Environmental Engineering / Çevre Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4321
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Article Pomza ve Nsdd-pomza ile Sabit Yataklı Kolon Reaktörde Metilen Mavisi Giderimi: Deneysel ve Modelleme Çalışması(2019) Balcı, Esin; Ökten, Hatice Eser; Genişoğlu, Mesut; Recepoğlu, Yaşar Kemal; Gören, Ayşegül YağmurNano sıfır değerlikli demir (nSDD) yüksek renk konsantrasyonlarına sahip tekstil atıksularının arıtımında ekonomik ve çevre dostu bir adsorban olarak ortaya çıkmaktadır. Ancak nSDD partikülleri sulu çözeltilerde elektrostatik etkileşimler sebebiyle kolayca topaklaşmakta ve bu da arıtma veriminin düşmesine neden olmaktadır. Dolayısıyla düşük maliyetli, doğal poröz yapıda ve ortalama 2m2/gr spesifik yüzey alanına sahip pomza, nSDD topaklaşmasını önleyici bir malzeme olarak kullanılabilir. Bu çalışmada sadece pomza ve pomzanSDD (ağırlıkça 9:1) karışımının kullanıldığı kolon reaktörde 25, 50, 75 ve 100 mg/L metilen mavisi konsantrasyonları için arıtma verimleri incelenmiştir. Pomzanın ve pomza-nSDD karışımının 100 mg/L metilen mavisi deneyindeki toplam kapasiteleri sırasıyla 2,8 ve 4,2 mg/g-adsorban olarak bulunmuştur. Özellikle düşük konsantrasyonlarda, pomza-nSDD karışımının arıtma performansını önemli ölçüde arttırdığı görülmüştür. Thomas modeli deneysel verilere uygulanmış ve modelin öngörü gücünün düşük konsantrasyonda yüksekken, yüksek konsantrasyonlarda ortalama olduğu kanısına varılmıştır.Article Citation - WoS: 3Citation - Scopus: 6Halogenated By-Products in Chlorinated Indoor Swimming Pools: a Long-Term Monitoring and Empirical Modeling Study(Amer Chemical Soc, 2023) Genişoğlu, Mesut; Minaz, Mert; Tanacan, Ertaç; Sofuoğlu, Sait Cemil; Kaplan-Bekaroğlu, Şehnaz Şule; Kanan, Amer; Ateş, NurayMonitoring the disinfection process and swimming pool water quality is essential for the prevention of microbial infections and associated diseases. However, carcinogenic and chronic-toxic disinfection by-products (DBPs) are formed with reactions between disinfectants and organic/inorganic matters. DBP precursors in swimming pools originate from anthropogenic sources (body secretions, personal care products, pharmaceuticals, etc.) or chemicals used in pools. Temporal (48 weeks) water quality trends of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and halonitromethanes (HNMs) in two swimming pools (SP-A and SP-B) and precursor-DBP relationships were investigated in this study. Weekly samples were taken from swimming pools, and several physical/chemical water quality parameters, absorbable organic halides (AOX), and DBPs were determined. THMs and HAAs were the most detected DBP groups in pool water. While chloroform was determined to be the dominant THM compound, dichloroacetic acid and trichloroacetic acid were the dominant HAA compounds. The average AOX concentrations were measured to be 304 and 746 mu g/L as Cl- in SP-A and SP-B, respectively. Although the amount of AOX from unknown chlorinated by-products in SP-A did not vary temporally, a significant increase in unknown DBP concentrations in SP-B was observed over time. AOX concentrations of chlorinated pool waters were determined to be an important parameter that can be used to estimate DBP concentrations.Article Citation - WoS: 13Citation - Scopus: 13Countrywide Spatial Variation of Potentially Toxic Element Contamination in Soils of Turkey and Assessment of Population Health Risks for Nondietary Ingestion(American Chemical Society, 2022) Gören, Ayşegül Yağmur; Genişoğlu, Mesut; Kazancı, Yiğithan; Sofuoğlu, Sait CemilCountrywide surface soil concentrations of potentially toxic elements (PTEs) in Turkey were reviewed in the Web of Science database. A total of 93 papers were investigated to compose a PTE dataset for determining spatial variations and estimating exposure and health risks. Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were selected as PTEs in surface soil. A compiled PTE concentration dataset was used to estimate chronic toxic risks (CTRs) and carcinogenic risks (CRs) according to the deterministic and probabilistic approaches. While the CTR and CR levels of age and sex groups were estimated using a deterministic approach, population risks were estimated using a probabilistic approach. CTR and CR levels in lower age groups and female sex groups were estimated to be higher than those in higher age groups and associated male sex groups. The average CTR levels of the nondietary ingestion of As-containing soil in <11 year age groups were near/just above the threshold level, while As-associated average CR levels of adults and other age groups were estimated to be in the acceptable risk range (10-6 < CR < 10-5) and low priority risk range (10-5 < CR < 10-4), respectively. As-, Cr(VI)-, and Pb-associated upper-bound CR levels of the Turkish population were simulated to be 5.14 × 10-4, 6.23 × 10-5, and 2.34 × 10-6, respectively. Health risk models show the significance of As in both chronic toxic and carcinogenic effects.Article Citation - WoS: 31Citation - Scopus: 35Electrochemical Degradation of Methylene Blue by a Flexible Graphite Electrode: Techno-Economic Evaluation(American Chemical Society, 2022) Gören, Ayşegül Yağmur; Recepoğlu, Yaşar Kemal; Edebali, Özge; Şahin, Çağrı; Genişoğlu, Mesut; Ökten, Hatice EserIn this study, electrochemical removal of methylene blue (MB) from water using commercially available and low-cost flexible graphite was investigated. The operating conditions such as initial dye concentration, initial solution pH, electrolyte dose, electrical potential, and operating time were investigated. The Box-Behnken experimental design (BBD) was used to optimize the system's performance with the minimum number of tests possible, as well as to examine the independent variables' impact on the removal efficiency, energy consumption, operating cost, and effluent MB concentration. The electrical potential and electrolyte dosage both improved the MB removal efficiency, since increased electrical potential facilitated production of oxidizing agents and increase in electrolyte dosage translated into an increase in electrical current transfer. As expected, MB removal efficiency increased with longer operational periods. The combined effects of operating time-electrical potential and electrical potential-electrolyte concentration improved the MB removal efficiency. The maximum removal efficiency (99.9%) and lowest operating cost (0.012 $/m3) were obtained for initial pH 4, initial MB concentration 26.5 mg/L, electrolyte concentration 0.6 g/L, electrical potential 3 V, and operating time 30 min. The reaction kinetics was maximum for pH 5, and as the pH increased the reaction rates decreased. Consequent techno-economic assessment showed that electrochemical removal of MB using low-cost and versatile flexible graphite had a competitive advantage.Article Yüzme Havuzlarında Karbon Bazlı Dezenfeksiyon Yan Ürünlerinin Oluşumu(Dokuz Eylül Üniversitesi, 2017) Harman, B. İlker; Tanaçan, Ertaç; Genişoğlu, Mesut; Kaplan, Ş. Şule; Ateş, Nuray; Yiğit, Nevzat Ö.; Kanan, Amer A.S.Bu çalışmada ülkemiz literatüründe ilk defa yer alacak ve oldukça önemli bir konu olan yüzme havuzlarındaki dezenfeksiyon yan ürünlerinin (DYÜ) türleri, DYÜ oluşumuna etki eden faktörler ve DYÜ'lerin sağlık etkileri konusunda bir derleme yapılmıştır. İçme suyu şebekesi ve yüzme havuzlarındaki patojen mikroorganizmaların engellenebilmesi amacıyla birçok dezenfektan kullanılmaktadır. Yüzme havuzlarında genellikle klor bazlı dezenfektanlar kullanılırken, bromlu dezenfektanlar da dezenfeksiyon için tercih edilmektedir. Havuz suyundaki organik madde kaynakları; i) doldurma suyunda bulunan doğal organik maddeler (DOM) ve ii) yüzücülerden gelen organik yüklemelerdir. Yüzme havuzları özelinde yüzücülerden kaynaklı daimi organik yükleme ve sürekli dezenfeksiyon sonucu (organik maddelerin oksidantlar/dezenfektanlar ile reaksiyonu sonucunda) mutajenik ve kanserojenik olmalarından şüphelenilen DYÜ oluşumu içme sularındakine nazaran daha fazladır. Trihalometan (THM) ve haloasetik asitler (HAA), havuz suyunda en sık karşılaşılan yan ürünlerdir. THM gibi uçucu olan yan ürünler sadece yüzme suyunda değil, havada da oldukça yüksek konsantrasyonlarda bulunabilmektedir. Bu yan ürünlerin oluşum mekanizmalarının bilinmesi ve kontrol altına alınması, yüzücüler ve bilhassa havuz çalışanlarının sağlığına olan etkilerinin en aza indirilmesi bağlamında önem arz etmektedir. Oluştuktan sonra giderilmesi zor ve maliyetli olan DYÜ'lerin oluşumunda etkili öncüllerin belirlenmesi ve kontrolü ile uygun dezenfektan türünün kullanılmasıyla yüzme havuzlarındaki DYÜ oluşumları azaltılabilir.Article Tuvalet Temizlik Ürünlerinin Kullanımı ile Salıverilen Karbon Tetraklorürün İç Hava Düzeyleri ve Sağlık Riskleri(TMMOB Makina Mühendisleri Odası, 2020) Ayri, İlknur; Genişoğlu, Mesut; Gaygısız, Handan; Sofuoğlu, Aysun; Sofuoğlu, Sait Cemilİç hava kirliliği açısından temizlik ürünleri kullanımı önemli bir kaynak oluşturmak-tadır. Bir Uçucu Organik