Sorption properties and thermal behaviour of Prunus persica L. waste biomass.

Rastuća industrijalizacija i smanjivanje energetskih rezervi uslovilo je istraživanja u pravcu razvoja novih tehnologija koje bi primenile obnovljive, lako dostupne i ekonomski isplative otpadne materijale.Poslednjih nekoliko decenija otpadna agroindustrijska lignocelulozna (LC) biomasa predstavlja predmet brojnih istraživanja širom sveta usled velike rasprostranjenosti, niske cene, obnovljivosti i strukturnih karakteristika...Growing industrialization and resource depletion induced the research of new clean up technologies that provide implementation of renewable, low cost waste materials. In the last few decades, agro industrial lignocellulosic waste biomass (LCW) appeared as an attractive feedstock worldwide. LCW’s abundance, multi functionality and low cost have influenced many investigationsin the field of its renewable potential..

Application of peach shells for the removal of methylene blue and brilliant green

Increased industrial, agricultural and domestic activities resulted in the production of large amount of wastewater containing a number of toxic materials which continuously polluting the available fresh water. Sorption is an effective method for water decontamination. Various types of pollutants such as metal ions, dyes, and a number of other organic and inorganic compounds and bio-organisms could be removed by different types of sorbents. Important properties of good sorbent material are high specific surface area and fast kinetics for the removal of pollutants. Natural materials such as oil palm fibers and shells, waste apricot and pitch, olive-seeds waste, peach stones, almond shells, walnut shells, hazelnut shells, kaolin, bentonite, zeolites, coal, etc., possess large capacities for removing of the water pollutants. The main advantages of these materials are wide availability, low cost and environmental safety. The peach shells (PS) were used as the raw material for removing of non-degradable toxic dyes from water solutions. Methylene blue (MB) and brilliant green (BG) were used as representatives of dyes which commonly are pollutant from the textile industry. The peach shells were milled in vibromill and sieved to desired sizes: (1) 100-500 μm, and (2) < 100 μm. The phase composition of the prepared particles fractions was identified by XRD. The BET specific surface area was determined from N2 adsorption/desorption experiments. The particles morphology was characterized by SEM, while the particle size distribution was measured by laser light-scattering particle size analyzer. In a typical experiment, 50 mg of PS particles as the sorbent was mixed on a magnetic stirrer with 50 ml of dye aqueous solution with the initial concentration of 5, 10 and 20 ppm, at room temperature. At time intervals of 5 to 120 minutes aliquots was withdrawn, centrifuged, and pollutant concentration was measured. The concentration of MB and BG in the solution before and after sorption by PS was calculated according to the absorbance value at 665 nm (for MB) and 624 nm (for BG) determined by UV measurements performed on a UV–Vis spectrophotometer in the wavelength range of 300–800 nm. Capacity of MB and BG sorption by prepared PS particles was found to be above 86 % after 120 minutes

Effects of different mechanical treatments on structural changes of lignocellulosic waste biomass and subsequent Cu(II) removal kinetics

In this paper, the character of structural changes induced by different mechanical treatments to Prunus persica stones (PSs), and its subsequent effect on biosorption kinetics of Cu(II) were investigated. PSs were processed in vibratory disk mill (PS-V) and ultra-centrifugal mill (PS-C) and characterized by XRD, BET, SEM and FTIR spectroscopy. It was shown that PS-V was smaller and more reactive with less crystallinity index and hydrogen bond intensity compared to PS-C. In opposite, surface area of the PS-C was bigger than that of the PS-V. The total pore volume was about threefold, while the volume of micro pores was 9.29 times higher in PS-Cs than in PS-Vs. The kinetics of Cu(II) biosorption by both PSs was tested through various kinetic models: pseudo-first and pseudo-second order rate equations, Elovich equation, Boyd model, Weber–Morris and Urano–Tachikawa intraparticle diffusion model. For both sample types, Cu(II) biosorption occurred through combination of intraparticle and film diffusion mechanism, while kinetic results were best described by the pseudo-second order kinetic model. At the same time, the results indicated that together with kinetic rate the biosorption capacity of PS-C (21.20 mg g−1) was higher than that of PS-V (16.30 mg g−1). Mechanical activation like crushing and grinding will change material particle size, specific surface area and porosity, as well as its crystallinity. However, this paper elucidates that such physical structural changes will impact on heavy metal ions removal efficiency. This investigation suggests that the type of size reduction in lignocellulosic biosorbent preparation plays a very important role in overall biosorption performance, so it should be carefully considered every time when the mechanical treatment of material is necessary to be applied

