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

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leachate in municipal wastewater treatment plants. A combined treatment may provide a better effluent quality as a result of the maintenance of a more heterogeneous population, increased availability of nutrient and possible dilution of potential inhibitors. Another advantage of co-treatment of leachate with domestic sewage is that leachate contains excess of nitrogen while sewage contains excess of phosphorus which eliminates the need for addition of nutrients. However, the main disadvantage is the high concentrations of organic and inorganic components contributed by both young and old leachate. To review the of co-treatment of leachate in MWW plants, Qasim and Chiang (1994) summarized research conducted by various researchers (Chian and DeWalle, 1977; Henry, 1985; Raina and Mavinic, 1985). From the review, it was evident that a disagreement arose as to whether this option was viable and under what conditions. Whilst Raina and Mavinic (1985) successfully treated leachate-MWW combinations of 20 to 40 %, Henry (1985), Chian and DeWalle (1977) and others reported poor performance in the co-treatment for leachate to MWW a ratio of less as 10 %. Since, there are contradicting results from various researchers, it is unknown whether this treatment option is suitable under practical application. Although BOD5, COD and heavy metal reduction is well established, the relative proportions of leachate effectively treated is effected by ammonia conversions, temperature, sludge production, foaming, poor solids settleability, heavy metal accumulation and precipitate formation. 2.9 Combined Treatment Facility A single treatment technology is not efficient in the leachate treatment due to the complexity involved in treating leachate having a varied composition and characteristic. Leachate treatment entails the integration of several treatment processes. The coupling of units for the development of treatment sequences should be modular to allow maximum flexibility in order to vary the order of arrangement and for addition/removal of unit operations. This effectively creates different treatment lines and thus better adapted to the changing qualitative conditions of the leachate (Qasim and Chiang, 1994; Bressi and Favali, 1997). Physical-chemical treatment processes for leachate from young landfills are not as effective as biological processes, whereas they are extremely efficient for stabilized leachate. COD/TOC and BOD/COD ratios, absolute COD concentration and age of the landfill are necessary determinants in the leachate characteristics for selection of appropriate treatment system. In treating leachate, the treatment sequence should be able to meet either the standards for discharge in receiving water bodies or an acceptable limit for discharge into water treatment works. To review the treatment sequences prior to development of optimum treatment sequence, few treatment combinations have been reviewed. 2.9.1 Biological Treatment and Reverse Osmosis A treatment sequence that is capable of removing mineralized material should include anaerobic digestion, suspended growth biological waste treatment, partial softening, filtration and reverse osmosis (RO). The anaerobic digester stabilizes the waste while the aeration system degrades the biological matter. The effluent could be polished in a gravity filter and demineralised in a RO unit, thus achieving an effluent devoid of dissolved salts and low in organics. The process train is as shown in Figure 2.7(a). With increase in age, 36
the biological treatment can be replaced by coagulation precipitation process followed by re-carbonation, filtration and RO in leachate treatment. The upgraded facility could be as shown in Figure 2.7(b). Influent Influent Anaerobic Digestion To Drying Bed Gas Gas Anaerobi c A Aerobic Treatment Return Sludge Sludge to Digestion Clarifier (a) (b) Figure 2.7 Schematic Diagram of Biological Treatment and Reverse Osmosis for Leachate Treatment (Qasim and Chiang, 1994) 2.9.2 Microfiltration and Reverse Osmosis M Chemical Treatment Clarifie Recarbonation Incorporation of a multiple membrane system by the combination of microfiltration (MF) and reverse osmosis (RO) could be the basis of the treatment sequence developed for leachate treatment. The process could be suitable for leachate of all ages and for low to medium flow processes. The two-stage processes entails precipitation and microfiltration for the removal of toxic metals and suspended solids and reverse osmosis for concentration of residual organics as shown in Figure 2.8. The first step of precipitation and microfiltration provides a simple pre-treatment for the RO unit and thus producing a high quality effluent free of solids and dissolved organics. However, similar to other membrane processes, the system is susceptible to fouling; hence, development of antifouling strategies and reduction in biofouling needs to be evaluated. 37 Granular Filter Media Granular Filter Media RO Concentrate RO Concentrate RO Permeate RO Permeate
