Thesis - faculty.ait.ac.th - Asian Institute of Technology

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treatment cost. Chemical cost required for MBR operation with and without ammonia stripping is given in Table H-5 and H-6 of Appendix H. Table 4.20 Cost of Chemical Used for pH Adjustment Item Equipments and Chemicals Quantity Cost (unit) (Baht) 1 NaOH (commercial grade) 25 kg/pk 750 2 H2SO4 (commercial grade) 30 L/container 420 While comparing the chemical cost required for the bacterial and yeast membrane bioreactor, it was found that the cost required for leachate treatment using the bacterial system is lower than that of the yeast system, though the difference between the two systems was not much. Table 4.21 Total Chemical Cost Requirement for Each Treatment System Treatment System Chemical Cost (Baht/m 3 ) YMBR 93 BMBR 5 Coupling ammonia stripping with YMBR 662 Coupling ammonia stripping with BMBR 565 Ozonation (YMBR) 665 Oxygen cost for ozonation Ozonation (BMBR) Oxygen cost for ozonation 118 4,800 565 2,400
Chapter 5 Conclusions and Recommendations This study investigated biological processes by using mixed yeast cultures and mixed bacteria cultures for treating landfill leachate containing high organic and ammonium nitrogen concentrations. Basic studies on biokinetic coefficient of yeast and bacteria sludge were carried out. The effects of high ammonium nitrogen on the yeast and bacteria sludge were evaluated using a respirometric method. The main part of this study was focused on the membrane bioreactor. The potential for developing a membrane bioreactor using mixed yeast sludge (YMBR) and mixed bacteria sludge (BMBR) for treating raw leachate and stripped leachate was examined. The last section of this study was focused on the sludge properties, and membrane performance was investigated. The summary and conclusions drawn from the experimental results are presented below. 5.1 Conclusions 1. In a membrane bioreactor which was used to treat raw leachate, it was found that the average COD removal efficiency of the YMBR was slightly higher than that of the BMBR for varied HRT. The average COD removal efficiency in YMBR system was 65±2% when HRT was in the range of 16 to 24 h, whereas in BMBR system, the average COD removal efficiency was 62±2% at the same range of HRT. At HRT of 12 h, the average COD removal efficiency in YMBR and BMBR were 60% and 51%, respectively. The decrease in removal efficiency in the bacterial system at a lower HRT was obviously seen. This can be due to the presence of ammonia in the leachate which posed toxicity to the bacterial culture. In addition to a better COD removal efficiency, YMBR was more stable than BMBR. This could be considered as a specific advantage with the yeast sludge over the bacteria sludge. 2. The average TKN removal efficiency for both YMBR and BMBR systems, treating raw leachate at different HRT, was from 19-29% and 14-25%, respectively. The concentration of nitrite and nitrate (NO2 - and NO3 - ) in YMBR and BMBR effluents were in the range of 0.8 to 6.4 mg/L and less than 1.0 mg/L, respectively. This can be due to high organic and ammonium nitrogen concentrations and pH ranges. 3. For the ammonia striping process, the average ammonia removal efficiency of 86% could be achieved through a stripping process carried out with a high speed velocity gradient (G) of 2,850 s -1 at pH from 11 to 12 for 5 h. 4. In MBR which was used to treat stripped leachate, it was found that the fluctuations in terms of COD removal with ammonia stripping were lower than that without ammonia stripping. The COD removal in both YMBR and BMBR with the ammonia stripping was the same. Both the membrane reactors showed a COD removal of 72% at 16 h HRT and 76% at 24 h HRT. It was clear that the ammonia stripping improved the performance of COD removal of the BMBR much more than that of the YMBR system as anticipated from the toxicity studies. The BOD removal in both YMBR and BMBR systems was above 94%. This means that the membrane bioreactors were 119
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APPLICATION OF MEMBRANE BIOREACTOR
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Abstract Landfill leachate is a com
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Table of Contents Chapter Title Pag
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4.5.6 Cost Analysis for Operation 1
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4.4 Effect of Free Ammonia Concentr
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4.16 COD Concentration in the Influ
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MWCO Molecular Weight Cut-off MWW M
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1.1 Background Chapter 1 Introducti
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generally unsuccessful in removal o
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2.1 Introduction Chapter 2 Literatu
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In the municipal solid waste landfi
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COD/TOC, VS/FS and VFA/TOC ratios o
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Table 2.3 presents the general leac
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Ground water 2.7.1 Seasonal Variati
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Table 2.5 Variation of COD, BOD & B
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entails the re-circulation of leach
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Table 2.8 Summary of Biokinetic Coe
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that extensive loss of nitrogen (up
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ammonia could only be achieved when
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Table 2.10 Treatment Efficiencies o
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Activated Carbon Adsorption Granula
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Colloidal material as well as metal
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iologically, physical-chemical proc
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Ammonia Stripping Air stripping of
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These systems are land intensive wh
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the biological treatment can be rep
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Table 2.16 Typical Leachate Composi
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influent reached 200 mg/L. For the
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Table 2.18 Advantages and Disadvant
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through the effluent. Different ope
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Mixed Liquor Suspended Solids and D
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2.12 Yeasts 2.12.1 Introduction The
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Nishihara ESRC Ltd. (2001) studied
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nitrification-denitrification proce
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Table 3.1 Composition of Simulated
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3.4.1 Ammonia Toxicity The experime
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Figure 3.4 Experiments Conducted to
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Leachate Option Ammonia Stripping R
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MW larger than 50 kDa, (2) MW betwe
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Figure 3.7 Flowchart Showing Ammoni
Page 81 and 82: Chapter 4 Results and Discussion 4.
