ABSTRACT
This study on the integrated solar and hydraulic jump enhanced waste stabilization pond (ISHJEWSP) is aimed at determining the effect of variations in solar radiation, hydraulic jump, hydro-kinematic factors and pond geometry, on the treatment efficiency of wastewater in the ISHJEWSP. An equation to account for these effects was derived, calibrated and verified. An empirical regression model for the prediction of the Biochemical Oxygen Demand (BOD5) in the ISHJEWSP for sewage treatment was also developed. Three sets of experimental ponds with varying locations of slopes were constructed using metallic tanks with each set consisting of eight numbers of ponds with varying width. Also, solar reflectors were constructed to increase the incident sunlight intensity. Wastewater samples collected from the inlet and outlet for varying inlet velocities of the ISHJEWSPs were examined for physicochemical and biological characteristics for a period of nine months. The parameters examined were temperature, pH, detention time, dissolved oxygen, total coliform count, total suspended solids, E-coli, algae concentration, BOD5 and tracers studies. The efficiencies of the ISHJEWSPs with respect to these parameters fluctuated with variations in solar radiation, width, inlet velocity and location of point of initiation of hydraulic jump with the smallest ISHJEWSP in width giving the highest treatment efficiency at higher intensities of solar radiation. It was generally observed that the treatment efficiencies of the ISHJEWSPs increased as the location of the point of initiation of the hydraulic jump decreased relative to the inlet and with increase in inlet velocity for all sets studied though with precedence to solar radiation and temperature. A comparison of the conventional WSP and the ISHJEWSP showed that the bacteria removal was significantly higher in the ISHJEWSP than the conventional pond at a significance level of 5%. The verification of the conventional model gave a good average coefficient of correlation of R = 0.800 (0.713 to 0.891) between the measured and calculated Ne/No with an average standard error of 0.173 (0.157 to 0.224) and average R = 0.924(0.858 to 0.965) and average standard error of 0.034 (0.010 to 0.060) for the ISHJEWSP, respectively. An empirical model was developed to predict the BOD5 in the ISHJEWSP based on the independent variables of pH, temperature, algae concentration, dissolved oxygen, inlet velocity, location of point of initiation of hydraulic jump, angle of inclination causing hydraulic jump and intensity of solar radiation. The empirical regression model developed gave a good multiple regression coefficient of correlation of 0.938 with a standard error of 5.224 at a significance level of 10%.
TABLE OF CONTENTS PAGE
TITLE PAGE……………………………………………………………………………………...i
CERTIFICATION………………………………………………………………………………..ii
APPROVAL PAGE....………………………………………………………………....…………iii
DEDICATION................................................................................................................................iv
ACKNOWLEDGEMENTS.……………………………..……………………………………….v
ABSTRACT……………………………………………………………………………………..vii
TABLE OF CONTENTS…………………………………………………………………….....viii
LIST OF TABLES…………………………………………………………………………….…xii
LIST OF FIGURES……………..…………………………………………………………...….xiii
CHAPTER ONE: INTRODUCTION
1.1 BACKGROUND OF STUDY……………………………………………………….....…1
1.2 RESEARCH PROBLEM………………………………………………………………….2
1.3 SIGNIFICANCE OF RESEARCH………………………………………………………..3
1.4 OBJECTIVES OF THE STUDY………………………………………………………….3
1.5 RESEARCH SCOPE ……………………………………………………………………..4
1.6 RESEARCH LIMITATIONS……………………………………………………………..4
CHAPTER TWO: LITERATURE REVIEW
2.1 OVERVIEW OF WASTE STABILIZATION POND…………….…………………..….5
2.2 WASTE STABILIZATION POND PROCESSES……………………………………….6
2.3 TYPES OF WASTE STABILIZATION PONDS…………….…………………………..7
2.3.1 Anaerobic ponds…………………………………..………………………………………8
2.3.2 Facultative Ponds………………………………………………………………………….9
2.3.3 Maturation Pond…………………………………………..……………………………...11
2.3.4 High Rate Agal Pond.........................................................................................................12
2.3.5 Microphyte Pond……………………………………………………..……………….….12
2.3.6 Other Types.................................................................................................................…...12
