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TWO-STAGE REMOVAL OF ZINC FROM AN AQUEOUS SOLUTION CONTAINING 500 mg Zn/L BY CHEMICAL PRECIPITATION AND SORPTION ON BIOSORBENTS : bachelor thesis
No full textU proteklih nekoliko desetljeća glavni izvor onečišćenja vodnih, ali i kopnenih ekosustava teškim metalima su industrija, rudarenje i poljoprivreda te sve više stanovnika ima problem s nedostatkom vode i njenom kakvoćom. Ispuštanje neobrađenih industrijskih te sanitarnih voda uzrokuje dugoročne posljedice na okoliš i sva živa bića te je pročišćavanje otpadnih voda ključno za očuvanje okoliša i zdravlja ljudi. Uklanjanje teških metala iz otpadnih voda provodi se brojnim metodama, a uz kemijsko taloženje adsorpcija je vrlo učinkovita i često primjenjivana metoda. Međutim, cijena aktivnog ugljena kao vrlo učinkovitog adsorbensa je visoka pa se istražuju novi ekonomičniji sorbensi, a obrada voda sve češće provodi kombinacijom više metoda. U ovome radu ispitano je dvostupanjsko uklanjanje cinka iz vodene otopine koncentracije 500 mg Zn/L kemijskim taloženjem uz neutralizaciju različitim taložnim sredstvima u pH području 7,0-7,5; 8,0-8,5 te 9,0-9,5, a potom sorpcijom na biosorbensima. Kemijskim taloženjem cinka uz neutralizaciju dokazana je značajna ovisnost o pH vode te je već u prvom stupnju obrade pri pH=9,0-9,5 koncentracija cinka smanjena na vrijednost ispod maksimalno dopuštene (2 mg/L) za sva ispitana taložna sredstva, s izvrsnom učinkovitošću ≥ 99,85%. Efluenti dobiveni kemijskim taloženjem uz neutralizaciju do pH=7,0-7,5 te pH=8,0-8,5 s koncentracijom cinka ˃ 2 mg/L podvrgnuti su drugom stupnju obrade sorpcijom na košticama maslina, trešanja i višanja. Postignuta je ostatna koncentracija cinka < 2 mg/L za sve ispitane biosorbense u efluentima nakon kemijskog taloženja do pH=8,0-8,5, dok za najniže pH područje nije postignuta. Ovim istraživanjem je dokazano da se onečišćena voda sa sadržajem cinka od 500 mg/L može uspješno pročistiti već u jednom stupnju obrade metodom kemijskog taloženja uz neutralizaciju do pH=9,0-9,5 bilo kojim od ispitanih taložnih sredstava. Također je moguće uspješno ukloniti cink dvostupanjskom obradom, najprije kemijskim taloženjem uz neutralizaciju do pH=8,0-8,5; a potom sorpcijom na biosorbensima. Koji način u praksi odabrati, ovisit će o potrošnji i cijeni taložnog sredstva kao i o troškovima i načinima zbrinjavanja nastalog otpada u obliku mulja cinkova hidroksida te cinkom zasićenih biosorbenasa.In the past few decades, the main source of heavy metal pollution of aquatic and terrestrial ecosystems is industry, mining and agriculture, and there is a growing problem with the lack of water and its quality. The discharge of untreated industrial and sanitary water causes long-term consequences, and the treatment of wastewater is essential for the preservation of the environment and human health. The removal of heavy metals from wastewater is carried out by numerous methods, and in addition to chemical precipitation, adsorption is a very effective and often used method. However, the price of activated carbon as a highly effective adsorbent is high, so new, more economical sorbents are being researched, and water treatment is increasingly being carried out using a combination of several methods. In this bachelor thesis, the two-stage treatment of zinc-contaminated water containing 500 mg Zn/L was performed, firstly by chemical precipitation with neutralization by different precipitating agents up to pH ranges of 7.0-7.5; 8.0-8.5 and 9.0-9.5, and then by sorption onto biosorbents. Chemical precipitation of zinc proved a significant dependence on water pH, and already in the first stage of treatment at pH=9.0-9.5, the zinc concentration was reduced to a value below the maximum allowed (2 mg/L) for all tested precipitating agents, with excellent efficiency ≥ 99.85%. Effluents obtained by chemical precipitation with neutralization to pH=7.0-7.5 and pH=8.0-8.5 with a concentration