Comparison of extraction agents for metal determination in sediments from artificial lakes and rivers in Serbia

The purpose of this paper was to investigate the effectiveness of three different extraction agents for the extraction of 25 elements from sediment samples collected from 4 artificial lakes and 12 rivers in Serbia (33 samples in total). The extraction efficiency of the agents was evaluated by its ability to extract the highest quantity of the elements. For that purpose, three acids (1M HCl, 2M HNO3 and 0.43M CH3COOH) have been used. Inductively coupled plasma atomic emission spectrometry (ICP-OES) was used for quantitative determination of following elements: Al, As, B, Ba, Be, Bi, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Li, Mg, Mn, Ni, Na, Pb, Sb, Se, Sr, V, and Zn. The extraction with 1M HCl has shown the best results for the majority of investigated elements (especially Sr, Mn and Ca). Antimony (Sb) was detected only after extraction with 0.43M CH3COOOH, while selenium (Se) could not be detected when 2M HNO3 was applied as extraction agents. The present study could be very useful for choosing a suitable method for specific elements and also can be helpful in the evaluation of the contaminants in freshwater sediments in Serbia. This might contribute to environmental risk assessment of the present elements

Synthesis and characterization of cobalt ferrite/ expanded vermiculite as a sorbent of nickel ions

The minerals with unique properties such as mica minerals have promising approach in environmental and industrial sphere. In this study, cobalt ferrite/expanded vermiculite (CoFe2O4/EV) composite was prepared by in-situ method. Both composite and base materials are characterized by FTIR, XRD and SEM techniques, while the CEC and point of zero charge (pHPZC) was also determined. The adsorption properties of CoFe2O4/EV and EV have been investigated in a batch system, for the Ni (II) sorption from water. Adsorption experimental results were fitted by kinetic and adsorption models, and resulted in ionic exchange mechanism with maximum adsorption capacity of 23.2mg g-1 (298 K)

Ispitivanje upotrebe otpadne biomase za uklanjanje naftnih ugljovodonika iz vodenog rastvora

Adsorption is one the best commonly used technique for treatment of petroleum contaminated water. The biosorption potential of waste biomass (peach shell, agro-industrial waste) as a low-cost biosorbent for petroleum hydrocarbon from aqueous solution was explored. Biosorption experiments were carried out using a shake-flask technique with a constant amount of (bio) sorbent of 1 g mixed with 100 ml of water contaminated with petroleum hydrocarbons at concentrations of 4 mg/L, 12 mg/L, 18 mg/L, 24 mg/L, 30 mg/L, 40 mg/L and 80 mg/L. The obtained results show that waste biomass is efficient in the removal of petroleum pollutants from the water solution. Biosorption is a potentially alternative technique for wastewater treatment. Their major advantages are low cost, high efficiency, renewability.Adsorpcija je jedna od najčešće korišćenih tehnika za tretiranje voda zagađenih naftom i njenim derivatima. U radu je ispitivana mogućnost primene otpadne biomase (koštice breskve, agroindustrijskog otpada), kao jeftinog biosorbenta, za uklanjanje nafnih zagađivača iz vodenog rastvora u stacionarnim uslovima. Biosorpcioni eksperimenti su obavljeni u erlenmajerima na na orbitalnom šejkeru u kojima je konstantna količina biosorbenta od 1 g mešana sa 100 ml vode kontaminirane naftnim ugljovodonicima u koncentacijama 4 mg/L, 12 mg/L, 18 mg/L, 24 mg/L, 30 mg/L, 40 mg/L and 80 mg/L. Dobijeni rezultati pokazuju da je otpadna biomasa efikasna u uklanjanju naftnih polutanata iz vodenog rastvora. Biosorpcija je potencijalno alternativna tehnika za prečišćavanje otpadnih voda. Njene glavne prednosti su niska cena, visoka efikasnost i obnovljivost.Related to: [https://cherry.chem.bg.ac.rs/handle/123456789/5411

A Mechanism Assessment and Differences of Cadmium Adsorption on Raw and Alkali-Modified Agricultural Waste

