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Öğe Biyobozunur Plastiklerin Evsel Kompostlama Sürecindeki Davranışı: Kompost Kalitesi, Polimer Yüzey Morfolojisi ve Yapısındaki Değişimler(2025) Akarsu, Ceyhun; Sönmez, V. Zülal; Acar, Ömer; Aslan, Merve Meryem; Hadrı, Molham; Sivri, NüketBu çalışmada, biyobozunur plastiklerin mezofilik şartlar altında standart alıkonma süresince kompost kalitesi üzerindeki etkileri incelenmiş ve kompostlama süresinin biyobozunur plastik degradasyonu için yeterli olup olmadığı araştırılmıştır. Sıcaklık, pH ve nem gibi kompost kalite parametreleri belirlenmiş; biyobozunur plastiklerin bozunma derecesi ise ağırlık kaybı, ATR-FTIR ile kimyasal yapı değişimleri ve SEM ile yüzey morfolojisi analiz edilerek değerlendirilmiştir. Çalışma sonucunda biyobozunur plastik ihtiva eden kompost ile geleneksel kompost karşılaştırıldığında, kompostun olgunlaşma sürecinde belirgin bir hızlanma veya kalite artışı gözlemlenmemiştir. Ancak süreç üzerinde ciddi bir olumsuzluk yaratmadığı da anlaşılmaktadır. Bununla birlikte, çalışmanın bulguları, biyobozunur plastiklerin süreç içerisinde tam olarak bozunmadığını, yani belirli bir oranda kompost içerisinde kalıntı bırakabildiğini göstermektedir. Doksan günlük süre sonunda, biyobozunur plastikler için %22,5 oranında ağırlık kaybının gerçekleştiği tespit edilmiştir. ATR-FTIR sonuçları simetrik C-H ve O-H bağlarındaki değişimler ile degradasyonu desteklerken, SEM analizleri yüzey pürüzlülüğündeki artış ve çatlak oluşumunu ortaya koymuştur. Bu nedenle, biyobozunur plastiklerin kompost süreçlerinde ne kadar süreyle ve hangi koşullarda tamamen ayrışabildiğinin daha uzun vadeli çalışmalarla belirlenmesi gerekmektedir.Öğe Cardiovascular Toxicity in Daphnia magna: Heart Rate Analysis Under Exposure to Crystal Violet, Ethanol, and Formaldehyde(Ordu University, 2025) Karademir, Arda Sarp; Can, Melisa; Sönmez, V. Zülal; Sivri, NüketWater fleas have become valuable model organisms for ecotoxicity studies due to their ease of cultivation, transparent bodies, and high sensitivity to chemical pollutants. In this study, heart rates in Daphnia magna were examined to assess basic behavioral and physiological characteristics under exposure to known toxic chemicals. Crystal violet, ethanol, and formaldehyde selected for their distinct chemical properties and documented toxicity were utilized as toxic solutions. A slow-motion, video-based method was implemented to evaluate cardiovascular performance by monitoring heart rates in water fleas. Data for important parameters like heart rates, body reactions, and heart contraction were extracted from video recordings. It was found that crystal violet increased the heart rates of Daphnia magna (489±14.19) more than ethanol (450±40.67) and formaldehyde (445±48.21). Compared to the control group, formaldehyde caused a 28.51% increase in the heart rates of daphnids, while exposure to ethanol (30.54%) and crystal violet (35.89%) resulted in a lower increase. The response of water fleas to each of the three chemicals studied was determined as a statistically significant and noticeable increase in heart rate.Öğe Identifying Knowledge Gaps on Ecotoxicological Assessment of Micro/Nanoplastics with Aquatic Keystone Species(2025) Sönmez, V. Zülal; Akarsu, Ceyhun; Aydın, Zeynep; Coşkun, Elif Naz; Güney, Ecem; İşlek, Şevval; Bostan, ZeynepThe pollution of aquatic environments by micro/nanoplastics (M/NPs) has been a growing public concern in recent years. This situation has the potential to threaten and affect both aquatic and terrestrial ecosystems simultaneously. Therefore, extensive research has been conducted over the past few years to determine the toxicity of M/NPs. This article investigated the global scientific literature on M/NPs’ toxicity on Daphnia magna by integrating social network analysis with bibliometrics. A total of 100 publications were downloaded and analyzed with the majority being academic journal articles. Network maps and graphics displayed the correlations between keywords, countries, and journals. Moreover, the type, size, and exposure time of M/NPs were also evaluated to expose current research trends. The results demonstrate that PS and PE are the primary polymer types employed in most toxicity studies. Researchers in China and Germany have provided a great contribution. The Journal of Environmental Pollution published the highest number of research articles. The top publishing countries and the top-cited publications and authors will likely pave the way for standardization in both microplastic and nanoplastic research.