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Biometric approach in selecting plants for phytoaccumulation of uranium
No full textThis paper promotes the biometric classification system of plant cultivars, unique characteristics, in terms of the uranium (U) uptake, primarily in the function of the application for phytoremediation. It is known that the degree of adoption of U depends on the plant species and its morphological and physiological properties, but it is less known what impact have plants cultivars, sorts, and hybrids. Therefore, we investigated the U adoption in four cultivars of three plant species (corn, sunflower and soy bean). Vegetation experiments were carried out in a plastic-house filled with soil (0.66 mgU) and with tailing (15.3 mgU kg(-1)) from closed uranium mine Gabrovnica-Kalna southeast of Serbia. Principal Component Analysis (PCA), Cluster Analysis (CA) and analysis of variance (ANOVA) were used for assessing the effect of different substrates cultivars, plant species and plant organs (root or shoot) on U uptake. Obtained results showed that a difference in U uptake by three investigated plant species depends not only of the type of substrate types and plant organs but also of their cultivars. Biometrics techniques provide a good opportunity for a better understanding the behavior of plants and obtaining much more useful information from the original data
Portable sensor for non-destructive determination of glucose in food, pharmaceuticals and medicine
No full textPortable and hand-held near-infrared (NIR) sensor for non-destructive
determination of glucose in food has become increasingly important
instrument to preserve food quality and safety. In this study, we developed
sensor on protobord for non-destructive measurement of glucose in NIR
region, which can be applied in food production, pharmaceuticals and
medicine
Heavy metals removal from aqueous solutions by waste corn biomass (Zea mays l.)
No full textPredmet rada ove doktorske disertacije je ispitivanje mogućnosti upotrebe otpadne
biomase na bazi kukuruza (oklasak kukuruza i kukuruzna svila) za adsorpciju Pb2+, Cu2+
i Zn2+ jona iz njihovih vodenih rastvora.
Karakterizacija uzoraka kukuruzne svile i oklaska kukuruza, u ovom radu vršena je:
određivanjem hemijskog i elementarnog sastava, određivanjem kapaciteta katjonske
izmene (KKI), tačke nultog naelektrisanja (pHPZC), određivanjem teksturalnih osobina
(BET), termijskom analizom (TGA / DTA), skenirajućom elektronskom mikroskopijom
i energijsko – disperzivnom rendgenskom spektroskopijom (SEM–EDX) i infracrvenom
spektroskopijom sa Furijeovom transformacijom (FTIR).
U cilju odabira uzorka sa boljim adsorpcionim karakteristikama izvršena su preliminarna
ispitivanja procesa biosorpcije Pb2+, Cu2+ i Zn2+ jona na oklasku kukuruza i kukuruznoj
svili. Maksimalne adsorbovane količine Pb2+, Cu2+ i Zn2+ jona na oklasku kukuruza
iznosile su 0,027; 0,0413 i 0,019 mmol g-1, respektivno, dok su maksimalno adsorbovane
količine Pb2+, Cu2+ i Zn2+ jona na kukuruznoj svili iznosile 0,400; 0,220 i 0,190 mmol g-
1, respektivno. Dobijeni rezultati ukazuju da je kukuruzna svila uzorak sa boljim
adsorpcionim karakteristikama u odnosu na oklasak kukuruza. Stoga je kukuruzna svila
odabrana za detaljna ispitivanja procesa biosorpcije Pb2+, Cu2+ i Zn2+ jona.
Uticaj radnih parametara kao što su: početna pH vrednost, masa biosorbenta, početna
koncentracija jona metala, vreme kontakta i temperatura na proces biosorpcije Pb2+, Cu2+
i Zn2+ jona na kukuruznoj svili, ispitan je u šaržnom sistemu. Proces biosorpcije Pb2+ jona
može se opisati Lengmirovim i Frojndlihovim modelom dok se proces biosorpcije Cu2+ i
Zn2+ jona najbolje opisuje Lengmirovim modelom. Afinitet kukuruzne svile ka vezivanju
jona metala opada u sledećem nizu: Pb2+ > Cu2+ > Zn2+. Ispitivanjem kinetike procesa
biosorpcije jona metala na kukuruznoj svili ustanovljeno je da kinetički model pseudo –
drugog reda najbolje opisuje eksperimentalne rezultate. Takođe, ispitivanja izvršena pri
različitim temperaturama ukazuju da je vezivanje Pb2+, Cu2+ i Zn2+ jona na kukuruznoj
svili u osnovi spontan i endoterman proces.
