Abstract The paper presents the results of Cr, Co, Cu, Fe, Ni, Mn, Pb, Zn, and four radionuclides (226Ra,232Th, 137Cs, and 40K) determination in transplanted lichens after two, four, and six months of exposure. Lichens were sampled from the area of Mountain Igman in Bosnia and Herzegovina (BiH) and transplanted to two locations (Pofalići and Bjelave) in Sarajevo, the capital city of BiH. The total metals content was determined by flame atomic absorption spectrometry (FAAS). Gamma spectrometry (GS) was used for radionuclide activity determination. Content of Cr, Co, Cu, Fe, Mn, Ni, Pb an Zn in lichen after two, four, and six months of exposure ranged as follows: <LOD-0.61, <LOD-1.55, 3.85–8.08, 332.5–497.9, 19.68–31.65, 2.29–4.24, <LOD-10.30, 32.76–58.58 µg/g, respectively. Cr was not detected in exposed lichen samples. A very strong positive correlation for Cu-Cu, Cu-Fe, Cu-Pb, Cu-Zn, Ni-Ni and Fe-Fe was obtained in lichens, while a strong correlation was between Co-Zn, Co-Cu, Pb-Pb and Mn-Mn. The specific activity of 137Cs ranged from 19.95 to 56.66 Bq/kg, while for 40K ranged from 49.65 to 330.61 Bq/kg. The specific activity of 226Ra and 232Th was below the GS limit of detection.

Adsorption for uranium removal from aqueous systems has been extensively studied, due to its many advantages. However, the great costs and complexity of many sorbent preparation methods are still restricting the progress. Hence, this research aimed to introduce a novel, simple and green method for enhancing Amberlite IR-120 properties for U(VI) removal. Adsorption process parameters were evaluated by batch method and sorbent was characterized before and after uranium adsorption by FTIR, SEM and EDS analysis. The results demonstrated that sorbent was effective for U(VI) removal at pH 5, 100 mg dose with 60 mg/L of U(VI) concentration within 40 min at higher temperatures. The removal efficiency was 87.7% and process was found feasible according to thermodynamic data. Kinetic modelling showed best correlation with pseudo-second order model (r2 = 0.999) and applied isotherms could all describe investigated process suggesting a complex mechanism of U(VI) uptake. Effect of interfering ions (Pb(II), Ni(II) and Co(II)) in a concentration of 45 and 60 mg/L decreased U(VI) removal to 45%. Additionally, AAS method confirmed that used sorbent has significant affinity towards Pb(II). Desorption study revealed successful uranium recovery in up to 3 cycles of sorption/desorption. The EDS analysis revealed the uranium presence with 4.7% and FTIR analysis revealed bands characteristic for stretching vibrations of O=U=O. Proposed mechanism involved U(VI) uptake via non-covalent interactions, inter/intra-molecular hydrogen bonding and intraparticle diffusion. Techno-economic analysis showed that with used preparation method 1 g of ASP costs 0.022 $. Hence, this study offers a novel method for sorbents properties enhancements.

The issue of water contamination by heavy metal ions as highly persistent pollutants with harmful influence primarily on biological systems, even in trace levels, has become a great environmental concern globally. Therefore, there is a need for the use of highly sensitive techniques or preconcentration methods for the removal of heavy metal ions at trace levels. Thus, this research investigates a novel approach by examining the possibility of using pomegranate (Punica granatum) peel layered material for the simultaneous preconcentration of seven heavy metal ions; Cd(II), Co(II), Cr(III), Cu(II), Mn(II), Ni(II) and Pb(II) from aqueous solution and three river water samples. The quantification of the heavy metals was performed by the means of FAAS technique. The characterization of biomaterial was performed by SEM/EDS, FTIR analysis and pHpzc determination before and after the remediation process. The reusability study, as well as the influence of interfering ions (Ca, K, Mg, Na and Zn) were evaluated. The conditions of preconcentration by the column method included the optimization of solution pH (5); flow rate (1.5 mL/min), a dose of biosorbent (200 mg), type of the eluent (1 mol/L HNO3), sample volume (100 mL) and sorbent fraction (<0.25 mm). The biosorbent capacity ranged from 4.45 to 57.70 μmol/g for the investigated heavy metals. The practical relevance of this study is further extended by novel data regarding adsorbent cost analysis (17.49 $/mol). The Punica granatum sorbent represents a highly effective and economical biosorbent for the preconcentration of heavy metal ions for possible application in industrial sectors.

