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</p><p> Title page – – – i<br> Declaration – – – – ii <br> Certification – iii<br> Dedication – iv<br> Acknowledgements – – – – – v<br> Table of Contents – – viii<br> List of Plates – – – xv<br> List of Figures – – xvi<br> List of Tables – xxiv<br> Abbreviations and symbols – – – xxvii<br> Abstract – – – – xxxii</p><p><b>
Chapter 1
: <br>Introduction – – 1</b><br>11 Background to the study – 1<br>12 Problem statement – – – – 5 <br>13 Aim of the research – 6<br>14 Objectives – 6<br>15 Scope of study – – – 6<br>16 Justification of study – 7<br>17 Limitation of the work – – – – 7<br><b> <br>
Chapter 2
: Literature review – 8</b><br> 21 The pressure on water demand 8<br> 22 Wastewater treatment systems in use – – – – 9<br> 23 Waste stabilization ponds – 11<br>231 Treatment units in Waste Stabilization Ponds – – – 12 <br> 232 Anaerobic ponds – 13<br> 232 1 Design approach for anaerobic pond15 <br> 233 Facultative ponds – – – – 17<br> 2</p><p>331 Design criteria for facultative pond – – – 17 <br> 2332 Surface BOD loading in facultative ponds – – – 19<br> 234 Model approaches for faecal coliform prediction in facultative pond – – 20<br> 2341 Continuous stirred reactor (CSTR) model approach21<br> 2342 Dispersed flow (DF) model approach – – – 23<br> 235 Maturation Pond24<br> 24 Waste Stabilization Ponds in Some Selected Institutions in Nigeria – 26<br> 241 Waste stabilization pond in University of Nssuka, Nigeria – 29<br> 242 Waste stabilization pond in Obafemi Awolowo University, <br> Ile-Ife, Nigeria – 30<br> 243 Waste stabilization pond in Ahmadu Bello University, Zaria, <br> Nigeria – 32<br> 25 Residence time-models in waste stabilization ponds – – – 35<br> 251 Plug flow pattern – 35<br> 252 Completely mixed flow pattern – – – – 37<br> 253 Dispersed hydraulic flow regime – – – – 39<br> 26 Wind effect and thermo-stratification on hydraulic flow regime – 42<br> 27 Tracer experiment43<br> 28 Effects of baffles on the performance of waste stabilization – – 44<br> 29 Computational Fluid Dynamics Approach to Waste Stabilization Ponds – – – 48<br> 210 Laboratory scale ponds – – – – 56<br> 211 Optimization of waste stabilization pond design – – – 59 <br> 212 Summary of literature review – – – – 61<br> <br><b>
Chapter 3
:<br>Methodology – – – 62</b><br> 31 Description of the study area – – – – 62<br>32 Collection of data on Water demand – – – – 65<br> 33 Estimation of wastewater generated – – – – 66<br> 34 Study of existing wastewater treatment system – – – 66<br> 35 Analysis of wastewater samples70<br> 36 Design of the laboratory-scale plant layout – – – – 70<br> 361 Design Guidelines for the University, Ota – – – 73<br> 3611 Temperature (T) – – – – 73<br> 3612 Population (P) – – – – 73<br> 3613 Wastewater generation (Q) and Design for 20 years period – 73<br> 3614 BOD Contribution per capita per day (BOD) – – 73<br> 3615 Total Organic Load (B) – – – 74<br> 3616 Total Influent BOD Concentration (Li) – – – 74<br> 3617 Volumetric organic loading (λv) – – – 74<br> 3618 Influent Bacteria Concentration (Bi) – – 74<br> 3619 Required effluent standards – – – 74<br>37 Waste stabilization pond design – 75<br> 371 Design of Anaerobic Pond – – – – 75<br> 372 Design of Facultative pond76<br> 373 Design of Maturation Pond77<br>38 Design of Laboratory scale model – – – – 79<br> 381 Modeling of the Anaerobic Laboratory-scale pond – – 79<br> 382 Modeling of the Facultative Laboratory-scale pond – – – 81<br> 383 Modeling of the Maturation Laboratory-scale pond – – – 82<br> 39 Laboratory Studies – – 85<br> 391 Construction of the laboratory-scale waste stabilization ponds – 85<br> 392 Materials