Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Removal of Pb(II) ions from aqueous solutions by Brevibacillus agri-loaded clay: Kinetic, isotherm, and artificial neural network modeling
Belduz, Ali Osman; Inan, Kadriye; Duran, Celal; Ozdes, Duygu; Ozeken, Sengul Tugba; Nalçaoğlu, Aleyna; Şeker, Serdal
In this study, a novel and efficient adsorbent was developed by immobilizing inactivated Brevibacillus agri biomass onto an abundant natural clay via a simple synthesis route for Pb(II) removal from aqueous media. The adsorption behavior of inactivated Brevibacillus agri-loaded clay (BLC) was evaluated using batch experiments by investigating the effects of initial solution pH (2.0–6.0), BLC dosage (0.5–4.0 g/L), contact time (1–180 min), initial Pb(II) concentration (10–420 mg/L), temperature (25–80°C), and the presence of foreign ions. The optimum conditions were determined to be an initial solution pH of 5.0 and a contact time of 120 min. Isotherm models were applied to elucidate the interactions between Pb(II) ions and BLC, while kinetic studies were conducted to evaluate the adsorption performance and underlying mechanisms. The maximum adsorption capacity of BLC was determined as 65.4 mg/g according to the Langmuir isotherm model. Thermodynamic parameters revealed that Pb(II) adsorption on BLC was exothermic, feasible, and spontaneous at 25ºC. Artificial neural network (ANN) studies provided highly accurate predictions by modeling and confirmed the reliability and applicability of the model for Pb(II) removal in industrial applications. This study presents an innovative and sustainable approach for heavy metal removal, offering an effective solution applicable to environmental remediation processes.
- MakaleAçık Erişim2026A novel cloud point extraction method using a benzimidazole-based ligand for the preconcentration of toxic heavy metals in water and food samples
Ozdemir, Olcay; Duran, Celal; Mentese, Emre; Ozdes, Duygu
In the present research, a novel cloud point extraction (CPE) method was developed for the separation and preconcentration of toxic Cu(ii), Ni(ii), Pb(ii), and Cd(ii) ions in environmental water and vegetable samples, prior to their determination by flame atomic absorption spectrometry (FAAS). The ligand 2-(2-(4-fluorobenzyl)-1H-benzo[d]imidazole-1-yl)acetohydrazide (FB-BIAH) was employed for the first time as an analytical complexing agent for the aforementioned metal ions, and Triton X-114 (TX-114) was preferred as the nonionic surfactant. Within the scope of optimizing CPE conditions, experimental parameters, such as pH, FB-BIAH and surfactant amounts, and incubation temperature and time, as well as centrifugation speed and duration, were systematically investigated. The optimal conditions for the simultaneous quantitative recovery of analyte ions were established as pH 7.0, an FB-BIAH amount of 2.5 mg, a TX-114 quantity of 25 mg, an incubation temperature of 60 °C, and an incubation time of 30 min. Under optimal conditions, the proposed method was successfully applied to river water and seawater, as well as different vegetable samples such as lettuce, parsley, and pepper. The results obtained demonstrated that the analyte ions could be reliably determined in complex matrices and that the method exhibited high analytical performance. Due to its simplicity, rapid applicability, environmentally friendly nature, and cost-effectiveness, the proposed CPE-FAAS method represents a promising approach for the routine analysis of toxic heavy metals in environmental water and food samples. This journal is
- MakaleAçık Erişim2026Enhanced cationic dye adsorption using Stenotrophomonas indicatrix -modified MnFe2O4: performance evaluation and adsorption mechanism
Ozdes, Duygu; Dede, Alper; Turfan, Fatma Asya; Seker, Serdal
In this study, MnFe2O4 magnetic nanoparticles were modified with the Stenotrophomonas indicatrix bacteria for the first time in the literature to develop an effective and novel bio-adsorbent for the remediation of toxic cationic dyes, specifically Rhodamine 6G (R6G) and Methylene Blue (MB), from contaminated aqueous media. MnFe2O4 and bacteria-loaded MnFe2O4 were thoroughly characterized using FTIR, XRD, and SEM-EDX analyses. XRD results confirmed that the cubic spinel structure of MnFe2O4 was preserved after bacterial modification, while FTIR spectra evidenced the successful incorporation of biological functional groups, including –NH, –OH, amide, and phosphate moieties, onto the nanoparticle surface. Adsorption performance of the dyes was evaluated in terms of parameters including aqueous solution pH, equilibrium time, bacteria-loaded MnFe2O4 dosage, and initial R6G and MB concentration. After investigating the effect of salt on adsorption efficiency, the applicability of the proposed adsorbent was assessed using real water samples. According to the experimental results, the optimum pH and equilibrium period for the uptake of both dyes were determined to be 8.0 and 60 min, respectively. Kinetic analyses showed that the pseudo-second order kinetic model exhibited a superior fit in representing the adsorption rates of both dyes, while isotherm studies indicated that both Langmuir and Freundlich isotherm models fit the experimental data well. While the adsorption capacities of pure MnFe2O4 for MB and R6G were 19.5 mg g− 1 and 15.3 mg g− 1, respectively, these values reached 67.6 mg g− 1 and 59.5 mg g− 1 for the bacteria-loaded MnFe2O4. The obtained data revealed that bacterial modification significantly increased the adsorption capacity of MnFe2O4, suggesting that the developed bio-adsorbent stands out as an effective and promising candidate for the remediation of dye-contaminated effluents.
