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Öğe A dual approach using response surface methodology and machine learning for optimization and enhancement of microalgae-based municipal wastewater treatment(Wiley, 2025) Kayan, İremsu; Ayman Öz, NilgünBACKGROUND Municipal wastewater comprises both organic and inorganic contaminants. Especially in rural areas, conventional municipal treatment plants primarily focus on carbon removal; therefore, nutrient removal should be prioritized for preventing environmental pollution. Mixotrophic microalgae such as Nannochloropsis sp. have significant potential for both carbon and nutrient removal. However, microalgae-based wastewater systems can be affected by many parameters and, using response surface methodology and decision tree, a machine learning model can help to determine the optimal conditions for the systems to operate more efficiently. RESULTS The optimal removal conditions were determined by response surface methodology to be a light period of 21 h at an intensity of 8000 lx and a temperature value of 30 °C. Under these optimal conditions, the respective removal efficiency for chemical oxygen demand, total organic carbon, total Kjeldahl nitrogen, and orthophosphate was 53%, 34%, 87%, and 70%, respectively. Chlorophyll-a concentration increased by as much as 49%. Real municipal wastewater was used instead of synthetic wastewater, yielding closer approximations to real situations. CONCLUSION The present study has underscored innovative, data-driven approaches as core in ensuring sustainable wastewater management and sets a useful framework for future research, which could be done with the aim of refining the methods to enhance efficiency in treatment. © 2025 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).Öğe Integrating response surface methodology and decision tree algorithms for valorization of cheese whey wastewater(Elsevier Science Inc, 2025) Kayan, İremsu; Ayman Öz, NilgünRecently, the potential of microalgae in wastewater treatment has attracted attention. The goal of this study is to find optimum conditions for microalgae growth and the concentration of cheese whey wastewater (CWW) to get the best treatment efficiency by using response surface methodology (RSM) and the decision tree algorithm for different pollutant parameters. The study used reactors with different amounts of CWW and Nannochloropsis sp. to find the best concentrations for each parameter. The best concentration of CWW was found to be 8000 mgCOD/L, and the best concentration of Nannochloropsis sp. microalgae was found to be 2200 mgVS/L. It was found that Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), Total Kjeldahl Nitrogen (TKN), and Orthophosphorus (Ortho-P) could be removed at different ranges, 77-96 %, 95-98 %, 51-97 %, and 60-99 % of CWW, respectively, depending on the different combinations of microalgae and CWW concentrations. The desirability values in RSM for COD, TOC, TKN, and Ortho-P parameters to be 0.99, 0.94, 0.78, and 0.63, respectively. The study suggests the marine microalgae (Nannochloropsis sp.) could be an alternative way to treat saline CWW, to create a circular economy. The machine learning (ML) method validates that RSM predictions are consistent and accurate. The results show that it is possible to combine traditional optimization methods with more advanced ML methods to facilitate the design and the operation of the treatment plants.Öğe The Role of Microalgae in Enhancing Anaerobic Digestion: A Bibliometric Review(Istanbul Univ Press, Fac Aquatic Sciences, 2025) Kayan, İremsu; Ayman Öz, NilgünAnaerobic digestion (AD) is a well-established and extensively explored technology for waste management. However, the literature review related to the effect of microalgae on biogas production in the anaerobic co-digestion with different substrates is limited. Using scientometric tools can offer valuable insights into research gaps and emerging trends, facilitate the updating of scientific datasets, and expand knowledge in this field. Therefore, this bibliometric review will focus on the investigation of the advancements, trends, and recent updates in the co-digestion of microalgae with different substrates. The Web of Science database was used for document selection, and the bibliometric analysis was conducted using the VOSviewer version 