THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHAM VIET HUNG BUBBLELESS AERATION FOR AMMONIA OXIDATION IN WASTEWATER TREATMENT USING MEMBRANE BIOFILM REACTOR (MBfR) BACHELOR THESIS Study Mode : Full-Time Major : Environmental Science and Management Faculty : International Programs Office Batch : 2013 - 2017 THAI NGUYEN - 2017 DOCUMENTATION PAGE WITH ABSTRACT Thai Nguyen University Of Agriculture And Forestry Degree Program: Bachelor of Environmental Science and Management Student name: Pham Viet Hung Student ID: DTN 1354120159 BUBBLELESS AERATION FOR AMMONIA OXIDATION IN WASTEWATER TREATMENT USING MEMBRANE Thesis Title: BIOFILM REACTOR ( MBfR) Professor Chun-Hsiung Hung, National Chung Hsing Supervisor (s): University, Taiwan. Nguyen The Hung - Thai Nguyen University of Agriculture and Forestry, Vietnam. Abstract: A hollow fiber membrane reactor was utilized to create a halfway nitrification reactor as a pre-treatment framework for ANAMMOX supplement removal. Using a silicone membrane to limit oxygen exchange, a biofilm treatment system was made, with biomass attaching on the membrane surface.
The framework operated at room temperature with a very low dissolved oxygen concentration. Nitrite production was evident, with little nitrate created in the system. The framework treated high ammonium concentration and low ammonium concentration. Ammonium oxidizing organisms dominated the microbial group, while nitrite oxidizing bacteria were suppressed and growth was limited.
This verified that a low dissolved-oxygen condition selects for AOB, and the silicone membrane is an effective method of controlling oxygen transfer. 1 Key-words: Hollow fiber, ANAMOX, silicone membrane, AOB, dissolved oxygen concentration Number of pages: 51 Date of submission: 25/9/2017 Supervisor‟s signature 2 ACKNOWDLEDGEMENTS I would like firstly to emphasize the sincere appreciation to lecturers in the Advanced Education Progarm (AEP) as well as lecturers in Thai Nguyen University of Agricultural and Forestry, who have lectured me profound knowledge not only for my subjects but also for my soft skills and gave me a chance to do my thesis abroad. In addition, I would like to thank all supports and help from Civil and Environmental Engineering Department, National Chung Hsing University for the time I conducted my research in Taiwan. It is my pleasure to work with a profound supervisor - Professor Chun-Hsiung Hung, who always helped me whenever I am in need.
He also provided me the best conditions, supported all materials for my research and discussed about any problems I got whenever I did experiments in his Biotechnology Lab. I would like to give special thank to Associated Professor. Nguyen The Hung, who always supported and cheered me up whole the time I worked oversea. He also helps me a lot in spending much time for checking my thesis report.
I consider it is an honor to work with Mr. Lin and Ms. Wendy, 2 exceptional master students, who particularly helpful in guiding me toward a qualitative methodology and inspiring me in whole period of internship time. They are always helpful, friendly and very kind with me.
Without their guidance, I cannot accomplish this thesis. 3 Finally, I would like to express my gratitude to my family and friends, who always beside me all the time. Their helps, supports and encouragements created the pump leading me to success. Sincerely, Pham Viet Hung 4 TABLE OF CONTENTS DOCUMENTATION PAGE WITH ABSTRACT.
3 TABLE OF CONTENTS. 5 LIST OF FIGURES. 6 LIST OF TABLES. 7 LIST OF ABBREVIATIONS.
10 PART 2: LITERATURE REVIEW. Nutrients in wastewater:. Nitrogen Removal Procedures:. Source-separated urine.
Models for bubble-less oxygen transfer. MBfR as biofilm treatment system. 15 PART 3: METHODS AND MATERIALS. Selection of Method:.
Preparation of the medium:. Analyzing the water samples:. 47 5 LIST OF FIGURES Figure 1: The Ion Chromatography Equipment. 24 Figure 2: Chromatogram and Results of AOB in (03/27/2017).