used for the construction of the inlet and outlet structures – 86<br> 393 Design of inlet and outlet structures of the WSP – – – 91<br> 394 Operation of the Laboratory-Scale waste stabilization pond – – 94<br> 395 Sampling and data collection – – – 95<br> 3951 Water temperature – – – 95<br> 3952 Influent and effluent samples – – – 95<br>310 Laboratory methods – 95<br> 3101 Feacal coliform – 96<br> 3102 Chloride – 96<br> 3103 Sulphate – 96<br> 3104 Nitrate – – 96<br> 3105 Phosphate – 96<br> 3106 Total Dissolved Solids – – – – 96<br> 3107 Conductivity – 97<br> 3108 pH – 97<br>311 Tracer Experiment – – 97<br> 3111 Determination of First Order Kinetics (K value) for Residence time <br> distribution (RTD) characterization – – – 99<br> 3112 The gamma extension to the N-tanks in series model approach – 101<br>312 Methodology and application of Computational Fluid Dynamics model – 103<br> 3121 Introduction 103<br> 3122 CFD Model Application – – – – 106<br> 31221 Simulation of fluid mechanics fecal coliform inactivation 106<br> 31222 Constants used in the application modes – – 109<br> 31223 Mesh generation for the computational fluid dynamics model110<br> 31224 Model test for the simulation of residence time distribution<br> curve in the CFD – – – 113<br> 31225 Model test for the simulation of faecal coliform inactivation in<br> the unbaffled reactor – – – – 114<br> 31226 Model test for the simulation of faecal coliform inactivation in<br> the baffled reactors – – – 116<br> 3123 Application of segregated flow model to compare RTD prediction <br> and the CFD predictions for feacal coliform reduction – 122 <br> 3124 Summary of the CFD model methodology – – – – 124<br> 3131 Optimization methodology and application – – – 125 <br> 31311 Integration of COMSOL Multiphysics (CFD) with <br> ModeFRONTIER optimization tool – – – 125<br>31312 The workflow pattern – – – – 126<br> 31313 Building the process flow – – – 127<br> 31314 Creating the application script – – 128<br> 31315 Creating the data flow – – – – 129<br> 31316 Creating the template input – – – 130<br> 31317 Mining the output variables from the output files – 131<br>3132 Defining the goals – – – – 132<br> 31321 The Objective functions for the optimization loop – – 132<br> 31322 The constraints for the optimization loop – – – 133<br> 31323 Cost objective Optimization – – – – 133<br> 31324 The DOE and scheduler nodes set up136<br> 31325 Model parameterization of input variables – – – 137 <br> 31326 DOE Algorithm – 140<br> 31327 Simplex algorithm – 140<br> 31328 Multi-Objective Genetic Algorithm II (MOGA-II) – – – – 141<br> 31329 Faecal coliform log-removal for transverse and longitudinal <br> baffle arrangements143<br> 3133 Sensitivity Analysis on the model parameters – – – 145 <br> 3134 Running of output results from modeFRONTIER with the CFD tool – – 146<br> 3135 Summary of the optimization methodology – – – – 146<br><b> <br>
Chapter 4
: Modeling results and Analysis </b><br> 41 Model results for the RTD curve and FC inactivation for unbaffled reactors – 147 <br> 42 Initial Evaluation of baffled WSP designs in the absence of Cost using CFD151<br> 421 Application of segregated flow model to compare the result of RTD <br> prediction and the CFD predictions for feacal coliform reduction – 163 <br> 43 Results of the N-Tanks in series and CFD models – – – 166<br> 431 General discussion on the results of the N-Tanks in series and CFD<br> Models – 173<br> 44 Results of some selected simulation of faecal coliform inactivation for 80%<br> Pond-width baffle Laboratory- scale reactors – – – 176<br>45 Optimization model results – 181<br> 451 The single objective SIMPLEX optimization