of zinc ˃ 2 mg/L were subjected to the second stage of treatment by sorption on the olives, cherries and sour cherries pits. A residual zinc concentration < 2 mg/L was achieved for all tested biosorbents only in effluents after chemical precipitation up to pH=8.0-8.5. This research has proven that contaminated water containing 500 mg Zn/L can be successfully purified in just one treatment stage using the chemical precipitation method with neutralization to pH=9.0-9.5, by any of the tested precipitating agents. It is also possible to successfully remove zinc by two-stage treatment, first by chemical precipitation with neutralization to pH=8.0-8.5; and then by sorption on biosorbents. Which method will be used in practice depends on the consumption and price of the precipitating agent, as well as on the costs and methods of disposal of the generated waste in the form of zinc hydroxide sludge and zinc-saturated biosorbents
Equilibrium adsorption of cobalt ions on humus : diploma thesis
No full textU kotlastim reaktorima, pri odabranim uvjetima provedbe eksperimenta (trajanje eksperimenta 96 h, brzini okretaja od 200 okr min-1, veličini čestica < 500 μm te temperaturi od 308 K), istraživana je adsorpcija kobaltovih iona kao iona teškog metala na humusu kao adsorbensu iz početnih koncentracija otopina kobaltovog(II) nitrata (4,692 mmol dm-3, 8,365 mmol dm-3, 11,427 mmol dm-3, 24,896 mmol dm-3 te 36,325 mmol dm-3). Dobiveni rezultat upućuju na nagli porast adsorbiranih kobaltovih iona na humusu porastom ravnotežnih koncentracija kobaltovih iona u otopini. Maksimalna vrijednost ravnotežne količine adsorbiranih kobaltovih iona na humusu postiže se pri najvišoj odabranoj početnoj koncentraciji otopine kobaltovih iona od 36,325 mmol dm-3 te iznosi 0,367 mmol g-1 dok se najviša adsorpcijska učinkovitost (8,699 %) dosegne pri najnižoj početnoj koncentraciji otopine od 4,692 mmol dm-3. Uzimajući u obzir procjenu kvalitete slaganja sorpcijskih modela s eksperimentalno dobivenim podatcima, zatim usporedbu izračunatih vrijednosti za maksimum kapaciteta sorpcije sa vrijednostima kapaciteta sorpcije eksperimentalno dobivenim, kao i vrijednosti za statističke parametare (RMSE i χ2-test) zaključuje se kako Redlich-Petersonov i Freundlichov izotermni model najbolje opisuju dobivene eksperimentalne podatke.: In batch reactors, under the selected experimental conditions (experiment duration 96 h, rotation speed of 200 rpm, particle size < 500 μm and temperature of 308 K), the adsorption of cobalt ions as heavy metal ions on humus as an adsorbent from initial concentrations of cobalt(II) nitrate solutions (4.692 mmol dm-3, 8.365 mmol dm-3, 11.427 mmol dm-3, 24.896 mmol dm-3 and 36.325 mmol dm-3) was investigated. The obtained results point to a sudden increase in adsorbed cobalt ions on the humus due to an increase in the equilibrium concentration of cobalt ions in the solution. The maximum value of the equilibrium amount of adsorbed cobalt ions on humus is achieved at the highest selected initial concentration of the cobalt ion`s solution of 36.325 mmol dm-3 with the value of 0.367 mmol g-1, while the highest adsorption efficiency (8.699%) is reached at the lowest initial concentration of the solution of 4.692 mmol dm-3. Taking into account the assessment of the quality of the agreement of the sorption models with the experimentally obtained data, then the comparison of the calculated values for the maximum sorption capacity with the values of the sorption capacity obtained experimentally, as well as the values for the statistical parameters (RMSE and χ2-test), it is concluded that the Redlich-Peterson and Freundlich isotherms models best describes the obtained experimental data
Determination of the minimum concentration od colloidal silver synthesized by natural reducers effective against Escherichia coli and Staphylococcus aureus bacteria : graduate thesis