Bileşik (UOB) olan karbon tetraklorürün emisyonu, diğer UOB’ler ile birlikte klorlanmış çeşme suyundan, özellikle su sıcaklığının artırıldığı yıkanma, çamaşır ve bulaşık yıkanması sırasında oluşur. Bununla birlikte, ağartıcı olarak hipoklorit (çamaşır suyu) içeren temizlik ürünlerinde ve kullanımı sırasında, çamaşır suyu ile organik maddelerin reaksiyona girmesiyle oluşumu bu bileşik için göreceli çok daha güçlü bir kaynak oluşturmaktadır. Karbon tetraklorürün hem kro-nik-toksik hem de karsinojenik sağlık etkileri olması sebebiyle bu temizlik ürünlerinin kullanımı durumunda iç ortam havasından etkin bir havalandırma ile uzaklaştırılma-sı gerekmektedir. Bu çalışmada, karbon tetraklorürün tuvalet ve banyolarda kullanı-lan klozet ve rezervuar tipi temizleyicilerden emisyonu deneysel olarak incelenmiş, iç hava düzeyleri modelleme ile tahmin edilmiş, solunum yoluyla maruziyet için kanser riski değerlendirmesi yapılmıştır. Ürünlerin emisyon potansiyeli tepe boşluğu katı fazlı mikroekstraksiyonu takiben GC/MS yöntemiyle incelenmiş, iç hava düzeylerinin modellenmesi için 8,9 m3 oda hacmi ve 0,5 ach hava değişimi hızı kullanılmıştır. Kul-lanılan bu hız ile ürünlerin kullanımından kaynaklanan karbon tetraklorür konsant-rasyonun sadece %0,6’lık kısmı uzaklaştırılabilmektedir. Ortalama ve 95. yüzdelik kanser risk değerleri kabul edilebilir risk olan milyonda birin altındadır ancak ürün-ler birer iç ortam karbon tetraklorür kaynağı oluşturmaktadır.Article Citation - Scopus: 5Effect of Covid-19 Pandemic on Ambient Air Quality and Excess Risk of Particulate Matter in Turkey(2021) Gören, Ayşegül Yağmur; Genişoğlu, Mesut; Ökten, Hatice Eser; Sofuoğlu, Sait CemilThe COVID-19 pandemic, which has reached 4 million global cases as of March 10, 2020, has become a worldwide problem. Turkey is one of the most affected (9th in the world) country with 139 771 cases. An intermittent curfew policy that differ for three age groups, and an intercity travel ban varying within the country have been implemented. The effects of changes in social life and industrial activity in terms of environmental pollution are not yet known. The short-term effects on PM2.5, PM10, SO2, NO2, NO, NOx, O3 and CO concentrations measured at 51 air quality measurement stations (AQMS) in 11 cities in March – April period of 2020 were statistically compared with that of the previous year. While PM2.5 (9/14 AQMS) and PM10 (29/35 AQMS) concentrations were not significantly affected, NO (12/24 AQMS), NO2 (20/29 AQMS), NOX (17/25 AQMS) concentrations were decreased, SO2 concentrations at half of the AQMSs (11/25) did not show a significant change. There were stations at which higher pollutant concentrations were measured in the study period in 2020 compared to that of 2019. Excess risks associated with PM2.5 and PM10 were estimated to be variable, albeit with a small difference. In conclusion, the heterogeneous actions taken in response to the COVID-19 pandemic resulted in mixed effects on ambient air quality.Article Citation - WoS: 20Citation - Scopus: 25Indoor Air Partitioning of Synthetic Musk Compounds: Gas, Particulate Matter, House Dust, and Window Film(Elsevier, 2020) Balcı, Esin; Genişoğlu, Mesut; Sofuoğlu, Sait Cemil; Sofuoğlu, AysunDue to diversity of contaminants indoors and complexity in the physical structure of particulate matter, partition process of chemicals affects indoor concentration distribution. Synthetic Musk Compounds (SMCs) are ubiquitously found in household and personal care products, thus, in the environment. Exposure to SMCs is important for human health, therefore, their partitioning in indoor environmental media is a key issue. In this study, gas particle, house dust, andwindowfilm partitioning of SMCs were investigated in an indoor micro-environment. In a sealed and unoccupied room, a polycyclic and nitro musk mixture was left for volatilization for an hour. Then, samples were collected using XAD-2 sandwiched between two PUF plugs, glass-fiber filter, and wipes for gas, PM10, window-film, house dust phases, respectively, for 145 h. Collected samples were analyzed using a GC-MS. Results demonstrated that MC concentrations decreased over time, non-linearly. Six of the SMCs partitioned to PM10 with at least 10% at beginning of the experiment, whereas the number of compounds dropped to two at the end, showing that SMCs may partition well between the two phases but they tend to be in the gas phase. They were also detected in the film and dust phases but a decrease pattern similar to gas-particle was not observed. Spearman correlations indicate that the dust and film-associated concentrations were governed by similar processes but PM-associated concentrations were not. SMCs may be found in all phases, mainly in house dust in terms of mass among the studied media and unaccounted surface reservoirs. Therefore, their partitioning between indoor media has key implications for human exposure. (C)20 Elsevier B.V. