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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 A COMPREHENSIVE BIBLIOMETRIC OVERVIEW ON THE TOXICITY OF TEXTILE DYES: 2010-2024(Gh Asachi Technical Univ Iasi, 2024) Salman, Busra; Sonmez, Vildan Zulal; Akarsu, Ceyhun; Sivri, NuketThere is a growing awareness in the literature of the potential hazards of dyestuffs in wastewater, particularly their toxicity and carcinogenic effects on aquatic life. This has led to an increasing focus on the need for alternative treatment methods in response to these concerns. This study, therefore, aims to conduct a bibliometric analysis utilizing the Scopus database, focusing on the keywords toxicity, dye, and textile to identify research trends, track research hotspots, and determine future research directions from 2010 to April 30, 2024. Bibliometric indicators and visual representation maps were used to analyse the retrieved data quantitatively and qualitatively. The results indicated that most studies were conducted using laboratory-prepared wastewater with a rate of 75%. It was also found that research on the acute toxicity of textile wastewater is mainly carried out with real wastewater. The leading journals for research in this area were found to be Chemosphere, Environmental Science and Pollution Research and Journal of Hazardous Materials with the countries of India and Brazil ranked first and second in the number of articles published. In addition, current regulations and procedures for wastewater treatment were examined, and several potential future study opportunities for researchers were suggested. The findings show that bibliometric analysis is a practical approach to measure research hotspots and trends both qualitatively and statistically.Öğe Fingerprinting of Critical Raw Materials in Lacustrine Systems on Horseshoe Island, Antarctic Peninsula(Central Fisheries Research Inst, 2024) Sivri, Nuket; Ercan, Nevra; Akarsu, Ceyhun; Erturac, M. Korhan; Altay, Melek Cumbul; Sonmez, Vildan Zulal; Hiz, Mustafa BurakModern industry increasingly relies on advanced technologies that require various critical raw materials (CRMs) for their development and functionality. These materials, which are essential for technological innovation and everyday applications, face significant supply risks, hence they are categorized as critical raw materials. Recent studies have highlighted the ecological and geochemical importance of CRMs in lakes of different geological origin, yet detailed studies on their distribution in polar lacustrine systems remain limited. This study, therefore, aims to address this gap by quantifying concentrations of specific CRMs- boron (B), cerium (Ce), gallium (Ga), germanium (Ge), gadolinium (Gd), lanthanum (La), lithium (Li), nickel (Ni), neodymium (Nd), palladium (Pd), platinum (Pt), titanium (Ti), and yttrium (Y)-in surface waters of nine lacustrine systems sampled during the T & uuml;rkiye's National Antarctic Scientific Expedition-2024. The analysis revealed measurable values for B, Ga, Nd, Ni and Ti, while the concentrations of Ce, Ge, Gd, La, Li, Pd, Pt and Y remained consistently below the detection limit. Of the lakes analyzed, Clincher Lake had the highest concentrations, with notable values for B (85.2 ppb), Ti (58.1 ppb) and Ni (18.2 ppb). Remarkably, these elevated levels were measured in a lake furthest from shore, highlighting the possible influence of unique environmental or geological factors. These results emphasize the importance of continuously monitoring and comprehensively analyzing the distribution of CRMs in polar lacustrine and marine ecosystems. Such efforts are crucial for assessing the environmental risks associated with CRMs and for understanding their broader ecological impacts.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 Kampüs Ortamındaki Plastik Atık Çeşitliliğinde Gözlemsel Öğrenmenin ve Akran Etkisinin ArcGIS ile Görselleştirmesi(2024) Sivri, Nuket; Aydoğdu, Atilla; Sönmez, Vildan Zülal; Akarsu, CeyhunPlastik kirliliği; ekosistemleri, yaban hayatını ve en çok da insan sağlığını etkileyen önemli bir çevresel sorun haline gelmiştir. Son dönemde yapılan çalışmalarda mikroplastiklere özellikle vurgu yapılmış olsa da bunların birincil kaynaklarından olan ve yetersiz/yanlış atık yönetim stratejileri nedeniyle doğal ortamlarda sıklıkla karşılaşılan mezo- ve makroplastiklerin varlığı ve çeşitliliğinin değerlendirilmesine ihtiyaç duyulmaktadır. Öyle ki atıkların tüketiciler tarafından biriktirme ekipmanları yerine doğal ortamlara bırakılması konusunda bazı ilişki ve etkileşimler, viral bir salgın tarzında yayılmakta ve ardından bir davranış paternine dönüşmektedir. Öğrenmede sosyal bilişsel yaklaşım olarak tanımlanan “gözlemsel öğrenme”nin ve “akran etkisi”nin, kampüs alanı içinde bilinçsizce bırakılan mezo/makroplastik malzeme çeşitliliğine etkisi ve bu ortamda oluşan plastik kirliliğinin arazi dağılımının görselleştirilmesi bu çalışmanın temelini oluşturmaktadır. Elde edilen bulgular, sürdürülebilirlik amaçları kapsamında gençlerin farkındalığını artırmak ve çevre eğitimi programlarına olan ihtiyacı ortaya koymak adına görsel verilerle desteklenmiştir. Bu çalışmanın en önemli bulgusu olarak; her alanda baskın olan polimer yapıların, öğrencilerin derslik/ ofis/ market/ kantin yakınlığı kaynaklı tükettiği plastik ambalajlı ürünler, tütün ürünleri kullanma alışkanlıkları nedeniyle sigara izmaritleri ve hızlı hijyen oluşturma alışkanlığı nedeniyle ıslak mendiller olduğu gözlenmiştir. Atıkların en yoğun olduğu dönem, ara sınav dönemi olarak bilinen Ekim ayı ve en yoğun alan yol kenarındaki oturma alanlarının olduğu bölge olarak belirlenmiştir. En çok kaydedilen meso-makroplastik parçaların FT-IR analizleri sonucunda, yoğunluğa göre polimer yapılara ait sıralamanın; PET, PE, PP ve PMMA olduğu tespit edilmiştir. Çalışma sonucunda, plastik atıkların çevresel etkileri konusunda farkındalıkların artmasına yardımcı olabilecek, sürdürülebilir uygulamaların benimsenmesinde, ekolojik uygulamaları örnekleyecek farklı girişimlerle gençlerin desteklenmesi ve yönetimlerin bir an önce aksiyon alması gerekliliği ortaya konulmuştur.