İleri biyolojik atıksu arıtma tesislerinde işletme parametrelerinin doğrudan sera gazı emisyon miktarı üzerindeki etkilerinin belirlenmesi

Öz

Küresel ısınmaya karşı alınan önlemlerin başında, farklı ekonomik sektörler için sera gazı emisyonu kontrolü gelmektedir. Türkiye’nin de taraf olduğu Birleşmiş Milletler İklim Değişikliği Çerçeve Sözleşmesi’ne göre taraflar ekonomik sektörlerden salınan sera gazı miktarlarını yıllık olarak raporlamakla yükümlüdürler. Atık sektörü, insan kaynaklı sera gazı emisyonunun %3’ünü, atıksu arıtımı ise atık sektöründen kaynaklanan sera gazı emisyonunun %20’sini oluşturmaktadır. Bu çalışmada, eşdeğer nüfusu 2344000 olan, biyolojik besi maddesi giderimi yapılan ve çamurun anaerobik olarak çürütüldüğü bir evsel atıksu arıtma tesisinde sera gazı emisyonunu etkileyen faktörler, GPS-X 6.5 model yazılımı kullanılarak incelenmiştir. Bu amaçla, çamur yaşı ve çözünmüş oksijen parametreleri ele alınmıştır. Çamur yaşı için 2, 5, 9, 13 ve 18 gün değerleri test edilmiş ve sırasıyla 0, 618508, 565961, 565681 ve 554684 t CO₂ eşd/yıl doğrudan emisyon miktarı tahmin edilmiştir. Beş günün üzerinde, artan çamur yaşıyla emisyon miktarının azaldığı görülmüştür. Çözünmüş oksijen konsantrasyonu parametresi için 0.5, 1.0, 1.5, 2.0, 2.5 ve 3.0 mg/L değerleri incelenmiştir ve sırasıyla 1455632, 999243, 719380, 583603, 503275 ve 449997 t CO₂ eşd/yıl doğrudan emisyon miktarı tahmin edilmiştir. Havalandırma tankında artan çözünmüş oksijen konsantrasyonu ile doğrudan sera gazı emisyonun azaldığı görülmüştür. Duyarlılık analizi ile sera gazı emisyonuna çözünmüş oksijen parametresinin, çamur yaşı parametresinden daha fazla etkisi olduğu görülmüştür.

Anahtar Kelimeler

• Atıksu arıtma,Çamur yaşı,Çözünmüş oksijen,Modelleme,Nütrient giderimi,Sera gazı emisyonu

Effects of operating parameters on direct greenhouse gas emission in advanced biological wastewater treatment plants

Öz

The major measure taken on global warming is to control greenhouse gas emission for different economic sectors. Within the context of the United Nations Framework Convention on Climate Change (UNFCCC), to which Turkey is party, parties are obliged to report annual greenhouse gas emissions from each economic sector. Greenhouse gas emissions from the waste sector account for approximately 3% of global human-induced greenhouse gas emissions, while wastewater treatment accounts for 20% of the greenhouse gas emissions from waste sector. In this study, factors effecting direct greenhouse gas emission in a wastewater treatment plant with an equivalent population of 2344000 were investigated by using GPS-X 6.5 software. Biological nutrient removal was conducted and sludge was digested under anaerobic conditions in the wastewater treatment plant. Both sludge age and dissolved oxygen parameters were investigated. 2, 5, 9, 13, and 18 days of sludge age were tested, and direct emissions of 0, 618508, 565961, 565681 and 554684 t CO₂ eq/year were calculated, respectively. Direct emission amount decreased with increasing sludge age over five days. Dissolved oxygen emissions of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mg/L were tested, and direct emissions of 1455632, 999243, 719380, 583603, 503275 and 449997 t CO₂ eq/year were calculated, respectively. Direct emission amount decreased with increasing dissolved oxygen concentration in the aeration tank. Considering sensitivity analysis, dissolved oxygen parameter is more effective on greenhouse gas emissions in comparison to the sludge age parameter.

Anahtar Kelimeler

• Wastewater treatment,Sludge age,Dissolved oxygen,Modelling,Nutrient removal,Greenhouse gas emission

Kaynakça

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