Application of Immobilized TiO2 for Removal of Cu(II) Ions

U ovoj studiji istraživana je adsorpcija Cu(II) iona na smjesi anatasa i rutila, dviju polimorfnih formi TiO2. Istražen je učinak vremena kontakta adsorbens/adsorbat i učinak početne koncentracije Cu(II) na adsorpciju. Rezultati su pokazali da ravnoteža nastupa već nakon jedne minute kontakta Cu(II) i TiO2 te da kapacitet adsorpcije raste s porastom početne koncentracije Cu(II) iona. Eksperimentalni podatci obrađeni su Langmuirovom i Freundlichovom izotermom. Dobiveni rezultati ukazuju da Freundlichov model bolje opisuje ispitivani adsorpcijski sustav te da je adsorpcija fizikalne prirode. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.The adsorption of Cu(II) ions on a mixture of anatase and rutile, two polymorphic forms of TiO2, was investigated. The influence of the adsorbent/adsorbate contact time as well as the influence of the initial concentration of Cu(II) on the adsorption was monitored. The results showed that equilibrium occurred after only one minute of contact of Cu(II) and TiO2, and that the adsorption capacity increased with initial concentration of Cu(II) ions. Experimental data were processed by Langmuir and Freundlich isotherm. The obtained results showed that the Freundlich model better described the investigated adsorption system, and that the adsorption was of a physical nature. This work is licensed under a Creative Commons Attribution 4.0 International License

Thermal Properties of Epoxy Resin/Layered Double Hydroxide Intercalated Nanocomposites

Pripravljen je Ca-Al slojeviti hidroksid (LDH) modifi ciran benzoatnim anionima (Ca4Al2(OH)12(C6H5COO)2 · x H2O, LDH-B) modifi ciranom metodom rehidratacije, tj. dodavanjem benzojeve kiseline i CaO u smjesu vode i acetona, kojom se trikalcijev aluminat (Ca3Al2O6) pretvara u konačni slojeviti hidroksid. Interkalacija benzoatnih aniona unutar LDH slojeva potvrđena je rendgenskom difrakcijom (XRD), spektroskopijom u infracrvenom području (FTIR) i termogravimetrijskom analizom (TGA). Interkalirani nanokompoziti na osnovi epoksidne smole i LDHB pripravljeni su in situ polimerizacijom, uz polioksipropilen diamin kao umreživalo. Uzorci s različitim udjelom LDH-B (5, 10 i 15 phr) ispitivani su XRD-om, FTIR-om, TGA-om, razlikovnom pretražnom kalorimetrijom i transmisijskom elektronskom mikroskopijom (TEM). Rendgenska difrakcija pokazala je nastajanje interkaliranih nanokompozita, a TEM analiza potvrdila raspršenje LDH-B unutar matrice i nastajanje interkalirane strukture, uz djelomično raslojavanje u nanokompozitu s 5 phr punila. Toplinska analiza pokazala je smanjenje početne temperature degradacije u usporedbi s nemodifi ciranim epoksidnim polimerom, dok se ostatak pri 1000 °C povećao, posebice kod djelomično raslojenog nanokompozita. Staklište se snizuje u usporedbi s nemodificiranim epoksidnim polimerom, što upućuje na slabije umreživanje epoksidne matrice.Ca-Al layered double hydroxide (LDH) modifi ed by the incorporation of benzoate anions (Ca4Al2(OH)12(C6H5COO)2 · x H2O, LDH-B) was prepared by a variation of the rehydration method, by adding benzoic acid and CaO into a mixture of water and acetone used to convert tricalcium aluminate (Ca3Al2O6) into fi nal layered structure. Intercalation of benzoate anions within LDH layers was confi rmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Intercalated nanocomposites based on an epoxy resin and LDH-B were prepared by in situ polymerisation, with poly(oxypropylene) diamine as a curing agent. Nanocomposites prepared with different contents of LDH-B (5, 10 and 15 phr) were characterised by XRD, FTIR, TGA, differential scanning calorimetry and transmission electron microscopy (TEM). The XRD results indicated formation of intercalated nanocomposites, and TEM analysis confi rmed that LDH-B was dispersed within the matrix forming an intercalated structure, which becomes partially exfoliated in the nanocomposite with 5 phr fi ller. Results of thermal analysis showed detrimental infl uence on initial degradation temperature in comparison to the neat crosslinked epoxy, while residue at 1,000°C increases, especially for the partially exfoliated nanocomposite. The glass transition temperature decreases in comparison with the neat crosslinked epoxy, indicating poorer crosslinking of the epoxy matrix

