se stoga CPV Južna Istra svrstava u dobro stanje s visokom pouzdanošću. No, prema preostalim testovima Generalne procjene kakvoće i Zonama sanitarne zaštite, zbog povišenih koncentracija nitrata koje u prosjeku iznose 40,38 mg NO3-/L - i više su od TV vrijednosti (37,5 mg NO3-/L) na gotovo svim postajama monitoringa, CPV Južna Istra je ocijenjena lošim kvalitativnim stanjem podzemnih voda s visokom pouzdanošću te se konačno na osnovu rezultata provedenih analiza klasifikacijskih testova CPV Južnu Istru svrstava u loše stanje podzemnih voda s visokom pouzdanošću. Nakon poznatoga kvalitativnoga stanja podzemnih voda na CPV Južna Istra pristupilo se daljnjoj karakterizaciji gdje je detaljno identificiran uzrok onečišćenja te su predložene mjere za poboljšanje stanja i dat prijedlog operativnoga monitoringa. Analizom utjecaja i pritisaka su prikupljani podatci o glavnim potencijalnim onečišćivačima, a to su Kazneno-popravni dom u Valturi u sklopu kojega se nalazi stočna farma i poljoprivredno gospodarstvo, nekoliko većih farmi, odlagalište otpada Kaštijun te pulski aerodrom. Dodatnu ugrozu predstavljaju i planovi navodnjavanja na užemu području Pule te brojni nekontrolirani privatni zdenci na ovome području. Smanjenje koncentracija nitrata u podzemnim vodama se planira ostvariti prijedlogom mjera sukladno Akcijskome programu zaštite voda od onečišćenja uzrokovanoga nitratima poljoprivrednoga podrijetla (NN 15/13; 22/15) i Nitratnoj direktivi (1991). Neke od mjera su: ograničenje gnojenja poljoprivrednih površina u toku jedne kalendarske godine, ograničenje veličine gnojovki, adekvatno zbrinjavanje i postupanje s gnojem te ispunjenje rokova za izgradnju spremnika s trenutkom ulaska Hrvatske u EU. Naposljetku je predloženo i provođenje operativnoga monitoringa gušćom mrežom opažanja s dodatnim vodoopskrbnim zdencima koji nisu uključeni u nadzorni monitoring, kao i povećanje minimalnih intervala opažanja na mjesečne intervale. Isto tako, predlaže se kontinuirano praćenje dinamike kolebanja razina podzemnih voda te praćenje električne vodljivosti i rada crpki na vodnim objektima uključenim u sustav nadzornoga i operativnoga monitoringa. Ključne riječ

ESTIMATION OF EMISSIONS OF AIR POLLUTANTS IN THE KRAPINA-ZAGORJE COUNTY

The Program for the protection of air quality, ozone layer, climate change mitigation and adaptation of the Krapina-Zagorje County is prepared in accordance with the Article 12 of the Air Protection Act (OG 130/11, 47/14, 61/17, 118/18). The Program sets targets and measures by priority sectors, deadlines and responsible authorities for measures implementation over a five-year period in the County. For the purpose of defining protection measures, based on available data, estimation of annual emissions of pollutants into air was performed: nitrogen oxides, carbon monoxide, sulphur oxides, particles, volatile organic compounds, ammonia, carbon dioxide, methane and dinitrogen monoxide from the main sectors. Emissions were estimated using the EMEP/EEA methodology and 2006 IPCC Guidelines for National Greenhouse Gas Inventories methodology. Road traffic emissions were estimated using DEFRA/DECC methodology. Based on the results on estimated pollutant emissions in the County, appropriate measures have been defined for the protection and improvement of air quality

Auswirkungen von Hochwasser auf den erhöhten Schwermetallgehalt im Inundationsgebiet des Flusses Drau im Landkreis Varaždin

