ATIK AKTİF ÇAMUR DEZENTEGRASYONU: MEKANİK, TERMAL VE KİMYASAL YÖNTEMLER

Abstract

Çamur dezentegrasyon yöntemleri, atıksu çamurlarının çürüme işleminde hız sınırlayıcı adım olan hidroliz aşamasını elimine etmek, stabilizasyon derecesini ve oluşan biyogaz miktarını arttırmak amacıyla uygulanan ön arıtma yöntemleridir. Bu çalışmada çamura uygulanan farklı dezentegrasyon yöntemlerinin  (mekanik, termal ve kimyasal) çamurun çözünebilirliğine olan etkisi, çözünmüş kimyasal oksijen ihtiyacı (ÇKOİ) parametresindeki değişimler üzerinden irdelenerek kıyaslanmıştır. Elde edilen sonuçlara göre uygulanan prosesler çamurun ÇKOİ içeriğini %34 ila %75 arasında değişen oranlarda arttırmıştır. 150^oC de uygulanan termal yöntem ile kavitasyon sayısının (KS) 0,2 olarak ayarlandığı şartlarda işletilen hidrodinamik kavitasyon en etkin dezentegrasyonu gerçekleştirmiştir. Kimyasal yöntemler kıyaslandığında ise alkali ilaveli yöntemlerin asidik yöntemlerden daha etkin olduğu tespit edilmiştir. Yüksek çözünebilirlik değerlerine ulaşılması ve diğer yöntemlere göre daha ekonomik bir alternatif olmasından dolayı hidrodinamik kavitasyon yönteminin anaerobik çamur çürütme performansının arttırılması için uygun bir yöntem olabileceği sonucuna varılmıştır.

Keywords

• Aktif Çamur,Dezentegrasyon Yöntemleri,Çözünebilir KOİ

Disintegration of Waste Activated Sludge: Mechanical, Thermal and Chemical Methods

Abstract

Sludge disintegration methods are the pretreatment methods applied for eliminating rate-limiting hydrolysis step of anaerobic digestion process and increasing stabilization level and the amount of produced biogas. In this study, the effect of several disintegration methods (thermal, mechanical and chemical) on the solubility of sludge components was evaluated and compared with respect to the variation of soluble chemical oxygen demand (SCOD) parameter. According to the results, the applied methods increased SCOD of sludge by 34% to 75%. The thermal method carried out at 150^oC and hydrodynamic cavitation operated under the condition of cavitation number (Cv) of 0.2 achieved the most efficient sludge disintegration. When the chemical methods were compared, alkali methods were found to be generally more efficient than acidic ones. While it  is a more economical alternative and higher solubilization was achieved, hydrodynamic cavitation can be an appropriate method for increasing the performance of anaerobic digestion process.

Keywords

• Activated sludge,Disintegration methods,Soluble COD

References

1. Anderson, N.J., Dixon, D.R., Harbour, P.J., Scales, P.J. (2002) Complete characterisation of thermally treated sludges, Water Science and Technology, 46(10), 51-54.
2. APHA, AWWA, WEF, (1998) Standard Methods for the Examination of Water and Wastewater, 20th ed., American Public Health Association, Baltimore.
3. Badve, M., Gogate, P., Pandit, A., Csoka, L. (2013) Hydrodynamic cavitation as a novel approach for wastewater treatment in wood finishing industry, Separation and Purification Technology, 106, 15-21. doi:10.1016/j.seppur.2012.12.029
4. Bougrier, C., Albasi, C., Delgen`es, J.P., Carr`ere, H. (2006) Effect of ultrasonic, thermal and ozone pre-treatments on waste activated sludge solubilisation and anaerobic biodegradability, Chemical Engineering and Processing, 45, 711-718. doi:10.1016/j.cep.2006.02.005
5. Filibeli, A. (1998) Arıtma Çamurlarının İşlenmesi, Dokuz Eylül Üniversitesi Yayınları, No: 225, ISBN 975-441-117-4.
6. Filibeli, A., Erden Kaynak, G. (2006) Arıtma çamuru miktarının azaltılması ve özelliklerinin iyileştirilmesi amacıyla yapılan ön işlemler, İtü dergisi/e Su Kirlenmesi Kontrolü , 16(1-3), 3-12.
7. Gogate, P. R., Pandit, A. B. (2000) Engineering design methods for cavitation reactors II:Hydrodynamic cavitation, AICHE Journal, 46(8), 1641-1649. doi: 10.1002/aic.690460815
8. Gogate, P. R., Pandit, A. B. (2001) Hydrodynamic cavitation reactors: A state of the art review, Reviews in Chemical Engineering, 17 (1), 1-85.

