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Bismuth basic nitrates (BBNs) were synthesized via an electrochemical method, i.e., by electrodeposition from an acidic solution of bismuth nitrate, followed by thermal treatment in an air environment. For the first time, the influence of various electrochemical parameters on the morphology, crystal structure, and chemical structure of BBNs was examined. The following synthesis parameters were investigated: electrodeposition current density, thermal treatment temperature of the obtained deposit, and working electrode material (cathode). The obtained materials were characterized by SEM-EDX, XRD, FTIR, TG, and N2 adsorption/desorption methods and were applied for the sorption of the textile dye RB19. The results showed that the electrodeposition current density and thermal treatment temperature affect the surface morphology, chemical composition, and crystal structure of the obtained materials, as well as the RB19 sorption efficiency. On the other hand, the working electrode material does not affect the properties of the synthesized materials mentioned. Kinetic, isotherm, and thermodynamic analysis of the sorption process were also examined.

Treatment of textile wastewater using heterogeneous photocatalysis began in the the last decade and attracted the attention of researchers due to its versatile application. The variety of applications of Ti[O.sub.2] as a photocatalyst was due toits numerous positive properties, such as low operating temperature, biologically inert nature, low energy consumption, water insolubility, availability and photoactivity, low toxicity, high chemical stability, suitable flat band potential, narrow bandgap and the fact that it is environmentally benign. Heterogeneous UV-Ti[O.sub.2] photocatalysis is capable of removing organic pollutants from textile wastewater; this has been widely studied, with the technology also having been commercialized in many developing countries. Decolorization of anthraquinone dye Reactive Blue 19 (RB 19) by heterogeneous advanced oxidation processes Ti[O.sub.2]/UV/[H.sub.2][O.sub.2], Ti[O.sub.2]/UV/KBr[O.sub.3] and Ti[O.sub.2]/UV/[(N[H.sub.4]).sub.2][S.sub.2][O.sub.8] was studied under different conditions and in the presence of electron acceptors such as hydrogen peroxide ([H.sub.2][O.sub.2]), potassium bromate (KBr[O.sub.3]) and ammonium persulphate ([(N[H.sub.4]).sub.2][S.sub.2][O.sub.8]). Decolorization was very fast for all three processes, and complete dye decolorization was achieved in 10 min. The effect of various ions ([Cl.sup.-], S[O.sub.4.sup.2-] and HC[O.sub.3.sup.-]) on RB 19 decolorization was also studied. The optimal condition for the decolorization of the dye were determined to be: Ti[O.sub.2] concentration 1 g-drrr (3), electron acceptor concentration 30.0 mmol*[dm.sup.-3], dye concentration 50.0 mg*[dm.sup.-3], UV intensity 1 950 [micro]W*[cm.sup.-2], at temperature 25 [+ or -] 0.5[degrees]C. In addition, experiments were performed and compared in three different matrices. In the surface water and dyebath effluent water, the removal efficiency for RB 19 was lower than that achieved in the deionized water because of the interference of complex constituents in the surface water and effluent. LC-MS analysis was carried out and the detected intermediates were compared with the previously published data for anthraquinone dyes. KEYWORDS anthraquinone dye electron acceptors photocatalysis Reactive Blue 19 titanium dioxide

Lagenaria vulgaris activated carbon (LVAC) was synthesized from Lagenaria vulgaris biomass by treatment with diluted H2SO4 followed by thermo-chemical carbonization and overheated steam activation process and used for removal of the herbicide 2,4-dichlo-rophenoxyacetic acid (2,4-D). Fourier transform infrared spectroscopy (FTIR) indicated that 2,4-D is adsorbed in micropores of the very porous LVAC (665 m2 g-1). LVAC showed high sorption capacity as compared to many previously used sorbents at optimal conditions: the stirring rate of 300 rpm, the sorbent dose of 1.0 g dm-3 and pH from 2 to 7. The experimental maximum sorption capacity of LVAC was 333.3 mg g-1. The pseudo-second-order model and Chrastil model described the 2,4-D sorption kinetics by LVAC. Thermodynamic studies have indicated that the sorption process was endothermic, spontaneous and physical in nature. LVAC was shown to be an ultrahighly efficient sorbent for removal of 2,4-D from groundwater, which could be also recycled and reused.

