Laboratuvar ölçekli hareketli yataklı biyofilm reaktöründe anammox kültürünün zenginleştirilmesi ve dinamik simülasyonla proses kinetiğinin belirlenmes
Enrichment of anammox culture in laboratory scale moving bed biofilm reactor and determination of processes kinetics by dynamic simulation
Yazar: MUHAMMET BURAK BOZÇELİK
Danışman: PROF. DR. HAYRETTİN GÜÇLÜ İNSEL ; DOÇ. DR. DİĞDEM GÜVEN
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Çevre Mühendisliği Ana Bilim Dalı / Çevre Bilimleri, Mühendisliği ve Yönetimi Bilim Dalı
Derece: Yüksek Lisans, 2020
Konu: Çevre Mühendisliği = Environmental Engineering
Dizin: Kinetik modelleme = Kinetic modelling

Özet:
Azot içeren atıksular su kaynaklarına deşarj edildiğinde çözünmüş oksijen konsantrasyonunun azalmasına ve ötrofikasyona sebep olarak su ekosisteminin dengesini bozarken, su kaynağının içme suyu olarak kalitesi de düşer. Atıksu içerisindeki azot bileşikleri, çevreye ve insan sağlığına olan zararlı etkileri sebebiyle bertaraf edilmek zorundadır. 
Dünyada ve ülkemizde genel olarak azot giderimi için nitrifikasyon ve denitrifikasyon proseslerinin ardışık olarak kullanımı yaygındır. Ancak nitrifikasyon prosesinin oksijen gereksinimine bağlı yüksek enerji ihtiyacı ve denitrifikasyon prosesinde ilave karbon ihtiyacı olması sebebiyle atıksu arıtma tesisleri için maddi yük oluşturmaktadır. Anaeorobik amonyum oksidasyonu (Anammox) prosesi nitrifikasyon ve denitrifikasyon proseslerine alternatif olabilecek yeni ve ekonomik bir proses olarak son yıllarda dikkat çekmektedir. Anammox prosesi anaeorobik şartlar altında amonyum ve nitriti birlikte oksitleyebilen mezofilik bakteriler yardımıyla işletilmektedir. Proses sonucunda azot gazı ve bir miktar nitrat oluşmaktadır.
Bu çalışmada laboratuvar ölçekli hareketli yataklı biyofilm biyoreaktöründe Anammox biyokütlesi zenginleştirilerek farklı koşullarda işletilmesi ve elde edilen datanın dinamik simülasyon uygulamasıyla kalibre edilerek model parametreleri ve proses kinetiğinin belirlenmesi amaçlanmıştır. 
Çalışma kapsamında atıksu arıtma tesisinden alınan aktif çamur aşı olarak kullanılmış ve yukarı akışlı reaktör içerisinde biyofilm taşıyıcı malzeme kültür yatağı olarak hazırlanmıştır. Reaktöre aşılama yapıldıktan sonra sentetik Anammox besi ortamıyla beslenmiştir. Besi yerinde bakterilerin biyofilm oluşturabilmesi amacıyla taşıyıcı malzeme kullanılmıştır. 60. günden itibaren hareketli yataklı biyofilm reaktöründe Anammox aktivitesi görülmeye başlamıştır. Takip eden 90 gün içerisinde aktif ve baskın Anammox kültürünün zenginleştiği görülmüştür. Reaktörün farklı besleme/işletme koşullarında çalıştırılması durumunda proses işletimi incelenerek performans değerlendirmesi yapılmıştır. Ayrıca çalışma kapsamında zenginleştirme dönemine ait data serisi SUMOTM 19 (Nyons, Fransa) programı kullanarak dinamik simülasyon çalışması gerçekleştirilerek proses kinetiği ve bileşenleri ortaya konmuştur. Anammox kültürünün hareketli yataklı biyofilm reaktöründe zenginleştirilmesi durumunda Anammox kültürünün ve reaktörde etkili olan heterotrofik organizmalar ve aerobik amonyum oksitleyicilerin proses kinetiğine ait bulgular detaylı olarak ortaya konmuştur. 
Çalışmada ortalama reaktör ömrü boyunca 350,42 kgN/m3.gün azot giderim hızına ulaşılmış, anammox stokiyometrisine uygun olarak NO3--N/NH4+-N oranı ortalama 0,22 olarak elde edilmiştir. NO2--N/NH4+-N oranı ise ortalama 1,4 olarak hesaplanmıştır. Simülasyon çalışmasıyla Anammox çoğalma hızı 20 °C için 0,06, ölüm hızı 0,015 olarak tahmin edilmiştir. 