1.6.19 software. The findings of this study reveal that, up until 2024, the major focus areas in the field are environmental studies related to biogas production, emphasizing microbiological and engineering aspects. Key opportunities and trends identified include the integration of feedstock pretreatment before AD to enhance biogas yield and quality. Adding microalgae as a co-substrate in anaerobic reactors has emerged as a promising strategy to boost AD process efficiency. Microalgae contribute additional organic matter and nutrients for AD and provide environmental benefits such as carbon sequestration and wastewater treatment, aligning with Sustainable Development Goals (SDGs). Gaining a deeper understanding of the role of microalgae in the systems is essential to establishing AD as a profitable and sustainable waste management solution, offering substantial economic and environmental advantages.Öğe Life Cycle Assessment of Medical Waste Management: Case Study for Istanbul(MDPI, 2025) Çetin, Ender; Esenlikci Yıldız, İlknur Aysel; Öz Yaşar, Çiğdem; Yulistyorini, AnieThe amount of medical waste is anticipated to increase significantly with population growth. Ineffective medical waste management has resulted in adverse impacts on environmental and human health. Therefore, this study aimed to develop the current medical waste management strategy in Istanbul. GaBi Education version 7.3 was used to conduct a life cycle assessment (LCA) to compare the current medical waste management system (baseline scenario) with alternative scenarios including different proportions of waste disposal methods from an environmental perspective. Global warming, acidification, eutrophication, ozone layer depletion, freshwater aquatic ecotoxicity, and human toxicity were selected as the environmental impact categories found in CML 2001 within GaBi software. Scenarios with a higher proportion of incineration had more negative environmental impact, whereas the scenario incorporating waste segregation/minimization contributed to reducing the environmental impact. Therefore, Scenario 4 (waste segregation at the generation points/waste minimization + incineration + steam sterilization + landfill) presented the best environmental performance with the lowest total environmental impact value of 14.21% among all scenarios and was recommended as the most sustainable alternative for medical waste management in İstanbul.Öğe Chlorophenolic Compounds and Their Transformation Products by the Heterogeneous Fenton Process: A Review(John Wiley & Sons Ltd., 2021) Kantar, Çetin; Oral, ÖzlemChlorophenolic compounds are persistent contaminants commonly observed in contaminated soil and groundwater due to their high toxicity and low biodegradability. While the classical homogenous Fenton process suffers from high operating costs and excessive sludge formation, heterogeneous Fenton processes show a viable, cost-effective solution to the oxidative dehalogenation of chlorophenolic compounds due to the use of solid-based catalyst materials with much lower chemical costs and less sludge production. The catalyst materials used in the heterogeneous Fenton degradation of chlorophenols include monometallic iron materials (e.g. Fe oxides/sulfides, zero-valent iron), multimetallic iron composites, and iron catalysts with support material. This chapter covers an extensive review of papers regarding the applicability of heterogeneous Fenton processes to the treatment of chlorophenolic compounds under different operating conditions, including catalyst type, size, and dose, chlorophenol type, pH, H2O2 requirements, and reactor configurations. In addition, reaction intermediate species and their biodegradability are discussed.Öğe Airborne bacteria and sick building syndrome (SBS)(Elsevier, 2022) Menteşe, SibelAirborne bacteria are found ubiquitously in the environment, and they can induce mild to severe several adverse health effects in human beings. Hence, monitor and control of airborne bacteria is important for protecting the public health as well as occupational health and safety. Particularly with the start of rapid urbanization and tight energy conservation applications in the built environments, frequent complaints raised by the occupants of the buildings describe complex and significant nonspecific symptoms. Those buildings are called “sick, " and the symptoms associated with the occupancy in the “sick” building is called “sick building syndrome” (SBS). The main risk factor of SBS is that the symptoms are more likely associated with time spent in the building. Identification of potential source(s) of SBS requires building walkthrough, occupants’ questionnaires, and indoor environmental quality (IEQ) monitoring. Among many potential source contributors, recent studies found a positive linkage between airborne bacterial composition and SBS.