- MakaleYayıncıda açık erişim2026Boric acid-activated carbon derived from Scots pine sawdust for phenol removal: adsorption mechanism, linear and nonlinear kinetic and isotherm modeling, and artificial neural network prediction
Ozdes, Duygu; Turfan, Fatma Asya; Seker, Serdal; Kavgaci, Gonca; Onal, Yunus
In this study, a sustainable activated carbon was successfully prepared from Scots pine sawdust via boric acid activation (H3BO3-AC-SPS) and evaluated for phenol adsorption from aqueous solutions. The physicochemical characteristics of the adsorbent were investigated using FTIR, SEM-EDX, XRD, and BET analyses, while the effects of solution pH, contact time, adsorbent dosage, initial phenol concentration, temperature, ionic strength, and reusability without regeneration on the adsorption performance were systematically examined. H3BO3-AC-SPS exhibited excellent adsorption performance over a wide pH range (5–8), showed good tolerance to coexisting inorganic ions and organic contaminants, and retained appreciable adsorption efficiency over five consecutive adsorption cycles without regeneration. Phenol uptake increased with temperature, and NaOH enabled partial desorption of phenol. The adsorption kinetics and equilibrium data were analyzed using both linear and nonlinear regression approaches and comparatively evaluated based on the coefficient of determination (R2), sum of squared errors (SSE), and root mean square error (RMSE). The pseudo-second order kinetic model and the Langmuir isotherm exhibited the best predictive performance, with the Langmuir model estimating a maximum adsorption capacity of 65.4 mg g−1. The adsorption mechanism may involve π–π interactions, hydrogen bonding, pore filling, and hydrophobic interactions. In addition, an artificial neural network (ANN) model accurately predicted the adsorption behavior, yielding a high correlation coefficient (R = 0.9789). The applicability of H3BO3-AC-SPS was further demonstrated in stream water and mining wastewater. These findings demonstrate that boric acid activation is an effective strategy for converting Scots pine sawdust into a high-performance adsorbent and that integrating linear and nonlinear adsorption modeling with statistical error analysis provides a reliable framework for interpreting adsorption behavior. This journal is
- MakaleAçık Erişim2026Waste to resource approach: CoFe2O4-modified spent tea waste for magnetic solid-phase extraction of toxic metal ions from water samples
Seker, Serdal; Ozdes, Duygu; Duran, Celal
In this research, within the framework of a waste-to-resource conversion approach, biochar obtained from spent tea waste (STWB), a widely available and cost-free biomass source, was modified with magnetic CoFe2O4 nanoparticles to develop an environmentally friendly adsorbent (CoFe2O4/STWB). The applicability of this material for efficient separation and preconcentration of Cd(ii), Pb(ii), and Ni(ii) ions from mining wastewater, stream water, and wastewater samples collected from an organized industrial zone was systematically investigated using the solid phase extraction (SPE) method. Optimization of the experimental variables was conducted to enhance the extraction performance of the target analyte ions. The fact that the adsorption and desorption equilibrium times occur in less than 1 min demonstrates the rapid and highly efficient extraction performance of the developed adsorbent. Langmuir isotherm model analysis revealed that CoFe2O4/STWB exhibits adsorption capacities of 69.4 mg g−1 for Cd(ii), 185.2 mg g−1 for Pb(ii), and 45.2 mg g−1 for Ni(ii). In contrast, the corresponding adsorption capacities obtained for unmodified STWB were considerably lower, with values of 42.9, 75.8, and 16.8 mg g−1 for Cd(ii), Pb(ii), and Ni(ii), respectively. These results clearly demonstrate that modification with CoFe2O4 significantly enhances the adsorption performance of STWB. Consequently, CoFe2O4-modified spent tea waste can be regarded as an effective, economical, and sustainable adsorbent for trace heavy metal analysis in environmental water samples, owing to its rapid extraction kinetics, high adsorption capacity, and low detection limits. This journal is