Ispitivanja adsorpciono – desorpcionih procesa pokazala su da se kukuruzna svila lako
može regenerisati rastvorom HNO3 i koristiti za dalju upotrebu kao efikasan biosorbent
za uklanjanje jona teških metala iz njihovih vodenih rastvora.
Na osnovu eksperimentalnih rezultata ustanovljeno je da se proces biosorpcije Pb2+, Cu2+
i Zn2+ jona na kukuruznoj svili odvija jonskom izmenom i hemisorpcijom pri čemu se
između jona metala i biosorbenta formiraju veze jonskog i kovalentnog karaktera.
Rezultati ispitivanja procesa biosorpcije jona metala iz uzoraka otpadnih voda Rudarskog
kombinata Trepča, Rudarsko – topioničarskog basena Bor i pogona za uslužno cinkovanje
ukazuju da je kukuruzna svila efikasan biosorbent za uklanjanje Pb2+, Cu2+ i Zn2+ jona iz
realnih industrijskih voda.
S obzirom na nisku cenu, dostupnost i visoku efikasnost, kukuruzna svila je nakon
imobilizacije Na – alginatom ispitana za uklanjanje Pb2+, Cu2+ i Zn2+ jona u kontinualnom
sistemu.This study aims to investigate the possibility of the usage of waste corn biomass (corn
cob and corn silk) for removal of Pb2+, Cu2+ and Zn2+ ions from aqueous solutions.
The characterization of corn silk and corn cob was performed by determination of
chemical and elemental composition, cation exchange capacity (KKI), point of the zero
charge (pHPZC), specific surface area and pore volume (BET analysis), thermal analysis
(TGA / DTA), scanning electron microscopy and energy dispersive X – ray analysis
(SEM – EDX) and Fourier transform infrared spectroscopy (FTIR).
In order to select material with better sorption performances the preliminary experiments
were done. The maximum biosorptive capacity for Pb2+, Cu2+ and Zn2+ ions by corn cob
was 0,027; 0,0413 and 0,019 mmol g-1, respectively, while the maximum biosorptive
capacity for Pb2+, Cu2+ and Zn2+ ions by corn silk was 0,400; 0,220 and 0,190 mmol g-1,
respectively. According to results, the corn silk is more efficient than corn cob to remove
chosen metal ions from aqueous solutions.
The effect of operating parameters such as: initial pH, amount of adsorbent, initial metal
ion concentration, contact time and temperature on biosorption process of Pb2+, Cu2+ and
Zn2+ ions by corn silk was investigated in batch system. The sorption process of Pb2+ ions
by corn silk could be described by Langmuir and Freundlich isotherm models, while the
equilibrium sorption process of Cu2+ and Zn2+ ions was well described by Langmuir
isotherm model. The affinity of corn silk by interaction with metal ions was in descending
order Pb2+ > Cu2+ > Zn2+. The kinetic study indicated that the removal of Pb2+, Cu2+ and
Zn2+ ions by corn silk follows pseudo – second order model. Also, investigations
performed at different temperatures indicated that removal of lead, copper and zinc from
aqueous solutions by corn silk is a spontaneous and endothermic process.
Based on adsorption – desorption study results, the corn silk can be efficienltly recovered
by HNO3 solution and used in new adsorption cicle as effective biosorbent for heavy
metals removal from aqueous solutions.
The biosorption process of Pb2+, Cu2+ and Zn2+ ions by corn silk is result of ion exchange
and chemisorption.
Biosorption experiments which have been performed with actual waste waters obtained
from: Trepča Mines, Mining and Smelting Basin Bor and from electroplating, indicates
that corn silk is very efficient biosorbent for removal of Pb2+, Cu2+ and Zn2+ ions from
the industrial effluents.