No full textPosljednjih godina znanstvenici intenzivno istražuju zelenu sintezu nanočestica jer se smatra da su nanočestice proizvedene ovom metodom, koristeći prirodne materijale kao redukcijska sredstva, sigurnije za korištenje od nanočestica sintetiziranih kemijskom metodom. Ova tehnika eliminira toksične kemikalije, smanjuje energetske zahtjeve i visoke temperature, čineći proces ekološki prihvatljivijim i ekonomičnijim. U ovom radu analizirana je zelena sinteza nanočestica srebra korištenjem meda od primorskog vriska (Satureja montana) s dalmatinskog područja i ekološkog zelenog čaja. Također je ispitana antibakterijska učinkovitost dobivenih otopina koloidnog srebra. Kao prekursor upotrijebljen je srebrov nitrat (AgNO 3 ), a željena pH vrijednost (pH = 6) korigirana je primjenom otopine natrijevog karbonata (Na 2 CO 3 ). Kao pokazatelj nastanka koloidnog srebra korišten je Tyndallov efekt, koji nastaje kao posljedica raspršenja laserske zrake na koloidnim česticama. Antibakterijska svojstva koloidnog srebra početne koncentracije (30 ppm) i razrijeđenih otopina koloidnog srebra (24, 18, 12 i 6 ppm) testirana su protiv bakterija Escherichia coli NCTC 13216 i Staphylococcus aureus ATCC 25923. Rezultati su potvrdili antibakterijsko djelovanje koloidnog srebra dobivenog korištenjem meda od primorskog vriska, s koncentracijom od 30 ppm, prema obje bakterije, dok razrijeđene otopine nisu pokazale antibakterijsko djelovanje. Također, rezultati za koloidno srebro dobiveno korištenjem ekološkog zelenog čaja pokazali su antibakterijsko djelovanje do određene koncentracije, 12 ppm, koloidnog srebra.In recent years, scientists have been intensively researching the green synthesis of nanoparticles, as it is belived that nanoparticles produced by this method, using natural materials as reducing agents, are safer to use than nanoparticles synthesized by chemical methods. This technique eliminates toxic chemicals, reduces energy requiremnets and high temperatures, making the process more environmentally friendly and cost-effective. This paper analyzes the green synthesis of silver nanonaprticles using mountain savory (Satureja montana) honey from the Dalmatian region and ecological green tea. The antibacterial effectivness of the obtained colloidal silver solutions was also tested. Silver nitrate (AgNO 3 ) was used as a precursor, and the desired pH value (pH = 6) was adjusted using a sodium carbonate (Na 2 CO 3 ) solution. The Tyndall effect, which occurs as a result of the scattering of a laser beam on colloidal particles, was used as an indicator of colloidal silver formation. The antibacterial properties of silver nanoparticles at an initial concentracion (30 ppm) and diluted colloidal silver solution (24, 18, 12 and 6 ppm) were tested against Escherichia coli NCTC 13216 and Staphylococcus aureus ATCC 25923. The results confirmed the antibacterial activity of colloidal silver obtained using mountain savory honey, with a concentration of 30 ppm, against both bacteria, while the diluted solutions did not show antibacterial activity. Additionally, the results for colloidal silver obtained using ecological green tea demonstrated antibacterial activity up to a certain concentracion, 12 ppm, of colloidal silver
Removal of zinc from aqueous solutions of different initial concentrations using food processing by-products/waste : diploma thesis
No full textPorastom svjetske populacije raste i potreba za proizvodnjom hrane, ali i materijala, što dovodi do iscrpljivanja prirodnih resursa te sve većeg onečišćenja okoliša. Zbog intenzivne poljoprivredne proizvodnje koja se oslanja na umjetna gnojiva i pesticide te rudarenja i industrijskih djelatnosti, dolazi do onečišćenja vodnih sustava teškim metalima. Cink je jedan od pet najviše eksploatiranih metala na svijetu. Ima važnu ulogu u raznim industrijama zbog čega su onečišćenja vodnih sustava cinkom vrlo česta. Iako je cink esencijalan metal, previsoka koncentracija može uzrokovati zdravstvene probleme, a najštetniji je za akvatične organizme. Stoga