Öğe Activation of zinc particles with 3-(N-morpholino)propanesulfonic acid buffer and ultrasound for nitrite reduction(Desalination Publications, 2023) Bute, Duygu Nur; Ayyıldız, ÖnderZinc (Zn0) is a potent zero-valent metal (ZVM) capable of promoting both oxidation and reduction reactions in water. Similar to other ZVMs, Zn0's reactivity is rapidly retarded in water. This study aims to improve the activation of zinc particles (Zn0) by ultrasound in aqueous solutions buffered with 3-(N-morpholino)propanesulfonic acid (MOPS). Nitrite (NO2-) was chosen as a model compound to evaluate the effectiveness of ultrasonic zinc-MOPS treatment (US/Zn0/MOPS). Under similar experimental conditions, the maximum percent nitrite removal by Zn0 (8 g/L) in MOPS buffered solutions was around 45%, but it increased above 99% when ultrasound was introduced at 220.5 W. Results obtained from scanning electron microscopy-energy-dispersive X-ray spectroscopy and X-ray diffraction measurements have suggested that during US/Zn0/MOPS treatment, nitrite was reduced to nitrogen gas (N2) while Zn0 was oxidized to Zn2+ and/or Zn(OH)2. The results also indicated that the high nitrite reduction achieved by the combined method was due to a joint effect of both catalysts on zinc activation.Öğe Predicting Drifting Polystyrene Degradation in World Oceans Based on Thermal Decomposition(Amer Chemical Soc, 2022) Kimukai, Hideki; Koizumi, Koshiro; Taguchi, Hiroyuki; Okabe, Akifumi; Takatama, Kohei; Chung, Seon Yong; Kwon, Bum Gun; Menteşe, SibelThe accumulation of plastic litter in natural environments has become a serious global issue. Since 1972, mega to micro/nanosized drifting plastics have been determined to be highly a significant pollutant in all oceans worldwide. To clarifying numerous problems such as entanglement or improper ingestion due to drifting and debris plastic, the amounts of currently drifting plastics should be determined. For this purpose, chemicals derived from polystyrene (PS) degradation were analyzed for 4000 sand and water samples taken from around the world including open sea sites (surface to 5000 m depth) during the period from 2000 to 2018. All styrene oligomers (SOs) of styrene (styrene monomer, SM), 2,4-diphenyl-1-butene (styrene dimer, SD2), and 2,4,6-triphenyl-1-hexene (styrene trimer, ST) were found to contain products from PS degradation. On the basis of survey SO values, 1.4 x 10(9) metric tons (MT) of SO were found to have been released into world oceans between 1950 and 2018. This SO subsequently underwent conversion to 2.7 x 10(6) MT of PS. Twenty percent underwent degradation, while 1.2 x 10(7) MT of PS apparently continued to drift about in ocean water. Drifting PS has been clearly shown not only to be crushed into micro/ nanoplastic particles but also to degrade into basic structural units of SOs constituting PS.Öğe Farklı inkübasyon koşullarının ve kültür ortamlarının havadaki bakteri ve mantar düzeyine etkisi(Pamukkale University, 2023) Palaz, Elif; Menteşe, Sibel; Bayram, Abdurrahman; Kara, Melik; Elbir, TolgaHavadaki bakteri ve mantarların örneklenmesinde kullanılan besiyerlerinin seçimi, bakteri ve mantarların nitel ve nicel olarak doğru belirlenmesine etki eden en önemli faktördür. Bu çalışmada, 8 ayrı besiyeri türü kullanılarak İzmir kent merkezi havasında eş zamanlı bakteri ve mantar örnekleri toplanmıştır. Bakteri örnekleri, Columbia blood agar (CBA), Chocolate agar (Choc), Tryptone Glucose Yeast Extract Agar (TGEA), Reasoner's 2A agar (R2A) ve Plate Count Agar (PCA) besiyerleri üzerinde toplanmış ve bu örneklere iki farklı inkübasyon sıcaklığı ve süresi uygulanarak bakterilerin gelişimi 2 gün boyunca 37 ᵒC ve 2 ile 15 gün arasında 50 ᵒC sıcaklıkta takip edilmiştir. Mantar örnekleri için ise Malt-Extract Agar (MEA), Dichloran Rose Bengal Chloramphenicol (DRBC) ve Potato Dextrose Agar (PDA) besiyerleri kullanılmıştır. Bunların tamamı ise 25 ᵒC’de 3-7 gün inkübe edilmiştir. İnkübasyon süreleri sonunda besiyerlerinde üreme gözlenen koloni sayıları ve toplam bakteri ve mantar konsantrasyonları belirlenmiştir. İnkübasyon sıcaklığının PCA hariç (p>0.05) diğer besiyerlerinde toplam bakteri konsantrasyonlarını etkilediği belirlenmiştir. Üç besiyerinde toplanan mantar örneklerinde en çok gözlenen cins Cladosporium sp’dir. Koloni sayıları bakımından besiyerleri PDA>MEA>DRBC şeklinde sıralanmıştır. Mantarlar arasında Chrysosporium sp. cinsinin MEA besiyerinde oluşturduğu koloni sayısı, PDA ve DRBC besiyerlerindekinden yaklaşık 10 kat daha fazladır. Eş zamanlı toplanan örnekler için kullanılan besiyerlerinde maksimum sayıda izole edilen mantar cinsi sıralaması MEA>DRBC>PDA şeklindedir. Bu çalışma, incelediği besiyeri ve inkübasyon koşulları çeşitliliği ile gelecekte kentsel bölgelerde yapılacak bakteri ve mantar örneklemelerine yön göstereceği gibi ekstrem koşullara (50 ᵒC) dayanabilen havadaki dirençli mikroorganizmaların farklı inkübasyon koşulları altında konsantrasyonlarının belirlendiği ilk çalışma niteliğindedir. Ayrıca, bu çalışma son yıllarda Dünya Sağlık Örgütü’nün Antimikrobiyal Direnç tehdidine karşı ülkeleri mücadeleye davet etmesi sebebiyle de önemlidir.Öğe Preparation of Poly(Humic Acid) Particles and Their Use in Toxic Organo-Phenolic Compound Removal from Aqueous Environments(Springer International Publishing Ag, 2014) Sağbaş, Selin; Kantar, Çetin; Şahiner, NurettinParticles derived from humic acid, as p(HA), are synthesized in a single step via a water-in-oil microemulsion system employing different cross-linkers such as divinylsulfone (DVS), glutaraldehyde (GA), epichlorohydrine (ECH), and adipochloride (AC). The different phenolic groups on humic moieties are connected via these cross-linkers to form particles. The prepared p(HA) particles were successfully used in the removal of toxic organo-phenolic such as phenol (Ph), 4-nitrophenol (4-NPh), 4-chlorophenol (4-CPh), 2-chlorophenol (2-CPh), and 2,3-dichlorophenol (2,3-CPh) from aqueous environments. Various parameters such as pH, contact time, reusability of particles, and the initial concentration of adsorbate are investigated. It is found that the absorption capacity of p(HA) particles for Ph is 180 mg/g, and the maximum absorption amount is obtained at pH 6. Furthermore, the reuse experiments are shown that p(HA) particles can release the absorbed Ph by the treatment of methanol, and an absorption capacity of 85 % is attainable up to five consecutive absorption and release cycles. p(HA) particles are characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta potential, thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) techniques.Öğe Effect of macronutrients (carbon, nitrogen, and phosphorus) on the growth of Chlamydomonas reinhardtii and nutrient recovery under different trophic conditions(Springer Heidelberg, 2023) Öz Yaşar, Çiğdem; Fletcher, Louise; Camargo-Valero, Miller AlonsoMore stringent discharge standards have led to the development of an alternative nutrient recovery system from wastewater. Microalgae cultivation in wastewater treatment works has presented considerable promise from the perspective of sustainable resource management. Growth kinetics models are useful tools to optimize nutrient recovery from wastewater by algal uptake. Therefore, this research aims to identify the growth kinetics of Chlamydomonas reinhardtii under both heterotrophic and phototrophic conditions with different nutrient concentrations that typify those found in wastewater treatment works. In addition, the effects of macronutrients (C, N, and P) on heterotrophic and phototrophic microalgae growth and nutrient recovery were studied. Greater specific growth rates were achieved under heterotrophic conditions than in phototrophic cultivation. The maximum specific growth rates and nutrient recovery efficiencies were achieved at 5 mg P L-1 under both heterotrophic and phototrophic growth conditions. Nitrate was the preferred form of nitrogen source under heterotrophic conditions, while nitrogen sources did not present any significant influences in the phototrophic cultivation. Specific growth rates reported for both heterotrophic and phototrophic microalgae at lower carbon concentrations (3.10 d(-1) and 0.46 d(-1), sequentially) were higher than those at higher carbon concentrations (1.95 d(-1) and 0.22 d(-1), respectively). C. reinhardtii presented an extreme capacity to adapt and grow at all experimental conditions tested in heterotrophic and phototrophic cultivations.