تأثیر پدیدۀ تخریب حد نصاب احساس بر عملکرد سازوکار شکار میکروبی درکاهش لجن مازاد

نوع مقاله : پژوهشی اصیل (کامل)

نویسندگان
پونه وثوقی 1
حسن امینی راد 2
1 دانشجوی کارشناسی ارشد مهندسی عمران-محیط زیست،دانشگاه صنعتی نوشیروانی بابل
2 دانشگاه صنعتی نوشیروانی بابل، دانشکده مهندسی عمران،گروه مهندسی محیط زیست
10.22034/22.6.125
چکیده
پیشینه: امروزه دفع و تصفیه لجن ناشی از تصفیه‌خانه‌های فاضلاب به دلیل عوامل زیست‌محیطی حائز اهمیت است. استفاده از راکتور بی‌هوازی جانبی در سیستم لجن فعال که با نام تجاری کانیبال(Cannibal) شناخته می‌شود، یکی از روش‌های به‌کار رفته برای کاهش نرخ تولید لجن در خط تصفیه فاضلاب می‌باشد. در این پژوهش با هدف طراحی یک سیستم ترکیبی مناسب از فرآیند کانیبال و پدیده‌ی تخریب حد نصاب احساس QQ(Quorum Quenching) و به‌دنبال آن تقویت مکانیسم شکار میکروبی به بهبود راندمان کاهش لجن مازاد پرداخته‌ شده‌است. روش: بر این اساس این پروژه در دو فاز آزمایشگاهی طراحی شد و راکتورهای مربوطه با فاضلاب مصنوعی راهبری شدند. در فاز اول از فرآیند کانیبال در قالب یک راکتور آزمایشگاهی استفاده شد و در فاز دوم با تعبیه کردن یک راکتور هوادهی مجزا و اضافه کردن باکتری Rhodococcus sp. BH4، باکتری خاموش‌کننده‌ی حدنصاب احساس(Quorum Sensing) که در یک ساختار پلیمری آلژینات قرار گرفتند و به‌عنوان دانه‌های QQ معرفی می‌شوند فرآیند کانیبال اصلاح شده طراحی شد. یافته‌ها: نتایج نشان داد که حضور دانه‌های QQ منجر به افزایش چشم‌گیر جمعیت یوکاریوت‌های شکارچی، پرتوزوآها، شده‌است. همچنین ضریب بازدهی (Yobs) در راکتور کانیبال شاهد و کانیبال اصلاح شده به ترتیب برابر 389/0 و 092/0 بدست آمد که کاهش چشم‌گیر 77 درصدی را به‌همراه داشته‌است. احداث تانک پیش‌تصفیه QQ باعث تقویت مکانیسم شکار میکروبی در سیستم کانیبال و افزایش چشمگیر راندمان این سیستم شده و لجن مازاد بیولوژیکی به‌طور قابل ملاحظه‌ای کاهش می‌یابد. کلمات کلیدی: لجن مازاد، فرآیند کانیبال، شکار میکروبی، تخریب حد نصاب احساس

کلیدواژه‌ها

موضوعات

عنوان مقاله English

The Effect of Quorum Quenching System on Microbial Predation Mechanism in Excess Sludge Reduction

نویسندگان English

P. Vosughi 1
H. Amini Rad 2
1 Department of Environmental Engineering, Faculty of civil engineering, Noshirvani University of technology
2 Assistance Professor, Department of environmental engineering, Faculty of civil engineering. Babol Noshirvani University of technology
چکیده English



Abstract:



The removal and treatment of sludge from municipal wastewater treatment plants is important due to environmental factors, so there is a significant incentive to discover and develop strategic plans to reduce excess sludge production in sewage treatment processes. Activated sludge system is used as the main biological process for municipal and industrial wastewater treatment and an excess sludge production rate in this process is between 15-100 liters per kilogram of removed BOD5. One of The usages an anaerobic reactor in the activated sludge system known as the Cannibal process that is one of the conventional methods used to reduce the sludge production rate at the sewage treatment line, which has low operating costs and relative simplicity to process design. The system's overall reducing efficiency is generally up to 50%. The purpose of this process is less production of sludge and also improvement of wastewater quality. In order to achieve reduction in excess sludge production, different mechanisms are considered which include microbial predation, uncoupling metabolism, endogenous metabolism and lysis-cryptic growth. The microbial predation mechanism is one of the important mechanisms in the cannibal process that is a suitable choice for reduction of excess sludge because of its low strategic cost and environmental compatibility. The objective of this research is the applicability of Quorum quenching (QQ) phenomenon in a conventional Cannibal process for enhancing the microbial predation mechanism to improve the efficiency of reducing sludge and other effective sludge parameters. Quorum sensing system is a new method of managing social behavior of microbial Population. The decomposition of Acyl Homosserine Lactones (AHL) is the most usable and practical way for creating disturbance in Quorum sensing system. For increasing the free bacteria population, Quorum quenching agent is used in the aerobic tank. These enhance microbial predation and show decrease in Extracellular Polymeric Substances (EPS). So far many bacteria with QQ feature are reported in biological wastewater treatment reactors. The basis of this project was designed in two laboratory phases and the reactors were operated with synthetic wastewater. In the first phase, the cannibal process was used in the form of a laboratory reactor, and in the second phase, by installing a separate aeration reactor and adding the Rhodococcus sp.BH4 bacteria, a quorum quenching bacteria, in a polymeric structure of alginate and introduced as QQ beads. The modified Cannibal process was designed. Microbial predation mechanism is one the methods that increase population of eukaryotic predators by changing the microbial structure of activated sludge system; by this method, efficiency of reduction of excess sludge production is increased. The results showed that the presence of QQ grains led to an increase in the number of eukaryotic species. The yield coefficient (Yobs) in the modified Cannibal and the control Cannibal was 0.389 and 0.092, respectively, with a significant decrease of 77%. Also, the results of EPS, which indicates the proper functioning of this system, has been analyzed and investigated. The applied QQ primary treatment enhances the Microbial predation mechanism in Cannibal system, significantly improve the efficiency of this system, and biological excess sludge notably is decreased.



