Çevre Mühendisliği Bölümü Makale Koleksiyonuhttps://hdl.handle.net/20.500.12418/6492024-03-28T17:55:33Z2024-03-28T17:55:33ZSulu çözeltilerden tetrasiklin giderimi için alg bazlı yeşil biyokompozit sentezi: kinetik, denge ve termodinamik çalışmalarGüler, Ülker AslıTürkay, Mervehttps://hdl.handle.net/20.500.12418/147082024-03-05T21:47:25Z2023-01-01T00:00:00ZSulu çözeltilerden tetrasiklin giderimi için alg bazlı yeşil biyokompozit sentezi: kinetik, denge ve termodinamik çalışmalar
Güler, Ülker Aslı; Türkay, Merve
Bu çalışmada, aljinat bazı kullanılarak Spirulina sp. biyokütlesinden boncukların geliştirilmesi ve sudaki tetrasiklinin giderimi için adsorbent potansiyellerinin değerlendirilmesi amaçlanmıştır. Bu amaçla biyokompozitin yeşil sentezi yapılmış ve karakterize edilmiştir. Kesikli sistemde yürütülen giderim çalışmalarında; tetrasiklin giderim verimine; çözelti pH’ının, biyokompozit miktarının, temas süresinin ve farklı sıcaklıklarda farklı başlangıç kirletici konsantrasyonunun etkisi çalışılmıştır. İzoterm çalışmalarından elde edilen verilere Langmuir, Freundlich ve 𝐷���−𝑅��� izotermleri uygulanmıştır. 25, 35 ve 45 oC için Langmuir izoterminden elde edilen Qm değerleri sırasıyla 108.95 mg/g, 191.25 mg/g ve 404.75 mg/g olarak bulunmuştur. Elde edilen biyokompozit, yüksek tetrasiklin biyosorpsiyonu ile ilişkili olabilecek hidrofobikliğe ve çeşitli fonksiyonel gruplara (CH2, C-N, C-O, CO3-2 vb.) sahiptir. Biyokompozitin yüksek Qm değerleri, π-π elektron-verici-alıcı etkileşimi ve fonksiyonel gruplar ile tetrasiklin molekülleri arasındaki kompleks oluşumu nedeniyledir. Tetrasiklin biyosorpsiyonu için determinasyon katsayıları dikkate alınarak yalancı ikinci derece model uygun bulunmuştur. Termodinamik verilerden; artan sıcaklıkla tetrasiklin biyosorpsiyonunun artması, biyosorpsiyon işleminin endotermik ve spontan bir yapıya sahip olduğunu göstermektedir. Sonuç olarak; sentezlenen alg bazlı yeşil biyokompozitin, tetrasiklini sulardan başarılı bir şekilde uzaklaştırmak için kullanılabileceği ortaya konulmuştur.
This study aimed to develop beads from biomass and evaluate their adsorbent potential for tetracycline removal from water. For this purpose, a green synthesis of the biocomposite was made and characterized. In the removal studies carried out in the batch system; the effects of solution pH, amount of biocomposite, contact time, and different initial pollutant concentrations at different temperatures on the efficiency of tetracycline removal were studied. Langmuir, Freundlich, and D-R isotherms were applied to the data obtained from isotherm studies. Qm values obtained from Langmuir isotherm for 25, 35 and 45 oC were found to 108.95 mg/g, 191.25 mg/g and 404.75 mg/g, respectively. The resulting biocomposite had hydrophobicity and various functional groups (CH2, CN, CO, CO3-2 vb.), which may be associated with high tetracycline biosorption. The high Qm values of the biocomposite are due to the π-π electron-donor-acceptor interaction and complex formation between functional groups and tetracycline molecules. Considering the determination coefficients for tetracycline biosorption, the pseudo-second order model was found suitable. From the thermodynamic data; the increase in tetracycline biosorption with increasing temperature indicates that the biosorption process has an endothermic and spontaneous nature. As a result; it has been demonstrated that the synthesized algae-based green biocomposite can be used to successfully remove tetracycline from water.
2023-01-01T00:00:00ZEvaluation of factors affecting tetracycline and diclofenac adsorption by agricultural soils using response surface methodologyGüler, Ülker AslıTuncel, ElizeErsan, Mehtaphttps://hdl.handle.net/20.500.12418/147072024-03-05T21:47:25Z2023-01-01T00:00:00ZEvaluation of factors affecting tetracycline and diclofenac adsorption by agricultural soils using response surface methodology
Güler, Ülker Aslı; Tuncel, Elize; Ersan, Mehtap
The adsorption process of the pharmaceutical pollutant in the soil is affected by its
physicochemical properties and soil properties. In this study, the factors affecting the
adsorption of tetracycline and diclofenac onto two different soils (S and M) were
investigated using response surface methodology (RSM). The RSM design was used
to optimize the five variable factors (pH (2–10), contact time (5–180 min), soil
amount (1–10 g/L), temperature (25–45 C)) on the adsorption of tetracycline and
diclofenac. The predicted optimal conditions obtained by RSM showed that pH was
the most important variable affecting the adsorption of tetracycline and diclofenac.
