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2.4.2 Septic tank and soak-away systems ................................................................................. 30 2.4.3 Treatment of domestic wastewater using conventional anaerobic digester technology .. 33 2.5 The anaerobic baffled reactor .............................................................................................. 37 2.5.1 Research on the performance of the ABR ........................................................................ 38 2.5.2 Full-scale ABR installations ............................................................................................ 46 2.5.3 The University of KwaZulu-Natal pilot-scale ABR ........................................................ 48 2.6 Summary ............................................................................................................................. 50 3 Pilot-scale ABR installations and operation ........................................................ 51 3.1 The Pilot-scale ABR ........................................................................................................... 51 3.1.1 Pilot-scale ABR design .................................................................................................... 51 3.1.2 Installations ...................................................................................................................... 56 3.1.3 Alkalinity in South African waters .................................................................................. 56 3.2 Materials and methods ........................................................................................................ 56 3.2.1 Sampling .......................................................................................................................... 56 3.2.2 Sample storage and preparation ....................................................................................... 58 3.2.3 Analytical methods .......................................................................................................... 58 3.2.4 Statistical analyses ........................................................................................................... 59 4 Experimental Phase I: Umbilo WWTP 2000-2001 ............................................. 61 4.1 Umbilo WWTP installation................................................................................................. 61 4.2 Operation of the pilot-scale ABR: Phase I .......................................................................... 62 4.2.1 Feed characteristics: Phase I ............................................................................................ 63 4.2.2 Hydraulic and organic loading rates during Phase I ........................................................ 66 4.3 ABR outflow stream characteristics: Phase I ...................................................................... 67 4.3.1 Influence of feeding interruptions on reported results ..................................................... 67 4.3.2 Total Solids ...................................................................................................................... 67 4.3.3 COD ................................................................................................................................. 68 4.3.4 Free and saline ammonia .................................................................................................. 69 4.3.5 Phosphorus ....................................................................................................................... 71 4.4 Compartment Dynamics: Phase I ........................................................................................ 71 4.4.1 Height of sludge bed ........................................................................................................ 71 4.4.2 COD ................................................................................................................................. 75 4.4.3 pH ..................................................................................................................................... 77 4.4.4 Alkalinity ......................................................................................................................... 79 4.5 Summary: Phase I – Operation at Umbilo WWTP 2000 -2001 .......................................... 81 4.5.1 Summary of reactor performance: Phase I –Umbilo WWTP 2000 - 2001 ...................... 81 4.5.2 Sludge bed accumulation during start-up ......................................................................... 81 4.5.3 Phase-separation between compartments ......................................................................... 82 5 Experimental phases II-IV: Kingsburgh WWTP 2002-2004 ............................. 85 5.1 Kingsburgh WWTP installation .......................................................................................... 85 5.2 Operation of the pilot-scale ABR: Kingsburgh WWTP Installations ................................. 87 5.2.1 Operation of the pilot-scale ABR: Phase II ...................................................................... 87 5.2.2 Operation of the pilot-scale ABR: Phase III .................................................................... 88 5.2.3 Operation of the pilot-scale ABR: Phase IV .................................................................... 89 viii