Keywords: Excess Sludge, Cannibal Process, Microbial Predation, Quorum Sensing/Quenching

کلیدواژه‌ها English

excess sludge
Canibal Process
Microbial predation
Quorum Quenching
1. Wei Y, Van Houten RT, Borger AR, Eikelboom DH, Fan Y. Minimization of excess sludge production for biological wastewater treatment. Water Res. 2003;37(18):4453–67.
2. Franzini AKLJB, Cairncross S, Carruthers I, Curtis D, Feachem R, Baldwin BG, et al. Water Resources Engineering t ~ Boher and R. Wastewater Engineering : Treatment, Disposal and Reuse Edited by Geor, qe Tchohano, qlous Evaluation for Village Water Supply Planning Hydraulics of Groundwater A Sourcebook of Basic Hydrologic and Ecologic. 1980;3:1980.
3. Erden G, Demir O, Filibeli A. Disintegration of biological sludge: Effect of ozone oxidation and ultrasonic treatment on aerobic digestibility. Bioresour Technol. 2010;101(21):8093–8.
4. Spinosa, L., Vesilind, P. A., Sludge into biosolids: processing, disposal and utilization, IWA Publishing, UK, 2001.
5. Chudoba, P., Chudoba J., Capdeville B., (1992), The Aspect of Energe2c Uncoupling of Microbial Growth in the Activated Sludge Process-OSA system, Wat. Sci. Tech., 26, 2477-2480.
6. Novak, J. T., Chon, D. H., Cur2s, B. A., Doyle, M., 2006, Reduc2on of Sludge Genera2on Using the Cannibal Process: Mechanisms and Performance, in: Residuals and Bio-solids managementConference.
7. Chudoba, P., Chudoba J., Capdeville B., (1992), The Aspect of Energe2c Uncoupling of Microbial Growth in the Activated Sludge Process-OSA system, Wat. Sci. Tech., 26, 2477-2480.
8. Huang, X., Liang, P., Qian, Y., (2007), Excess sludge reduc2on induced by Tubifex in a recycled sludge reactor, Journal of Biotechnology, 127, 443-451.
9. J.T. Novak, D.H. Chon, B.A. Curtis, M. Doyle, Biological solids reduction using the Cannibal process, Water Environ. Res. 79 (2007) 2380–2386. doi:10.2175/106143007x183862.
10. L. Sun, C.W. Randall, J.T. Novak, The influence of sludge interchange times on the oxic-settling-anoxic process, Water Environ. Res. 82 (2010) 519–523.
11. A. Takdastan, N. Mehrdadi, A. Eslami, Effect of various ORP on excess sludge reduction in oxic-settling-anaerobic batch activated sludge, Int. J. Microbiol. Immunol. Res. 2 (2014) 41–47.
12. A. Takdastan, F. Karimi, N. Orooji, Effect of Oxic-Settling Anoxic Process on Operation Parameters and Biological Excess Sludge Reduction in Sequencing Batch Reactor Activated Sludge, J. Maz. Univ. Med. Sci. 28 (2018).
13. Vitanza R, Arana Sarabia ME. Preliminary Evaluation of Sludge Minimization by a Lab Scale OSA (Oxic-Settling-Anaerobic) System Chemical Eeginearing Transaction 2016; 49: 469-474.
14. Fuqua, W. C., Winans, S. C., Greenberg, E. P., (1994), Quorum sensing in bacteria: the LuxR-LuxI family of cell density-responsive transcrip2onal regulators, Journal of Bacteriology, 176, 269-275.
15. Hooshangi, S., Bentley, W. E., (2008), From unicellular proper2es to mulcellular behavior: bacteria quorum sensing circuitry and applica2ons, Current opinion in biotechnology, 19.555-550.
16. Hu, J. Y., Fan, Y., Lin, Y. H., Zhang, H. B., Ong, S. L., Dong, N., Xu, J. L., Ng, W. J ,.Zhang, L. H., (2003), Microbial diversity and prevalence of virulent pathogens in biofilms developed in a water reclama2on system, Research in microbiology, 154, 623-629.
17. Cheong, W.-S., Lee, C.-H., Moon, Y.-H., Oh, H.-S., Kim, S.-R., Lee, S. H ,.Lee, C. H., Lee, J.-K., (2013), Isola2on and Identification of Indigenous Quorum Quenching Bacteria, Pseudomonas sp. 1A1, for Biofouling Control in MBR, Industrial & Engineering Chemistry Research, 52, 10554-10560.