Öğe Microplastic Distribution and Composition in Various Ecosystems of the Marmara Region: Current Gaps and Research Needs(2025) Akarsu, Ceyhun; Sönmez, V. Zülal; Bisiriyu, Aminat; Sivri, NüketMicroplastics are ubiquitous worldwide and are increasingly recognized as a significant environmental problem. In Türkiye, research on microplastics has expanded over the years, providing valuable insights into the issue. However, studies focusing on different ecosystems are still limited and critical knowledge gaps have not been filled. The aim of this study, therefore, is to compare the composition of microplastics in five different ecosystems—marine water, freshwater, marine sediment, freshwater sediment and soil—across Istanbul and the Marmara region, while also identifying similarities and potential sources of pollution. Furthermore, the study emphasizes the need for more comprehensive research on microplastic pollution and its prevention within the different ecosystems of the region. For this purpose, a total of 26 studies were reviewed, in which 312 samples were collected from 304 stations, 222 of which were located in Istanbul. These stations were categorized by ecosystem type and the predominant composition of microplastics. Results revealed that there is a lack of studies on microplastics in surface waters and soil samples at various locations in Istanbul. While studies in the Marmara region have primarily focused on surface water samples from different locations in the Sea of Marmara, research on lentic and lotic systems, sediments and soils is still insufficient. The results also show that various environmental and anthropogenic factors, including water currents and direction, meteorological conditions, maritime traffic, human and industrial activities, proximity to residential areas and wastewater treatment plants, and atmospheric transport influence the concentration and composition of microplastics. In addition, seasonal and annual variations and the effect of station depth on the accumulation of microplastics were observed. Given that, the analyzed stations represent only a small fraction of the region’s ecosystems, this study underlines the urgent need for further research to address existing knowledge gaps. The lack of comprehensive studies hinders the effective management of plastic and microplastic litter in the Marmara region. To enable meaningful comparisons at both local and international scales, adapting standardized methodologies in microplastic research is essential.Öğe Modeling The Toxicity of Textile Industry Wastewater Using Artificial Neural Networks(Ieee, 2017) Şamlı, Rüya; Sönmez, V. Zülal; Sivri, NüketToxicity tests are required to detect the possible effects of pollutants on organisms. This study investigates the effect of Chemical Oxygen Demand (COD), suspended solid (SS) and pH parameters on toxicity of textile industry wastewaters except for the color parameter, effect of which is well known. Fish bioassay taking place in legal regulation of Turkey was used as toxicity test. At the end of the toxicity test, various values of the parameters were predicted through Artificial Neural Networks (ANN). In addition, Artificial Neural Networks were used to calculate the effect of each parameter on toxicity (%). Accordingly, COD is the parameter which mostly affects toxicity following color parameter and SS is the parameter which has the minimum effect. It is found that results deviate at the rate of 15.41% when values of COD parameter are excluded from the model input data and the error rate becomes 5.07% when SS parameter is excluded. In this study, the effect of each input of each parameter, which is an open ecosystem, based on selected parameters is successfully predicted through Artificial Neural Networks which is a heuristic method.