Page 1 and 2: APPLICATION OF MEMBRANE BIOREACTOR
Page 3 and 4: Abstract Landfill leachate is a com
Page 5 and 6: Table of Contents Chapter Title Pag
Page 7 and 8: 4.5.6 Cost Analysis for Operation 1
Page 9 and 10: 4.4 Effect of Free Ammonia Concentr
Page 11 and 12: 4.16 COD Concentration in the Influ
Page 13 and 14: MWCO Molecular Weight Cut-off MWW M
Page 15 and 16: 1.1 Background Chapter 1 Introducti
Page 17 and 18: generally unsuccessful in removal o
Page 19 and 20: 2.1 Introduction Chapter 2 Literatu
Page 21 and 22: In the municipal solid waste landfi
Page 23 and 24: COD/TOC, VS/FS and VFA/TOC ratios o
Page 25 and 26: Table 2.3 presents the general leac
Page 27 and 28: Ground water 2.7.1 Seasonal Variati
Page 29 and 30: Table 2.5 Variation of COD, BOD & B
Page 31 and 32: entails the re-circulation of leach
Page 33 and 34: Table 2.8 Summary of Biokinetic Coe
Page 35 and 36: that extensive loss of nitrogen (up
Page 37 and 38: ammonia could only be achieved when
Page 39 and 40: Table 2.10 Treatment Efficiencies o
Page 41 and 42: Activated Carbon Adsorption Granula
Page 43 and 44: Colloidal material as well as metal
Page 45 and 46: iologically, physical-chemical proc
Page 47 and 48: Ammonia Stripping Air stripping of
Page 49: These systems are land intensive wh
Page 53 and 54: Table 2.16 Typical Leachate Composi
Page 55 and 56: influent reached 200 mg/L. For the
Page 57 and 58: Table 2.18 Advantages and Disadvant
Page 59 and 60: through the effluent. Different ope
Page 61 and 62: Mixed Liquor Suspended Solids and D
Page 63 and 64: 2.12 Yeasts 2.12.1 Introduction The
Page 65 and 66: Nishihara ESRC Ltd. (2001) studied
Page 67 and 68: nitrification-denitrification proce
Page 69 and 70: Table 3.1 Composition of Simulated
Page 71 and 72: 3.4.1 Ammonia Toxicity The experime
Page 73 and 74: Figure 3.4 Experiments Conducted to
Page 75 and 76: Leachate Option Ammonia Stripping R
Page 77 and 78: MW larger than 50 kDa, (2) MW betwe
Page 79 and 80: 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
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fraction and slowly biodegradable C
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BOD (mg/L) BOD (mg/L) 6000 5000 400
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Figure 4.39 Molecular Weight Cut-of
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COD (mg/L) 8000 6000 4000 2000 COD
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Though, the obtained COD removal ef
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cake used on the top of the membran
Page 133 and 134:
Chapter 5 Conclusions and Recommend
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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
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Raw Leachate YMBR Effluent BMBR Eff
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Appendix B Leachate Characteristics
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Table B-2 Acclimation of Mixed Yeas
Page 163 and 164:
Appendix C Experimental Data of Bio
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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
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Table D-4 Experimental Data for Det
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Pressure (kPa) Pressure (kPa) 25 20
Page 177 and 178:
Appendix E MBR without Ammonia Stri
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Day HRT (h) pH COD (mg/L) Feed Reac
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Day HRT (h) pH COD (mg/L) Feed Reac
Page 183 and 184:
Table E-3 Variation in TMP with Tim
Page 185 and 186:
Appendix F Ammonia Stripping Studie
Page 187 and 188:
Table F-5 Pilot Scale Study on Ammo
Page 189 and 190:
Table G-1 Feed, Reactor and Effluen
Page 191 and 192:
Table G-3 Feed, Reactor and Effluen
Page 193 and 194:
Appendix H Other Studies 179
Page 195 and 196:
Table H-2 Membrane Resistance of th
Page 197:
Table H-6 Chemical Cost for the Yea
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