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Öğe Biodegradability enhancement of landfill leachate nanofiltration concentrate using sequential and combined electrochemical processes(Elsevier, 2025) Yucel, Esra; Ozen, Irem; Cene, Gulay Arslan; Ilhan, Hilal; Guvenc, Senem Yazici; Can-Guven, Emine; Demir, AhmetIn this study, the treatment of landfill leachate nanofiltration concentrate (LNFC) was investigated using sequential (two distinct stages, one following the other) and combined (two mechanisms operating simultaneously in a single reactor) electrochemical processes. In the first stage, initial pH, applied current, and reaction time were optimized for individual processes: electro-oxidation (EO), peroxi-coagulation (PC), and electrochemical-peroxidation (EP). In the second stage, sequential (EO-PC, PC-EO, EO-EP, EP-EO) and combined (EO/PC, EO/EP) processes were applied with the optimal conditions determined in the first stage. Under optimum conditions (pH 5; applied current 1 A; reaction time 60 min), chemical oxygen demand (COD) removal efficiencies of 38.9 %, 42.1 %, and 53.1 % were obtained for the EO, PC, and EP processes, respectively. Enhanced COD removal was obtained by sequential processes, yielding removal rates of 65.6 % for EO-PC, 71.1 % for PC-EO, 78.3 % for EO-EP, and 83.6 % for EP-EO. The highest efficiencies were observed in the combined systems, with COD removals of 76.4 % for EO/PC and 89.1 % for EO/EP. The lowest specific energy consumption (SEC) was calculated as 31.2 kWh/kg COD for EP among the single processes, 41.0 kWh/kg COD for EP-EO among the sequential processes, and 47.5 kWh/kg COD for EO/EP among the combined processes. These findings suggest that EP-based systems require less energy than EO-based systems. The EO/EP process can be proposed as an alternative treatment for LNFC due to its compliance with the discharge standards (500 mg/L for COD for leachate) specified in the Water Pollution Control Regulation of T & uuml;rkiye and its relatively low SEC.Öğe CBS tabanlı AHP yöntemiyle orman yangını risk haritasının geliştirilmesi(Bursa Teknik Üniversitesi, 2023) Demir, Ahmet; Akay, Abdullah EminÜlkemiz, özellikle güney ve batı kıyılarının Akdeniz iklimi, bitki örtüsü ve topgrafik yapısı sebebiyle orman yangınlarına hassas bölgede yer almaktadır. Her yıl çeşitli sebeplerle çıkan orman yangınları binlerce hektar orman alanının kül olmasına neden olmaktadır. Yangınlar ekosisteme zarar verdiği gibi ekonomik sonuçları da olmaktadır. Orman yangınlarıyla etkin mücadele için ilk olarak yapılacak iş yangın riski bulunan alanların tespit edilmesidir. Akdeniz ikliminin ve yangına karşı hassas ağaç türlerinin hâkim olduğu Akdeniz, Ege ve Marmara kıyıları orman yangınlarına karşı birinci derecede tehlike altında iken, Karadeniz ikliminin hâkim olduğu Karadeniz kıyılarında bulunan ormanlar yangın açısından daha düşük risklidir. Yangın riski çeşitli parametrelere göre değişiklik göstermektedir. Orman yapısı, topografik özellikler, iklim, çeşitli noktalara (yol, yerleşim yeri, ziraat alanları gibi) yakınlık gibi parametreler analiz edilerek risk haritası oluşturulabilmektedir. Yangın risk verileri, yangına karşı alınabilecek tedbirlere ışık tutacaktır. Bu çalışmada, yangına hassas ormanlara sahip Mersin Orman Bölge Müdürlüğü'nün yangın risk haritasının oluşturulması amacıyla CBS (Coğrafi Bilgi sistemleri) tabanlı Analitik Hiyerarşi Süreci (AHP) yöntemi kullanılmıştır. Daha sonra, Bölge Müdürlüğünde daha önce çıkan yangınlar dikkate alınarak yangın riski haritasının doğruluğu değerlendirilmiştir. Sonuç olarak çalışma alanının %13,87'si çok yüksek, %25,87'si yüksek, %24,68'i orta, %22,44'ü düşük ve %13,14'ü çok düşük riskli alanlar olarak belirlenmiştir. Sonuçlar ağaç türlerinin orman yangınlarında en etkili risk faktörü olduğunu, meşcere çağlarının da ikinci sırada geldiğini göstermiştir. Mersin Orman Bölge Müdürlüğünde 2003-2022 yılları arasında 0,5 hektardan büyük çıkan ve orman alanlarına zarar veren toplam 562 yangına ait konum bilgileri kullanılarak, AHP yöntemiyle oluşturulan yangın risk haritasının doğruluğu değerlendirilmiştir. Yangın risk haritasının doğruluğunun belirlenmesi için ArcGIS ortamında ROC (Receiver Operating Characteristic) eğrisi yöntemi kullanılmıştır. Sonuç olarak AUC (Area Under Curve) değeri yaklaşık %74 bulunmuş olup, be değer Mersin Orman Bölge Müdürlüğü için geliştirilen yangın risk haritasının orta düzeyde güvenilir olduğunu göstermiştir. Bu çalışma ile CBS tabanlı AHP yöntemi kullanılarak kısa zamanda güvenilir yangın risk haritası üretiminin mümkün olduğu ortaya konulmuştur.