In this study, raw corn silk was considered for the removal of cadmium ions from aqueous solutions. In order to improve adsorption characteristics, the KOH treatment was applied as a route to obtain modified materials. Both materials before and after metal adsorption were characterized by pHPZC, SEM-EDX and FTIR analysis. SEM images and FTIR spectra revealed that alkali modification caused some structural changes that could improve the adsorption properties of the investigated material. The experimental results and the ion-exchange study revealed that the biosorption process of cadmium ions on to raw and modified corn silk was caused predominantly by the ion-exchange mechanism, followed by chemisorption. The kinetic parameters implied that there are three stages in the biosorption process. In addition, the cadmium adsorption on both materials is very fast and is followed by the pseudo-second-order kinetic model. The experimental results were fitted by two and three parameter isotherm models, while the Sips isotherm model best describes the biosorption process on both materials. According to the Sips isotherm model, the maximum adsorption capacity of cadmium adsorbed on modified materials was 49.06 mg g−1, which is 2.23 times greater in comparison to the raw material (21.96 mg g−1). Furthermore, the mechanisms of cadmium adsorption onto the investigated materials are summarized in order to better understand the modification influence on the adsorption properties of corn silk. In order to examine reusability of the investigated material, diluted nitric acid was used for regeneration. A desorption study was performed in three adsorption-desorption cycles. A high desorption efficiency (˃85%) indicated that MCS after Cd adsorption can be efficiently recovered and reused for a new adsorption cycle

Ispitivanje upotrebe otpadne biomase za uklanjanje naftnih ugljovodonika iz vodenog rastvora

Adsorption is one the best commonly used technique for treatment of petroleum contaminated water. The biosorption potential of waste biomass (peach shell, agro-industrial waste) as a low-cost biosorbent for petroleum hydrocarbon from aqueous solution was explored. Biosorption experiments were carried out using a shake-flask technique with a constant amount of (bio) sorbent of 1 g mixed with 100 ml of water contaminated with petroleum hydrocarbons at concentrations of 4 mg/L, 12 mg/L, 18 mg/L, 24 mg/L, 30 mg/L, 40 mg/L and 80 mg/L. The obtained results show that waste biomass is efficient in the removal of petroleum pollutants from the water solution. Biosorption is a potentially alternative technique for wastewater treatment. Their major advantages are low cost, high efficiency, renewability.Adsorpcija je jedna od najčešće korišćenih tehnika za tretiranje voda zagađenih naftom i njenim derivatima. U radu je ispitivana mogućnost primene otpadne biomase (koštice breskve, agroindustrijskog otpada), kao jeftinog biosorbenta, za uklanjanje nafnih zagađivača iz vodenog rastvora u stacionarnim uslovima. Biosorpcioni eksperimenti su obavljeni u erlenmajerima na na orbitalnom šejkeru u kojima je konstantna količina biosorbenta od 1 g mešana sa 100 ml vode kontaminirane naftnim ugljovodonicima u koncentacijama 4 mg/L, 12 mg/L, 18 mg/L, 24 mg/L, 30 mg/L, 40 mg/L and 80 mg/L. Dobijeni rezultati pokazuju da je otpadna biomasa efikasna u uklanjanju naftnih polutanata iz vodenog rastvora. Biosorpcija je potencijalno alternativna tehnika za prečišćavanje otpadnih voda. Njene glavne prednosti su niska cena, visoka efikasnost i obnovljivost.Related to: [https://cherry.chem.bg.ac.rs/handle/123456789/5412

Contemporary methods of testing human milk quality

Infant nutrition is essential for their growth and development. This research aims to determine the total antioxidant capacity of the infant food for preterm infants and indicate adequate methods for testing the quality and biological value of milk and infant food. The total antioxidant capacity (TAC) was determined in human milk and an infant formula for premature infants. The determination of the total antioxidant capacity was made using cyclic and differential pulse voltammetry, potentiometry and electron paramagnetic resonance spectroscopy. The results of three comparative electrochemical methods indicate that human milk has a higher antioxidant potential compared to infant formula, which contributes to better physiological development of the child. Fenton-based electron paramagnetic resonance spectroscopy method provides additional insight into TAC analysis, whereby a carbon-centered radical and an ascorbyl radical are formed in infant food. All methods can be used to determine TAC, since the results obtained individually with each method follow the same trend

Investigation of adsorption and bioremediation in a combined procedure for purification of water contaminated with disel

U ovom radu je ispitivano kombinovanje adsorpcije i bioremedijacije u postupku prečišćavanja voda kontaminiranih dizelom. Prva faza je ispitivanje adsorpcije dizela na biouglju, dobijenom pirolizom koštica šljive. Druga faza je biorazgradnja dizela zaostalog u rastvoru nakon adsorpcije. Oba procesa podržavaju koncept održivog razvoja, kome je imperativ obnovljivost, efikasnost i ekološka prihvatljivost