18. Salehiziri M, Amini H, Novak JT. Disruption of cell to cell communication in the aeration unit of a cannibal process : Sludge reduction efficiency and related mechanisms. Biochem Eng J. 2018;137:326–33.
19. Salehiziri M, Amini H, Novak JT. Chemosphere Preliminary investigation of quorum quenching effects on sludge quantity and quality of activated sludge process. Chemosphere. 2018;209:525–33.
20. S.R. Kim, H.S. Oh, S.J. Jo, K.M. Yeon, C.H. Lee, D.J. Lim, C.H. Lee, J.K. Lee,Biofouling control with bead-entrapped quorum quenching bacteria inmembrane bioreactors: physical and biological effects, Environ. Sci. Technol.47 (2013) 836–842.
21. Association APH, Federation WPC, Federation WE, “Standard methods for the examination of water and wastewater“ Vol 2 American Public Health Association, 1915.
22. Wang, J., Zhao, Q., Jin, W., Lin, J. (2008). “Mechanism on minimization of excess sludge in oxicsettling anaerobic (OSA) process”, Frontiers of Environmental Science & Engineering in China, 2(1), 36–43.
23. M.F. Dignac, V. Urbain, D. Rybacki, A. Bruchet, D. Snidaro, P. Scribe, Chemical description of extracellular polymers: Implication on activated sludge floc structure, in: Water Sci. Technol., 1998: pp. 45–53. doi:10.1016/S0273-1223(98)00676-3.
24. S. R. Kim et al., “Biofouling control with bead-entrapped quorum quenching bacteria in membrance bioreactors: Physical and biological effects, ’’ Environ. Sci. Technol., vol. 47, no. 2, pp. 836-842, 2013.
25. G.P. Sheng, H.Q. Yu, Characterization of extracellular polymeric substances of aerobic and anaerobic sludge using three-dimensional excitation and emission matrix fluorescence spectroscopy, Water Res. 40 (2006) 1233–1239. doi:10.1016/j.watres.2006.01.023.
26. X.Y. Li, S.F. Yang, Influence of loosely bound extracellular polymeric substances (EPS) on the flocculation, sedimentation and dewaterability of activated sludge, Water Res. 41 (2007) 1022–1030. doi:10.1016/j.watres.2006.06.037.
27. Y.C. Li, J.R. Zhu, Role of N-acyl homoserine lactone (AHL)-based quorum sensing (QS) in aerobic sludge granulation, Appl. Microbiol. Biotechnol. 98 (2014) 7623–7632. doi:10.1007/s00253-014-5815-3.
28. C.H. Tan, K.S. Koh, C. Xie, M. Tay, Y. Zhou, R. Williams, W.J. Ng, S.A. Rice, S. Kjelleberg, The role of quorum sensing signalling in EPS production and the assembly of a sludge community into aerobic granules, ISME J. 8 (2014) 1186–1197. doi:10.1038/ismej.2013.240.
29. A.J. Silva, J.A. Benitez, J.H. Wu, Attenuation of bacterial virulence by quorum sensing-regulated lysis, J. Biotechnol. 150 (2010) 22–30. doi:10.1016/j.jbiotec.2010.07.025.
30. H.S. Oh, S.R. Kim, W.S. Cheong, C.H. Lee, J.K. Lee, Biofouling inhibition in MBR by Rhodococcus sp. BH4 isolated from real MBR plant, Appl. Microbiol. Biotechnol. 97 (2013) 10223–10231. doi:10.1007/s00253-013-4933-7.
31. N. Bouayed, N. Dietrich, C. Lafforgue, C.H. Lee, C. Guigui, Process-oriented review of bacterial quorum quenching for membrane biofouling mitigation in membrane bioreactors (MBRs), Membranes (Basel). 6 (2016). doi:10.3390/membranes6040052.
32. L. SHAO, P. HE, G. YU, P. HE, Effect of proteins, polysaccharides, and particle sizes on sludge dewaterability, J. Environ. Sci. 21 (2009) 83–88. doi:10.1016/S1001-0742(09)60015-2.
33. P. Madoni, Estimates of ciliated protozoa biomass in activated sludge and biofilm, Bioresour. Technol. 48 (1994) 245–249. doi:10.1016/0960-8524(94)90153-8.
34. W. Pauli, K. Jax, S. Berger, Protozoa in Wastewater Treatment : Function and Importance, Handb. Environ. Chem. Vol. 2 Part K. 2 (2001) 203–252. doi:10.1007/10508767-3.
مهندسی عمران مدرس
دوره 22، شماره 6
آذر و دی 1401
صفحه 125-133