25 Figure 3: Chromatogram and Results of water samples in Control tube (04/05/2017). 26 Figure 4: Chromatogram and Results of Water sample in Test tube (04/05/2017). 28 Figure 5: Chromatogram and Results of Water samples in Control tube (04/10/2017). 29 Figure 6: The Chromatogram and Results of Water samples in Test tube (04/10/2017).
30 Figure 7: The Chromatogram and Results of Water samples in Control tube (04/17/2017). 31 Figure 8: The Chromatogram and Results of Water samples in Test tube (04/17/2017). 32 Figure 9: The Chromatogram and Results of Water samples in Test tube (04/24/2017). 33 Figure 10: The Chromatogram and Results of Water samples in Control tube (01/05/2017) 35 Figure 11: The Chromatogram and Results of Water samples in Test tube (05/01/2017).
36 Figure 12: The Chromatogram and Results of Water samples in Control tube (05/08/2017) 37 Figure 13: The Chromatogram and Results of Water samples in Test tube (05/08/2017). 39 Figure 14: The Chromatogram and Results of Water samples in Control tube (05/15/2017) 40 Figure 15: The Chromatogram and Results of Water samples in Test tube (05/15/2017). 41 Figure 16: The Chromatogram and Results of Water samples in Control tube (05/22/2017) 42 Figure 17: The Chromatogram and Results of Water samples in Test tube (05/22/2017). 44 6 LIST OF TABLES Table 1: Nitrogen metabolisms related to wastewater treatment.
13 Table 2: The amount of constituents in the medium. 18 Table 3: (*)Trace element solution in the medium. 19 Table 4: The exact amount of chemical compounds for preparation of medium. 22 Table 5: Summary of the Chromatogram Results by NO2- component.
34 7 LIST OF ABBREVIATIONS MBfR Membrane Biofilm Reactor MBAR Membrane Aerated Biofilm Reactors NOB Nitrite-oxidizing organisms LDL Low Density Lipoprotein DO Dissolved Oxygen SRT Solid Retention Time BOD Biochemical Oxygen Demand HEPES A zwitterionic organic chemical buffering agent AOB Ammonia-oxidizing Bacteria 8 PART 1: INTRODUCTION 1. Research Rationale The membrane biofilm reactor (MBfR) is a mechanical treatment which depends on gas-exchanging membranes. The membranes typically supply a vaporous electron donor or acceptor substrate, such as hydrogen, oxygen and methane. The electron substrate diffuses through the membrane to a biofilm and shaping on the membrane in the outside of the surface.
Biofilms procedures are of bringing the interest in environmental science and biotechnology due to its capacity to accumulate the high biomass densities and hold it inside the reactor. Almost all the biofilm procedures are based on attachment surfaces, such as stone, dense plastic, plastic foams. Both electron donor and acceptor substrates are supplied from the bulk liquid which can be called „co-diffusional‟ biofilms. The biofilms can also grow on reactive surfaces that release electron acceptor or donor substrate into the biofilm.
Counter-diffusional biofilms can likewise be found in natural frameworks and built frameworks. In environmental systems, counter-diffusional biofilms can be found on gas-fluid interfaces, such as plant roots, air bubbles and the roots may supply organic exudates or oxygen to biofilms creating on their surface. In engineered systems, counter-diffusional biofilms can grow on inorganic solids such as elemental sulfur or organic solids such as chitin and biodegradable polymers. Membrane-biofilm reactor is an essential counter-diffusional biofilm procedure in the environmental biotechnology.
It is depended on gas-permeable membranes that deliver a gaseous substrate to biofilms naturally forming on the membrane the 9 outer surface areas. The procedures with the supply of air or oxygen are called Membrane aerated biofilm reactors (MABRs). This engineered procedure has been studied since the 1970s but it has gained intense interest from the researchers in recent years. Also, the technologies have been launched in commercial technologies in recent years.