2.4 POND PARAMETERS DETERMINATION…………………………………………...13
2.4.1 Tracer Studies ……………………………………………………………………………13
2.4.2 Velocity Measurement…………………………………………………………………...14
2.5 EFFECTS OF DISPERSION NUMBER ON WASTE STABILIZATION POND….…15
2.6 GEOMETRICAL FACTORS AFFECTING DISPERSION NUMBER………………..15
2.6.1 Inlet and Outlet Structures……………………………………………………………….16
2.7 ENVIRONMENTAL FACTORS AFFECTING WASTE STABILIZATION PONDS..............................................................................................16
2.7.1 Temperature……………………………………………………………………………...17
2.7.2 Solar Radiation……………………………………………………………………..…....17
2.7.3 Mixing…………………………………………………………………………………...18
2.8 OTHER FACTORS AFFECTING THE EFFICIENCY OF WASTE STABILIZATION PONDS……………………………………..............................……19
2.8.1 Pond Position…………………………………………………………………………….19
2.8.2 Solar Azimuth Angle……………………………………………………………….……19
2.8.3 Solar Altitude Angle………………………………….…………………………….……19
2.8.4 Hydrogen Ion Concentration (pH)………………………………………………………20
2.9 THE KINETIC MODELS OF BACTERIA DIE-OFF…………….……………………20
2.10 EFFLUENT STANDARDS……………………………………………………….….…22
2.11 WASTE STABILIZATION POND MODELS…………………………………….……22
2.12 INTEGRATED SOLAR AND HYDRAULIC JUMP ENHANCED WASTE STABILIZATION POND…………………………………………………………….…25
2.13 DESIGN OF THE INTEGRATED SOLAR AND HYDRAULIC JUMP ENHANCED WASTE STABILIZATION POND……....................………………..….26
2.13.1 Hydraulic Jump Consideration…………………………………………………………..26
2.13.2 Solar Reflector Consideration……………………………………………………………28
CHAPTER THREE: RESEARCH METHODOLOGY
3.1 STUDY AREA…………………….…………………………………………………….31
3.2 EXPERIMENTAL INVESTIGATION AND SETUP……….…………………………32
3.3 SAMPLE COLLECTION……………………………………………………………….36
3.4 DATA COLLECTION…………………………………………………………….…….36
3.5 LABORATORY METHODS……………………………………………………….…...37
3.5.1 Total Coliform Count Test……………………………………....……………………….37
3.5.2 Biochemical Oxygen Demand……………………………….…………………………..37
3.5.3 Dissolved Oxygen………………………………………………………………………..38
3.5.4 Total Suspended Solids (TSS)…………………………………………...………………38
3.5.5 E- Coli…………………………………………………………………………………...39
3.5.6 Algae Concentration............................…………………………………………………..39
3.5.7 pH…………………………………………………………………………………….….39
3.5.8 Tracer Studies………………………………………………………………………..…..40
3.6 ANALYTICAL METHODS…………………………………………………….……....40
3.7 FORMULATION AND DEVELOPMENT OF THE PERFORMANCE MODEL OF THE ISHJEWSP………………………...……………………………...….40
3.8 FORMULATION AND DEVELOPMENT OF THE EMPIRICAL REGRESSION MODEL FOR THE PREDICTION OF THE BIOCHEMICAL OXYGEN DEMAND IN THE ISHJEWSP................................43
CHAPTER FOUR: RESULTS AND DISCUSSION
4.1 EFFECT OF POND WIDTH ON TREATMENT EFFICIENCY………….........…......45
4.1.1 Temperature…………………………………………………………………....………...45
4.1.2 Dissolved Oxygen…………………………………..…………………………………...45
4.1.3 pH…………………………………………………………………………………...…..46
4.1.4 Algae Concentration…………...............…………………………………………..……47
4.1.5 Total Coliform Count…………………………………………………………………...48
4.1.6 Biochemical Oxygen Demand……………………………………………………….......49
4.1.7 Total Suspended solids………………………………………………………………......49
4.1.8 E-Coli………………………………………………………………………………….....50
4.2 EFFECT OF INLET VELOCITY ON TREATMENT EFFICIENCY………………….87
4.3 EFFECT OF SOLAR RADIATION ON TREATMENT EFFICIENCY……………….93
4.4 EFFECT OF LOCATION OF POINT OF INITIATION OF HYDRAULIC JUMP..............................................…105
4.5 EMPIRICAL REGRESSION MODEL FOR THE PREDICTION OF THEBIOCHEMICAL OXYGEN DEMAND IN THE INTEGRATED SOLAR AND HYDRAULIC JUMP ENHANCED WASTE STABILIZATION POND FOR SEWAGE TREATMENT…………………………....110
4.6 COMPARISON BETWEEN THE CONVENTIONAL POND (POND A) AND THE ISHJEWSP (POND D)………………………………..........................……111
4.6.1 Model Calibration……………………….………………..…………………………….111
4.7 EFFECT OF DETENTION TIME ON THE PERFORMANCE OF THE ISHJEWSP…………………………………….……....………………………….112
4.8 VERIFICATION OF MODELS……………………………………..………………...115
CHAPTER FIVE: CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION…………………………………………………………………………120
5.2 RECOMMENDATIONS..................…………………………………..……………….121
REFERENCES……………………………………………..……………………………….....123
APPENDICES.…..............................................................…………………………..………...132