Öğe Sono-degradation of Reactive Blue 19 in aqueous solution and synthetic textile industry wastewater by nanoscale zero-valent aluminum(Academic Press Ltd- Elsevier Science Ltd, 2022) İleri, Burcu; Dogu, İremReactive dyes, which are commonly used in the textile industry, are toxic and carcinogenic for the ecosystem and human health. The objective of this study was to investigate the removal of Reactive Blue 19 (RB19) from aqueous solution and synthetic textile industry wastewater using nanoscale zero-valent aluminum (nZVAl), ultrasonic bath (US-40 kHz), and combined US/nZVAl through the consideration of varying experimental parameters such as pH, nZVAl dosage, contact time, and initial RB19 dye concentration. The acidic pH value was an effective parameter to degrade RB19. As the nZVAl dosage and contact time increased, the degradation of RB19 dye from aqueous solution and synthetic textile industry wastewater increased using combined US/nZVAl process. A similar result was obtained for RB19 removal with combined US/nZVAl using 0.10 g dosage at 30 min, whereas it was obtained with nZVAl alone using 0.20 g dosage at 60 min. The sono-degradation process activated the nZVAl surface depending on US cavitation effect and shock waves, and increased RB19 dye uptake capacity with a shorter contact time and lower nZVAl dosage. Increasing the initial dye concentration decreased the removal efficiency for RB19. According to the obtained reusability results, nZVAl particles could be reused for four and two consecutive cycles of combined US/nZVAl and nZVAl alone, respectively.Öğe Methylene blue treatment with zero-valent iron/pyrite/H2O2 system under static and continuous flow conditions: Reaction mechanism and toxicity evaluation(Elsevier Science Inc, 2024) Oral, Özlem; Arslan, Şevki; Doğan, Nazime Mercan; Yıldız, İlker; Kantar, Çetin; Abdelsalam, Amine Hafis; Kuzucu, VolkanLaboratory batch and continuous flow studies, coupled with surface and toxicity analysis, were performed to evaluate methylene blue treatment by heterogeneous Fenton process using zero-valent iron (ZVI) and pyrite as co-catalyst. The use of pyrite in batch reactors significantly enhanced methylene blue treatment by the ZVI/H2O2 system because of improved iron redox cycling. The continuous-flow experiments revealed that the reactor performance increased in the order of: ZVI/H2O2 < pyrite/H2O2 < ZVI/pyrite/H2O2 under dynamic flow conditions. The methylene blue treatment by the ternary ZVI/pyrite/H2O2 system was described by an initial degradation of methylene blue with *OH radicals, followed by the adsorption and/or co-precipitation of degradation intermediates with some spherical particles. The surface analysis showed that these spherical particles formed, even at pH less than 4. The genotoxicity and cytotoxicity tests performed on mouse embryonic fibroblast (3 T3-L1) and human embryonic kidney (HEK293) cell lines showed that the Fenton treatment of methylene blue using the ZVI/pyrite/H2O2 system resulted in the formation of degradation species with much lower toxicity levels relative to methylene blue. Moreover, the Fenton degradation species of methylene blue significantly enhanced the metabolic activity of several bacterial strains, including E. coli ATCC 8739 and P. aeruginosa PAO1.Öğe Seasonal variability of airborne mold concentrations as related to dust in a coastal urban area in the Eastern Mediterranean(Springer Heidelberg, 2023) Palaz, Elif; Menteşe, Sibel; Bayram, Abdurrahman; Kara, Melik; Elbir, TolgaRecent studies have demonstrated that the amount of specific airborne mold types and their concentrations increase during dust events. This study investigates the seasonal variation of airborne mold concentrations before, during, and after the dust transport in an eastern Mediterranean coastal area, Izmir city, Turkey. A total of 136 airborne mold samples were collected between September 2020 and May 2021. Two different culture media, namely Potato Dextrose Agar (PDA) and Malt-Extract Agar (MEA), were used for enumeration and genus-based identification of the airborne