9 research outputs found

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

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    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

    Food Waste (Beetroot and Apple Pomace) as Sorbent for Lead from Aqueous Solutionsā€”Alternative to Landfill Disposal

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    This article presents studies, whose main goal was to minimize food waste. To achieve this goal, it is necessary to expand the scope of their application, for example, for the purification of polluted water from heavy metals. Millions of tons of waste from the fruit and vegetable industry, including pomace of apples and beetroots, are thrown into landfills, posing a danger to the environment. In order to solve the problems with the disposal of these wastes, the authors investigated their sorption potential for the removal of lead from wastewater. The sorbents, dried apple (AP), and beetroots (BR) pomaces were characterized by various methods (study of composition, zeta potential, FTIR-ATR, and SEM-EDX). Various models of sorption kinetics and sorption isotherms were analyzed. Kinetical studies under optimal conditions showed that the sorption process occurs through complexation and ion exchange and the determining stage limiting the rate of sorption is the diffusion of lead ions in the sorbent. The maximum sorption capacity was 31.7 and 79.8 mg/g for AP and BR, respectively. The thermodynamic data revealed the spontaneous sorption of lead ions by sorbents. The temperature rise contributes to the sorption increase by the AP sorbent, while for the BR sorbent, the opposite effect is observed. The obtained results showed that apple and beetroots pomaces can serve as effective renewable materials for the preparation of sorbents, contributing to the solution of complex environmental problems

    Nova tehnologija za tretman podzemnih i industrijskih voda kontaminiranih naftnim ugljovodnicima

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    Ovo tehničko reÅ”enje se odnosi na reÅ”avanje problema prečiŔćavanja industrijskih i podzemnih voda kontaminiranih naftnim zagađivačima. Ono daje prikaz kombinovane tehnike prečiŔćavanja voda kontaminiranih naftnim ugljovodonicima primenom mehanički tretiranog sorbenta na bazi koÅ”tica breskve (otpad iz industrije za preradu voća) koji pored uloge sorbenta imai ulogu nosača mikroorganizama u bioloÅ”kom procesu remedijacije.Š¢ŠµŃ…Š½ŠøчŠŗŠ¾ рŠµŃˆŠµŃšŠµ ŠøŠ· ŠŗŠ°Ń‚ŠµŠ³Š¾Ń€ŠøјŠµ Šœ8

    Study of heavy metals biosorption on native and alkali-treated apricot shells and its application in wastewater treatment

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    Locally available apricot (Prunus armeniaca L.) shells classified as a waste product from fruit processing, were alkali activated in order to develop an efficient heavy metal ions sorbent for water purification. To examine the changes occurred after alkali treatment, raw (SH) and modified apricot shells (SHM) were thoroughly characterized in terms of their chemical composition and surface properties. Chemical analysis revealed that alkaline treatment causes the disintegration of hemicellulose (its content decreased from 19.2 to 3.5%), which was in accordance with FTIR results. SEM micrographs and the mercury intrusion porosimetry revealed a larger surface area and porosity of SHM. Bohem's acid-base titration method indicated that the most of the SHM surface carboxylic groups were in sodium salt form and together with the pH of points of zero charge showed increase of surface alkalinity after modification. Treatment with NaOH enhanced the adsorption capacity by 154, 61 and 90% for Cu2+, Zn2+ and Pb2+, respectively. The amount of cations released from SHM was almost equal to the amount of adsorbed metal ions, suggesting ion exchange mechanism. The pseudo-second order kinetic indicated that the heavy metals cations were bound predominantly by complexation. In order to establish the effectiveness of the biosorbent in real wastewater sample, SHM was employed for cleaning-up of drain water emanating from atomic adsorption spectrophotometer. The SHM showed high removal efficiency towards multiple metal ions. The amounts of Fe, Pb, Cu and Cr ions were reduced by 97, 87, 81 and 80%, respectively, while Ni and Zn amounts were reduced for 33 and 14%. Used biosorbent SHM can be successfully regenerated with HCl (desorption gt 95%) and after regeneration biosorbent can be reused or it can be safely disposed. (C) 2018 Elsevier B.V. All rights reserved.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/2969]Peer-reviewed manuscript: [http://cherry.chem.bg.ac.rs/handle/123456789/2970

    Pb(II) removal from aqueous solution by Myriophyllum spicatum and its compost: equilibrium, kinetic and thermodynamic study

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    BACKGROUND Lead is one of the frequent contaminants of industrial wastewater. Since it has been shown that aquatic plants can be used for the removal of heavy metals, herein Pb(II) biosorption by Myriophyllum spicatum and its compost were investigated. Effects of pH, ionic strength and contact time were analyzed using a batch experiment. Biomasses were characterized chemically and by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction techniques. RESULTS The adsorption process of both biosorbents followed a pseudo-second-order kinetic model. Compost exhibits better Pb(II) removal from solution (71%) compared with the plant (61%). Lead binding capacities for M. spicatum and its compost were 0.234 mmol g(-1) and 0.287 mmol g(-1) at pH 5.0, respectively. Lead binding takes place mainly through an ion exchange mechanism, but chemisorption via identified functional groups cannot be neglected. The Langmuir, Freundlich and Sips adsorption models for compost were applied. The Sips isotherm model gave the best fit with the equilibrium experimental data. The sorption process by compost was endothermic and spontaneous. CONCLUSION Aquatic weed compost as a low cost biosorbent with high biosorption capacity can potentially be used for the removal of lead from wastewaters

