Tekstil endüstrisinde su geri kazanım teknolojilerinin seçimine yönelik karar destek programının geliştirilmesi
Developing decision support program for selection of water recovery technologies in textile industry
Yazar: UMUT ZENGİN
Danışman: DOÇ. DR. DERYA YÜKSEL İMER
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Çevre Eğitimi Ana Bilim Dalı / Çevre Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2021
Konu: Kamu Yönetimi = Public Administration ; Çevre Mühendisliği = Environmental Engineering
Dizin: Atık su = Waste water ; Atık su arıtma = Waste water treatment ; Karar destek sistemleri = Decision support systems ; Su = Water ; Su arıtma = Water treatment ; Tekstil endüstrisi = Textile industry ; Tekstil sektörü = Textile sector ; Yeniden kazanma = Recycling

Özet:
Son  birkaç yüzyıldır insani tüketimin hızlı bir şekilde artması sanayi endüstrilerininde çeşitli ürün üretmesine neden olmaktadır. Ürünlerdeki çeşitlilik tüketilen doğal kaynaklarında aynı şekilde artmasına sebebiyet vermektedir. Her yeni ürün beraberinde farklı endüstrilerinde gelişmesine sebebiyet vermekte, bu endüstrilerde üretimlerinde doğal kaynakları tüketmektedirler. Gelişen dünya ve tüketim ihtiyacının artması sebebiyle endüstriler sürekli gelişim göstereceğinden ve bunun sonucu olarakta doğal kaynakların kullanılacağı kaçınılmaz bir gerçekliktir. Doğal kaynakların verimli bir şekilde üretimde kullanılması için sürdürülebilir yaklaşımlar yarım yüzyıldır tartışılmakta modellemeler geliştirilmektedir. Son yıllarda döngüsel ekonomi gerçek ölçektede üretim yapan endüstrilerde uygulanmaktadır. Döngüsel ekonominin gerekliliği olarak üretim sonucu açığa çıkan atıkların, tekrar kullanımı şimdi ve önümüzde ki yıllarda kaçınılmaz bir gerçeklik olacaktır. Doğal kaynaklardan biri olan suyun tüketimi de tekstil sektöründe kendine yer bulmaktadır. Tekstil sektörü endüstriler arasında en fazla su tüketimi ve atık su oluşturan sektörler arasında yer almaktadır. Üretimde kullanılan su sonucu açığa çıkan atık suyun deşarj edilmesi yerine üretimde tekrar kullanılması tekstil sektörü için bir gerçekliktir. Hali hazırda belli bölgelerde yer altı su seviyesinde ki düşüşler ve satın alınan su birim fiyatlarında ki artış sonucu tekstil sektörü su geri kazanım tesislerine yönelmektedirler. 
Su geri kazanım uygulamalarının tekstil sektöründe desteklenmesiyle beraber, kurulan arıtma tesislerinin de geniş çerçevede sürdürülebilirliğe katkı yapması gerekmektedir. Sektör su geri kazanımının önemini kabullendikten sonra uygulanacak arıtma tesisininde bir endüstri olduğu burada kullanılacak ekipmanların, kimyasalların ve arıtma teknolojilerininde sürdürülebilir bir yaklaşım temelinde değerlendirilmesi gerekmektedir. Atık su geri kazanım tesisinin gerek enerji tüketimi, gerekse kimyasal tüketimi gibi etkenler sebebiyle sürdürülebilir bir yaklaşım temelinde inşa edilmesi gerekmektedir. 
Günümüzde genellikle uygulanan arıtma metotunun seçiminde arıtma endüstrisi tarafından en çok tecrübe edilmiş arıtma prosesleri uygulamalarda kendine yer bulmaktadır bununla beraber tecrübe edilmiş arıtma proseslerinin kriterler çerçevesinde kıyaslaması yapılamamaktadır. Özellikle atık su geri kazanım tesislerinden kaynaklanan ekipmanların sebebiyet verdiği karbondioksit salınımı gibi harici negatif etkiler düşünülmemektedir. Yüksek miktarda kullanılacak kimyasalların işletme maliyeti negatif etkisinin yanı sıra, kimyasalların tüketiminde harici negatif etkileri göz ardı edilmektedir. 