Intenzivnim razvojem industrije, poljoprivrede i urbanizacije dolazi do pretjerane emisije teških metala u okoliš koji zbog svojih svojstava bioakumulacije mogu imati negativan utjecaj na sve sastavnice okoliša. U okviru ovoga rada je istražena prisutnost pojedinih teških metala u uzorcima tla i biljaka na sjeverozapadu Hrvatske, uz tok rijeke Drave. Ukratko su razmotrene i predložene mogućnosti uklanjanja teških metala iz tla. U svrhu utvrđivanja stvarne prisutnosti akumuliranih teških metala na obalnom području rijeke Drave u travnju 2014. godine pristupilo se prikupljanju uzoraka tla i biljaka na ukupno sedam lokacija na području Varaždinske županije. Ta područja su povremeno izložena poplavama zbog izlijevanja rijeke Drave i nanosa mulja onečišćenog teškim metalima koji su u rijeku dospjeli kao posljedica antropogenih i prirodnih procesa na uzvodnim dijelovima toka Drave u Sloveniji i Austriji. U uzorcima biljaka i tla određene su koncentracije arsena (As), bakra (Cu), kadmija (Cd), kroma (Cr), kobalta (Co), cinka (Zn), željeza (Fe), mangana (Mn), nikla (Ni), olova (Pb) i žive (Hg). Dobiveni rezultati ukazuju da na pojedinim lokacijama koncentracije nekih teških metala premašuju zakonom propisane maksimalno dopuštene koncentracije (MDK). Utvrđeno je prekoračenje MDK za kadmij, olovo, cink, bakar i nikal. Biljke krasolika, maslačak, zlatošipka i lucerna su pokazale vrlo dobar fitoakumulacijski, fitoeksploatacijski i indikatorski potencijal za daljnja opažanja i istraživanja.Intensely developing industry and agriculture as well as urbanization have led to excessive heavy metal emissions into the environment that, due to their bioaccumulation properties, may have a negative impact on all components of the environment. The paper explores the presence of certain heavy metals in the soil and plant samples taken along the Drava River course in northeast Croatia. The possibilities of heavy metal removal from the soil are briefly considered and proposed. In order to determine the actual presence of accumulated heavy metals in the Drava riverbank area, soil and plant sampling was carried out at seven Varaždin County locations in April 2014. These areas are occasionally exposed to flooding by the Drava River, which includes its bedload polluted with heavy metals that entered the river consequential to anthropogenic and natural processes in the upstream Drava sections in Slovenia and Austria. The concentrations of arsenic (As), copper (Cu), cadmium (Cd), chrome (Cr), cobalt (Co), zinc (Zn), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and mercury (Hg) have been determined in the plant and soil samples. The obtained results indicate that the concentrations of certain heavy metals exceed the legally prescribed maximum permissible concentrations (MPCs) in some locations. The MPC exceedances were determined for cadmium, lead, zinc, copper and nickel. The plants fleabane, dandelion, goldenrod and alfalfa showed very good phytoaccumulation, phytoexploitation and indicator potentials for further observation and exploration.Die intensive Entwicklung von Industrie und Landwirtschaft sowie Urbanisierung führen zur hohen Umweltbelastung mit Schwermetallen, die wegen ihrer Fähigkeit zur Bioakkumulation eine negative Auswirkung auf alle Bestandteile der Umwelt haben können. In dieser Studie wurden Konzentrationen einzelner Schwermetalle in Boden- und Pflanzenproben entlang des Flusses Drau im Nordwesten Kroatiens bestimmt. Überblicksartig werden die Möglichkeiten zur Entfernung von Schwermetallen aus dem Boden in Betracht gezogen und dargestellt. Zum Zwecke der Bestimmung der akkumulierten Schwermetalle im Ufergebiet der Drau fand in April 2014 die Entnahme von Boden- und Pflanzenproben an insgesamt sieben Standorten im Landkreis Varaždin statt. Diese Standorte werden gelegentlich dem Hochwasser ausgesetzt, wenn die Drau bei Hochwasser über die Ufer tritt, und der mit Schwermetallen verschmutzte Schlamm abgelagert wird. Die Schwermetalle gelangen in den Fluss infolge sowohl anthropogener als auch natürlicher Prozesse, die flussaufwärts in Slowenien und Österreich stattfinden. In den Boden- und Pflanzenproben wurden die Konzentrationen von Arsen (As), Kupfer (Cu), Kadmium (Cd), Chrom (Cr), Kobalt (Co), Zink (Zn), Eisen (Fe), Mangan (Mn), Nickel (Ni), Blei (Pb) und Quecksilber (Hg) bestimmt. Die Ergebnisse zeigen, dass an einigen Standorten die Konzentrationswerte einiger Schwermetalle (Kadmium, Blei, Zink, Kupfer und Nickel) die gesetzlich vorgeschriebenen maximalen erlaubten Konzentrationen überschreiten. Die Pflanzen Feinstrahl, Löwenzahn, Riesen-Goldrute und Luzerne weisen eine sehr gute Fähigkeit zur Phytoakkumulation und -ausnutzung sowie Anzeigefähigkeit für weitere Untersuchungen auf