Anammox zenginleştirmesinin dinamik simülasyon ile modellenmesi ve kinetiğinin belirlenmesi ile ilgili literatürde sınırlı sayıda çalışma olması nedeniyle, bu çalışma literatür açısından önemlidir.

Abstract:
When nitrogen-containing wastewaters discharged into water bodies or marine ecosystems, it disrupts the balance of the water ecosystem by causing decrease in dissolved oxygen concentration, eutrophication and the quality of the water source decreases as drinking water. 
Also nitrogen containing waters threat to public health. Nitrogen causes blue diaper syndrome, neural birth defects and some specific types of cancer. For this reason, nitrogen-containing wastewaters should not be discharged into receiving environments.
Sequantial use of nitrification and denitrification processes is common in the world and in our country. However, due to the high energy requirement by aeration of the nitrification process due to the oxygen requirement and the additional carbon requirement for denitrification process, they cause financial commitment for wastewater treatment plants. 
Also nitrification and denitrification processes have high amount sludge production and this situation increases the need for labor and causes sludge management problems for wastewater treatment plants. Because of these mentioned reasons new nitrogen removal processes are investigated around the world.
Anaerobic ammonium oxidation (Anammox) process draws attention as a new and economical process that is an alternative to nitrification and denitrification processes. The Anammox process is efficient for removal of wastewaters that have high nitrogen concentration. 
The Anammox process is operated with the help of mesophilic bacteria that can oxidize ammonium and nitrite together under anaerobic conditions. Dinitrogen gas and some nitrate are formed at the final of the process. Anammox bacteria has lower maximum spesific growth rate according to nitrification or denitrification. Because of this reason sludge production of process is lower. 
However Anammox bacteria are sensitive species, that can easily effected by temperature or pH. Also it can easily inhibited by dissolved oxygen concentration, dissolved nitrogen inorganics or solid or dissolved organic concentrations. The Anammox process has become widespread arund the world in recent years and therefore information about it is limited. 
Especially many studies are carried out on Anammox biofilms and a wide variety of results are obtained. The reason of this; biofilms are mixed cultures and many bacteria species can be lived on this mixed culture. Therefore, it is difficult to obtain absolute information about pure Anammox cultures in biofilm processes. For this reason, many studies are conducted on biofilms.
The aim of the study is to enrich Anammox culture from activated sludge. With this aim a laboratory scale moving bed biofilm bioreactor was operated under different conditions. The study also aims to determine the model parameters and process kinetics by calibrating the obtained reactor information and data with dynamic simulation. 
Within the scope of the study, activated sludge that taken from the wastewater treatment plant was prepared for enrichment process. Then activated sludge was used as an inoculum and biofilm carriers were prepared as a culture bed in the upstream reactor. After the inoculation, it was fed with synthetic Anammox nutrients and trace elements. 
As of the 60th day, Anammox bacteria have been observed in the moving bed biofilm reactor. It was observed that the active and dominant Anammox culture was enriched in the following 90 days. 
With the enrichment of the Anammox culture, in case the reactor is operated in different feed / operating conditions. In accordance the purpose of the study, aeration process were carried out for the process for partial nitrification and Anammox combine test. Also wastewater feeding trials carried out for wastewater adaptation of Anammox bacteria. 
The process operation was examined and performance evaluation was made according to tests. As a result, information about the Anammox bacteria has been obtained through experimental studies.
After the enrichment of the Anammox bacteria culture, the process operations were examined and performance evaluation was accomplished according to different feed and operating conditions of reactor. 
Additionally, in the scope of the thesis, the process kinetics and components were revealed by the data series of the enrichment period was processed as dinamic simulation in the SUMOTM 19 (Nyons, France) program. 
As a result of this study, process kinetics of the Anammox culture and the heterotrophic organisms and aerobic ammonium oxidizers, that are effective in the reactor, have been presented in detail when the Anammox culture is enriched in a moving bed biofilm reactor. 
As a result of the study, average nitrogen removal rate of reactor was reached to 350.42 kgN/m3.day during the reactor life. 
And the average NO3--N/NH4+-N ratio was obtained as 0,22. The average ratio of NO2--N/NH4+-N was calculated as 1,4 on average. 
With the dynamic simulation of study, the maximum spesific growth growth rate of Anammox was estimated as 0,06 for 20 ° C and the death rate as 0,015. 
It is thought that more accurate results will be obtained according to the Anammox process and Anammox bacteria with the increase of studies on determining the kinetics of the Anammox process and Anammox bacteria with dynamic simulation over time. Thus, by making comparisons between studies, it will be possible to have a wider information about Anammox bacteria and its process.
However recently around the globe, due to the restricted number of studies in the literature about modeling of Anammox enrichment with dynamic simulation and determining its kinetics with dinamic simulation, this study is important in terms of the literature.