For practical application corn silk was immobilised in Na – alginate and it was
investigated for Pb2+, Cu2+ and Zn2+ ions removal in a fixed bed system
Aflatoxin b-1 adsorption by the natural aluminosilicates - concentrate of montmorillonite and zeolite
No full textAflatoxin B-1 adsorption by the concentrate of bentonite clay - montmorillonite and the natural zeolite -clinoptilolite and was investigated at the initial toxin concentration of 4 ppm, with different amounts of solid phase in suspension (1, 0.5, 0.2 and 0.1 g/L) and different pH values - 3, 7 and 9. Results indicated that for both minerals, decreasing the amount of solid phase in suspension, decrease the amount of active sites relevant for adsorption of aflatoxin B-1. Thus, for concentrate of montnorillonite, at the lowest level of solid phase in suspension (0.1 g/L), aflatoxin B-1 adsorption indexes were 97% at pH 3, 88% at pH 7 and 82% at pH 9, while for the natural zeolite, adsorption of toxin was 9% at pH 3 and 7% at pH 7 and 9. Since inorganic cations in minerals are mainly responsible for aflatoxin B-1 adsorption, even the natural zeolite - clinoptilite has much higher cation exchange capacity (the content of inorganic exchangeable cations) compared to the concentrate of montmorillonite, adsorption of aflatoxin B-1 by this mineral is much lower. Comparing the molecular dimensions of aflatoxin B-1 molecule with the dimension of channels of clinoptilolite and interlamellar space of montmorillonite it is obvious that this toxin is adsorbed only at the external surface of clinoptilolite while in the montmorillonite all active sites are equally available for its adsorption. Thus, the concentrate of montmorillonite possesses higher adsorption capacity for aflatoxin B-1. Results presented in this paper confirmed the fact that the differences in the structure of minerals led to their different efficiency for adsorption of aflatoxin B-1. Mineralogical and chemical composition, determination of cation exchange capacity, etc., are very important parameters influencing the effectiveness of minerals as aflatoxin B-1 adsorbents
Crystallization and sintering behaviors of the polyphosphate glass doped with Zn and Mn
No full textThe crystallization and sintering behaviors of polyphosphate glass doped with trace elements Zn and Mn were examined. The heating experiments on bulk and powder glass samples were performed. The parent glass revealed low crystallization ability and the glass crystallization carried out under simultaneous acting of the surface and volume mechanisms. The bulk glass sample isothermally heated at T (c) = 500 A degrees C commences to crystallize after 12 h, and KPO3 and Ca2KP3O10 crystalline phases appeared. The dendritic morphology of the crystals growing on sample surface was determined. The DTA and HSM results showed that the sintering and crystallization processes are independent. Phosphate glass-ceramics containing KPO3, K2Mg(PO3)(4), Ca(PO3)(2) and KCa(PO3)(3) crystalline phases has been prepared by sintering of the glass powder compacts at T (c) = 500 A degrees C for t = 12 h. A plate-like morphology of crystals which grow on glass grains surface was observed. The activation energies of crystal growth, E (a,k) = (246.6 +/- A 19.74) kJ mol(-1) (Kissinger) and E (a,oz) = (258.80 +/- A 19.70) kJ mol(-1) (Ozawa), were calculated
Effect of KOH activation on hydrochar surface: FT-IR analysis
No full textIn this study, hydrothermal carbonization (HTC) at five temperatures (180, 200, 220, 240,
and 260 C) was applied to transform Paulownia leaves (PL) into a carbonaceous sorbent of Pb(II)
from aqueous solutions. To enhance the adsorption efficiency of the obtained hydrochar (PH),
subsequent alkali activation was performed using NaOH. Preliminary results of the Pb(II) adsorption
(CPb = 200 mg/L) showed removal coefficients after 48 h of 73.44 mg/g, 82.37 mg/g, and 110.9 mg/g
for PL, PH-220, and MPH-220, respectively. The selected hydrochar (PH-220) and modified hydrochar
(MPH-220) were further investigated by scanning electron microscopy (SEM) and Fourier transform
infrared spectroscopy (FTIR). The results revealed that alkali treatment changed the hydrochar
structure and, thus, improved its adsorption performance. The kinetic parameters showed that
the Pb(II) sorption onto MPH-220 followed a pseudo-second-order model, while the intra-particle
diffusion went through two simultaneous stages. The Langmuir isotherm model best described the
experimental data and indicated the value of 174.75 mg Pb(II)/g as the maximum adsorption capacity.