The impact of multiwall carbon nanotubes on the photocatalytic properties of imobilizied TiO2

Industry development, Earth’s population growth, ever increasing need for greater pharmaceuticals production causes irreversible changes in the environment. Photocatalysis is a process that leads to complete decomposition of pharmaceuticals to non-hazardous degradation products under the influence of solar radiation in the presence of a photocatalyst. A photocatalyst, such as titanium dioxide (TiO2), is required for photocatalysis. The efficiency of using TiO2 is limited due to the high energy banned zone (3-3.2 eV) so only UV-A light, which makes up 5% of solar radiation, activates the photocatalyst. In order to overcome the problem of prohibited zones and to shift the light response threshold of TiO2 into the visible part of the spectrum, different methods can be used. One of the methods showing the potential is the use of multiwall carbon nanotubes (MWCNT). In this paper a TiO2 / MWCNT composites with various concentrations of MWCNT were prepared. The concentrations of MWCNT ranged from 1.5, 5, 10, 25, 50 and 100 wt. % MWCNT relative to the mass of TiO2. It was observed that the concentration of MWCNT affects the photocatalytic activity of the composite obtained. Photocatalytic activity was followed by a degradation of salicylic acid, in a pilot reactor followed by UV-ViS spectrometry, as a modal solution and an example of a pharmaceuticals present in the water. The prepared catalysts were characterized by scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX)

The impact of multiwall carbon nanotubes on the photocatalytic properties of imobilizied TiO2

Industry development, Earth’s population growth, ever increasing need for greater pharmaceuticals production causes irreversible changes in the environment. Photocatalysis is a process that leads to complete decomposition of pharmaceuticals to non-hazardous degradation products under the influence of solar radiation in the presence of a photocatalyst. A photocatalyst, such as titanium dioxide (TiO2), is required for photocatalysis. The efficiency of using TiO2 is limited due to the high energy banned zone (3-3.2 eV) so only UV-A light, which makes up 5% of solar radiation, activates the photocatalyst. In order to overcome the problem of prohibited zones and to shift the light response threshold of TiO2 into the visible part of the spectrum, different methods can be used. One of the methods showing the potential is the use of multiwall carbon nanotubes (MWCNT). In this paper a TiO2 / MWCNT composites with various concentrations of MWCNT were prepared. The concentrations of MWCNT ranged from 1.5, 5, 10, 25, 50 and 100 wt. % MWCNT relative to the mass of TiO2. It was observed that the concentration of MWCNT affects the photocatalytic activity of the composite obtained. Photocatalytic activity was followed by a degradation of salicylic acid, in a pilot reactor followed by UV-ViS spectrometry, as a modal solution and an example of a pharmaceuticals present in the water. The prepared catalysts were characterized by scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX)

Use of the steel electric arc furnace slag as an additive for the plant nutrition