The optimum pH for the adsorption of tetracycline and diclofenac onto the soil samples
S and M were found to be 4 and 2, respectively. The adsorbed amounts of tetracycline
and diclofenac onto the soils S and M were calculated to be 14.82 mg/g,
12.43 mg/g, 189.40 mg/g, and 144.81 mg/g, respectively. In addition, the effects of soil
organic matter, salt, and divalent cations on the adsorption of tetracycline and diclofenac
onto soils were studied. The removal of soil organic matter slightly increased tetracycline
adsorption, while inhibiting diclofenac adsorption. The presence of salt and divalent cations
prominently suppressed the adsorption of tetracycline and diclofenac onto soils. A
possible complex mechanism was proposed for TC and DCF adsorption, including ion
exchange, electrostatic interaction, and some chemical bonds.
2023-01-01T00:00:00ZRemoval of Cr(VI) from tanning wastewater using chitosan-SDS complexes in PEUF: Optimization and analysis via response surface methodologyKÖKER BERK, SARIOĞLU CEBECİ MELTEM,https://hdl.handle.net/20.500.12418/146572024-03-05T21:47:24Z2023-01-01T00:00:00ZRemoval of Cr(VI) from tanning wastewater using chitosan-SDS complexes in PEUF: Optimization and analysis via response surface methodology
KÖKER BERK, SARIOĞLU CEBECİ MELTEM,
In this study, we addressed the removal of hexavalent chromium (Cr(VI)), a highly toxic and soluble anionic
heavy metal, using enhanced ultrafiltration (UF). The objective was to eliminate Cr(VI) species with molecular
weights beyond the retention capability of standard UF membranes and achieve their retention through the
incorporation of polymers and polymer-surfactant complexes within the UF membrane. Chitosan, a cationic
polymer, and sodium lauryl sulfate (SDS), an anionic surfactant, were used in this context. The Cr(VI) solution
was subjected to ultrafiltration in a laboratory-scale membrane cell, and its removal was assessed spectrophotometrically.
Polymer and surfactant structures were characterized using turbidity, electrical conductivity, SEMEDX,
and FTIR analyses. Experimental studies were conducted using the face-centered central composite design
(CCD) of the response surface methodology (RSM) to determine optimal removal and permeate flux values, as
well as to unveil the relationships between the studied factors and the resulting responses.
The results revealed that 100 % of the Cr(VI) species were removed from wastewater in the chitosan-based
polymer-enhanced ultrafiltration (PEUF) study. With the chitosan-SDS complex, a removal efficiency of 98.33
% was achieved in synthetic wastewater. The PEUF study employing chitosan and the chitosan-SDS complex
yielded permeate flux values of 30.73 L/h/m2 and 53.89 L/h/m2, respectively. The optimized conditions obtained
from the models were then applied to real wastewater obtained from a leather industry tanning process. In
the case of chitosan and the chitosan-SDS complex, the Cr(VI) removal efficiencies in the real wastewater were
4.40 % and 98.33 %, respectively.
2023-01-01T00:00:00ZTREATMENT OF WASTE METALWORKING FLUIDS BY COAGULATION AND CROSS-FLOW MEMBRANE FILTRATIONKÖKER BERK, SARIOĞLU CEBECİ MELTEM,https://hdl.handle.net/20.500.12418/146562024-03-05T21:47:24Z2023-01-01T00:00:00ZTREATMENT OF WASTE METALWORKING FLUIDS BY COAGULATION AND CROSS-FLOW MEMBRANE FILTRATION
KÖKER BERK, SARIOĞLU CEBECİ MELTEM,
The primary objective of this study was to treat waste metalworking fluids (MWFs) originating from the metalworking industry. To
achieve this goal, a series of treatment methods were employed in sequence, and various parameters were analyzed, including
chemical oxygen demand (COD), pH, total suspended solids (TSS), turbidity, oil/grease, total organic carbon (TOC), and
biochemical oxygen demand (BOD). In the initial stage of wastewater pre-treatment, cross-flow microfiltration (MF) and chemical
coagulation using FeCl2•4H2O as the coagulant were implemented. The results revealed that the MF membrane (TM10) exhibited
removal efficiencies of 67.2% for COD, 93.2% for suspended solids (SS), 99.3% for turbidity, and 98.6% for oil/grease. On the
other hand, coagulation with ferric chloride achieved removal rates of 24.9% for COD, 66.8% for SS, 50.2% for turbidity, and
91.6% for oil/grease. Clearly, the TM10 MF membrane was more effective in the pre-treatment stage. Following the pre-treatment,
the wastewater underwent further treatment using three different ultrafiltration (UF) membranes with molecular weight cut-offs
(MWCO) ranging from 1 to 10 kDa in a cross-flow system. The GE (1 kDa) membrane demonstrated the highest removal efficiency,
which was comparable to the GH (2 kDa) membrane. However, both the GH and GE membranes achieved fluxes of 25.58 and
20.43 L/m2/h at 6 bar pressure, respectively. For the final stage of treatment, the most efficient nanofiltration (NF) membrane (TS80)
achieved removal efficiencies of 96.2%, 99.9%, 100%, and 70.7% for COD, SS, oil/grease, and electrical conductivity (EC),
respectively. It was concluded that the NF filtrate could be reused as process water. This study successfully implemented a series
of treatment methods for waste metalworking fluids (MWFs), effectively removing various pollutants and providing potential
options for reusing the treated wastewater in the metalworking industry.
2023-01-01T00:00:00Z