- MakaleYalnız künye2026Valorization of tea industry waste into boric acid–activated carbon for phenol removal from aqueous solutions
Duran, Celal; Ozdes, Duygu; Ozdemir, Olcay; Onal, Yunus; Gundogdu, Ali
The tea industry generates substantial quantities of solid waste with limited high-value industrial applications. In this study, tea industry waste was converted into boric acid-activated carbon (BA–TAC) through a simple one-step chemical activation process and evaluated as an adsorbent for phenol removal from aqueous solutions. BA–TAC exhibited a mixed micro–mesoporous structure with a BET surface area of 592.59 m2 g−1. The adsorption performance was investigated as a function of solution pH, contact time, and initial phenol concentration. Adsorption kinetics were evaluated using pseudo-first order, pseudo-second order, Elovich, Avrami, and intraparticle diffusion models, whereas equilibrium data were analyzed using Langmuir, Freundlich, and Sips isotherms. Linear, pseudo-linear, and non-linear regression approaches were comparatively evaluated, demonstrating the limitations of conventional linearization and the superiority of direct non-linear regression. Moreover, the so-called linearized forms of multi-parameter models such as Sips are not truly linear because iterative parameter estimation remains necessary. The maximum experimental phenol adsorption capacity reached 101.80 mg g−1 despite the moderate BET surface area of BA–TAC. The experimentally determined natural pH and pHpzc values, together with the limited desorption efficiency, indicated that adsorption was governed predominantly by surface chemical interactions rather than electrostatic attraction alone. XPS analysis confirmed the incorporation of boron-containing surface functionalities, highlighting their contribution to phenol adsorption. Overall, this study demonstrates the successful valorization of tea industry waste into a functional boron-modified activated carbon while providing methodological guidance for reliable adsorption kinetics and equilibrium modeling, thereby supporting sustainable waste valorization.
- MakaleAçık Erişim2026Selective Determination of Trace Co(II) and Cu(II) in Food and Environmental Matrices via Carrier Element-Free Coprecipitation Using a Novel Thiosemicarbazone-Derived Schiff Base
Bulut, Volkan N.; Demirci, Hamit; Ozdes, Duygu; Gundogdu, Ali; Bektas, Hakan; Soylak, Mustafa; Duran, Celal
A carrier element-free coprecipitation (CEFC) method was developed for the preconcentration and determination of trace Co(II) and Cu(II) in environmental and food samples using a novel thiosemicarbazone-derived Schiff base ligand (MBITAH). Unlike conventional coprecipitation approaches, the proposed strategy eliminates the need for inorganic carriers, reducing potential interferences and improving selectivity toward the target analytes. Under optimized conditions (pH 7.0, 1.5 mg ligand), quantitative recoveries were achieved with limits of detection of 1.16 and 0.79 µg L⁻1 for Co(II) and Cu(II), respectively. A preconcentration factor of 50 enabled sensitive determination by flame atomic absorption spectrometry (FAAS) with good precision (RSD ≤ 3.7%). The method exhibited good tolerance toward common matrix ions and was validated using certified-reference material (CRM-SA-C Sandy Soil C) and spike/recovery tests, showing agreement with certified values (p > 0.05). Its applicability was demonstrated in sea water, stream water, and food samples (red lentil and bulgur), confirming reliable performance in complex matrices. Compared with previously reported approaches, the proposed CEFC method offers a favorable balance between analytical performance, simplicity, and cost-effectiveness. In addition, greenness assessment using the AGREE tool yielded a score of 0.45, indicating a moderate-to-good level of environmental friendliness.