Öğe Forest Fire Risk Mapping Using GIS Based Analytical Hierarchy Process Approach(Forest Engineering and Technologies Platform, 2024) Demir, Ahmet; Akay, Abdullah EminTurkiye is located in a region sensitive to forest fires due to its climate, vegetation characteristics, and topography. Every year, forest fires, for various reasons, cause burning of thousands of hectares of forest area. Fires damage the ecosystem and have economic consequences. The Mediterranean, Aegean and Marmara coasts, where the Mediterranean climate and fire-sensitive tree species dominate, are at primary risk against forest fires. For an effective fight against forest fires, it is crucial to identify zones with fire risk based on various parameters such as forest structures (tree species, crown closure, stand development class), topographic features (slope, aspect), climate, and proximity to certain points (such as roads, settlements, agricultural areas). Fire risk data will shed light on the measures that can be taken against fire. In this study, GIS (Geographic Information Systems) based Analytical Hierarchy Process (AHP) method, one of the well know Multi-Criteria Decision Making Analysis (MCDA) methods, was used to develop the fire risk map of Mersin Forestry Regional Directorate (FRD) within the Mediterranean region of Turkiye. Then, the accuracy of the fire risk map was evaluated by taking into account the previous fires in the regional directorate. As a result, the findings showed that 13.87% of the study area was classified as very high, 25.87% as high, 24.68% as medium, 22.44% a low, and 13.14% as very low risk areas. The results also indicated that tree species are the most influential risk factor in forest fires, and followed by stand development class factor. The accuracy of the fire risk map was evaluated by using the location information of a total of 562 forest fires in Mersin FRD between 2003-2022. In order to determine the accuracy of the fire risk map, the Receiver Operating Characteristic (ROC) curve method was used in the ArcGIS environment. As a result, the Area Under Curve (AUC) value was approximately 74%, which showed that the fire risk map developed for Mersin FRD was moderately reliable. With this study, it has been demonstrated that it is possible to produce reliable fire risk maps in a short time using the GIS-based AHP method. © Copyright 2024 by Forest Engineering.Öğe Forest Fire Risk Mapping Using GIS Based Analytical Hierarchy Process Approach(2024) Demir, Ahmet; Akay, Abdullah EminTurkiye is located in a region sensitive to forest fires due to its climate, vegetation characteristics, and topography. Every year, forest fires, for various reasons, cause burning of thousands of hectares of forest area. Fires damage the ecosystem and have economic consequences. The Mediterranean, Aegean and Marmara coasts, where the Mediterranean climate and fire-sensitive tree species dominate, are at primary risk against forest fires. For an effective fight against forest fires, it is crucial to identify zones with fire risk based on various parameters such as forest structures (tree species, crown closure, stand development class), topographic features (slope, aspect), climate, and proximity to certain points (such as roads, settlements, agricultural areas). Fire risk data will shed light on the measures that can be taken against fire. In this study, GIS (Geographic Information Systems) based Analytical Hierarchy Process (AHP) method, one of the well know Multi-Criteria Decision Making Analysis (MCDA) methods, was used to develop the fire risk map of Mersin Forestry Regional Directorate (FRD) within the Mediterranean region of Turkiye. Then, the accuracy of the fire risk map was evaluated by taking into account the previous fires in the regional directorate. As a result, the findings showed that 13.87% of the study area was classified as very high, 25.87% as high, 24.68% as medium, 22.44% a low, and 13.14% as very low risk areas. The results also indicated that tree species are the most influential risk factor in forest fires, and followed by stand development class factor. The accuracy of the fire risk map was evaluated by using the location information of a total of 562 forest fires in Mersin FRD between 2003-2022. In order to determine the accuracy of the fire risk map, the Receiver Operating Characteristic (ROC) curve method was used in the ArcGIS environment. As a result, the Area Under Curve (AUC) value was approximately 74%, which showed that the fire risk map developed for Mersin FRD was moderately reliable. With this study, it has been demonstrated that it is possible to produce reliable fire risk maps in a short time using the GIS-based AHP method.