Treatment of textile wastewater using heterogeneous photocatalysis began in the the last decade and attracted the attention of researchers due to its versatile application. The variety of applications of TiO2 as a photocatalyst was due to ts numerous positive properties, such as low operating temperature, biologically inert nature, low energy consumption, water insolubility, availability and photoactivity, low toxicity, high chemical stability, suitable flat band potential, narrow bandgap and the fact that it is environmentally benign. Heterogeneous UV-TiO2 photocatalysis is capable of removing organic pollutants from textile wastewater; this has been widely studied, with the technology also having been commercialized in many developing countries. Decolorization of anthraquinone dye Reactive Blue 19 (RB 19) by heterogeneous advanced oxidation processes TiO2/UV/H2O2, TiO2/UV/KBrO3 and TiO2/UV/(NH4)2S2O8 was studied under different conditions and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate ((NH4)2S2O8). Decolorization was very fast for all three processes, and complete dye decolorization was achieved in 10 min. The effect of various ions (Cl–, SO4 2– and HCO3 –) on RB 19 decolorization was also studied. The optimal condition for the decolorization of the dye were determined to be: TiO2 concentration 1 g∙dm–3, electron acceptor concentration 30.0 mmol∙dm–3, dye concentration 50.0 mg∙dm–3, UV intensity 1 950 μW∙cm–2, at temperature 25 ± 0.5°C. In addition, experiments were performed and compared in three different matrices. In the surface water and dyebath effluent water, the removal efficiency for RB 19 was lower than that achieved in the deionized water because of the interference of complex constituents in the surface water and effluent. LC-MS analysis was carried out and the detected intermediates were compared with the previously published data for anthraquinone dyes.

Lagenaria vulgaris activated carbon (LVAC) was synthesized from Lagenaria vulgaris biomass by treatment with diluted [H.sub.2]S[O.sub.4] followed by thermo-chemical carbonization and overheated steam activation process and used for removal of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Fourier transform infrared spectroscopy (FTIR) indicated that 2,4-D is adsorbed in micropores of the very porous LVAC (665 [m.sup.2] [g.sup.-1]). LVAC showed high sorption capacity as compared to many previously used sorbents at optimal conditions: the stirring rate of 300 rpm, the sorbent dose of 1.0 g [dm.sup.-3] and pH from 2 to 7. The experimental maximum sorption capacity of LVAC was 333.3 mg [g.sup.-1]. The pseudo-second-order model and Chrastil model described the 2,4-D sorption kinetics by LVAC. Thermodynamic studies have indicated that the sorption process was endothermic, spontaneous and physical in nature. LVAC was shown to be an ultrahighly efficient sorbent for removal of 2,4-D from groundwater, which could be also recycled and reused. Keywords: Activated carbon; 2,4-D; groundwater; recycling and reusing; thermodynamics Dostupno na Internetu sa adrese casopisa: (Naucni rad) Aktivni ugalj Lagenaria vulgaris (LVAC), sintetisan iz biomase Lagenaria vulgaris tretiranjem sa razblazenom [H.sub.2][SO.sub.4], pracenim termohemijskom karbonizacijom i procesom aktivacije pomocu pregrejane pare, koriscen je za uklanjanje herbicida 2,4-dihlorofenoksi sircetne kiseline (2,4-D). Infracrvena spektroskopija sa Furijeovom (Fourier) transformacijom (FTIR) je ukazala da se sorpcija 2,4-D odvija u mikroporama vrlo poroznog LVAC (665 [m.sup.2] [g.sup.-1]). LVAC je pokazao veliki kapacitet sorpcije u poredenju sa mnogim prethodno koriscenim sorbentima u optimalnim uslovima: brzina mesanja od 300 rpm, doza sorbenta 1,0 g [dm.sup.-3] i pH od 2 do 7. Maksimalni eksperimentalni sorpcioni kapacitet LVAC bio je 333,3 mg [g.sup.-1]. Model pseudo-drugog reda i Krastilov (Chrastil) model su dobro opisali sorpciju 2,4-D na LVAC. Termodinamicka ispitivanja su pokazala da je proces sorpcije bio endoterman, spontan i fizicke prirode. LVAC se pokazao kao ultra-efikasan sorbent za uklanjanje 2,4-D iz podzemnih voda, a takode moguce ga je reciklovati i ponovo koristiti. Kljucne reci: aktivni ugalj; 2,4-D; podzemna voda; recikliranje i ponov-na upotreba; termodinamika