- MakaleAçık Erişim2025Removal of anionic and cationic dyes from aqueous solutions using drinking water treatment plant sludge (DWTS): Equilibrium and kinetic evaluation
Duran, Celal; Ozdes, Duygu; Turfan, Fatma Asya; Kılıç, Neslihan; Yaltirik, Fatma
The present research investigates the removal of Brilliant Green (BG) and Remazol Brilliant Blue R (RBBR) dyes by an adsorption system utilizing drinking water treatment sludge (DWTS) as an adsorbent. It aims to contribute to sustainable treatment methods by evaluating waste sludge as a low-cost and environmentally friendly adsorbent. In the study, the significant parameters affecting the adsorption process were systematically investigated. During the experiments, the effects of factors such as initial pH of the solution, equilibrium time, adsorbent amount and initial dye concentration on the adsorption efficiency were evaluated. The obtained data were tested with Langmuir and Freundlich isotherm models and it was determined that adsorption occurred on both homogeneous and heterogeneous surfaces. The maximum adsorption capacity of DWTS was calculated as 100.0 mg g-1 and 38.9 mg g-1 for BG and RBBR, respectively. Kinetic analyses were performed to understand the dynamics of the adsorption process. Pseudo-first order and Pseudo-second order kinetic models were evaluated and it was noticed that the pseudo-second order model explained the adsorption data better. As a result, DWTS has been proven to be an effective adsorbent in the removal of BG and RBBR. The findings indicated that DWTS has significant potential for evaluation in advanced treatment processes in terms of environmental sustainability.
- MakaleYalnız künye2025Determination of selection-focused physicochemical properties in the local Eğrisap pear (Pyrus communis L.) clone grown in Rize
Kalkisim, Ozgun; Aydin, Mehmet Zahit; Ozdes, Duygu; Duran, Celal
Turkey, located within the Western Asia gene center, is a significant genetic center for many fruit species, including pears. Rize, a province in the Northeastern part of Turkey, is located within the Northeast Anatolia Region, which falls within the genetic center area where pears have undergone evolutionary development. This study aimed to identify promising local Eğrisap pear clone genotypes with superior traits and to introduce them into economic use. For this purpose, Rize province and its districts were surveyed, and fruit and leaf samples were collected from pre-selected Eğrisap pear clone types. These samples were subjected to pomological, morphological, and chemical analysis. The JMP 13 statistical software package was used to compare the Eğrisap pear clone types. According to the research results, the pomological and morphological traits of the clone types varied as follows: fruit weight (99.10–139.54 g), fruit width (54.52–65.41 mm), fruit length (57.58–68.83 mm), fruit stem length (50.75–59.50 mm), fruit stem thickness (2.36–2.91 mm), core width (5.15–7.55 mm), core length (9.73–14.51 mm), flesh firmness (3.61–7.13 lb), seed number (5.30–8.55), leaf width (45.80–60.04 mm), leaf length (64.53–82.37 mm), petiole length (37.04–60.99 mm), petiole thickness (0.83–1.20 mm), and soluble solid content (SSC) (9.10 %-16.0 %). Regarding chemical composition, the pH values of the clone types ranged from (3.78–4.22), titratable acidity (0.22 %-0.47 %), protein content (1.50 %-4.95 %), vitamin C content (0.92–2.28 mg/100 g), ash content (1.16 %-4.30 %), and total sugar content (9.66 %-17.28 %). Mineral element analysis of the local pear varieties revealed that iron content ranged from (0–14.7 µg/g), copper (2.90–9.12 µg/g), manganese (2.9–11.6 µg/g), magnesium (321.7–771.5 mg/g), zinc (0 µg/g), sodium (9.6–39.6 µg/g), potassium (5.43–14.50 µg/g), calcium (50.1–219.7 µg/g), cobalt (0.01–0.31 µg/g), cadmium (0–0.1 µg/g), and nickel (0.08–4.41 µg/g). Among the local Eğrisap pear clones grown in Rize, clone type 53 IYD 01 was identified as having the most superior quality criteria and chemical composition. Consequently, it is recommended that this clone type be introduced to producers for cultivation.
