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.
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Adsorpcija Zn(II) iona na metalurškom otpadu Anita Štrkalj; Luka Mesek; Vesna Ocelić Bulatović ...
Kemija u industriji; časopis kemičara i tehnologa Jugoslavije,
11/2022, Letnik:
71, Številka:
11-12
Journal Article
Recenzirano
Odprti dostop
Metalurški otpad ima velik potencijal za uporabu kao adsorbens za uklanjanje teških metala iz otpadnih voda, ističući se kao mogući jeftini adsorbens. U ovom članku prikazano je adsorpcijsko ...ponašanje Zn(II) iona na dva kruta metalna otpadna materijala – otpadnoj kalupnoj mješavini (OKM) i otpadnoj anodnoj prašini (AP). Dobiveni rezultati pokazali su da se oba otpadna materijala mogu upotrebljavati kao potencijalni adsorbensi. Anodna prašina ima bolja adsorpcijska svojstva. Ravnotežni podatci za adsorpciju Zn(II) na otpadnim metalurškim materijalima ispitani su Freundlichovim i Langmuirovim izotermnim modelima. Utvrđeno je da je Langmuirov model prikladniji te da se adsorpcija odvija kao kemisorpcija.
Due to good properties, which meet the requirements for use as biomaterials, titanium and titanium alloys have been increasingly used as dental implants. Until recently, dental titanium alloys were ...produced
by casting. Since this process does not meet the terms of economy and efficiency, the production of titanium implants by powder metallurgy are
very promising. Therefore, in this work titanium alloy with addition of
10 at. % zirconium is prepared by powder metallurgy with the goal of obtaining the best producing conditions, which would result in the titanium alloy of the adequate properties for use as dental implants. High values of green densities were achieved even only by uniaxial pressing. Further, sintering temperature of 1673 K resulted in the alloy
of the highest sintered density and microhardness. The results of this investigation revealed the processing parameters applicable for the production of titanium-zirconium dental implants by powder metallurgy.
In this study the use of carbon anode dust (CAD), which is the solid residue from aluminum production, as a low-cost adsorbent for the removal of Ni(II) ions from wastewater was investigated. A ...mechanism of adsorption kinetics and thermodynamics was proposed. In order to investigate the adsorption process of nickel ions on CAD three kinetic models were used: Lagergren's pseudo-first-order model, pseudo-second-order model, and the intra-particle diffusion model. Various thermodynamic parameters, such as the energy of activation (E
a
), activation enthalpy (ΔH*), activation entropy (ΔS*), and free energy of activation (ΔG*), were evaluated. Observation of the value of the energy of activation suggests that the process uptake of Ni(II) ions can be described as activated chemisorption. The positive values of enthalpy of activation and free energy of activation, as well as negative values of entropy of activation, mean that the process of removal of Ni(II) ions is endothermic, non-spontaneous, and without structural changes in the solid carbon anode dust particles.
Instrumentalne metode analize nezamjenjive su u znanstvenim istraživanjima, a sve više i u praksi gdje se zahtijeva što brže dobivanje rezultata, kao i što veća točnost. U metalurškoj praksi već se ...dulji niz godina primjenjuju spektrometrijske metode analize i to najčešće optička emisijska spektrometrija s izravnim očitanjem. Međutim koncentracija pojedinih legirnih elemenata u suvremenim metalnim materijalima vrlo je niska, često niža od granice detekcije optičkih emisijskih spektrometara s izravnim očitanjem.
U ovom radu određivana je koncentracija bora u nodularnom lijevu primjenom optičke emisijske spektrometrije s izravnim očitanjem (OES), optičke emisijske spektrometrije s induktivno spregnutom plazmom (ICP-OES) te atomske apsorpcijske spektrometrije s grafitnom tehnikom (AAS-GF). Dobiveni rezultati pokazali su da se optička emisijska spektrometrija s izravnim očitanjem i optička emisijska spektrometrija s induktivno spregnutom plazmom mogu primijeniti za određivanje bora u ispitivanim uzorcima (tablica 1). Ako se zahtijeva vrlo točna analiza, a posebno ako se radi o vrlo niskim koncentracijama, optička emisijska spektrometrija s induktivno spregnutom plazmom pogodnija je metoda, uz uvjet da su uzorci pravilno pripremljeni. Atomska apsorpcijska spektrometrija s grafitnom tehnikom nije pogodna za određivanje bora u uzorcima ovog tipa. Tijekom provođenja analize dodatna pažnja usmjerena je na eliminaciju negativnog utjecaja grafitne kivete na rezultat analize.
Osim toga, u radu je praćen utjecaj načina otapanja uzoraka na rezultate analize bora spomenutim metodama. Rezultati su pokazali da pažljiva priprema uzoraka u zatvorenom sustavu pridonosi točnijem rezultatu analize.
This article deals with the analysis of the adsorptive properties of the waste produced during the shot blasting of castings in foundries. During this process, particles of moulding mixture and scale ...that remained on the surface of the casting after removal from the mould are removed. Since this waste contains particles of moulding mixture (SiO2, carbon, ...) and scale (i.e. iron oxides), which as individual components are known as satisfactory adsorbents, its adsorption properties towards Cu(II) ions in aqueous solution were investigated. The obtained results show that the investigated waste has a significant adsorption capacity for binding Cu(II) ions.
In this paper, the adsorption properties of two metallurgical wastes (slag and anode dust) and two municipal wastes (eggshells and coffee grounds) were described. Acetic acid was used as the ...adsorbate Adsorption kinetic was monitored during the adsorption process. The obtained results showed that all tested waste materials can be used as potential cheap adsorbents. Adsorption took place relatively quickly. Equilibrium was reached in 15 minutes, and the adsorption kinetics followed the pseudo-first-order reactions, i.e., can be described by the Lagergren model. All qe values calculated using Ho's model have a negative sign. That indicates that the Ho model is not suitable for describing the kinetics of the tested adsorption systems.
In this paper, blast furnace slag was investigated as a potential adsorbent for the removal of zinc and copper ions from the aqueous solution. The adsorption was performed by a static, so-called ..."batch" process. Adsorption properties were studied by monitoring the influence of contact time adsorbent with adsorbate. Performed studies have shown that the equilibrium in the tested system is achieved in 30 minutes. Intraparticle diffusion model, heterogeneous diffusion model and film diffusion model were used to test the zinc and copper ion diffusion in a competitive adsorption. The obtained results showed that intraparticle diffusion controlled the adsorption process.
The use of low-cost adsorbents has been investigated as a replacement for costly adsorbents and methods of removing nickel ions from aqueous solution. The purpose of this review article is to provide ...the scattered available information on various aspects of utilization of low-cost adsorbents derived from agricultural waste, industrial by-products and waste material or natural material. To highlight their technical applicability, selected information on initial nickel concentration, pH level, dose required, adsorption capacity, temperature, thermodynamic data, adsorption isotherm, adsorption kinetics is presented. In generall, technical applicability and cost-effectiveness are the key factors in the selection of the most suitable adsorbent to treat aqueous solution contain nickel ions.
Adsorption is one of the effective methods of advanced wastewater treatment, which industries employ to reduce hazardous organic and inorganic wastes in effluents. The use of low cost adsorbent has ...been investigated as a replacement for current costly methods of removing toxic substances from wastewater. In this article, the use of low cost adsorbents for the removal of toxic substances from wastewater has been reviewed.
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