je za očuvanje bioraznolikosti vodnih sustava te zdravlja ljudi važno učinkovito upravljati otpadnim vodama te ukloniti cink prije ispuštanja u površinske vode. U ovome radu ispitana je mogućnost primjene nusproizvoda/otpada od prerade hrane u uklanjanju cinka iz onečišćenih voda. Uklanjanje cinka iz vodenih otopina koncentracija 30,2 mg Zn/L te 112,7 mg Zn/L provedeno je sorpcijom šaržnim postupkom na košticama maslina, trešanja i višanja te na ostacima hridinskog ježinca, preuzetima iz lokalnih pogona za preradu i proizvodnju hrane. Učinkovitost uklanjanja za nižu početnu koncentraciju cinka bila je u rasponu ≈ 40‒65%, s najboljim uklanjanjem na košticama maslina. Učinkovitost uklanjanja za višu početnu koncentraciju cinka bila je u rasponu ≈ 21‒40%, s najboljim uklanjanjem na košticama višanja. Za ispitane eksperimentalne uvjete, bolje uklanjanje cinka postignuto je pri nižoj početnoj koncentraciji cinka. Rezidualna koncentracija cinka (do ≈ 18,14 mg/L za nižu, odnosno ≈ 88,7 mg/L za višu početnu koncentraciju) u pročišćenoj vodi premašila je maksimalno dopuštenu koncentraciju od 2 mg/L. Korišteni nusproizvodi/otpad imaju potencijal za obradu voda onečišćenih cinkom, barem u stupnju predobrade, prije uporabe skupljih konvencionalnih sorbenasa. Njihovo korištenje pridonijelo bi boljem gospodarenju krutim otpadom te smanjenju ukupnih troškova obrade voda.With the growth of the world's population, the need for food and materials production also increases, leading to the depletion of natural resources and increasing environment pollution. As a result of intensive agricultural production that relies on artificial fertilizers and pesticides, as well as mining and industrial activities, water systems are polluted with heavy metals. Zinc is one of the five most exploited metals in the world. It plays an important role in various industries, which is why contamination of water systems with zinc is very common. Although zinc is an essential metal, too high concentration can cause health problems, and is most harmful to aquatic organisms. Therefore, in order to preserve biodiversity of water systems and human health, it is important to effectively manage wastewater and remove zinc before discharge into surface waters. In this paper, the possibility of using food processing by-products/waste in the zinc removal from polluted waters was examined. The removal of zinc from aqueous solutions containing 30.2 mg Zn/L and 112.7 mg Zn/L was carried out by sorption using a batch performance on the waste materials from local plants for food processing and production: olive, cherry and sour cherry pits, and the residues of sea urchin. The removal efficiency for the lower initial zinc concentration was in the range ≈ 40‒65%, with the best removal on olive pits. The removal efficiency for the higher initial zinc concentration was in the range ≈ 21‒40%, with the best removal on the cherry pits. For the tested experimental conditions, better zinc removal was achieved at a lower initial zinc concentration. The residual concentration of zinc (up to ≈ 18.14 mg/L for the lower, and ≈ 88.7 mg/L for the higher initial concentration) in the treated water exceeded the maximum allowable concentration of 2 mg/L. The by-products/waste could be used for the treatment of zinc-contaminated water at least in the pretreatment stage, before using of more expensive conventional sorbents. This approach could contribute to more sustainable management of solid waste, as well as to reducing the total water treatment costs
ANALYSIS OF THE INTEGRATED ELECTROCOAGULATION WITH ZINC ELECTRODES AUGMENTED WITH ZEOLITE AND ULTRASOUND : bachelor thesis
