Evaluation of water quality modelling parameters: towards the evolvement of re-aeration coefficient for rivers in the nigerian environment

• Title Page         i   Declaration         ii   Certification         iii Dedication         iv Acknowledgement       v Table of Contents         vii List of Figures         x List of Tables         xi List of Plates         xiv Abbreviations and Symbols       xv Abstract         xvi  

Chapter ONE

INTRODUCTION

• 11 Background Information       1                             12   Water Quality modelling       3 13   Description of Study Location     5 14   Statement of The Problem     6 15   Aim         6 16   Objectives       6 17   Significance of Study       6 18   Scope of Study       7    

Chapter TWO

LITERATURE REVIEW

• 21 Water Quality Modelling as a Field of Study   8 22   Coefficient of Re-aeration, k2     9 223 The Indian k2 Model       13 224 The Chilean k2 Model       14 225 The Nigerian k2 Model     15 23   Water Laws and Standards       15 24   Statistical Analysis       17 241 Some Relevant Statistical Operations   17 242 Statistical Software     19 243 Model Calibration and Validation in Water Quality Data       20 2431     Sum of Squares Due to Error 21 2432     R-Square       21 2433     Degrees of Freedom Adjusted R-Square 22 2434     Root Mean Squared Error   22  

Chapter THREE

SYSTEM DESIGN AND IMPLEMENTATION

•           31   Selection of the Study Area       24       32   Determination of Sampling Stations     27       33   Field Activities       49   331 Field Observations     31   332 Field Sampling Visits     31   3321     Rationale for Gathering Data Once Every Month 32     3322     Activities During the Field Exercises 33             34     Materials       34             35     Laboratory Analysis       36       36     Data Analysis       37             361   Time of Travel       38           362   Re-aeration Coefficient Model     39  

Chapter FOUR

SYSTEM TESTING AND EVALUATION

• AND INTERPRETATION   41 Data Gathering       40   411   Hydraulic Data     41   412   Physico-Chemical Data     50     413 Monthly Variations in DO, Temperature, Stream Depth       57   42 Computation of Measured k2                                                             63             43 Re-arrangement of Sampling Stations   67 431 Time of Travel     68 432 Hydraulic Radius                 80 433 Ultimate BOD and De-oxygenation Rate             80 434 Saturation DO and the Upstream and Downstream DO deficits 80  435 Determination of k2                 80 436 Model Parameters                 80 437 The Model                 83 438 Comparison with other Selected Models             83 44 Water Use Practices                             103  45       Pollutants and Public Health Implications             106  