- MakaleYayıncıda açık erişim2025Efficient extraction and determination of Au(iii) ions from acid mine drainage and water samples using silica gel immobilized with Brevibacillus borstelensis
Camoglu, Aslihan Yilmaz; Duran, Celal; Ozdes, Duygu; Nalcaoglu, Aleyna; Bektas, Kadriye Inan; Belduz, Ali Osman
The analysis of gold, which is a precious metal with limited resources, in environmental samples is crucial for the sustainable utilization of natural resources. Therefore, in the present research we have aimed to develop a novel and environmentally friendly bioadsorbent, Brevibacillus borstelensis loaded on silica gel (BB@Si), with outstanding adsorptive properties that can be implemented for quantitative recovery of Au(iii) ions via the solid phase extraction (SPE) technique. After characterizing the developed adsorbent using FTIR and SEM techniques, we conducted a detailed investigation of the critical parameters that influence the extraction performance of Au(iii) ions. Optimum parameters were observed as follows: pH 3.0, adsorption contact time 30 min, eluent type 0.1% (w/v) thiourea in 0.5 M HNO3, elution time 60 min, BB@Si amount 1.0 g L−1, and sample volume 400 mL. Some of the well-known isotherm and kinetic models were applied to the results observed from the adsorption studies. Equilibrium adsorption capacity of BB@Si was estimated to be 66.2 mg g−1 utilizing the Langmuir isotherm model while the limit of detection (LOD) and relative standard deviation (RSD%) were established as 0.99 μg L−1 and 3.7%, respectively. The developed method was utilized smoothly for the quantification of Au(iii) ions in mining wastewater, acid mine drainage (AMD), streams and seawater.
- MakaleYalnız künye2025Kinetics and Isotherm Evaluation for Adsorptive Removal of Anionic and Cationic Dyes from Aqueous Media by Sulfuric Acid-Modified Beech Sawdust
Ozdes, Duygu; Ozeken, Sengul Tugba; Top, Yener; Kalkisim, Ozgun; Duran, Celal
A novel and efficient adsorbent was prepared by modifying Fagus orientalis L. (beech) sawdust with H2SO4. The adsorption behavior of H2SO4-modified beech sawdust (SMBS) was investigated by batch experiments to offer a straightforward, inexpensive, and effective method for the retention of anionic and cationic model dyes, indigo carmine (IC) and methylene blue (MB), from wastewater. The experimental conditions were optimized by investigating the effects of the initial pH, initial concentrations of IC and MB dyes, dosage of SMBS, period of the contact, and the presence of salts in the aqueous media on the adsorptive performance of SMBS. The initial pH values of the aqueous solutions, from which IC and MB dyes will be removed, were optimized as 2.0 and 6.5 (natural), respectively. The optimum contact time for the adsorption of both dyes onto SMBS was determined to be 240 min. The mechanisms in the adsorption of IC and MB onto SMBS were investigated by evaluating the experimental data through different isotherm and kinetic models. The Langmuir isotherm model and pseudo-second order kinetic model performed well in explaining the mechanism of adsorption. Langmuir monolayer adsorption capacity of SMBS adsorbent was 38.85 mg g−1 for IC and 58.82 mg g−1 for MB. As a result, CMCP exhibited excellent performance in adsorbing organic pollutants, providing a low-cost and easily prepared alternative to other adsorbents found in the literature.