5.3 Feed characteristics and loading rates: Phase II-IV ............................................................ 90 5.3.1 Characterisation of Kingsburgh WWTP wastewater ....................................................... 90 5.3.2 Analysis of variations in feed wastewater between phases of operation ......................... 91 5.3.3 Hydraulic and organic loading rates: Phase II – IV ......................................................... 92 5.4 ABR outflow stream characteristics: Phase II - IV ............................................................. 93 5.4.1 COD ................................................................................................................................. 93 5.4.2 Total and volatile solids ................................................................................................... 95 5.4.3 Alkalinity ......................................................................................................................... 95 5.4.4 Free and saline ammonia and Total Kjeldahl Nitrogen ................................................... 97 5.4.5 Phosphorus ....................................................................................................................... 98 5.4.6 Sulphate ........................................................................................................................... 98 5.5 24 h sampling campaign – Phase III, day 99-101 ............................................................... 99 5.5.1 Diurnal variation of inflow characteristics ...................................................................... 100 5.5.2 Diurnal variation of outflow characteristics .................................................................... 102 5.5.3 Conclusions – 24 h sampling campaign .......................................................................... 104 5.6 Compartment Dynamics: Phase II - IV ............................................................................... 105 5.6.1 Solids levels and concentration ........................................................................................ 105 5.6.2 pH value and soluble COD concentration ....................................................................... 112 5.6.3 pH values during souring incident ................................................................................... 115 5.7 Microbiological studies of the pilot-scale ABR .................................................................. 116 5.7.1 Pathogen indicator organisms .......................................................................................... 116 5.7.2 Microbial community studies .......................................................................................... 117 5.8 Summary of operation at Kingsburgh Wastewater Treatment Plant .................................. 123 5.8.1 Outflow characteristics .................................................................................................... 123 5.8.2 Diurnal variation in inflow characteristics ....................................................................... 124 5.8.3 Sludge dynamics within compartments ........................................................................... 124 5.8.4 Soluble COD and pH dynamics within compartments .................................................... 125 6 Discussion: Implications for design and operation .............................................129 6.1 Pilot-scale ABR study – implications for design ................................................................ 129 6.1.1 pH buffering and phase separation .................................................................................. 129 6.1.2 Sludge accumulation and microbial community dynamics ............................................. 132 6.1.3 Pathogen removal and effluent characteristics ................................................................ 137 6.1.4 Gap analysis ..................................................................................................................... 137 6.2 Mass balance to determine probable sludge/methane production rates .............................. 138 6.2.1 COD mass balance ........................................................................................................... 139 6.2.2 Nitrogen mass balance ..................................................................................................... 142 6.3 Development of a sludge age model for an accumulating system ...................................... 144 6.4 Calculation of range of outflow characteristics .................................................................. 145 6.4.1 Sötemann et al. (2005) model of steady-state anaerobic digestion .................................. 145 6.4.2 Steady-state model implementation ................................................................................. 146 6.4.3 Inputs into the steady-state model of the ABR ................................................................ 148 6.4.4 Comparison of steady-state model predictions with experimental data .......................... 149 6.4.5 Significance of steady-state modelling study .................................................................. 152 6.5 Biochemical model of the ABR .......................................................................................... 153 6.5.1 Model construction .......................................................................................................... 154 ix
Page 1: ANALYSIS OF A PILOT-SCALE ANAEROBIC
Page 5: i DECLARATIONS I, Katherine Maria F
Page 8 and 9: My deepest thanks must be extended
Page 11: vii TABLE OF CONTENTS ANALYSIS OF A
Page 15 and 16: xi LIST OF TABLES Table 1.1: List o
Page 17 and 18: xiii LIST OF FIGURES Figure 1.1: Gr
Page 19 and 20: Figure 5.1 Installation of the ABR
Page 21 and 22: Figure 6.8: WEST® representation o
Page 23 and 24: xix LIST OF ABBREVIATIONS A-HRT App
Page 25 and 26: 1 1 INTRODUCTION The work presented
Page 27 and 28: obtained from anaerobic systems rel
Page 29 and 30: • Lalbahadur (MTech, 2005) perfor
Page 31 and 32: 1.7 ORGANISATION OF THE THESIS This
Page 33 and 34: 9 2 LITERATURE REVIEW A detailed re
Page 35 and 36: • Disintegration of composite par
Page 37 and 38: Homoacetogens are one of the most v
Page 39 and 40: Most of the control in anaerobic di
Page 41 and 42: therefore the sensitivity of the ov
Page 43 and 44: ∆Gº (W) [kcal] -10 -8 -6 -4 -2 L
Page 45 and 46: For systems with low potential for
Page 47 and 48: design of the digester in which the
Page 49 and 50: 2.2.2 Expanded granular sludge bed
Page 51 and 52: fact that for most non-ideal flow s
Page 53 and 54: hydrolysis steps to convert them to
Page 55 and 56: from the clarified zone between the
Page 57 and 58: Table 2.4: Typical pathogen surviva
Page 59: Table 2.5: Studies using anaerobic
Page 62 and 63:
• There is no requirement for bio
Page 64 and 65:
Kennedy and Barriault (2005) perfor
Page 66 and 67:
methanogenic (Akunna and Clark, 200
Page 68 and 69:
and 6 h with no significant differe
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2.5.1.12 Granule formation in ABRs