The two possible mechanisms of Pb(II) binding were complexation and/or Pb- electron interaction.
The obtained results indicate the great potential of MPH-220 for Pb(II) removal from aqueous media
and its potential utilization as an effective adsorbent for wastewater purification
Selection of low-cost sorbents as a potential possible material for a permeable reactive barrier based on a batch study
No full textMaintaining of good quality of groundwater is of great public interest worldwide.
However, this source is highly vulnerable to different pollution sources such as
industry, mining, irrigation, and so on. The pollution problems are more often
observed in Karst areas where large amounts of fresh water can be contaminated in a
short time. The application of an in situ technique for remediation of contaminated
groundwater is highly recommended due to its simplicity of performance and
economic benefit. Among in situ techniques, the permeable reactive barrier is the
most attractive method as it allows for using different materials in the barrier for
remediation of contaminated groundwater. Materials for PBR must demonstrate
good contaminant binding properties, the ability of their retention, excellent
hydraulic properties, satisfactory mechanical properties for safe performance, and
ensure a smooth flow through the barrier without disturbing the natural flow.
Nowadays the research is focused on investigation of different natural materials to
protect the environment, due to their low cost and availability in nature in large
quantities. The purpose of this work is to investigate the efficacy of various natural
materials such as natural and iron-modified zeolite, apatite, concentrated apatite,
kaolin and raw bentonite to remove heavy metals (lead and cadmium) from
contaminated groundwater using the in situ PBR. The batch test involves sorption
experiments followed by leaching experiments. In sorption experiments, the
amounts of metal removal by different sorbents were evaluated for cadmium and
lead from simulated wastewater with similar initial metal concentrations. The
leaching experiment included evaluation of metal retained by the saturated sorbents
in ultrapure water with adjusted pH values at 2.98 and 6.07. Additionally, pH values
of solutions were recorded during both experiments. Based on obtained results, the
sorbents that provide the optimal metal removal and their retaining from the
contaminated groundwater were selected
Izučavanje meljivosti nehomogenih kompozitnih materijala i testiranje skraćenog postupka za određivanje Bondovog radnog indeksa
No full textOvaj doktorska disertacija bavi se istaživanjem usitnjavanja mineralnih mešavina sa različitim meljivostima u Bondovom mlinu sa kuglama. Razumevanje kako se mešavine različitih sirovina sa različitim meljivostima melju, od velike je važnosti u pripremi mineralnih sirovina. Energija neophodna za drobljenje i mlevenje pretstavlja se Bondovim radnim indeksom i određuje se pomoću Bondovog testa meljivosti, u Bondovom mlinu sa kuglama. Njegova vrednost je karakteristika rude i služi za dizajniranje industijskih postrojenja za usitnjavanje. Određivanje vrednosti Bondovog radnog indeksa je dosta komplikovano, zahteva utrošak vremena i obučeno osoblje za rad i zbog toga je podložno proceduralnim greškama. U radu je dat kraći pregled skraćenih postupaka za određivanje vrednosti Bondovog radnog indeksa zajedno sa uporednim rezultatima dobijenim ovim postupcima i standardnim Bondovim postupkom na različitim uzorcima. U ovoj doktorskoj disertaciji predstavljen je skraćeni postupak za određivanje približne vrednosti Bondovog radnog indeksa, koji se bazira na zakonu kinetike mlevenja prvog reda. Ovaj skraćeni postupak može da se radi sa dva, tri ili četiri ciklusa mlevenja, u zavisnosti od željene preciznosti traženog podatka. Ispitivanja su vršena na uzorcima andezita, krečnjaka, topioničke šljake i rude bakra, kao i na dvokomponentnim kompozitnim uzorcima andezita i krečnjaka i kompozitnim uzorcima topioničke šljake i rude bakra u različitim masenim odnosima. Ispitivanja su vršena standardnim Bondovim postupkom za određivanje meljivosti i skraćenim postupkom. Tokom izvođenja eksperimenata meljivosti na kompozitnim uzorcima andezita i krečnjaka, praćena je promena sastava proizvoda mlevenja i kružne šarže mlina za prvih devet ciklusa mlevenja standardnog Bondovog testa. Na osnovu rezultata