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 An overview of the occurrence and distribution of plastics in wastewater treatment plants and the necessity of developing up-to-date management strategies(Cambridge University Press, 2023) Akarsu, Ceyhun; Sonmez, V. Zulal; Sivri, N.Although studies suggest that wastewater treatment plants (WWTPs) are the main pathway for plastics into receiving waters, studies on the origin and fate of plastics entering WWTPs are imprecise and largely unexplored. The analysis of plastics in samples from WWTPs is also a relatively young and growing field compared with the marine environment. Furthermore, recent studies have shown that plastics are not uniformly distributed in WWTPs due to environmental factors and the inherent properties of plastics. Accordingly, this review article attempts to describe the current state of knowledge on plastic pollution in WWTPs and identify future research areas. In particular, this study describes the sources of plastics entering WWTPs and the analytical techniques used for the occurrence and properties of plastics in WWTPs. It also defines the role of these plastics as a possible source of microplastics and discusses the problems they can cause in WWTPs. The factors that can influence the variations in the number of plastics are defined. Furthermore, the policy needs for managing plastic pollution as a contribution to achieving the United Nations Sustainable Development Goals are assessed. © 2025 Elsevier B.V., All rights reserved.Öğe Rhamnolipid: nature-based solution for the removal of microplastics from the aquatic environment(Oxford Univ Press, 2025) Sonmez, Vildan Zulal; Akarsu, Ceyhun; Sivri, NuketOver the past two decades, research into the accumulation of small plastic particles and fibers in organisms and environmental settings has yielded over 7,000 studies, highlighting the widespread presence of microplastics in ecosystems, wildlife, and human bodies. In recent years, these contaminants have posed a significant threat to human, animal, and environmental health, with most efforts concentrated on removing them from aquatic systems. Given this urgency, the purpose of this study was to investigate the potential of rhamnolipid, a biosurfactant, for the removal of microplastics from water. Specifically, this study evaluates the effects of water matrix, initial pH of the solution (7.0, 7.5, 8.0, 8.5, 9.0, 9.5, and 10.0), concentrations of alum (5, 10, 20, 30, 40, and 50 mg/L), and concentrations of rhamnolipid (1, 5, 10, 20, 40, 80, and 100 mg/L). Optimum removal was achieved at alum and rhamnolipid concentrations of 5.0 mg/L and 1.0 mg/L, respectively, with a solution pH of 8.0. In both types of water tested, a removal efficiency of about 74% was determined, indicating the potential of rhamnolipid as a nature-based solution to control microplastic pollution in surface waters.Öğe Seasonal Distribution, Characterization, Indexing and Risk Assessment of Micro- and Nanoplastics in Coastal Sediments: a Case Study from Istanbul(Springer Int Publ Ag, 2024) Akarsu, Ceyhun; Sonmez, Vildan Zulal; Sivri, NuketMicroplastics (MPs) and nanoplastics (NaPs) in coastal regions, particularly in sediments, have gained increasing attention. However, in T & uuml;rkiye, research on sediment pollution by MPs and NaPs is still limited. To fill this knowledge gap, the distribution, composition, and ecological impact of MPs and NaPs were investigated for the first time in the literature over a one-year period at three sampling stations on the south coast of Istanbul. The average total particle concentration was 1364.17 +/- 600.51 particles.kg-1 dw sediment. Most of the MPs detected in the sediments were in the form of fibers with a size of 100-250 mu m and were black and transparent. The study found that NaPs accounted for only 17%, 13.8% and 11.8% of the particles collected at stations S1, S2 and S3, respectively. According to the FTIR results, polyethylene and polyethylene terephthalate were the most abundant compared to polypropylene, polyamide and other polymers. The hazard index was classified as level V with a value of 17,261. This classification emphasizes the urgent need for further comprehensive studies on the risk assessment of MPs and NaPs. Scanning electron microscopy results showed microorganisms on the particle surface, indicating the MP-associated passing-through mechanism. Moreover, energy dispersive spectroscopy detected several unexpected elements such as Nb, Sr, Mo, Bi, Ta and Rn on MP and NaP surfaces. The results indicate that MP and NaP pollution in Istanbul's coastal sediments may pose a major risk to the environment through the leaching of inherent/adsorbed elements and therefore requires future investigation.