mold. In addition to culture media, the influences of air temperature, relative humidity, and particulate matter equal to or less than 10 µm (PM10) were also investigated seasonally. The HYSPLIT trajectory model and web-based simulation results were mainly used to determine dusty days. The mean total mold concentrations (TMC) on dusty days (543 Colony Forming Unit (CFU)/m3 on PDA and 668 CFU/m3 on MEA) were approximately 2–2.5 times higher than those on non-dusty days (288 CFU/m3 on PDA and 254 CFU/m3 on MEA) for both culture media. TMC levels showed seasonal variations (p < 0.001), indicating that meteorological parameters influenced mold concentrations and compositions. Some mold genera, including Cladosporium sp., Chrysosporium sp., Aspergillus sp., Bipolaris sp., Alternaria sp., and yeast, were found higher during dusty days than non-dusty days. Thus, dust event impacts levels and types of airborne molds and has implications for regions where long-range dust transport widely occurs.Öğe Assessment of physical carrying capacity of a mariculture zone designated in the Aegean Sea(Springer, 2024) Yiğit, Murat; Ergün, Sebahattin; Büyükateş, Yeşim; Ateş, Abdullah Suat; Özdilek, H. Göksel; Acar, SeçilThe present study was conducted to evaluate the physical carrying capacity in a mariculture zone designated for cage aquaculture in the Aegean Sea (Mersin Bay, Izmir, Turkiye). Rapid assessment of carrying capacity for the approval of new investments or capacity increase requests environment-regulated timely management procedures for the sustainable development of the drastically growing cage aquaculture industry in the Mediterranean. Hence, the mathematical estimations earlier developed for the Mediterranean area have been applied for the carrying capacity assessment using the data gathered from eight fish farms operating in the area. The data collected from the farms comprised the information such as current granted production level, surface area, location depth, current speed, shore distance, and coordinates of the farm sites. The results obtained showed an estimated carrying capacity for the investigated mariculture zone as 252,852 tons which is about 18 times the current production level of 13,500 tons that was granted in total for the sum of eight cage farms in the region with a total of 50.89-ha surface area. It can be concluded that, with the condition of periodic environmental monitoring to keep the marine ecosystem below eutrophication risk, the production capacity of farms in the designated mariculture zone, comprising a surface area of 50.89 ha, could be increased by 18-fold over the present production level, which is far below the risk threshold. The findings of this study provide important support for decision-makers in the management of intensive cage aquaculture operations in the Mediterranean region.Öğe Effect of pyrite on the treatment of chlorophenolic compounds with zero-valent iron-Fenton process under uncontrolled pH conditions: reaction mechanism and biodegradability(Springer, 2024) Oral, Özlem; Kantar, Çetin; Yıldız, İlkerThis current study explored the effect of pyrite on the treatment of chlorophenolic compounds (CP) by Fenton process with micron-sized zero-valent iron (ZVI) as the catalyst. The experiments were conducted in batch reactors with 100 mg L?1 CP, 0–0.02 M H2O2, and variable pyrite and ZVI doses (0–1 g L?1). Our findings show that while the reactor with 1 g L?1 ZVI as the only catalyst achieved only 10% CP removal efficiency due to rapid ZVI surface passivation and ZVI particle aggregation, the CP removal efficiency increased with increasing pyrite dose and reached 100% within couple of minutes in reactors with 0.8 g L?1 pyrite and 0.2 g L?1 ZVI. The CP removal was mainly driven by the oxidative treatment of CPs with some strong radicals such as hydroxyl radicals (•OH) while the adsorption onto the catalyst surface was only responsible for 10 to 25% of CP removals, depending on the type of CP studied. The positive impact of pyrite on CP removal by the ZVI/H2O2 system could be attributed to the ability of pyrite to (1) create an acidic environment for optimum Fenton process, (2) provide support material for ZVI to minimize ZVI particle agglomeration, and (3) stimulate iron redox cycling for improved surface site generation. Following oxidative Fenton treatment, the degradation intermediate products of CPs, including some aromatic compounds (benzoquinone, hydroquinone, etc.) and organic acids (e.g., acetic acid), became more biodegradable in comparison to their mother compounds. Overall, the treatment systems with a mixture of ZVI and pyrite as catalyst materials could offer a suitable cost-effective technology for the treatment of wastewater containing biologically non- or low-degradable toxic compounds such as chlorophenols. © The Author(s) 2024.