configuration results – 181<br> 452 The Multi-objective MOGA II optimization configuration results – 195 <br> 453 Scaling up of Optimized design configuration – – 216<br> 4531 Scaling up of Anaerobic Longitudinal baffle arrangement – – 216<br> 4532 Scaling up of Facultative Transverse baffle arrangement – 218<br> 4533 Scaling up of Maturation Longitudinal baffle arrangement – 219<br> 4534 Summary of results of scaling up of design configuration – 220<br> 454 Results of sensitivity analysis for Simplex design at upper and lower <br> boundary – 220<br> 455 Results of sensitivity analysis for MOGA II design at upper and lower <br> boundary – 235<br> 456 Summary of the optimization model result – – – – 249<br> <br><b>
Chapter 5
: Laboratory-Scale WSP post-modeling results and verification of the <br> Optimized models – – – – 250<br></b>51 Introduction – 250<br>52 Microbial and physico-chemical parameters – – – 251 <br> 521 Feacal coliform inactivation in the reactors – – – 251<br> 522 Phosphate removal256<br> 523 Chloride removal – – – – 258<br> 524 Nitrate removal – – – – 259<br> 525 Sulphate removal – – – – 260<br> 526 pH variation265<br> 527 Total dissolved solids removal – – – 266<br> 528 Conductivity variation – – – – 266<br> 529 Summary of laboratory experimentation – – – 267<br><b> <br>Chapter 6: Discussion of results – – – – 269</b><br> 61 Experimental results of Laboratory-scale waste stabilization ponds <br> in series – 269<br>62 Hydraulic efficiency of CFD model laboratory-scale waste stabilization<br> ponds in series – 270<br> 63 Optimization of laboratory-scale ponds by Simplex and MOGA II <br> Algorithms – 274<br> 64 Summary of discussion – – – – 275<br> <br><b>Chapter 7: Conclusions and recommendations for further work – 277</b><br> 71 Conclusions277<br> 72 Contributions to knowledge – – – 278<br> 73 Recommendation for further work – – – 279<br> <br><b>References – 280<br> <br>Appendix A – 298</b><br> A1 COMSOL Multiphysics Model M-file for Transverse baffle <br> anaerobic reactor – – – – , – 298<br> A2 COMSOL Multiphysics Model M-file for longitudinal baffle <br> anaerobic reactor – 302<br> A3 COMSOL Multiphysics Model M-file for Transverse baffle <br> facultative reactor306<br> A4 COMSOL Multiphysics Model M-file for longitudinal baffle <br> facultative reactor – – – – 310<br> A5 COMSOL Multiphysics Model M-file for Transverse <br> Maturation reactor – – – – 314<br> A6 COMSOL Multiphysics Model M-file for longitudinal<br> Maturation reactor – – – – 318<br> <br><b>Appendix B322</b><br>B1 Transverse baffle arrangement scripting – – – 322<br>B2 Longitudinal baffle arrangement scripting – – 324</p><p><b>List of Plates</b><br>Plate 31 Tanker dislodging wastewater into the treatment chamber – – 67<br>Plate 32 The water hyacinth reed beds showing baffle arrangement <br> at opposing edges68<br>Plate 33 The inlet compartment showing gate valve – – 68<br>Plate 34 The Outfall waterway leading into the valley below the cliff – 69<br>Plate 35 Effluent discharging through the outfall into the thick <br> vegetation valley – – – – 69<br>Plate 36 Front view of the laboratory-scale pond – 88<br>Plate 37 Areal view of the laboratory-scale pond close to source of sunlight – – 88<br>Plate 38 An elevated tank serving as reservoir – 89<br>Plate 39 Inlet-outlet alternation of laboratory-scale WSP – – 89<br>Plate 310 Laboratory-scaled anaerobic ponds – – – 90<br>Plate 311 Laboratory-scaled facultative ponds – – – 90<br>Plate 312 Laboratory-scaled maturation ponds – – – 91<br>Plate 313 Inlet and outlet structure of the laboratory-scale <br> waste stabilization pond – – – 92<br>Plate 314 Two 25-mm PVC hoses linked with the