Effects of low temperatures on flexural strength of macro-synthetic fiber reinforced concrete: experimental and numerical investigation

Fiber-reinforced concrete (FRC) is an attractive alternative to traditional steel bar-reinforced concrete structures, as evidenced by the constantly increasing market consumption of structural fibers for this purpose. In spite of significant research dedicated to FRC, less attention has been given to the effects of low temperatures on the mechanical properties of FRC, which can be critical for a variety of structural typologies and regions. With this in mind, an experimental program was carried out to assess the flexural behavior of macro-synthetic fiber-reinforced concrete (MSFRC) at different temperatures (from 20 °C to -30 °C) by means of three-point bending notched beam tests. The tested MSFRCs were produced by varying the content of polypropylene fibers (4 and 8 kg/m3). The results proved that the flexural strength capacity of all MSFRCs improved with decreasing temperature. Finite element analyses were then used to calibrate constitutive models following fib Model Code 2010 guidelines and to formulate empirical adjustments for taking into account the effects of low temperatures. The outcomes of this research are the basis for future experimental and numerical efforts meant to improve the design of MSFRCs subjected to low temperatures during service conditions.Peer ReviewedPostprint (published version

Nasleđe srpske hemije u Galeriji nauke i tehnike SANU

У септембру 2013. године навршило се 160 година од тренутка када је 1853. године кнез Александар Карађорђевић одобрио ново устројство београдског Лицеја, једине високошколске установе у ондашњој Србији. Документом „Устројеније Књажеско-Србског Лицеја“ предвиђено је увођење нових предмета „Химија“ и „Технологија“ у наставни план Лицеја. За потребе ових предмета Устројенијем су предвиђени „Химическа Лабораторија“ и „Технологически кабинет“. На место професора за ове предмете изабран је 26-годишњи Михаило Рашковић (1827–1872). Не занемарујући значај дела Павла Илића (1807–1871), државног апотекара и касније државног хемичара, чијим радом је заправо започела хемијска струка код нас, са оснивањем лицејске хемијске лабораторије дошао је нови период развоја хемијске струке и наставе хемије у Србији. Захваљујући прегалаштву Михаила Рашковића у обезбеђивању добрих услова за лабораторијски рад, постављен је темељ и за почетак хемијске науке код нас. То ће се догодити почетком 70-их година 19. века, пре свега у делу Симе Лозанића (1847–1935). Са намером да се обележи 160. годишњица отварања хемијске лабораторије на Лицеју, приређена је изложба Лабораторија великана–наслеђе српске хемије у Галерији науке и технике Српске академије наука и уметности. Овај рад представља кратак извештај о изложби

Multi-recycling of polypropylene fibre reinforced concrete: Influence of recycled aggregate properties on new concrete

Herein, an investigation of multi-generational recyclability of polypropylene fibre reinforced concrete (PPFRC) was performed. The parent concretes were produced with 0 and 6 kg/m3 of polypropylene fibres. After recycling, the obtained coarse recycled concrete aggregates (RCAs) were used in new concrete with 0 and 6 kg/m3 of polypropylene fibres, repeating for three generations always with the same quantities of fibres. Properties of RCA, the mechanical properties of recycled aggregate concrete, the recovery rate of polypropylene fibres and the content of fibres embedded within the RCA were measured. The results of the study show that RCA obtained by PPFRC recycling offers significant benefits to new concrete production. This is achieved through the recovered fibres reintroduced into the new concrete, as well as through the fibres embedded in the recycled aggregates, leading to increased residual tensile strength.This study has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 836270. This support is gratefully acknowledged. The authors also wish to express their acknowledgement to the Ministry of Economy, Industry and Competitiveness of Spain for the financial support received under the scope of the projects PID2019-108978RB-C32. Any opinions, findings, conclusions, and/or recommendations in the paper are those of the authors and do not necessarily represent the views of the individuals or organizations acknowledged.Peer ReviewedPostprint (published version