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 7Bleach-Containing Automatic Toilet-Bowl Cleaners as Sources of Vocs, Associated Indoor Air Concentrations and Carcinogenic Risk(Turkish National Committee for Air Pollution Research (TUNCAP), 2020) Ayrı, İlknur; Genişoğlu, Mesut; Gaygısız, Handan; Sofuoğlu, Aysun; Sofuoğlu, Sait CemilHousehold cleaning products are sources of volatile organic compounds (VOCs). Bleach containing products are a special case because reactions occur between chloride and their organic content such as surfactants, perfumes, etc., generating VOCs. This study aimed to determine concentration of 13 VOCs in bleach-containing automatic toilet cleaners, to estimate their indoor air concentrations and associated exposure and health risk levels. Experiments with products purchased from supermarkets were conducted in 20-mL headspace vials by placing 1 g of sample with and without water. Solid-phase micro extraction with a DVB/CAR/PDMS fiber assembly was used for adsorption of VOCs from the headspace, and analyzed using a GC-MS. The median carbon tetrachloride and chloroform concentrations of the studied products ranged from 5.03 × 10?3 to 2.37 × 10?2 ?g/g and 2.53 × 10?2 to 2.37 ?g/g, respectively. The modeled 95th percentile indoor air concentrations in a 1.6 m3 bathroom with no ventilation were estimated to be 1 and 20 ?g/m3 for carbon tetrachloride and chloroform, respectively. The 95th percentile carcinogenic risk associated even with the use of the highest content product, 3.72 × 10?7 and 8.62 × 10?7 for carbon tetrachloride and chloroform respectively, were below the acceptable risk. In conclusion, automatic toilet-bowl cleaners were found to be sources of VOCs, but their emission potentials are not high to cause considerable indoor air concentrations over their suggested product lifetime. In turn, carcinogenic risks associated with inhalation exposure are below the de Minimis risk level of 10?6. © 2020Article Citation - WoS: 15Citation - Scopus: 19Brominated Flame Retardants in a Computer Technical Service: Indoor Air Gas Phase, Submicron (pm1) and Coarse (pm10) Particles, Associated Inhalation Exposure, and Settled Dust(Elsevier Ltd., 2019) Genişoğlu, Mesut; Sofuoğlu, Aysun; Kurt Karakuş, Perihan Binnur; Birgül, Aşkın; Sofuoğlu, Sait CemilBrominated flame retardants (BFRs) are found in multi-media indoors, therefore, may pose serious risks to human health. This study investigated the occurrence of BFRs in particulate matter (PM1 and PM10) and gas phase by active and passive sampling, and settled dust to estimate potential exposure in a computer technical service. Polybrominated diphenyl ethers (PBDEs) and their alternatives (novel BFRs, NBFRs) were studied. PM and gas phase were collected on glass fiber filters and polyurethane foam plugs, respectively, and analyzed with a GC/MS after extraction, clean-up, and concentration. Inhalation exposure of the staff was estimated based on the measured concentrations using Monte Carlo simulation. BDE-209 was the dominating PBDE congener in all media while bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate and 1,2-bis(2,4,6-tribromophenoxy)ethane were those of NBFRs. Submicron particulate matter (PM1) BFR levels constituted about one half of the PM10-associated concentrations, while average PM10 mass concentration (69.9 μg m−3) was nine times that of PM1 (7.73 μg m−3). Calculated log10 dust-gas and PM-gas partitioning coefficients ranged from −5.03 to −2.10, −2.21 to −0.55, and −2.26 to −1.04 for settled dust, PM10, and PM1, respectively. The indoor/outdoor concentration ratios were >1 for all compounds indicating the strength of indoor sources in the service. The estimated potential inhalation exposures, for future chronic-toxic and carcinogenic risk assessments, indicated that the levels of gas-phase and PM1-associated exposures were similar at approximately one half of PM10-associated levels. Results of this study indicate that the occurrence of BFRs in all studied media should be taken into consideration for occupational health mitigation efforts.