T-connector – – 92<br>Plate 315 Control valves screwed to position for wastewater flow – 93<br>Plate 316 Outlet structures connected to two pieces of ½ inch hoses <br> for effluent Discharge – – – – 93<br>Plate 317 Tracer experiment with Sodium Aluminum Sulphosilicate – – 97<br>Plate 318 Tracer chemical diluting with the wastewater before <br> getting to the outlet – – – – 98<br>Plate 319 Improvement in wastewater quality along the units – – 98</p><p><b>List of Figures</b><br>Figure 21 Waste stabilization pond configurations 12<br>Figure 22 Operation of the Anaerobic Pond 14<br>Figure 23 Operation of the facultative pond 23<br>Figure 31 Bar chart of staff and student population trend 63<br>Figure 32 Template for calculating the per-capita water use 65<br>Figure 33 A sketch of the laboratory-scale WSP and operating conditions 72<br>Figure 34 Configuration of the designed WSP for Covenant University 79<br>Figure 35 Different baffle arrangements with 70% pond width <br> anaerobic pond 99<br>Figure 36 Different baffle arrangements with 70% pond width <br> facultative pond 100<br>Figure 37 Different baffle arrangements with 70% pond width<br> maturation pond 100<br>Figure 38 Data conversion for reactor length to width ratio to N for<br> N-tanks in series model 102<br>Figure 39 Description of length to width ratio for the laboratory-scale <br> model 102<br>Figure 310 Triangular meshes for the model anaerobic reactor 111<br>Figure 311 Triangular meshes for the model facultative reactor 111<br>Figure 312 Triangular meshes for the model maturation reactor 112<br>Figure 313 Model Navigator showing the application modes 113<br>Figure 314 Correlation data of the predicted-CFD and observed effluent Faecal <br> coliform counts in baffled pilot-scale ponds 115<br>Figure 315 General arrangements of conventional longitudinal baffles of <br> different lengths in the anaerobic pond 117<br>Figure 316 General arrangements of conventional longitudinal baffles of <br> different lengths in the facultative pond 117<br>Figure 317 General arrangements of conventional longitudinal baffles of <br> different lengths in the maturation pond 118<br>Figure 318 Mesh structure in a 4 baffled 70% Transverse Anaerobic reactor 118 <br>Figure 319 Mesh structure in a 4 baffled 70% Longitudinal Anaerobic reactor 119<br>Figure 320 Mesh structure in a 4 baffled 70% Transverse Facultative 119<br>Figure 321 Mesh structure in a 4 baffled 70% Longitudinal Facultative <br> reactor 120<br>Figure 322 Mesh structure in a 4 baffled 70% Transverse Maturation <br> reactor 120<br>Figure 323 Mesh structure in a 4 baffled 70% Longitudinal Maturation <br> reactor 121<br>Figure 324 Workflow showing all links and nodes in the user application <br> interface 127<br>Figure 325 Logic End properties dialogue interface 128<br>Figure 326 Data variable carrying nodes and the input variable properties <br> Dialogue interface 129<br>Figure 327 Template for the calculator properties and JavaScript <br> expression editor 130<br>Figure 328 Output variable mining interface and input template editor 131<br>Figure 329 DOS Batch properties and batch test editor for mined data 132<br>Figure 330 Constraint properties dialogue in the workflow canvas 135<br>Figure 331 Objective properties dialogue in the workflow canvas 135<br>Figure 332 DOE properties dialog showing the initial population of designs 136<br>Figure 333 Scheduler properties dialog showing optimization wizards 137<br>Figure 334 Designs table showing the outcomes of different reactor <br> configurations 144<br>Figure 335 History cost on designs table showing the optimized cost &a</p>
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