U današnje vrijeme eksponencijalnog rasta korištenja prirodnih resursa, oporaba otpada vodi poboljšanju stanja okoliša te istovremeno može biti i okidač ekonomskog rasta. Europa 2020, specifično, Europska strategija za pametan, održiv i uključiv rast, temelji se na okretanju prema kružnoj ekonomiji koja može osigurati postizanje učinkovitosti korištenja svih prirodnih resursa. Ovome može značajnije doprinijeti učinkovitije gospodarenje otpadom pri čemu se prije svega misli na njegovo bezdeponijsko zbrinjavanje odnosno racionalnije iskorištavanje proizvodnih ostataka, a posebice njihov transfer iz kategorije otpada u kategoriju nusproizvoda. Kako se ovo odnosi na sve industrijske grane, tako je i u metalurgiji, prisutan problem neopravdanog razvrstavanja, po količini najzastupljenijeg proizvodnog ostatka – troske, u otpad umjesto u nusproizvod. Iz ovog razloga, bez obzira na činjenicu da se metalurgija ubraja na najstarije zanate ljudskog roda, još uvijek se provode intenzivna istraživanja primjene metalurške troske u drugim granama industrije i ostalih ljudskih djelatnosti. S obzirom na kemijski sastav troske i njezin relativno visok sadržaj kalcija i magnezija, istraživanja su se provodila na distrično smeđem kiselom tlu uzetog s područja Like u blizini mjesta Smiljan. Biljke su uzgajane u loncima napunjenim sa 2 kg tla bez i sa dodatkom troske. Istraživanje utjecaja troske provedeno je u kontroliranim uvjetima kroz 5 tjedana. Količina troske određena je na temelju rezultata prethodno provedenih istraživanja i primjenjena je u dozi 0, 0, 5, 1, 0, 3, 0, 6, 0 i 9, 0 g kg-1 tla. U ovom radu ispitivan je utjecaj čeličanske, tzv. crne troske na rast kukuruza (Zea mays L.) i usvajanje hranjiva. Dobiveni rezultati ukazuju na pozitivan utjecaj troske na neke pokazatelje rasta i usvajanje N, P2O5, K2O, Ca i Mg

Comparison of photocatalyst preparation by TiO2 deposition on a support using different methods

Problematika zaštita voda već dugo je jedna od najvažnijih tema zaštite okoliša. Kada se govori o mikroonečišćenjima u vodi jedan od najvećih problema su farmaceutici. Utvrđivanje njihove prisutnosti nije samo posljedica razvoja analitičkih metoda nego i masovne uporabe farmaceutika te njihove sve veće koncentracije u okolišu. U ovom radu su pripremljeni i karakterizirani napredni fotokatalizaori dobiveni kroz dva različita postupka imobilizacije titanijeva dioksida (TiO2) na nosač sol-gel metodom. Imobilizacija je provedena klasičnim i mikrovalnim sušenjem te su katalizatori karakterizirani pretražnom elektronskom mikroskopijom (SEM), energijsko disperzivnom rendgenskom spektroskopijom (EDS) i rendgenskom difrakcijskom analizom (XRD). Aktivnost fotokatalizatora je ispitana kroz sposobnost fotokatalitičke razgradnjom salicilne kiseline (SA) u pilot reaktoru, čija je razgradnja praćena UV-ViS spektrometrom.The issue of water protection has long been one of the most important environmental issues. When it comes to the micropollutants, one of the greatest problems is pharmaceuticals. Their detection is not only a consequence of the development of analytical methods but also of the massive use of pharmaceuticals and their increasing concentration in the environment. In this paper, advanced photocatalysts were prepared and characterized by two different processes of titanium dioxide immobilization (TiO2) on the support through sol-gel method. Immobilization was performed by the classical and microwave-assisted drying, and the catalysts were characterized by scanning electron microscopy (SEM), energy dispersion X-ray spectrometry (EDS) and X-ray diffraction analysis (XRD). The photocatalyst activity was tested through the photocatalytic degradation of salicylic acid (SA) in the pilot reactor, monitoring the degradation by the UV-vis spectrometry

Comparison of photocatalyst preparation by TiO2 deposition on a support using different methods