With co-diffusional biofilms, the most metabolically active region of the biofilm is normally the exterior, the electron donor and acceptor substrates are at their highest concentrations. The most active zone is typically situated in the interior of the biofilm. This counter diffusion of donor and acceptor leads to unique behavior which contains three primary differences: development of unique microbial community structures, greater sensitivity to biofilm accumulation and reduced susceptibility to liquid diffusion layer resistance. Research’s Objectives The objective of this research is to test the novel method of wastewater treatment by using the membrane-biofilm reactors.
The expected results would produce nitrate from the reactor and create insignificant amount of nitrate. Definitions Development of unique microbial community structures: The counter diffusion of substrates can lead to unique microbial community structures in the membrane-biofilm reactors. Most of biofilms for wastewater treatment , the aerobic nitrifying microorganism grow in the deeper regions of the biofilm where the organic carbon concentration get the lowest point. This region has minimized 10 competition from heterotrophic microorganisms.
It is also the location when the concentration of oxygen gets lowest which leads to low nitrification. Oxygen is supplied from the base of the biofilm so the nitrifiers experience low organic carbon and high oxygen concentrations, promoting high nitrification activity. This unique stratification may favor suppression of nitrite-oxidizing organisms (NOB). Greater sensitivity to biofilm accumulation: In conventional biofilms, the initial contaminant transformation fluxes are low, due to low biofilm thicknesses.
The fluxes then increase as the biofilm thicknesses increases, until the biofilm growth is balanced by decay and detachment. In counter-diffusional biofilms, fluxes rise up to a point but then reduce as the thickness increases further. This is because of donor acceptor counter diffusion. The biofilm interior has low activity due to the limitation of one substrate, while the exterior has low rates due to the limitation of the other.
Lower susceptibility to LDL resistance: In a conventional biofilm, the LDL limits substrate fluxes into the biofilm. As the biofilm thickness and flux increase, the biofilm, the LDL provides a barrier to loss of the internal substrate to the bulk liquid. As long as the substrate from the bulk is present at non-rate limiting concentrations, the LDL will not limit and may actually enhance, microbial activity. In addition to the aforementioned, the mode of gas supply and biofilm development in the membrane-biofilm reactors can lead to special behavior.
For instance, when gas is supplied via hollow-fiber membranes, other dissolved gases in the bulk liquid, gases 11 formed in the biofilm, can diffuse back into the membrane, diluting the supply gas. When operating an MBfR with sealed membranes, these gases concentrate at the distal end of the membrane, decreasing its effectiveness and leading to thinner biofilms. Also several hollow-fiber membranes can clump together, effectively forming one large biofilm with individual membranes which provides point gas sources in the biofilm interior. Biofilms can assume uneven or rough morphologies, which result from an interplay between cell growth rates, shear conditions, microbial cell types, and other factors.
The roughness of counter-diffusional biofilms can affect their behavior. In particular, roughness increases the effective LDL thickness, which limits fluxes in conventional biofilms. The fluid flow regime is important for all biofilm processes. Thus, computational fluid dynamics can be an important tool for membrane-biofilm reactors studies, either to determine the flow regime around membranes or to couple with a model of biofilm growth and deformation.
It is especially essential when biofilm- covered membranes contact each other, as they may bundle and cause dead zones without flow. The bundle might behave like a singular with gaseous substrates sources in the interior. 12 PART 2: LITERATURE REVIEW 2. Nutrients in wastewater: In municipal wastewater, the priority of nitrogen is in the reduced form, for instance, organic amine group R-NH3 or R-NH4, ionized ammonium NH4+ or free ammonia NH3.
During collection process, most of the organic nitrogen in wastewater is ammonified to NH4+. The terms ammonia and ammonium are used to refer to the decreased form of inorganic nitrogen. Total nitrogen removal requires denitrification to nitrogen gas which are released to the air. In addition, the sufficient oxygen and organic carbon present the majority of resources associated with conventional nitrification and denitrification.
There are multiple step processes of nitrification and denitrification, demonstrated in the Table 2.