Publication: A fuzzy novel model for process selection of wastewater treatment technologies
Abstract
ATIKSU ARITMA TEKNOLOJİLERİNİN PROSES SEÇİMİ İÇİN BULANIK YENİ BİR MODEL Atıksu arıtma tesislerinin (AAT'ler) optimum teknoloji seçimi, kentsel ekosistemin sürdürülebilirlik gereksinimlerini karşılayan veriye dayalı bilimsel yaklaşımların benimsenmesini gerektirir. Bu tür yaklaşımlar, artan nüfus, arazi kıtlığı ve arıtma tesislerinin işlevsellik kaybı gibi faktörlerle kısıtlanan karar vericilere (DM'ler) eyleme geçirilebilir öngörüler sağlayabilmelidir. Atıksu arıtma teknolojisi seçimi, birçok amaç fonksiyonu ve belirsiz koşulları barındıran çok boyutlu bir problemdir. Atıksu arıtma teknolojisinin seçiminde, tesislerin tasarımdan işletme sürecine belirleyici olan sürdürülebilirlik perspektifini dikkate alan bir kriter sisteminin kurulması, bu karmaşık sorunun çözümünde kilit rol oynamaktadır. Gerçek hayatta, ekonomik, sosyal ve çevresel koşullara ilişkin tahminlerin belirsizlikleri, paydaşların tutumlarına etki ederek (örneğin, riskten kaçınma veya risk arama) olası sonuçlar hakkında yeterli bilgi gerektiren tamamen rasyonel karar vermeyi gerektirir. Ayrıca hatalı ve yetersiz veriler karar verme sürecinde belirsizliğin artmasına neden olmaktadır. Bu çalışmada, çevresel koşulların belirsizliklerinin üstesinden gelmek için karar vericilerin riskten kaçınmaları dikkate alınarak yenilikçi bir bulanık çok kriterli karar verme (ÇKKV) çerçevesi önerilmiştir. AAT teknolojisi seçimi için kriterlerin etkileşimi, Beklenti Teorisinin üyelik fonksiyonu aracılığıyla yorumlanarak sistematik bir karar verme süreci ele alınmaktadır. Öne çıkan referans kriteri, riskten kaçınma eğilimlerinin fonksiyon davranışına göre diğer alt kriterleri yönetir. Alternatifler, karar vericilerin risk algısı dikkate alınarak hesaplanan toplu ağırlıklar da dahil olmak üzere analitik hiyerarşi sürecine (AHP) entegre edilmiş α-kesim kümelerine dayalı olarak bulanık TODIM tarafından sıralanır. Önerilen karar verme modelinin kullanışlılığını doğrulamak için İstanbul'da dört tam ölçekli AAT ile yürütülen bir vaka çalışması sunulmuştur. Model, çamur bertaraf maliyetinin (C25) referans kriter olarak hesaplandığını ortaya koymuştur. Alternatiflerin baskınlık derecesine dayalı sıralama sonuçları, ön arıtma yapılmadan anaerobik-anoksik-oksik (A2O) işleminin en etkili süreç olduğunu göstermiştir. Son olarak, önerilen karar verme modelinin, karar vericilerin risk algısını yansıtarak kentsel alanların geliştirilmesi için AAT'lerin teknoloji seçiminde nasıl kullanılabileceği gösterilmiştir.
A FUZZY NOVEL MODEL FOR PROCESS SELECTION OF WASTEWATER TREATMENT TECHNOLOGIES Optimum technology selection of wastewater treatments plants (WWTPs) necessitates adoption of data-driven scientific approaches that satisfy sustainability requirements of urban ecosystem. Such approaches should be able to provide actionable insights to decision makers (DMs) constrained with factors such as rising population, land shortage, and loss of functionality of treatment plants. Wastewater treatment technology selection is a multidimensional problem including many objective functions and uncertain conditions. A key role in solving this complex problem is played by the establishment of a criteria system that takes into account the sustainability perspective, which is decisive for the selection of wastewater treatment technology from the design of the plants to the operational process. In real life, the uncertainties of forecasts of economic, social, and environmental conditions constarin purely rational decision-making that requires adequate knowledge of possible outcomes by manipulating stakeholders’ attitudes (e.g., risk aversion or risk seeking). In addition, inaccurate and insufficient data lead to an increase in uncertainty in the decision-making process. In this study, an innovative fuzzy multi-criteria decision making (MCDM) framework is suggested considering the risk aversion of decision makers to overcome uncertainties of environmental conditions. A systematic decision-making process is addressed by interpreting the interaction of criteria for the WWTP technology selection through the membership function of the Prospect Theory. The prominent reference criterion manages other sub-criteria according to the function behavior of the risk aversion tendencies. The alternatives are ranked by the fuzzy TODIM based on α-cuts sets integrated into the analytical hierarchy process (AHP) including the aggregated weights calculated taking into account the risk perception of decision makers. To validate the usefulness of the proposed decision-making model, a case study conducted with four full-scale WWTPs in Istanbul is presented. The model revealed that sludge disposal cost (C25) was calculated as the reference criterion. The ranking results based on dominance degree of alternatives showed that anaerobic-anoxic-oxic (A2O) without pre-clarification was the most effective process. Finally, it is demonstaretd how the proposed decision-making model can be used in the technology selection of WWTPs for developing urban areas by reflecting the risk perception of decision makers.
A FUZZY NOVEL MODEL FOR PROCESS SELECTION OF WASTEWATER TREATMENT TECHNOLOGIES Optimum technology selection of wastewater treatments plants (WWTPs) necessitates adoption of data-driven scientific approaches that satisfy sustainability requirements of urban ecosystem. Such approaches should be able to provide actionable insights to decision makers (DMs) constrained with factors such as rising population, land shortage, and loss of functionality of treatment plants. Wastewater treatment technology selection is a multidimensional problem including many objective functions and uncertain conditions. A key role in solving this complex problem is played by the establishment of a criteria system that takes into account the sustainability perspective, which is decisive for the selection of wastewater treatment technology from the design of the plants to the operational process. In real life, the uncertainties of forecasts of economic, social, and environmental conditions constarin purely rational decision-making that requires adequate knowledge of possible outcomes by manipulating stakeholders’ attitudes (e.g., risk aversion or risk seeking). In addition, inaccurate and insufficient data lead to an increase in uncertainty in the decision-making process. In this study, an innovative fuzzy multi-criteria decision making (MCDM) framework is suggested considering the risk aversion of decision makers to overcome uncertainties of environmental conditions. A systematic decision-making process is addressed by interpreting the interaction of criteria for the WWTP technology selection through the membership function of the Prospect Theory. The prominent reference criterion manages other sub-criteria according to the function behavior of the risk aversion tendencies. The alternatives are ranked by the fuzzy TODIM based on α-cuts sets integrated into the analytical hierarchy process (AHP) including the aggregated weights calculated taking into account the risk perception of decision makers. To validate the usefulness of the proposed decision-making model, a case study conducted with four full-scale WWTPs in Istanbul is presented. The model revealed that sludge disposal cost (C25) was calculated as the reference criterion. The ranking results based on dominance degree of alternatives showed that anaerobic-anoxic-oxic (A2O) without pre-clarification was the most effective process. Finally, it is demonstaretd how the proposed decision-making model can be used in the technology selection of WWTPs for developing urban areas by reflecting the risk perception of decision makers.