Öğe Determination of Culturable Airborne Mold on Dusty Days in an Urban Atmosphere in the Eastern Mediterranean(Springer Nature, 2024) Palaz, Elif; Elbir, Tolga; Menteşe, Sibel; Bayram, Abdurrahman; Kara, MelikRecent studies have demonstrated that the amount of specific airborne mold types and their concentrations increase during dust events. This study investigates the effect of long-range dust transport on airborne mold composition between September 2020 and May 2021 in the urban atmosphere of Izmir, Turkey, a coastal city in the Eastern Mediterranean. A total of 136 airborne mold samples, 107 in non-dusty days and 29 in dusty days, were collected. Two different culture media, Potato Dextrose Agar (PDA) and Malt Extract Agar (MEA), were used to enumeration and genus-based identification of the airborne mold. Also, the effects of several meteorological parameters such as wind, air temperature and humidity, as well as particulate matter (PM10) concentrations, on the composition of airborne mold assemblages, were estimated seasonally. To determine the dusty and non-dusty days, several tools such as HYSPLIT Trajectory Model, NASA EOSDIS Worldview, WMO SDS-WAS North Africa-Middle East-Europe (NA-ME-E) and ECMWF CAMS Forecast Model were used. The total mold concentrations on PDA and MEA culture media ranged 49–1400 CFU/m3 and 28–1400 CFU/m3, respectively. Total mold concentrations that determined in PDA or MEA in spring and autumn were significantly higher than those occurred in winter, indicating that seasonal patterns of the meteorological parameters influenced the mold levels and genus prevalence in the region. Some of the mold genera, including Cladosporium sp., Chrysosporium sp., Aspergillus sp., Bipolaris sp., Alternaria sp. and yeasts, were more abundant during dusty days than non-dusty days. The correlation analysis showed a significant relation between airborne mold concentration, wind velocity and air temperature (p < 0.05). However, the relation between the total mold concentration and relative humidity (p > 0.05) was only significant in winter.Öğe Comparison of treatability of four different chlorophenol-containing wastewater by pyrite-Fenton process combined with aerobic biodegradation: Role of sludge acclimation(Academic Press, 2021) Kayan, İremsu; Ayman Öz, Nilgün; Kantar, ÇetinAerobic biodegradation combined with pyrite-Fenton process was used for the treatment of wastewater containing different chlorophenols (4-CP, 2,3-DCP, 2,4-DCP, 2,4,6-TCP). Fenton degradation using pyrite as the low cost iron catalyst was used as a pre-treatment step to lower the toxicity of CPs prior to aerobic biodegradation. Synthetic wastewater spiked directly with either 100 mg/L CPs or pyrite-Fenton pre-treated CPs was fed to the batch bioreactors inoculated with unacclimated or acclimated activated sludge using glucose as the C-source. The results show that the CP biodegradation under aerobic conditions was highly dependent on the type of CP treated. Except for 2,4-DCP, all other CPs investigated caused severe sludge toxicity, and thus significantly hindered glucose degradation by unacclimated sludge. The CP toxicity decreased in the order of: 2,4,6-TCP > 2,3-DCP > 4-CP > 2,4-DCP. The toxic effect was explained through an interaction of CPs with the lipid fraction of cell membrane. While the pyrite-Fenton pre-treatment improved the COD removal efficiency using unacclimated sludge, the sCOD removal efficiency was still less than the control reactor operated with no CP addition. With sludge acclimation, however, the sCOD removal efficiencies increased, and approached 74% for 2,4-DCP, 61% for 4-CP, 56% for 2,4,6-TCP and 46% for 2,3-DCP, suggesting an enhanced biomass tolerance to CP toxicity. On the other hand, the sludge acclimation combined with pyrite Fenton pre-treatment provided the best bioreactor performance for all CPs with the sCOD removal efficiencies reaching 81% for 2,4,6-TCP, 78% for 2,4-DCP, 73% for 4-CP and 62% for 2,3-DCP. This suggests that the dechlorination of CPs with Fenton process, in conjunction with sludge acclimation, not only reduced the sludge toxicity, but also enhanced the bioavailability of CP-containing wastewater for microorganisms, especially for highly chlorinated toxic CPs such as 2,4,6-TCP. Overall, the findings highlight the need for sludge acclimation for effective treatment of chlorophenol-containing wastewater by a combined pyrite-Fenton and aerobic biodegradation system.