- MakaleAçık Erişim2025Insight into the adsorptive removal of Cr(VI) ions and 4-chlorophenol from aqueous media on cationic surfactant-modified cucumber peels
Ozeken, Sengul Tugba; Ozdes, Duygu; Duran, Celal
A new and cost-effective adsorbent material was developed by chemical modification of cucumber peels (CP) with a cationic surfactant, cetyltrimethylammonium bromide (CTAB). The adsorptive behavior of CTAB-modified cucumber peels (CMCP) was investigated in the retention of an organic pollutant (4-chlorophenol) and an inorganic pollutant (Cr(VI)) through batch experiments. The adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscopy (SEM) technique. Influences of initial concentrations of both pollutants, dosage of CMCP, initial solution pH, contact time, and foreign ions were parameters used to specify the optimized conditions. Results of the experiments were evaluated by three kinetic models, namely pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, to find out the dominant mechanisms in the retention of 4-chlorophenol and Cr(VI). Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were applied to the adsorption data to estimate the adsorption capacity of CMCP and to describe the interactions between the species. Langmuir isotherm model fitted the data well, and the maximum Cr(VI) and 4-chlorophenol adsorption capacities of CMCP were 84.03 mg g−1 and 107.5 mg g−1, respectively. Consequently, CMCP demonstrated outstanding performance in the adsorption of both inorganic and organic pollutants, offering a low-cost, easily prepared alternative to other adsorbents reported in the literature.
- MakaleAçık Erişim2025Sol–Gel Synthesized CuFe2O4-Modified Biochar Derived from Tea Waste for Efficient Ni(II) Removal: Adsorption, Regeneration, and ANN Modeling
Duran, Celal; Ozeken, Sengul Tugba; Seker, Serdal; Ozdes, Duygu
In the present research, a novel magnetic adsorbent was developed via the sol–gel method by coating CuFe2O4 nanoparticles on biochar sourced from brewed tea waste. The synthesized adsorbent was utilized for the removal of Ni(II) ions from aqueous media. The adsorption efficiency of Ni(II) ions was assessed under crucial experimental conditions such as initial solution pH, contact time, adsorbent dosage, and initial Ni(II) concentration. The adsorbent exhibited rapid adsorption kinetics, achieving equilibrium in approximately 15 min, and maintained high efficiency across a wide pH range. Adsorption experiments were conducted for Ni(II) solutions at their natural pH (5.6) to minimize chemical usage and enhance process simplicity. An impressive maximum adsorption capacity of 232.6 mg g−1 was recorded, outperforming many previously reported adsorbents. Furthermore, desorption studies demonstrated nearly 100% recovery of Ni(II) ions using 1.0 M HCl solution, indicating excellent regeneration potential of the adsorbent. Additionally, the prediction performance of an artificial neural network (ANN) model was evaluated to predict Ni(II) removal efficiency based on experimental variables, showing strong agreement with experimental data. Isotherm and kinetic models were also applied to the data to estimate the adsorption mechanisms. These findings demonstrate the promise of CuFe2O4-modified tea waste biochar for sustainable water treatment applications.
- MakaleYalnız künye2024Adsorption of Azocarmine G dye on H2SO4-modified acacia sawdust
Duran, Celal; Ozeken, Sengul Tugba; Camoglu, Aslihan Yilmaz; Ozdes, Duygu
Presence of hazardous dyes in water cause considerable risks to the human health and environment due to their potential toxicity and ecological disruptions. Therefore, in the present research, to suggest an alternative method for the retention of toxic Azocarmine G (ACG) dye from aqueous media, natural and H2SO4-modified acacia sawdust were performed for the first time as low-cost and efficient adsorbents. Based on batch experiments, it was determined that the best conditions for the developed dye retention process were an initial pH of 2.0 and an equilibrium time of 240 min. Analysis of the data using both pseudo-first order and pseudo-second order kinetic models showed that the retention of ACG onto the adsorbents predominantly occurred through chemical adsorption. Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models were employed to provide insights into the interaction between the adsorbate and adsorbent and the mechanism of the adsorption process. Maximum monolayer adsorption capacities of natural and H2SO4-modified acacia sawdust were determined as 28.01 and 64.90 mg g-1, respectively by Langmuir isotherm model. Results of the study clearly indicated that the modification of acacia sawdust with H2SO4 leads to a substantial increase in the adsorption performance of anionic dyes.