Kinetic behavior of MgH2-transition metal composites: towards hydrogen storage

Hydrogen as an energy vector represents great potential, due to its high gravimetric density and low mass, as well as the fact that combustion does not emit harmful chemical byproducts. Hydrogen has the highest energy density per unit mass compared to any other fuel but a rather low energy density per unit volume. Further, hydrogen storage is a key technology for developing a hydrogen and fuel cell-based economy [1]. Metal hydrides as alternative hydrogen carriers have a wide range of performance parameters such as operating temperature, sorption kinetics, activation conditions, cyclic options, and equilibrium hydrogen pressure. These parameters can be improved or adjusted to meet the technical requirements of different applications. The most commonly used method for hydride destabilization is nanostructuring by mechanical milling which leads to a reduction in the particle and crystallite size of the MgH2 powder. Nanostructuring is often combined with catalyst addition and composite formation [2,3]. The most of research is focused on the morphological, structural, and thermodynamic effects typical for long milling times, while in this work we have followed the changes taking place under short milling times. The thermal stability of magnesium hydride is related to - changes in the crystallites and powder particle size. The analysis also considered the changes in activation energy. MgH2-M composites were prepared by mechanical milling of the as-received MgH2 powder (Alfa Aesar, 98% purity) with the addition of 2 and 5 wt.% of M (M= V, W, Mo). Mechanical milling was performed in s SPEX 5100 Mixer Mill using 8mm diameter milling ball. Samples were milled for 15-45 minutes under the inert atmosphere of argon and a ball-to-powder ratio 10:1 Figure 1. shows the kinetic curves obtained for composites with 5wt% of vanadium. To investigate the desorption process in detail, different models of solid-state kinetics were used as implemented in the code developed in our group. The ratelimiting step of the desorption reaction was determined using the iso-conversional kinetic method due to better accuracy of obtained apparent activation energies. As shown in Table 1 a decrease in apparent activation energies has been observed. It is obvious that the sorption kinetics is affected by material preparation because the reactivity of magnesium with hydrogen is strongly modified by changes in several surface parameters that govern the chemisorption, the dissociation of molecular hydrogen, and hydride nucleation7th MESC-IS 2023 : International Symposium on Materials for Energy Storage and Conversion : 11th INESS : International Conference on Nanomaterials & Adv. Energy Storage Systems : October 7-10, Baku, 2023

Uklanjanje teških metala fitoremedijacijom

Sveprisutnost teških metala i njihove prekomjerne koncentracije u okolišu uzrokovane su u najvećoj mjeri antropogenim djelovanjem kao što je izgaranje fosilnih goriva, rudarska aktivnost i metalurška industrija koji su ujedno najprisutniji i najčešći izvori koji dovode do emisija ovih elemenata u okoliš, prije svega u zrak, vodu i tlo. Budući da su teški metali nerazgradivi, akumuliraju se u okolišu te ulaze u hranidbene lance. Time takav način opterećenja okoliša predstavlja rizik ne samo za okoliš, već i za ljudsko zdravlje. Neki teški metali su kancerogeni, mutageni i teratogeni, dok drugi uzrokuju neurološke i bihevioralne promjene, posebno kod djece. Prema tome, sanacija (remedijacija) onečišćenja teškim metalima predstavlja veliki izazov u inženjerstvu okoliša te joj se u posljednje vrijeme posvećuje velika pozornost. Različite fizikalne i kemijske metode koje se koriste za remedijaciju imaju brojna ograničenja; kao što su visoke cijene, potrebna velika radna snaga, promjena svojstava tla i narušavanje izvorne mikroflore tla. U usporedbi s navedenim metodama, fitoremedijacija kao in situ metoda predstavlja bolje rješenje za rješavanje problema onečišćenja tla teškim metalima. Fitoremedijacija je metoda korištenja biljaka i povezanih mikroba tla kako bi se smanjile koncentracije ili toksični učinci teških metala u okolišu. Relativno je nova metoda koja se ističe kao isplativa, učinkovita, ekološki prihvatljiva tehnologija uz vrlo dobru društvenu prihvaćenost. Trenutno se istražuju novi učinkoviti hiperakumulatori teških metala za primjenu u fitoremedijaciji i fitorudarenju. Ovaj završni rad nastojao je razmotriti pozadinu, koncepte i budući napredak fitoremedijacije teških metal