Problematika zaštita voda već dugo je jedna od najvažnijih tema zaštite okoliša. Kada se govori o mikroonečišćenjima u vodi jedan od najvećih problema su farmaceutici. Utvrđivanje njihove prisutnosti nije samo posljedica razvoja analitičkih metoda nego i masovne uporabe farmaceutika te njihove sve veće koncentracije u okolišu. U ovom radu su pripremljeni i karakterizirani napredni fotokatalizaori dobiveni kroz dva različita postupka imobilizacije titanijeva dioksida (TiO2) na nosač sol-gel metodom. Imobilizacija je provedena klasičnim i mikrovalnim sušenjem te su katalizatori karakterizirani pretražnom elektronskom mikroskopijom (SEM), energijsko disperzivnom rendgenskom spektroskopijom (EDS) i rendgenskom difrakcijskom analizom (XRD). Aktivnost fotokatalizatora je ispitana kroz sposobnost fotokatalitičke razgradnjom salicilne kiseline (SA) u pilot reaktoru, čija je razgradnja praćena UV-ViS spektrometrom.The issue of water protection has long been one of the most important environmental issues. When it comes to the micropollutants, one of the greatest problems is pharmaceuticals. Their detection is not only a consequence of the development of analytical methods but also of the massive use of pharmaceuticals and their increasing concentration in the environment. In this paper, advanced photocatalysts were prepared and characterized by two different processes of titanium dioxide immobilization (TiO2) on the support through sol-gel method. Immobilization was performed by the classical and microwave-assisted drying, and the catalysts were characterized by scanning electron microscopy (SEM), energy dispersion X-ray spectrometry (EDS) and X-ray diffraction analysis (XRD). The photocatalyst activity was tested through the photocatalytic degradation of salicylic acid (SA) in the pilot reactor, monitoring the degradation by the UV-vis spectrometry

Use of the steel electric arc furnace slag as an additive for the plant nutrition

U današnje vrijeme eksponencijalnog rasta korištenja prirodnih resursa, oporaba otpada vodi poboljšanju stanja okoliša te istovremeno može biti i okidač ekonomskog rasta. Europa 2020, specifično, Europska strategija za pametan, održiv i uključiv rast, temelji se na okretanju prema kružnoj ekonomiji koja može osigurati postizanje učinkovitosti korištenja svih prirodnih resursa. Ovome može značajnije doprinijeti učinkovitije gospodarenje otpadom pri čemu se prije svega misli na njegovo bezdeponijsko zbrinjavanje odnosno racionalnije iskorištavanje proizvodnih ostataka, a posebice njihov transfer iz kategorije otpada u kategoriju nusproizvoda. Kako se ovo odnosi na sve industrijske grane, tako je i u metalurgiji, prisutan problem neopravdanog razvrstavanja, po količini najzastupljenijeg proizvodnog ostatka – troske, u otpad umjesto u nusproizvod. Iz ovog razloga, bez obzira na činjenicu da se metalurgija ubraja na najstarije zanate ljudskog roda, još uvijek se provode intenzivna istraživanja primjene metalurške troske u drugim granama industrije i ostalih ljudskih djelatnosti. S obzirom na kemijski sastav troske i njezin relativno visok sadržaj kalcija i magnezija, istraživanja su se provodila na distrično smeđem kiselom tlu uzetog s područja Like u blizini mjesta Smiljan. Biljke su uzgajane u loncima napunjenim sa 2 kg tla bez i sa dodatkom troske. Istraživanje utjecaja troske provedeno je u kontroliranim uvjetima kroz 5 tjedana. Količina troske određena je na temelju rezultata prethodno provedenih istraživanja i primjenjena je u dozi 0, 0, 5, 1, 0, 3, 0, 6, 0 i 9, 0 g kg-1 tla. U ovom radu ispitivan je utjecaj čeličanske, tzv. crne troske na rast kukuruza (Zea mays L.) i usvajanje hranjiva. Dobiveni rezultati ukazuju na pozitivan utjecaj troske na neke pokazatelje rasta i usvajanje N, P2O5, K2O, Ca i Mg

Opinion paper about organic trace pollutants in wastewater: Toxicity assessment in a European perspective

This opinion paper focuses on the role of eco- toxicological tools in the assessment of possible impacts of emerging contaminants on the aquatic ecosystem, hence, on human health. Indeed, organic trace pollutants present in raw and treated wastewater are the pivot targets: a multidisciplinary approach allows defining the basic principles for managing this issue, from setting a proper monitoring campaign up to evaluating the optimal process treatment. Giving hints on trace pollutants fate and behavior, attention is focused on the choice of the bioassay( s), by analyzing the meaning of possible biological answers. Data interpretation and exploitation are detailed with the final goal of providing criteria in order to be able to select the best-targeted treatment options. The manuscript deals with conventional and innovative analytical approaches for assessing toxicity, by reviewing laboratory and field assays ; illustrative real scale and laboratory applications integrate and exemplify the proposed approach