Page 83 and 84: COD Removal Effeciency (%) COD Remo
Page 85 and 86: MLSS (mg/L) 14000 12000 10000 8000
Page 87 and 88: Specific Growth Rate ( d -1 ) 0.50
Page 89 and 90: change in the predominant species w
Page 91 and 92: Table 4.4 Effect of Free Ammonia Co
Page 93 and 94: Table 4.5 Substrate Utilization by
Page 95 and 96: 4.3.1 Initial Membrane Resistance P
Page 97 and 98: when compared with the present stud
Page 99 and 100: COD Removal Efficiency (%) 90 80 70
Page 101 and 102: (2) TKN Removal Efficiency Prior to
Page 103 and 104: As there was no significant improve
Page 105 and 106: The probable reason for frequent fo
Page 107 and 108: Ammonia Concentration (mg/L) Ammoni
Page 109 and 110: concentration after treatment. Othe
Page 111 and 112: After the chemical cleaning of the
Page 113 and 114: emoval of 38%. A higher removal in
Page 115 and 116: Influent BOD (mg/L) Influent BOD (m
Page 117 and 118: (3) TKN Removal Efficiency The TKN
Page 119 and 120: Figure 4.34 gives the overall TKN r
Page 121 and 122: fraction and slowly biodegradable C
Page 123 and 124: BOD (mg/L) BOD (mg/L) 6000 5000 400
Page 125 and 126: Figure 4.39 Molecular Weight Cut-of
Page 127 and 128: COD (mg/L) 8000 6000 4000 2000 COD
Page 129 and 130: Though, the obtained COD removal ef
Page 131: cake used on the top of the membran
Page 135 and 136: 0.02, respectively. This can be con
Page 137 and 138: References Abeling, U., and Seyfrie
Page 139 and 140: Brown, M.J., and Lester, J.N., 1980
Page 141 and 142: Diamadopoulos, E., 1994. Characteri
Page 143 and 144: Grady, C.P.L., Daigger, G.T., and L
Page 145 and 146: Keenan, J.D., Steiner, R.L., and Fu
Page 147 and 148: Martin, G.M.A., Auzmenti, A.I., and
Page 149 and 150: Pohland, F.G., and Harper, S.R., 19
Page 151 and 152: Shin, H.S., An, H., Kang, S.T., Cho
Page 153 and 154: Visvanathan, C., Ben Aim, R., and P
Page 155 and 156: Appendix A Pictures of Experiments
Page 157 and 158: Raw Leachate YMBR Effluent BMBR Eff
Page 159 and 160: Appendix B Leachate Characteristics
Page 161 and 162: Table B-2 Acclimation of Mixed Yeas
Page 163 and 164: Appendix C Experimental Data of Bio
Page 165 and 166: y: Where: OUR at line g: This is th
Page 167 and 168: Table C-3 Experimental Results for
Page 169 and 170: Appendix D Membrane Resistance Stud
Page 171 and 172: Table D-3 Experimental Data for Det
Page 173 and 174: Table D-4 Experimental Data for Det
Page 175 and 176: Pressure (kPa) Pressure (kPa) 25 20
Page 177 and 178: Appendix E MBR without Ammonia Stri
Page 179 and 180: Day HRT (h) pH COD (mg/L) Feed Reac
Page 181 and 182: Day HRT (h) pH COD (mg/L) Feed Reac
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Table E-3 Variation in TMP with Tim
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Appendix F Ammonia Stripping Studie
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Table F-5 Pilot Scale Study on Ammo
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Table G-1 Feed, Reactor and Effluen
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Table G-3 Feed, Reactor and Effluen
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Appendix H Other Studies 179
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Table H-2 Membrane Resistance of th
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Table H-6 Chemical Cost for the Yea
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