No full textIspitana je učinkovitost procesa obrade kompostne otpadne vode sa tri hibridna procesa elektrokoagulacije sa cinkovim elektrodama: elektrokoagulacija sa zeolitom, simultana elektrokoagulacija sa zeolitom i ultrazvukom te dvostupanjska elektrokoagulacija sa zeolitom i ultrazvukom. Usporedba učinkovitosti procesa provedena je preko sljedećih parametara: pH, električna vodljivost, temperatura, mutnoća, kemijska potrošnja kisika i ukupni isparni ostatak. Također su ispitane promjene mase elektroda te test taloživosti suspenzija nakon provedbe hibridnih procesa. Rezultati su pokazali da je za obradu kompostne otpadne vode najbolje upotrijebiti elektrokoagulaciju sa zeolitom ili dvostupanjsku elektrokoagulaciju sa zeolitom i ultrazvukom.The effectiveness of the compost wastewater treatment process with three hybrid processes of electrocoagulation with zinc electrodes was tested: electrocoagulation with zeolite, simultaneous electrocoagulation with zeolite and ultrasound, and two-stage electrocoagulation with zeolite and ultrasound. The comparison of process efficiency was carried out using the following parameters: pH, electrical conductivity, temperature, turbidity, chemical oxygen demand and total solids. The changes in the mass of the electrodes and the settling test of the suspensions after the implementation of the hybrid processes were also examined. The results highlight the electrocoagulation with zeolite and two-stage electrocoagulation with zeolite and ultrasound the best option for treatment of compost wastewater
KNJIGA SAŽETAKA: 5 th ZORH INTERNATIONAL CONFERENCE ON ENVIRONMENTAL PROTECTION, SUSTAINABLE PRODUCTION, AND EXAMPLES OF BEST PRACTICES April 9 – 11, 2025 SPLIT, CROATIA
No full textInfluence of temperature on depassivation of tin in NaCl solution : diploma thesis
No full textU radu je ispitivano korozijsko ponašanje uz naglasak na pojavu depasivacije (pitting korozije) kositra u NaCl otopini različitih temperatura (od 10 do 40 o C). Anodnom polarizacijom dolazi do razaranja oksidnog filma i lokalnog otapanja kositra. Oštećenja na površini metala imaju oblik sitnih rupica ili pitova, čiji se broj i gustoća uglavnom povećavaju s porastom temperature otopine. Najveću otpornost na koroziju kositar ima pri 20 o C. Naime pri tim uvjetima zabilježene su najpozitivnije vrijednosti korozijskog potencijala i potencijala depasivacije, najmanji iznosi korozijske struje i struje pasivacije te najmanja gustoća, iznimno uskih i plitkih pitova (dubina najvećeg izmjerenog pita iznosi svega 0.35 µm). Porastom koncentracije Cl - iona potencijal depasivacije Sn postaje negativniji, a polarizacijski otpor se značajno smanjuje. Nasuprot tome, porastom brzine promjene potencijala, potencijal depasivacije postaje pozitivniji, dok se vrijednost polarizacijskog otpora ne mijenja, što znači da je za pojavu pitting korozije potrebno određeno vrijeme indukcije nakon uspostave stvarnog potencijala depasivacije. Porastom temperature otopine, nukleacija pitting korozije započinje pri negativnijim potencijalima, a vrijeme indukcije pitting korozije postaje kraće.In the work, the corrosion behavior was studied focusing on the occurrence of depassivation (pitting corrosion) of tin in NaCl solution at different temperatures (from 10 to 40 o C). The anodic polarization leads to the destruction of the oxide film and local dissolution of tin. The damage to the metal surface appears in the form of tiny holes or pits, the number and density of which generally increase with increasing temperature of the solution. Tin exhibits the highest corrosion resistance at 20 o C. Indeed, under these conditions, the most positive values of corrosion potential and depassivation potential, the lowest amounts of corrosion current and passivation current, and the lowest density of extremely narrow and shallow pits were observed (the depth of the largest pit measured is only 0.35 µm). As the concentration of Cl - ions increases, the depassivation potential of Sn becomes more negative, and the polarization resistance decreases significantly. On the other hand, as the rate of change of the potential increases, the depassivation potential becomes more positive, while the value of the polarization resistance does not change, which means that the occurrence of pitting corrosion requires a certain induction time after the actual depassivation potential is built up. As the temperature of the solution increases, pitting corrosion begins to occur at more negative potentials, and the induction time for pitting corrosion becomes shorte