- MakaleYalnız künye2024Development of a New and Facile Carrier Element-Free Coprecipitation Procedure for Separation, Preconcentration and Sensitive Determination of Cu(II) and Cd(II) Ions in Water and Vegetable Samples
Duran, Celal; Ozdes, Duygu; Mentese, Emre; Bektas, Hakan
A facile and sensitive method predicated on carrier element free coprecipitation (CEFC) using 2-(2-(2-(4-bromobenzyl)-1H-benzo[d]imidazole-1-yl)acetyl)-N-ethylhydrazine-1-carbothioamide (BIMANEC) is reported for trace determination of Cu(II) and Cd(II) in vegetables and water. BIMANEC was used for the first time for the quantitative determination of these trace heavy metals. Flame atomic absorption spectrometer (FAAS) was used for quantitation. The preconcentration conditions were optimized with respect to pH (8.0), BIMANEC mass (4.0 mg), volume of sample (100 mL), standing time (5 min), and centrifugation time and rate (3 min and 2500 rpm). The influence of potentially interfering ions was scrutinized for the recovery of analyte ions. Under the optimum conditions, the limits of detection (LODs) were 0.51 and 2.28 µg L−1 for Cu(II) and Cd(II), respectively. The relative standard deviations were < 5% for both. The recoveries from the spiked vegetable samples were from 94.9 to 102.8% and from the spiked water samples between 93.2 and 101.6%. Consequently the developed new, facile, rapid, and highly efficient CEFC process was employed for the trace determination of Cu(II) and Cd(II).
- MakaleAçık Erişim2023Natural and H2SO4 modified plane sawdust as a low-cost adsorbent: Removal of anionic and cationic dyes from aqueous solutions
Duran, Celal; Kalkışım, Özgün; Ozdes, Duygu; Ozeken, Sengul Tugba; Top, Yener
Natural and H2SO4-modified plane (Platanus orientalis L.) sawdust were used for the adsorptive removal of cationic methylene blue (MB) and anionic indigo carmine (IC) dyes from aqueous media to suggest a new and cost-effective method for wastewater treatment applications. The influences of initial pH values, concentrations of MB and IC, period of contact, dosages of the natural and modified plane sawdust, and the presence of foreign ions on the adsorption of dyes were investigated in the experimental studies to describe the best conditions of the most efficient adsorption processes. Initial pH values were optimized to be between 6.0-8.0 for MB and 2.0 for IC. Experimentations of Boehm titration, FTIR analysis, pHpzc value, and moisture content determinations were utilized to characterize the natural and modified sawdust materials. Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models were used to evaluate the sorption mechanism. Maximum adsorption capacities of natural plane sawdust (NPS) and H2SO4-modified plane sawdust (MPS) calculated from the Langmuir isotherm model were 55.56 and 38.46 mg g-1 in MB adsorption, and 55.82 and 55.55 mg g-1 in IC adsorption, respectively. Results showed that the natural and H2SO4-modified plane sawdust serve as low-cost and efficient materials in the adsorptive removal of MB and IC dyes for industrial wastewater treatment applications.
- MakaleAçık Erişim2023Adsorptive removal of Cr(VI) and Cu(II) ions from aqueous solutions by a natural moss
Ozeken, Sengul Tugba; Ozdes, Duygu; Duran, Celal
The aim of the present research is to develop a new, fast, and easily applicable adsorption method for the removal of hazardous Cr(VI) and Cu(II) ions from the polluted industrial wastewater by using Racomitrium ericoides (Brid.) Brid. (REB), a type of moss. Although there are studies in the literature in which different moss species were used for the removal of heavy metals (HMs), REB was used for the first time in this study. Adsorption experiments were carried out through a batch system. The impact of significant experimental parameters showed that the optimum values of initial pH were 2.0 for Cr(VI) retention and 5.0 for Cu(II), and 360 min was selected as the optimum contact time for both HMs. An artificial neural network (ANN) model was applied to create a predictive model for the uptake efficiency of HMs. Adsorption kinetics of Cr(VI) and Cu(II) ions followed the pseudo-second order model. The maximum adsorption capacities of REB identified through the Langmuir model were 41.2 mg g-1 for Cr(VI) and 22.7 mg g-1 for Cu(II) ions. The results of the study demonstrated that REB can be utilized as an abundant, low-cost, and effective adsorbent in removal of HMs from aqueous solutions.