9. Haug, T.R., Stuckey, D.C., Gossett, J.M., McCarty, P.L. (1978) Effect of thermal pretreatment on digestibility and dewaterability of organic sludges, Water Environment Federation, 50, 73-85.
10. Kepp, U., Solheim, O.E. (2001) Meeting increased demands on sludge quality experience with full scale plant for thermal Disintegration, Proceedings 9th World Congress, Anaerobic Conversion for Sustainability, Antwerpen, Belgium.
11. Kim, J., Park, C., Kim, T-H., Lee, M., Kim, S., Kim, S-W., Lee, J. (2003) Effects of various pretreatments for enhanced anaerobic digestion with waste activated sludge, Journal of Bioscience and Bioengineering, 95, 271–275. doi:10.1016/S1389-1723(03)80028-2
12. Lee, I., Han, J.I. (2013) The effects of waste-activated sludge pretreatment using hydrodynamic cavitation for methane production, Ultrasonics Sonochemistry, 20(6), 1450-1455. doi:10.1016/j.ultsonch.2013.03.006
13. Myszograj, S., Jędrczak, A., Suchowska-Kisielewicz, M., Sadecka Z. (2013) Thermal and chemical disintegration of excessive sewage sludge, The 1st Global Virtual Conference, Goce Delchev University Macedonia & Thomson Ltd., Slovakia.
14. Neyens, E., Baeyens, J. (2003) A review of thermal sludge pretreatment processes to improve dewaterability, Journal of Hazardous Materials, 98, 51-67.doi:10.1016/S0304-3894(02)00320-5
15. Odegaard, H., Paulsrud, B., Karlsson, I. (2002) Wastewater sludge as a resource: sludge disposal strategies and corresponding treatment technologies aimed at sustainable handling of wastewater sludge, Water Science and Technology, 46(10), 295-303.
16. Ozonek, J. 2012. Application of Hydrodynamic Cavitation in Environmental Engineering, Taylor and Francis Group, London.
17. Ray, B.T., Rajan, R.V., and Lin, J.G. (1990) Low-level alkaline solubilization for enhanced anaerobic digestion, Research Journal of the Water Pollution Control Federation, 62(1), 81-87.
18. Valo, A., Carre, H., Delgenes, J.P. (2004) Thermal, chemical and thermo-chemical pre-treatment of waste activated sludge for anaerobic digestion, Journal of Chemical Technology and Biotechnology,79, 1197-1203. doi: 10.1002/jctb.1106
19. Vranitzky, R., Lahnsteiner, J. (2005) Sewage sludge disintegration using ozone – A method of enhancing the anaerobic stabilization of sewage sludge, VA TECH WABAH, R&D Process Engineering, Siemensstrasse 89, A-1211, Vienna, Austria.
20. Wilson, C.A., Novak, J.T. (2009) Hydrolysis of macromolecular components of primary and secondary wastewater sludge by thermal hydrolytic pretreatment, Water Research, 43(18), 4489-4498. doi:10.1016/j.watres.2009.07.022
21. Woodard, S., Wukasch, R. (1994) A hydrolysis/thickening/filtration process for the treatment of waste activated sludge, Water Science and Technology, 30(3), 29-38.
22. Yinguang Chen_, Su Jiang, Hongying Yuan, Qi Zhou, Guowei Gu (2007) Hydrolysis and acidification of waste activated sludge at different pHs, Water Researh, 41, 683-689. doi:10.1016/j.watres.2006.07.030