Bu sebeple su geri kazanım tesisleri için, maliyet-çevresel ve teknik kriterleri içeren çok yönlü bir yaklaşımın düşünülmesi gerekmektedir. Su geri kazanımı tekstil sektöründe uygulanması acil olmakla beraber uygulanmadan önce bütünleşik bir yaklaşımla ele alınması gerekliliği hayati önem arz etmektedir. 
Bu çalışmanın amacı, tekstil sektörü için su geri kazanım proseslerinin kriterlere göre birbiri ile kıyaslanabildiği ve en uygun arıtma senaryosunun karar destek programı tarafından kullanıcıya sunulduğu bir karar destek programının geliştilmesidir. Kriterler kullanıcı endeksli olmakta ve kriterler kullanıcı tarafından kendi tercihlerine göre puanlama ile ağırlıklandırıldıktan sonra en uygun arıtma senaryosu karar destek programı tarafından sunulmaktadır. Karar destek programlarının matematiksel modellemelerle ve bilimsel temellere dayanan kriterler bütünü ile arıtma/geri kazanım endüstrisinde uygulanması, gelecekte yoğun ilgi görecek ve çalışılacak konulardan birisi olacaktır.

Abstract:
The rapid increase in consumption in recent centuries has resulted in industry producing a variety of products. The variety of products causes the consumption of natural resources to increase in the same way. Every new product causes the development in different industries and these industries consume natural resources in their production. Due to the developing world and the increasing need for consumption, it is an unavoidable reality that industries are constantly developing and as a result, natural resources are consumed. Sustainable approaches to the efficient use of natural resources in production have been discussed and models developed for half a century. In recent years, the circular economy has been applied in industries that produce on a real scale. The reuse of waste generated as a result of production, as a necessity of the circular economy, will be an inevitable reality now and in the years to come.
This situation has prompted many municipalities and industies to identify more efficient uses of water resources, including more widespread acceptance of the use of non-conventional water sources (Bixio D., 2006). In this sense, wastewater reuse has emerged as the most viable alternative since it performs two key functions: (i) increasing water supply and (ii) reducing pollution by discharging less wastewater into the environment (Hochstrat R., 2007). There are the many reasons for industries to use its wastewater as a source because of the awareness of community in the recent year. Public verge the companies, which has defined environmental company. Another reason of wastewater reuse in industry is to limitation of water scarcity in their area. Level of ground water decreases due to population growth and inaccessibility of water. In this situation, reusing the advanced industrial wastewater treatment for industrial consumption can be intensively considered as a practical solution for providing the required industrial water and preventing environmental damages resulting in obtaining sustainable development goals in terms of water and wastewater management (Piadeh ve diğ., 2014; Elabras Veiga ve Magrini, 2009). 
Today, in the selection of the treatment method, the most experienced treatment procedures usually find their place in the applications by the treatment industry, but there is no comparison of the experienced treatment procedures within the criteria. In particular, external negative effects, such as carbon dioxide emissions from wastewater treatment plants, are not taken into account. The eminent challenge in wastewater  reuse management lies in the selection of the best available technology for a particular types of criterias for users. The selection of wastewater treatment technology is a multi criteria analysis task. Many factors (criteria) are involved in the decision-making process. There can be many candidate technologies for cirterias. Therefore, selecting the "appropriate technology" is the biggest challenge faced by experts in the wastewater reuse management (Kalbar, 2012).
In addition to the negative effects on operating costs of chemicals used in large quantities, external negative effects on the consumption of chemicals are also ignored. In addition to supporting wastewater reuse in the textile sector, the treatment plants constructed are also expected to contribute to sustainability in a wide range of areas.
This highlights the need to develop a decision support tool that can help decision-makers to select appropriate technology from available wastewater treatment technologies. The decision support tool should provide the ratio-nale behind selecting the appropriate technology based on the decisive factors such as sustainability, life cycle assessment and life cycle costing. The multi criteria decision-making techniques can be efficiently used to evaluate the alternatives (Kalbar, 2012).
After the sector has accepted the importance of wastewater reuse,  the equipments of plant, chemicals and treatment technologies to be used here should be evaluated based on a sustainable approach. The wastewater reclamation plant should be built based on a sustainable approach due to factors such as energy consumption and chemical usage.