In this study, it was performed identification and quantification of flavonoids (apigenin, chrysin, hesperetin, kaempferol, luteolin, naringenin, and quercetin) and flavonoid glycosides (rutin and vitexin) in total 49 samples of five different honey types from Bosnia and Herzegovina: meadow honey (MH, 22 samples), forest (FH, 10), acacia (AH, 7), chestnut (CH, 5), and heather honey (HH, 5). Additionally, evaluation of correlations between FC and total hydrophilic antioxidant score (antioxidant activity against both: ROO· + OH·) in supernatants (s) and in bulk (noncentrifuged) solution (b) of these honey types was performed. Moreover, correlations between flavonoids content (FC) and previously reported antioxidant activity against both peroxyl and hydroxyl free radicals (AC(ROO·) and AC(OH·)) for the same honey samples was examined. High performance liquid chromatography with photodiode array detector (HPLC-DAD) and isocratic elution mode was used as method of analysis. Flavonoids were extracted by solid phase extraction (SPE). The average contents of three flavonoids (chrysin, naringenin, and luteolin) in MH were statistically higher than in AH (p**<0.01). Also, the average content of naringenin in FH was statistically higher than in CH (p*<0.05). We observed a high (positive) linear correlation between FC and AC(ROO·) in s of four honey types (FH, AH, HH, CH) (R2=0.920). If we correlate FC and AC(ROO·)s of three honey types (FH, AH, HH), linearity is very high (R2=0.968), and for FH, AH, CH linearity is complete. The correlation between FC and AC(ROO·) in b of the same honey types is similar, but lower. The correlation does not exist between FC and AC(OH·) neither in s nor in b of five or four honey types, but for FC to both (AC(OH·)s and AC(OH·)b) of three honey types (FH, AH, CH), linearity is moderate (R2=0.732 and R2=0.696, respectively). Keywords: antioxidant activity, correlations, flavonoids, honey, HPLC-DAD.

Wastewater from industrial process of uranium ore mining contains a large amount of this radioactive pollutant. Regarding the advantages of biosorption, it was found that varieties of biomasses such as agricultural waste, algae and fungi are effective for uranium removal. However, there is limited research on cyanobacteria, therefore, cyanobacteria, Anagnostidinema amphibium (CAA) was investigated by batch method for the first time for biosorption of uranium (VI). Optimization of biosorption parameters showed that maximum removal efficiency of 92.91% was reached at pH range of 9-11 with 50 mg of cyanobacteria to 100 mg/L U(VI) initial concentration, at 25 °C within 40 min. Used biosorbent exhibited very good selectivity for U(VI) ions and reusability in IV sorption/desorption cycles. Characterization of CAA surface was performed by FTIR, EDS, EDXRF and SEM analysis and it has shown various functional groups (CONH, COOH, OH, PO alkyl group) and that it is very rich in elements such as iron, potassium and calcium. In binary systems, contained of U(VI) and selected ions, CAA exhibits very good selectivity towards U(VI) ions. Kinetic data revealed the best accordance of experimental data with the pseudo-second-order model, and isotherms data agreed with Freundlich model. Thermodynamic data implied that U(VI) biosorption process by A. amphibium exhibited spontaneity and modelling of the investigated process showed that the adsorption of uranium ions occurs mainly via peptidoglycan carboxyl groups. Overall results show that these cyanobacteria with a maximum sorption capacity of 324.94 mg/g have great potential for the processing of wastewater polluted with uranium (VI).

A feasible and cost-effective process for utilization of toluene and heavy reformate is the conversion of its streams by transalkylation reaction into highly valuable xylenes. The process is usually catalysed by zeolites and the challenges to overcome in transalkylation of heavy reformate with toluene over zeolites are their selectivity, activity, long-term stability, and coke formation. Current study aimed to investigate xylenes production by transalkylation reaction on the synthesized metal-doped zeolite catalysts and to characterize prepared catalysts by FTIR, SEM, EDS and BET analysis. Toluene/heavy reformate modelled mixture was utilized as a feed. For the first time Beta and ZSM-5 catalysts with 10% (w/w) cerium and 0.1% (w/w) palladium were synthesized by calcination and wet impregnation method. Catalytic tests were performed by continuous-flow gas/solid catalytic fixed bed reactor at atmospheric pressure, 2 h-1 and 5 h-1 and 250, 300, 350 and 400 °C. Experimental results revealed that the highest heavy reformate conversion (98.94%) and toluene conversion (9.82%) were obtained over H-ZSM-5, at 400 °C and 2 h-1 WHSV. The highest xylene selectivity (11.53) was achieved over H-ZSM-5, and the highest p-xylene percentage (62.40%), using Ce-ZSM-5 catalyst. ZSM-5 catalysts showed more resistance to coke deposition than Beta zeolites. The present study delivers novel approach and catalysts, which have immense potential for developing safer and inexpensive transalkylation process in industry.