Chapter FIVE

SUMMARY, CONCLUSION AND RECOMMENDATIONS

• AND RECOMMENDATION 51 Conclusion                 110 52 Contribution to Knowledge               111 53 Recommendations                 111         REFERENCES                   113   APPENDICES   Appendix 1: Matlab Code for Beta               121 Appendix 2: Matlab Model Output                         128 Appendix 3: Matlab Code and Output for Plot of all Models           132 Appendix 4: Mix Calculations               140 Appendix 5: Laboratory Reports               147   Appendix 6: Procedure for data Analysis             160 LIST OF FIGURES                                           PAGE Figure 11 – Nigerian Household distribution by source of water supply 2 Figure 12 – Nigerian Household distribution by Toilet Facilities   3 Figure 13 â“ General Layout of the Study area     5 Figure 31â“ Field Sampling Stations       28 Figure 32 â“ Linear representation of Sampling Points   29 Figure 33 – Sampling Cross-section       33 Figure 41 â“ An 8-month mean stream velocity record   59 Figure 42 â“ An 8-month mean ambient temperature record   60 Figure 43 â“ An 8-month mean water temperature record   61 Figure 44 â“ An 8-month mean stream depth record     61 Figure 45 â“ DO Fluctuations over an 8-month period   62 Figure 46 – Flowchart showing the progression of the statistical analysis           86 Figure 47 â“ Plot of 11 models using January data               93 Figure 48 â“ Plot of measured k2 against computed k2 using January data           94 Figure 49 â“ Plot of 11 models using March data               96 Figure 410 – Plot of measured k2 against computed k2 using March data           97 Figure 411 â“ Plot of 11 models using July data               99 Figure 412 – Plot of measured k2 against computed k2 using July data           100 LIST OF TABLES                                                                                 PAGE   Table 21 â“ The self-purification factor, f, of different water bodies at 20oC 9 Table 22 â“ Solubility of Oxygen in water     10 Table 31 – Details of Sampling Stations     30 Table 32 â“ Parameters Measured with Relevance to study   32 Table 33 â“ Parameters, equipment and Processes of parameter determination Schedule for field work       34 Table 41 – Sampling dates and conditions     40 Table 42a â“ Hydraulic Data for January     42 Table 42b â“ Hydraulic Data for February     43 Table 42c â“ Hydraulic Data for March     44 Table 42d â“ Hydraulic Data for April     45 Table 42e â“ Hydraulic Data for May       46 Table 42f â“ Hydraulic Data for July       47 Table 42g â“ Hydraulic Data for August     48 Table 42h â“ Hydraulic Data for September     49 Table 43a â“ Physico-Chemical Parameters for January   50 Table 43b â“ Physico-Chemical Parameters for February   51 Table 43c â“ Physico-Chemical Parameters for March     52 Table 43d â“ Physico-Chemical Parameters for April     53 Table 43e â“ Physico-Chemical Parameters for May     54 Table 43f â“ Physico-Chemical Parameters for July     55 Table 43g â“ Physico-Chemical Parameters for August   56 Table 43hâ“ Physico-Chemical Parameters for September   57 Table 44 â“ Mean Monthly Ambient and Water Temperatures   60 Table 45 â“ Determination of Reaches for the River     64 Table 46 – Dilution Effects for January     65 Table 47 – Dilution Effects for February     65 Table 48 – Dilution Effects for March     65 Table 49 – Dilution Effects for July       66 Table 410 – Dilution Effects for August     66 Table 411 – Dilution Effects for September     66 Table 412 â“ Re-arrangement of station numbers     67 Table 413 â“ Computation of time of travel on Programmed Excel Spreadsheet for January         68 Table 414 â“ Computation of time of travel on Programmed Excel Spreadsheet for February         69 Table 415 â“ Computation of time of travel on Programmed Excel Spreadsheet for March           70 Table 416 â“ Computation of time of travel on Programmed Excel Spreadsheet for July           71 Table 417 â“ Computation of time of travel on Programmed Excel Spreadsheet for August                     72 Table 418 â“ Computation of time of travel on Programmed Excel Spreadsheet for September                     73 Table 419 â“ Computation of k1 and k2 on Programmed Excel Spreadsheet for JanuaryTable 420 â“ Computation of k1 and k2 on Programmed Excel Spreadsheet for February                     75 Table 421 â“ Computation of k1 and k2 on Programmed Excel Spreadsheet for March                       76 Table 422â“ Computation of k1 and k2 on Programmed Excel Spreadsheet for July                                           77 Table 423 â“ Computation of k1 and k2 on Programmed Excel Spreadsheet for August                                 78 Table 424 â“ Computation of k1 and k2 on Programmed Excel Spreadsheet for September                     79 Table 425â“ Model fit and goodness of fit Summary for Dry Season             81 Table 426â“ Model fit and goodness of fit Summary for Rainy Season           82 Table 427 â“ Selected Models for Model Validation (Test of performance)   84 Table 428â“ Goodness of fit using January Data                 91 Table 429- Goodness of fit using March Data                 91 Table 430- Goodness of fit using July Data                           92 Table 431: Graphical Goodness of fit using January, March and July Data 102 Table 432 â“ Order of Composite Goodness of Fit               103 Table 433 â“ Comprehensive River water and Industrial Effluent Analysis   107 LIST OF PLATES                                           PAGE Plate 31 â“ The industrial effluent flowing along the road down towards the river 25 Plate 32 â“ the effluent accumulates (left) from where it seeps into the river body 25 Plate 33 â“ Effluent accumulation beside the river body   26 Plate 34 â“ Villagers of Iju tapping the river water for domestic use   26 Plate 35 â“ Sewage being taken near the river for disposal   27 Plate 36 â“ Field pH meter       35 Plate 37 â“ Eurolab digital thermometer with sensitive probe   35 Plate 38 – Geopacks Stream flow sensor with its pole and fan-like impeller 36 Plate 39 – Measuring the river width with a tape     36 Plate 310 â“ the Speedtech Portable Depth Sounder (yellow torchlight shaped instrument)         57 Plate 41 â“ Sampling Station 10 in Rainy season (August)   58 Plate 42 â“ Sampling Location 10 in Dry season (March)   58 Plate 43 â“ Human skeleton found in the River               104 Plate 44 â“ Pollution along the river channel                         104 Plate 45 â“ The research team could not proceed because of blockage of the river 105 Plate 46 â“ Water intake station for Ogun State Water Corporation                       105 Plate 47 â“ Man swimming after the dayâs work               106ABBREVIATIONS AND SYMBOLS 1 DO â“ Dissolved Oxygen 2 BOD – Biochemical Oxygen Demand 3 QUAL â“ Stream Water Quality models 4 CORMIX â“ Cornell Mixing Zone Expert 5 WASP â“ Watershed Quality Analysis Simulation Programme 6 FEPA â“ Federal Environmental Protection Agency 7 USEPA â“ United States Environmental Protection Agency 8 USGS â“ United States Geological Society 9 UNESCO â“ United Nations Education, Scientific and Cultural Organization 10 DV â“ Dependent Variable 11 IV â“ Independent Variable 12 ANOVA â“ Analysis of Variance 13 SSE â“ Error Sum of Squares 14 SSR â“ Residual sum of squares 15 SST â“ Total sum of squares 16 R2 â“ correlation coefficient 17 Adj R2â“ Adjusted Correlation coefficient 18 RMSE â“ Root mean square error 19 APHA – American Public Health Association 20 SPSS â“ Statistical Package for Social Sciences 21 MATLAB â“ Matrix Laboratory software 22 GPS â“ Global Positioning System 23 k2 â“ re-aeration coefficient 24 k1 â“ de-oxygenation coefficient 25 f â“ self purification factor 26 2 ^Ï – estimated variance 27 mg/l â“ milligram per litre