Duygu Ozdes

A boric acid-activated carbon derived from Scots pine sawdust exhibited efficient phenol adsorption through multiple adsorption mechanisms, supported by linear/nonlinear modeling and artificial neural network prediction. Image generated using Google Gemini (Nano Banana).

Brevibacillus agri was immobilized onto an abundant natural clay through a simple synthesis route to develop a novel and efficient adsorbent for the removal of Pb(II) ions from aqueous media. The adsorption behavior of Brevibacillus agri-loaded clay (BLC) was evaluated using batch experiments by investigating the effects of initial solution pH, BLC dosage, contact time, initial Pb(II) concentration, temperature, 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 65.4 mg g-1. 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.

Tea waste-derived biochar magnetically modified with CoFe ₂ O ₄ enables ultrafast and efficient solid-phase extraction of Cd( ii ), Pb( ii ), and Ni( ii ) ions from environmental waters, offering a low-cost and sustainable adsorbent.

In the present research, a novel 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 FAAS.

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.

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.

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.

In the present investigation, the application of an organic coprecipitant, 2-[5,6-dichloro-2-(2-bromobenzyl)-1H-benzimidazole-1-yl]acetohydrazide (DIBBA), for separation and preconcentration of Cu(II) ions in fruit and water samples through a new carrier element free coprecipitation (CEFC) method was researched for the first time. Flame atomic absorption spectrometer (FAAS) was used for the analyses of Cu(II) ions. The main effective experimental factors such as solution pH, DIBBA quantity, waiting time, centrifuge speed and duration and volume of sample on the recovery efficiency of Cu(II) ions were explored in detail. Under the optimized conditions the preconcentration factor (PF), relative standard deviation (RSD), and limits of detection (LOD) was achieved as 50, 3.4 % and 0.44 ?g L-1, respectively. No interference effects were detected by virtue of the presence of various foreign ions. Satisfactory recoveries (in the range of 94.4 to 103.0 %) in the environmental sample matrix were acquired. After being validated the recommended selective, low cost, simple and rapid CEFC method by spike/recovery tests, it was properly implemented for the low levels detection of Cu(II) ions in sour cherry, mulberry, apple, and peach as fruit samples and stream and sea water samples without any significant matrix effects.

Günümüzde su kaynaklarını kirleten en önemli etmenlerden biri biyobirikme eğiliminde olan ve yerkabuğunda doğal olarak bulunan ağır metallerdir. Kurşun ve kadmiyum gibi bazı ağır metallerin çok düşük derişimlerde bile vücuda alınımı, kan bileşiminin bozulmasına, merkezi sinir sistemi fonksiyonlarında azalmaya ve akciğer, böbrek ve karaciğer gibi organlarda hasarlara neden olabilir. Bu nedenle ağır metal iyonlarının, alıcı ortama verilmeden önce sulardan ve atık sulardan uzaklaştırılması gerekmektedir. Bu çalışmada, Cd(II) iyonlarının sulardan ve atık sulardan adsorpsiyon tekniğiyle gideriminde etkili ve ucuz bir adsorban olarak kızılçam (Pinus Brutia Ten.) talaşının kullanılabilirliği değerlendirilmiştir. Adsorpsiyon deneylerinde kullanılan kızılçam talaşı fiziksel veya kimyasal herhangi bir ön işleme tabi tutulmadan doğal olarak kullanılmıştır. Kızılçam talaşı, çeşitli yöntemlerle karakterize edildikten sonra adsorpsiyon verimi üzerine başlangıç sulu çözelti pH’ı, denge süresi, adsorban miktarı ve başlangıç Cd(II) derişimi gibi deneysel faktörlerin etkileri incelenmiş ve ayrıca endüstriyel atık sularda Cd(II) iyonlarıyla birlikte bulunabilecek bazı tuzların etkileri araştırılmıştır. Elde edilen sonuçlardan optimum pH 6.0 ve denge süresi 240 dk olarak belirlenmiştir. Mekanizma hakkında fikir edinmek için elde edilen verilere izoterm modelleri (Langmuir ve Freundlich) uygulanmıştır. Kızılçam talaşının maksimum adsorpsiyon kapasitesi Langmuir izoterm modeli kullanılarak 11.88 mg g-1 olarak hesaplanmıştır. Sonuç olarak kızılçam talaşının atık sulardan Cd(II) iyonlarının uzaklaştırılmasında etkili bir adsorban olarak kullanılabileceği ortaya konulmuştur.

Bu çalışmada, canlı metabolizmasında toksik etki gösteren katyonik yapıda boyarmadde olan Rodamin 6G’nin (R6G) sulardan ve atık sulardan uzaklaştırılmasında doğal karaağaç (Ulmus glabra) (UGT) ve dut (Morus alba) (MAT) talaşlarının ucuz ve etkili adsorbanlar olarak kullanılabilirliği araştırılmıştır. R6G’nin gideriminde adsorban olarak literatürde ilk defa bu çalışmada kullanılan UGT ve MAT çeşitli yöntemlerle karakterize edilmiştir. Adsorpsiyon deneyleri kesikli sistemle yürütülmüş olup, R6G’nin adsorpsiyon verimi üzerine başlangıç sulu çözelti pH’ı, denge süresi ve başlangıç R6G konsantrasyonu gibi deneysel parametrelerin etkileri incelenmiştir. R6G’nin her iki adsorban üzerine adsorpsiyonu için optimum sulu çözelti pH’ının 7.0 ve denge süresinin 180 dakika olduğu görülmüştür. Adsorpsiyon mekanizmasının aydınlatılabilmesi için elde edilen deneysel verilere çeşitli kinetik (yalancı birinci ve ikinci mertebeden kinetik model ile parçacık içi difüzyon modeli) ve izoterm modelleri (Langmuir, Freundlich, Temkin ve Dubinin-Radushkevich) uygulanmıştır. Adsorpsiyon kinetiğinin, ikinci mertebeden kinetik modeli takip ettiği ve deneysel verilerin hem Langmuir hem de Freundlich izoterm modellerine iyi bir uyum gösterdiği tespit edilmiştir. UGT ve MAT’in maksimum adsorpsiyon kapasitesi Langmuir izoterm modeli kullanılarak sırasıyla 50.5 ve 31.8 mg g-1 olarak hesaplanmıştır. Yapılan çalışma sonucunda karaağaç ve dut talaşının boyarmadde gideriminde kullanılacak etkili ve düşük maliyetli alternatifler olabileceği görülmüştür.