Öğe Hydrometallurgical recovery of neodymium from spent hard disk magnets: A life cycle perspective(Elsevier Ltd, 2021) Karal, Engin; Küçüker, Mehmet Ali; Demirel, Burak; Copty, Nadim K.; Kuchta, KerstinRare earth elements (REEs) are commercially used in an increasing number of critical or widely popular consumer and industrial products. Neodymium (Nd) element has emerged in recent years as one of the most critical REE, due to risks associated with its security of supply at required amounts. It has been widely reported that end of life (EoL) consumer electrical products contain significant amounts of metals and plastics. Thus, recovery of Nd from magnet scraps, EoL appliances or industrial applications is gaining even more strategic importance nowadays. In this study, an ex-ante life cycle assessment (LCA) of the hydrometallurgical recovery of Nd from waste electric and electronic equipment (WEEE) was conducted. The hydrometallurgical Nd recovery route consists of pretreatment, chemical leaching and Nd metal precipitation The feasibility and environmental performance of Nd metal recycling experiment model was investigated with an LCA scenario focusing on neodymium-iron-boron (Nd-Fe-B) magnet production. The LCA results were compared to that due to Nd-Fe-B magnet production from bastnäsite/monazite mineral ores using the traditional sintered magnet route. LCA sensitivity analysis and cost analysis were also performed. It was found out that, from both an economical and environmental point of view, magnet production from recovered Nd performed better than that of virgin magnet production. The scaled-up Nd metal recovery system reduced environmental impacts of Nd-Fe-B magnet production system by up to 65% for eight of the eleven environmental impact categories. Nd recycling reduced production cost from 8.55 to 3.98 USD/kg.Öğe Heavy Metal and Mineral Composition of Soil, Atmospheric Deposition, and Mosses with Regard to Integrated Pollution Assessment Approach(Springer, 2021) Menteşe, Sibel; Tonguç Yayıntaş, Özlem; Baş, Batuhan; İrkin, Latife Ceyda; Yılmaz, SelehattinThe fact that there are no real borders between the biosphere, atmosphere, lithosphere, and hydrosphere means that environmental pollution monitoring studies should not only include one of the environmental spheres. Thus, integrated environmental pollution assessment studies conducted in the biosphere, lithosphere, and atmosphere promote the “whole system” approach. In this study, the aim was to determine the pollution in the atmosphere, soil, and plants by taking advantage of the high pollution accumulation characteristics of the mosses. Prevailing wind has the potential to distribute pollutants emitted into the air throughout its path. With this regard, soil, mosses, and atmospheric deposition samples were collected in Çanakkale, Turkey, in two seasons. Concentrations of selected elements were measured by Inductively Coupled Plasma-Mass Spectrometry. The enrichment factor of the selected elements in the soil, moss, and deposition samples was calculated. The highest enrichments were found for Lead in atmospheric deposition, Arsenic in soil, and Mercury in moss samples. Cobalt and chromium accumulated more in mosses than in soil. Elevated arsenic levels found in the samples can pose a great risk for public health and agriculture. The study result showed that the elemental composition of the samples was influenced by the enhanced air plume dispersion of anthropogenic pollution sources along the Northeast-Southwest directions due to wind characteristics in the province. As expected, strong correlations were found among the moss, soil, and atmospheric deposition samples indicating the vital interactions between the environmental components.
