Selda MURAT HOCAOĞLU, İpek ERZİ, Şeyla ERGENEKON

CENTRALIZED VERSUS DECENTRALIZED WASTEWATER REUSE: A CASE STUDY FOR A TOURISTIC AREA

In this study, centralized and decentralized wastewater reuse alternatives were compared in terms of water saving potential and costs for a touristic case study area in Antalya, Turkey. The results of decentralized reuse revealed that the maximum water saving of a hotel is limited with either amount of wastewater generated or ratio of irrigated landscape area to bed number. The breakpoint for the case study area is estimated as 50 m2 /bed. As a result, in hotels where the ratio of irrigated area is less than 50 m 2 /bed, wastewater reuse may not be cost effective. In case of centralized wastewater reuse, supply and demand is balanced and as a result 60% more water saving may be achieved for the case study area. Furthermore, investment and operation cost of centralized reuse are considerably low and the price of reclaimed water is lower than price of service water. The average unit price of reclaimed water used as irrigation water was found to be 1.29 €/m3 in decentralized reuse, while the unit price was found to be 0.35 €/m3 in centralized reuse; which brings forth an internal rate of return by 20% and a 5-year payback period.

Merkezi ve Yerinde Atıksu Geri Kazanımının Karşılaştırılması: Bir Turizm Bölgesi için Örnek Çalışma

Bu çalışmada, merkezi ve yerinde atıksu geri kazanım alternatiflerinin, su tasarruf potansiyeli ve maliyeti, Antalya’daki bir turizm bölgesi için karşılaştırılmıştır. Yerinde atıksu geri kazanımı uygulamasında, geri kazanılabilecek su miktarının, oluşan atıksu miktarı ve otelin sulama yapılan yeşil alan büyüklüğünün, yatak sayısına oranı ile ilgili olduğu belirlenmiştir. Ġncelenen turizm bölgesi için, kırılma noktasının 50 m2 /yatak olduğu tahmin edilmiştir. Bu doğrultuda, sulanan yeşil alan büyüklüğünün yatak sayısına oranının, bu değerin altında olduğu otellerde, yerinde atıksu geri kazanımı ekonomik olmayabilir. Merkezi atıksu geri kazanım uygulanması durumunda ise, atıksu kaynağı ve ihtiyaç arasında denge sağlanabilecek, incelenen turizm bölgesi için yerinde arıtmaya kıyasla %60 daha fazla su geri kazanılabilecektir. Merkezi atıksu geri kazanımının ilk yatırım ve işletme maliyetleri de yerinde arıtmaya kıyasla oldukça düşük bulunmuş ve geri kazanılacak suyun maliyetinin, şebeke suyunun altında olacağı tahmin edilmiştir. Yerinde geri kazanım için, sulama suyu olarak kullanılabilecek arıtılmış suyun, ortalama birim fiyatı 1,29 €/m3 olarak hesaplanmış, buna karşın, merkezi atıksu geri kazanımında, arıtılmış suyun 0,35 €/m3 bedel ile otellere satılması durumunda, % 20 iç verim oranı ve 5 yıllık geri ödeme süresinin sağlanabileceği belirlenmiştir.

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