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• A baffled reactor is described
Page 74 and 75:
2.5.3.4 Scanning electron microscop
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spacing on flow patterns in a singl
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Figure 3.5: Orthographic projection
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PLC calculated the fraction of that
Page 82 and 83:
epresent buulk conditionns. Compart
Page 85 and 86:
The rreactor was initially commmiss
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Phase I Phase II Phase III Phase IV
Page 89 and 90:
Table 4.1: Characteristics of degri
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Table 4.2: Pilot-scale ABR approxim
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COD [mgCOD/ℓ] 2000 1800 1600 1400
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4.3.5 Phosphorus Figure 4.8 present
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Observation of sludge in compartmen
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Another interesting observation is
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4.4.3 pH pH measurements were perfo
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esult in low pH values. The reasons
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4.5 SUMMARY: PHASE I - OPERATION AT
Page 107 and 108:
than the optimal range for methanog
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5 EXPERIMENTAL PHASES II-IV: KINGSB
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sludge on a number of occasions. Wh
Page 113 and 114:
On days 99 and 100 of Phase III, a
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5.3.2 Analysis of variations in fee
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Table 5.2: Pilot-scale ABR average
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5.4.1.2 Phase III In Phase III, (Fi
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Phase II: Alkalinity [mgCaCO3/ℓ]
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Eq. 5-1 However, at a COD/SO4 2- ra
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wastewater was probably higher than
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5.5.2.2 Damping Figure 5.12 and Fig
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• The outflow COD values were not
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• Information about the volume of
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As with the total volume of sludge
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It is not clear why the rate of acc
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most compartments was exactly 6.5,
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Soluble COD [mg/ℓ] 600 500 400 30
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pathogens and parasites, which may
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% Probe of DAPI % Probe of DAPI % P
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later compartments at all. Furtherm
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and 4, with decreasing observations
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• The mechanism of sludge build-u
Page 151:
Table 5.6: Inflow and outflow chara
Page 154 and 155:
Behling et al. (1997) studied the p
Page 156 and 157:
organisms in previous compartments.
Page 158 and 159:
velocities. Unfortunately, these tw
Page 160 and 161:
Thus for a fixed sludge load, at hi
Page 162 and 163:
sampling was not possible since in
Page 164 and 165:
Wentzel (2006) recommends a COD to
Page 166 and 167:
6.2.1.4 Calculation of CH4 producti
Page 168 and 169:
organically bound N) or that N accu
Page 170 and 171:
All VFA is consumed in the process,
Page 172 and 173:
However, these assumptions are clea
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The calculated pH value is compared
Page 176 and 177:
influent alkalinity will increase d
Page 178 and 179:
The original objective to develop a
Page 180 and 181:
• It was not possible to simulate
Page 182 and 183:
employed for a medium strength wast
Page 184 and 185:
6.6.4 Alternative baffle design Thi
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6.7.3 Monitoring requirements The m
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compartments (Section 6.1.1) pH val
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generally about anaerobic digestion
Page 192 and 193:
7.1.1.6 Effect of sludge age on bio
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7.1.2.4 Critical design parameters
Page 196 and 197:
172
Page 198 and 199:
Batstone D. J., Keller J., Angelida
Page 200 and 201:
Gopala K. G. V. T. (2007). Treatmen
Page 202 and 203:
MacLeod F. A., Guiot S. R. and Cost
Page 204 and 205:
Sasse L. (1998). Decentralised wast
Page 206 and 207:
Wanasen (2003). Upgrading conventio
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METTHODS OFF SAMPLINNG AND ANNALYSI
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3.6 Enumeration of total coliforms
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that the means are the same, or con
Page 215 and 216:
And the significance of the regress
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ADDITIONAL RESULTS 193 APPENDIX A3
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Table A3. 1 cont. Phase I Phase II
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each of the eight compartments were
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3.2 Pathogen indicator organisms A
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APPLIED VS. APPARENT HYDRAULIC RETE
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19 h apparent HRT 14 h apparent HRT
Page 229 and 230:
205 APPENDIX A5 CALCULATION OF SOLI
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i.e. the average SRT of an accumula
Page 233:
X X = P Inert ⋅ where Xinert is t
Page 236 and 237:
iodegradable organic material may b
Page 238 and 239:
Substituting Eq. A6- 1 in Eq. A6- 7
Page 240 and 241:
1.5 Implementation of steady-state
Page 242 and 243:
X = 7⋅ Y = 7 Z = 7⋅ A = 7⋅ (
Page 244 and 245:
Dama, P., Bell J., Naidoo, V., Foxo
Page 246:
Lalbahadur T. (2004) Characterisati
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