meljivosti dobijenih standardnim Bondovim postupkom, pokazani su odnosi potrošnje energije za usitnjavanje, kada se komponente mešavine andezita I krečnjaka i mešavine topioničke šljake i rude bakra melju zasebno, i kada se melju zajedno kao mešavina. Predstavljene su uporedne vrednosti Bondovog radnog indeksa dobijene standardnim I skraćenim postupkom na svim jednokomponentim i dvokomponentnim uzorcima, koji su bili predmet ispitivanja ove doktorske disertacije. Takođe su pokazane greške koje se dobijaju skraćenim postupkom u odnosu na standardni postupak.This doctoral thesis investigates grinding of mineral mixtures with different grindabilities in the Bond ball mill. Understanding the ore mixture grinding is of great importance in mineral processing. The energy required for crushing and grinding is presented by the Bond work index and is determined by means of Bond grindability test. Its value constitutes ore characteristic and it is used for industrial comminution plants designing. Determining the Bond work index value is quite complicated, time-consuming and requires trained operating personnel and therefore is subjected to procedural errors. The paper gives a brief abbreviated procedures overview for determining the value of Bond work index, together with the comparative results obtained by these methods and standard procedures Bond on various samples. A abbreviated method for the Bond work index approximate value determining, which is based on the first order grinding kinetics law, is presented in this doctoral thesis. This procedure can be performed by two, three or four cycles of grinding depending on the desired precision of the required data. Tests were conducted on samples of andesite, limestone, smelter slag and copper ore, as well as two-component composite samples of andesite and limestone and composite samples of smelter slag and copper ore in different weight ratios. The tests were performed by standard Bond procedure and abreviated procedure for grindability determination. During the Bond work index value determining, changes in the composition of the milling products and mill circulating load for the first nine cycles of standard Bond grinding test was monitored. Based on the results obtained by standard Bond grindability procedure, comminution energy consumption relations, when mixtures component andesite and limestone and mixtures component smelter slag and copper ore are grinding separately and together as a mixture, are presented. Comparative values obtained by standard and abbreviated Bond work index procedure for all single component and two component samples that were the subject matter of this doctoral thesis, are presented. The error of values that are obtained by abbreviated procedure compared to standard procedure, are also shown
Synthesis and characterization of luminescent fluorapatite nanomaterial as potential dosimeter for food irradiation
No full textInorganic luminescent nanomaterials on apatite basis are potentially
attractive for application as dosimeter material. Nanostructure fluorapatite was synthesized by precipitation method at room temperature. Characterization was done by XRD, FTIR and SEM in order to confirm the nanostructure of monophase material. Material has luminescence in a violet region
A review of Pb-Sb(As)-S, Cu(Ag)-Fe(Zn)-Sb(As)-S, Ag(Pb)-Bi(Sb)-S and Pb-Bi-S(Te) sulfosalt systems from the Boranja orefield, West Serbia
No full textRecent mineralogical, chemical, physical, and crystallographic investigations of the Boranja orefield showed very complex mineral associations and assemblages where sulfosalts have significant role. The sulfosalts of the Boranja orefield can be divided in four main groups: (i) Pb-Sb(As)-S system with ±Fe and ±Cu; (ii) Cu(Ag)-Fe(Zn)-Sb(As)-S system; (iii) Ag(Pb)-Bi(Sb)-S; (iv) and Pb-Bi-S(Te) system. Spatially, these sulfosalts are widely spread, however, they are the most abundant in the following polymetallic deposits and ore zones: Cu(Bi)-FeS Kram-Mlakva; Pb(Ag)-Zn-FeS2 Veliki Majdan (Kolarica-Centralni revir-Kojići); Sb-Zn-Pb-As Rujevac; and Pb-Zn-FeS2-BaSO4 Bobija. The multi stage formation of minerals, from skarnhydrothermal to complex hydrothermal with various stages and sub-stages has been determined. All hydrothermal stages and sub-stages of various polymetallic deposits and ore zones within the Boranja orefield are followed by a variety of sulfosalts