PRODUCTION AND CHEMICAL ANALYSIS OF THE POMEGRANATE WINES FROM VARIETIES BARSKI SLATKI, SLATKI CRVENI AND SLATKI TANKORAC : graduate thesis
No full textVoćna vina su prehrambeni proizvodi nastali fermentacijom soka ili masulja različitog voća. Odlikuju ih specifične boje, ugodne arome i okusi te izuzetna pitkost. Cilj ovog diplomskog rada bio je proizvesti vino od šipka od sorti 'Barski slatki', 'Slatki crveni' i 'Slatki tankokorac' te pratiti tijek fermentacije određivanjem suhe tvari, parametara boje, sadržaja ukupnih fenola Folin-Ciocalteu metodom i sadržaja antocijana metodom bisulfitnog izbjeljivanja. Proizvedenim vinima potom je određen sadržaj alkohola, hlapivih i ukupnih kiselina te individualnih antocijana. Analizom su utvrđene razlike među pojedinim sortama pri čemu je vino sorte 'Barski slatki' u konačnici sadržavalo najviše antocijana, ukupnih kiselina te imalo najveći udio alkohola.Fruit wines are food products made by fermenting the juice or pulp of various fruits. They are characterized by specific colors, pleasant aromas and flavors, and exceptional drinkability. The aim of this thesis was to produce pomegranate wine from the varieties 'Barski slatki', 'Slatki crveni', and 'Slatki tankokorac' and to monitor the fermentation process by determining dry matter, color parameters, total phenol content using the Folin- Ciocalteu method, and anthocyanin content using the bisulfite bleaching method. The alcohol content, volatile and total acids, and individual anthocyanins were then determined for the produced wines. The analysis determined differences between individual varieties, with the wine of the 'Barski slatki' variety ultimately containing the most anthocyanins, total acids, and having the highest alcohol content
Equilibrium analysis copper ions sorption on zeolite from various heavy metal sources : master thesis
No full textIspitana je sorpcija bakrovih iona na sintetskom zeolitu NaX u ovisnosti o različitim početnim koncentracijama otopina bakrovog(II) nitrata i bakrovog(II) klorida. Eksperiment je proveden u šaržnim reaktorima pri stalnoj temperaturi od 306 K, brzini miješanja od 200 okr min-1, u trajanju od 3 h. Uočeno je da kod sorpcije bakrovih iona iz otopine bakrovog(II) nitrata kapacitet sorpcije naglo raste s porastom početne koncentracije bakrovih iona do koncentracije od 22,909 mmol dm-3 te se neznatno mijenja daljnjim povećanjem početne koncentracije. Kod sorpcije bakrovih iona iz otopine bakrovog(II) klorida kapacitet sorpcije cijelo vrijeme raste s porastom početne koncentracije bakrovih iona te dostiže svoj maksimalni kapacitet sorpcije pri najvišoj odabranoj koncentraciji. Analizom dobivenih rezultata za obje otopine uočava se neprestani pad učinka sorpcije bakrovih iona na zeolitu s porastom početne koncentracije, a primijećeno je da je i učinak sorpcije bakrovih iona iz otopine bakrovog(II) klorida uvijek viši od učinka sorpcije bakrovih iona iz otopine bakrovog(II) nitrata za sve početne koncentracije osim za najnižu odabranu početnu koncentraciju. Dobiveni eksperimentalni podatci su testirani različitim sorpcijskim modelima. Kako bi procjena kvalitete slaganja modela izotermi s eksperimentalnim podatcima bila što preciznija uzeto je u obzir i slaganje izračunatih ravnotežnih kapaciteta sorpcije bakrovih iona s maksimalnim eksperimentalnim kapacitetom sorpcije bakrovih iona, kao i vrijednost statističkih parametara izračunatih za RMSE i χ2. Uzimajući u obzir sve navedeno može se zaključiti da najbolje slaganje s eksperimentalnim podatcima pokazuje Tothova izoterma kod sorpcije bakrovih iona iz otopine bakrovog(II) nitrata, dok je kod sorpcije bakrovih iona iz otopine bakrovog(II) klorida nabolje