    Influence of pH value on Cu (II) biosorption by lignocellulose peach shell waste material

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    In the last decade, the pollution made by anthropogenic sources has reached large amounts with special attention on heavy metals because of their high toxicity, persistence and bioaccumulation tendency. Since the conventional methods for their removing are either too expensive or create large quantities of toxic sludge, the great attention has been paid to the new technologies such as biosorption, technology that use cheap, abundant, organic waste for sequestering pollutants from contaminated mediums. Among the other factors that affect biosorption process, pH value is one the most important because it directs both the metal solution chemistry as well as the activity of the biomass functional groups. In this paper the influence of pH value on biosorption of Cu (II) by unmodified low-cost lignocellulose biosorbent - peach shell (PS) particles, have been studied. The chemical composition of PS, point of zero charge (pHPZC) as well as its surface morphology is also presented. Results have showed that this biosorbent contains mainly cellulose and lignin, the components that carry the functional groups responsible for metal binding. Its multilayer surface contains many pores and channels that help diffusion in deeper layers and force biosorption process. Point of zero charge determination was performed with three different KNO3 ionic strengths: 0,1M, 0,01M and 0,001M. The obtained value for pHPZC was 4,75Ā±0,1 and showed that this biosorbent is non-sensitive to ionic strength of electrolyte applied. Biosorption experiments were done with peach shell particles whose diameter was -0,5+0,1mm at 25oC . The initial copper (II) concentration was 50 mg/dm3 while the biosorbent concentration was 10g/dm3. Experiments were done with and without keeping pH constant. The influence of pH on biosorption process was examined in 2-6 pH range. The percentage of Cu (II) removed by PS, reaches its maximum at pH 6, with the 90,43% removing but this percentage can also be attributed to precipitating of metal at this pH value. However, under the same operational conditions, but at pH 2, the retention of copper is equal to 2,62%. The results also indicate that it is necessary to lead the biosorption process with keeping pH constant all the time, since the copper removal was about 46 % less when the pH value was not kept constant during the biosorption process. The pH value obtained as optimal was slightly higher than pHPZC value which indicates that electrostatic attraction is one of the possible binding mechanisms in biosorption process. The results have showed that the removal of Cu (II) with peach shell particles is very sensitive to solution pH and that this parameter should be thoroughly investigated and strongly controlled during the whole removal process

    Compost of Aquatic Weed Myriophyllum spicatum as Low-Cost Biosorbent for Selected Heavy Metal Ions

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    Aquatic weed Myriophyllum spicatum L. is one of the most invasive water plants known. In many countries, it is usually harvested and landfilled, where aerobic and anaerobic decomposition takes place. In this research, the kinetic, equilibrium, and desorption studies of biosorption of Pb(II), Cu(II), Cd(II), Ni(II), and Zn(II) ions onto compost of M. spicatum were investigated in batch experiments. Biosorbent was characterized by scaning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). SEM analysis showed that ion exchange between divalent cations Ca(II) and selected metals takes place. The results of FTIR exposed that carbonyl, carboxyl, hydroxyl, and phenyl groups are main binding sites for those heavy metal ions. The rate of adsorption of the five heavy metals was fast, which achieved equilibrium in 40 min, and followed the pseudo-second-order model well. Langmuir, Freundlich, and Sips equilibrium adsorption models were studied, and Sips isotherm gave the best fit for experimental data. Desorption by 0.1 M HNO3 did not fully recover the metals sorbed onto the compost, indicating that reusing this material as biosorbent is not possible. Furthermore, the use of spent biosorbent as a soil fertilizer is proposed

    Usefulness of ANN-based model for copper removal from aqueous solutions using agro industrial waste materials

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    The purpose of this study was to investigate the adsorption properties of locally available lignocelluloses biomaterials as biosorbents for the removal of copper ions from aqueous solution. Materials are generated from juice production (apricot stones) and from the corn milling process (corn cob). Such solid wastes have little or no economic value and very often present a disposal problem. Using batch adsorption techniques the effects of initial Cu(II) ions concentration (Ci), amount of biomass (m) and volume of metal solution (V), on biosorption efficiency and capacity were studied for both materials, without any pre-treatments. The optimal parameters for both biosorbents were selected depending on a highest sorption capability of biosorbent, in removal of Cu(II). Experimental data were compared with second order polynomial regression models (SOPs) and artificial neural networks (ANNs). SOPs showed acceptable coefficients of determination (0.842 - 0.997), while ANNs performed high prediction accuracy (0.980-0.986) in comparison to experimental results. [Projekat Ministarstva nauke Republike Srbije, br. TR 31003, TR 31055
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