- MakaleAçık Erişim2023Adsorption Behaviour of EDTA Modified Magnetic Fe3O4 Coated Brewed Tea Waste on Cr(VI) Removal
Yilmaz Camoglu, Aslihan; Ozdes, Duygu; Duran, Celal
The study focused on fabricating a novel magnetic Fe3O4 loaded and EDTA modified brewed tea waste (TW-Fe3O4-EDTA) as a cheap, environmentally friendly, and efficient adsorbent for the removal of Cr(VI) ions from aqueous medium in a batch system. Characterization of the prepared adsorbent was performed with different techniques. Adsorption experiments were implemented at different conditions including initial solution pH (1.0–7.0), equilibrium time (1–480 min), adsorbent dosage (1.0–20.0 g L–1), and initial Cr(VI) concentration (50–1000 mg L–1). The optimum adsorption performance was observed at pH 2.0 with 120 min of contact time. Maximum adsorption capacity of 114.9 mg g–1 was acquired for TW-Fe3O4-EDTA which is much higher than the recently developed adsorbents for Cr(VI) removal. Adsorption process was well explicated by Freundlich isotherm model and the adsorption rate is described in accordance with pseudo-second order kinetic model. It was observed that common salts did not have a notable influence on Cr(VI) adsorption. The results of the study indicated that TW-Fe3O4-EDTA can be applied as an effective adsorbent in heavy metal removal as an alternative to many expensive adsorbents available in the literature.
- MakaleAçık Erişim2023A green and simplified approach for the quantitative and sensitive analysis of heavy metal ions in sea and stream waters
Duran, Celal; Camoglu, Aslihan Yilmaz; Ozdes, Duygu; Bekircan, Olcay
Elimination of the matrix effect is a major challenge in developing a method for the quantification of heavy metals (HMs) in water samples. In this regard, the current research describes the simultaneous analyses of Cu(II), Cd(II), and Ni(II) ions in water matrices through flame atomic absorption spectrophotometry (FAAS) after preconcentration with carrier element-free co-precipitation (CEFC) technique by the help of an organic co-precipitant, 3-{[5-(4-Chlorobenzyl)-3-(4-chlorophenyl)-1H-1,2,4-triazol-1-yl]-methyl}-4-[2,4-(dichlorobenzylidene)amino]-1H-1,2,4- triazole-5(4H)-thione (CCMBATT). Based on our literature research, CCMBATT was employed for the first time in this study as an organic co-precipitant for the preconcentration of HMs. Factors such as solution pH, concentration of co-precipitant, sample volume, standing time, centrifugation rate, and time were thoroughly examined and optimized to achieve the highest efficiency in terms of HM recovery. The limits of detection (LODs) (with 10 number of tests) of 0.54, 0.34, and 1.95 μg L-1 and the relative standard deviations (RSD %) of 2.1, 3.3, and 3.0 were determined for Cu(II), Cd(II) and Ni(II) ions, respectively. Recovery results of HMs for the spiked samples were in the range of 92.8-101.0%, demonstrating the trueness of the method and its applicability to the water samples matrix.
- MakaleAçık Erişim2023Enhancement of adsorptive removal efficiency of an anionic dye from aqueous solutions using carboxylic acid-modified mulberry leaves: Artificial neural network modeling, isotherm, and kinetics evaluation
Duran, Celal; Ozeken, Sengul Tugba; Camoglu, Aslihan Yilmaz; Ozdes, Duygu
Natural mulberry leaves and carboxylic acid-modified mulberry (Morus alba L.) leaves were used for the first time to scrutinize the effects of modification on the retention efficiency of an anionic dye (Remazol Brilliant Blue R (RBBR)) from aqueous solutions to suggest an economical and promising adsorbent for the treatment of dye-contaminated water. The characterization of the adsorbents was accomplished through common techniques including SEM, FTIR, and pHpzc determination. Several parameters studied in batch experiments pointed out that the initial pH of 2.0 and the contact time of 240 min were optimum conditions for all the developed RBBR uptake processes. An artificial neural network (ANN) model was applied to formulate a forecast model for the uptake efficiency of RBBR. The experimental data were assessed by different kinetic and isotherm models to explain the mechanism of the developed processes in more detail. Maximum monolayer adsorption capacities of natural mulberry leaves and acetic acid-, citric acid-, and oxalic acid-modified mulberry leaves were determined as 64.5, 95.2, 84.8, and 91.7 mg g1, respectively, by the Langmuir isotherm model. These results demonstrated that the modification with carboxylic acids significantly increases the anionic dye adsorption capacity of the mulberry leaves.