slaganje postignuto primjenom Langmuirove izoterme.Sorption of copper ions on a synthetic zeolite NaX was examined depending on different initial concentrations of copper (II) nitrate and copper (II) chloride solutions. The experiment was conducted in batch reactors at a constant temperature of 306 K, stirring speed of 200 rpm, for 3 hours. It was observed that for the sorption of copper ions from a solution of copper (II) nitrate, the sorption capacity increases rapidly with an increase in the initial concentration of copper ions until the concentration of 22.909 mmol dm-3 and slightly changes at the higher concentrations. In the case of copper ions sorption from a solution of copper (II) chloride, the sorption capacity increases all the time with an increase in the initial concentration of copper ions and reaches its maximum sorption capacity at the highest selected concentration. The analysis of the obtained results for both solutions shows a constant decrease in the sorption efficiency of copper ions on the zeolite with an increase in the initial concentration. It was also observed that the sorption efficiency of copper ions from copper (II) chloride solution is consistently higher than the sorption efficiency of copper ions from copper (II) nitrate solution for all initial concentrations except for the lowest selected initial concentration. To make the assessment as precise as possible the maximum experimental capacity of sorption of copper ions and value of the statistical parameters calculated, RMSE and χ2 were also taken into account. Taking everything into account all of the above, it can be concluded that the best agreement with the experimental data is shown by the Toth isotherm for the sorption of copper ions from a solution of copper (II) nitrate, while the best agreement with the sorption of copper ions from a solution of copper (II) chloride is achieved by using the Langmuir isotherm
Evaluation of the effects of air pollution on cultural heritage : diploma thesis
No full textU ovom radu analiziran je utjecaj onečišćujućih tvari (SO 2 , NO x , klorida, prizemnog ozona, krutih čestica i pH kiše), meteoroloških i hidroloških parametara na brzinu korozije materijala spomenika kulturne baštine (čelika, cinka, aluminija, bakra i bronce) i na površinsko propadanje vapnenca i pješčenjaka za aglomeraciju Zagreb i aglomeraciju Rijeka. Na osnovi dobivenih rezultata uočena je međuovisnost poboljšanja kvalitete zraka, tj. smanjenje srednjih godišnjih koncentracija onečišćujućih tvari u zraku i brzine korozije promatranih metala i legura te površinskog propadanja vapnenca i pješčenjaka. Također, gubitak materijala ovisi i o geografskim, meteorološkim i hidrološkim parametrima kao što su temperatura zraka, relativna vlažnost zraka i količina oborina. Različiti materijali ponašaju se različito ovisno o tome jesu li osjetljivi na onečišćujuću tvar prisutnu u svom okolišu ili pak na smjesu onečišćujućih tvari koje mogu djelovati i sinergijski.This thesis analyzes the impact of pollutants (SO 2 , NO X , chloride, ground-level ozone, solid particles and rain pH), meteorological and hydrological parameters on the corrosion rate of cultural heritage materials (steel, zinc, aluminum, copper and bronze) and on the surface recession of limestone and sandstone for the Zagreb agglomeration and the Rijeka agglomeration. Based on the obtained results, the interdependence of air quality improvement, i.e. reduction of average annual concentrations of air pollutants and corrosion rates of observed metals and alloys and surface recession of limestone and sandstone, was observed. Also, the material loss depends on geographical, meteorological and hydrological parameters such as air temperature, relative humidity and amount of precipitation. Different materials behave differently depending on whether they are sensitive to the pollutant present in their environment or to a mixture of pollutants that can also act synergistically