The textile industry is considered to be one of the most sector, which used huge amount of water in their production process. Nearly whole dyes and chemicals are implemented in the textile sector. This diversity direct to public institutions to apply high wastewater standard parameters to discharge the wastewater to receiving environment. High standard parameters mean that proven treatment technology should be implemented to industry such as membrane processes, advanced oxidation process. Usage of this treatment technology may be meet the parameters of process water in the textile sector or just adding one treatment train to meet the standard of process water. The whole idea of wastewater reuse is related to sustainability. Sustainability comprise multidimensional concept such as environment, technical, economical and social impact. 
To evaluate all this impact during wastewater reuse project is important to understand of importance of wastewater reuse. In order to apply the treatment technolgy in the facilities mainly based on private company experiences. There is a lack of holistic view in the sector. There are numerous treatment technology but every technology has its advantages and disadvantages in terms of chemical usage, electrical consumption, reliability, investment cost, operational cost becasue of that decision making is important when decided to establish water recovery facilities. Among whole these treatment technology, the integrated sustainability assessment method is necessary in order to choose the best technology by  considering economical, technical and environmental aspects.
In recent decades, there are some decision making software program to compare treatment technology each other. Such as these tools help to decision maker to imply best treatment technology due to demand of end user of water recovery facilities. It is possibility that shareholder can demand less chemical usage in its facility or there can be field limitation. This is because internal and external impacts of criterias should be clarified while assessing of project. All these items show to authorities have to develop decision making tools. 
In this thesis decision making program has been developed in order to choose best treatment technology for wastewater reuse of textile. According to other tools and studies, in this tool scenarios can be compared to each other. All requirements can be different due to demand of end user. According to the importance of criteria can be weighted by user. If importance of land requirement is high user will weight this  
criteria between 0 and 100%. In the decision support program, there are six cirtieria. These are investment cost, operational cost, land requirement, global warming potential, electricity consumption, treatability degree of scenario. These criteria can be increased due to demand of end user but in this thesis decision support program is considered to give simply and quickly conclusion to decision maker. In the program, there are twenty four treatment scenario. All these scenario can be compared each other at the same time. Treatment technologies are separeted three categories. Primary, secondary and tertiary treatment has been chosen. Primary treatment includes Dissolved Air Flotation, Coagulation and Flocculation, Electro coagulation. Secondary treatment includes Conventional Activated Sludge, Sequencing Batch Reactor, Membrane Bio Reactor based on polimeric material (hollow fiber), Membrane Bio Reactor based on ceramaic material (flat sheet). Tertiary treatment includes Nanofiltration and Reverse Osmosis. Microsoft Excel was used to calculate the criteria of the technologies. The criteria were based on flow rate. All criteria can be calculated by the decision support program after the end user enters the flow rate.
For example, the investment cost was calculated between 5 and 100 m3 /hour, then an equation was derived from the graph. This equation is the formula for the investment cost. After determining all criteria, the formula was converted to MATLAB code. TOPSIS was choosen as the method to solve this decision-making problem. All value of criterias is on a cardinal scale. 
End User chooses due to his/her request from these treatment technologies then enter the flow rate, and six wastewater parameter, which is conductivitiy, color, hardness, chemical oxygen demand, total suspended solid, bicarbonate. Limit of these parameters are ristricted limit value. Also target value can be determined by user. Process water demand can be different due to alt categories of textile sector. All criteria, exclude treatment degree, has been connected to flow parameters. Some criteria, such as investment costs, operating costs, are entirely subjective. Within the decision support program, there are default values for calculating these criteria, but they can be changed at the user's request.
The scenarios of water recovery facilities comparision methodology developed in this work can be applied to various decision-making situations encountered while determing the treatment technolgoies scenarios. The decision support tool, used for ranking the scenarios, is simple to understand and easy to implement in a user-friendly computing environment. In addition to, it is flexible enough to incorporate additional criteiras such as relaibility, chemical consumption. The proposed decision support system has been validated through real water recovery facilities. 
Consequently, any criteria that may be important for the user can be brought to the forefront in the selection of treatment scenario. The sub-categories of problems by artificial intelligence with integrated approaches is one of the issues that will find a place in the treatment industry in recent years.