Modeling of Water Quality of Bindare Stream in Zaria-Nigeria Using Matlab

ABSTRACT

The of this study was to develop a MATLAB based modeling using SIMULINK tools that produced dissolved oxygen sag curve, and applied it to Bindare stream in Zaria,

Kaduna State-Nigeria, in order to assess the stream dissolved oxygen level and its self-purification capacity as a mitigation measure in stream pollution control.

test of selected water quality which includes Dissolved Oxygen (DO), Biochemical Oxygen (BOD), pH, Total Dissolved Oxygen (TDS), alkalinity, Electrical Conductivity (EC), and the temperature was carried out in four sections of the stream as stipulated by “Standard Method” along the 6-kilometer stream stretch.

Results generated by the model simulation included critical dissolved oxygen deficit D_c, critical time t_c of travel by the stream to attain D_c. The stream means dissolved oxygen DO of 6.4mg/L was obtained which was within the range Stipulated by APHA, AWWA, and WEF 1995.

Determination Coefficient R² (found to be 0.86) was applied to check the correlation between simulated and theoretical calculated results using the Streeter-Phelps dissolved oxygen sag formula.

It was therefore concluded that the Dissolved Oxygen Sag generated using MATLAB Simulink is a time-saving calculation tool for DO studies, user friendly, and can be applied to any stream/river of known required input parameters.

TABLE OF CONTENTS

Title page        i

Declaration        ii

Certification   iii

Acknowledgment   iv

Abstract      v

Table of Contents    vi

List of Figures  vii

List of Tables    viii

List of Plates   ix

List of Appendices     x

Abbreviations  xi

CHAPTER ONE: INTRODUCTION

• Background 1
• Studied Area 4
• Statement of the Problem 6
• Aim and Objective of the research 6
• Significance of Study 7

CHAPTER TWO: LITERATURE REVIEW

• Preamble 8
• Mathematical Model for the biochemical oxygen dissolved (BOD) curve 8
• First Order Reaction 9
• Determination of Parameters Re-Oxidation Rate Constant K₁ and Ultimate 9
  • Slope Method 10
  • Moment Method 11
  • Logarithmic Formula Method 14
  • Rapid Method 16
• Streeter-Phelps Oxygen Sag Formula 17
  • Standard Methods of Analysis 17
  • Sample Collection Method 18
  • Impact and Measurement of Water Quality Parameters 19
  • Determination of Re-Oxidation Rate Constant K₂ 29
• Water Quality Models 29
• Description of MATLAB modeling 30
• The Determination Coefficient R² 32
• Description of the Traditional Oxygen Sag Curve 33

CHAPTER THREE: MATERIAL AND METHODS

• Material 36
• Methods 37
  • Experimental Determination of DO and BOD 37
  • Experimental Determination of pH, Total Dissolved Solids,

Alkalinity, Electrical Conductivity        38

CHAPTER FOUR: RESULTS AND DATA ANALYSES

• Preparation of Input Data for the Model Simulation 39
• SIMULINK: Block Diagram 43
  • Streeter-Phelps Dissolved Oxygen Sag Curve 45
  • Variation of Dissolved Level down Bindare Stream 47
  • Stream Dissolved Oxygen and Stream Depth Comparison 47
• Results Comparison 48
  • Calculation Using Streeter-Phelps First Order Equation 48
  • The Determination Coefficient R² 50
  • The Stream Water Quality Level in terms of pH, Total Dissolved Solids, 52

Alkalinity, Electrical Conductivity52

CHAPTER FIVE: CONCLUSIONS AND RECOMMENDATION

• Conclusion 57
• Recommendation 59

Reference 60

Appendices  66

INTRODUCTION

1.1 Background

Water quality directly affects virtually all water uses, fish survival, diversity, and growth; recreational activities, municipal, industrial, and private water supplies, agricultural uses, waste disposal, and general aesthetics-all are affected by the physical, chemical, biological, and microbiological conditions.

Water quality impairment is often a trigger for conflict in a watershed, simply because degraded water quality means that desired uses are not possible or not safe (Heathcote, 1998).

Water quality can be defined as the physical, chemical, biological composition of water as related to its intended use for such purposes as drinking, recreation, irrigation, and fisheries.

Major rivers in developing countries serve multiple functions as an ecosystem, economic basis, water resource, and receiving water body, thus providing a livelihood basis for people living in the surroundings of its banks. Many of these rivers suffer increasingly severe pollution problems.

By developing tools to effectively address river water pollution, such global core problems as inadequate availability of freshwater and pollution and overuse of renewable natural resources (Hurni et al., 2004) are addressed.

Broadly, the pollution in a river occurs due to the disposal of untreated point and nonpoint source pollutants. Point-source pollution refers to the pollutants discharged to the river from one discrete location or point, such as industrial or municipal wastewater.

However, the nonpoint source pollution enters the receiving surface water diffusely at intermittent intervals.

REFERENCES

Andrew, C.S. 2007. “E105: Simulink Tutorial”
Ambrose, R. B., Barnwell, T. O., McCutcheon, S. C., and Williams, J. R.  1996.  “Computer models for water quality analysis.” Water re- sources handbook, L. W. Mays, ed., Chap. 14, McGraw-Hill, New York.
Ambrose, R.B., Wool, T. and Martin, J.L. 1993. WASP5, User’s manual. US Environmental Protection Agency, Environmental Research Laboratory, Athens, Georgia, GA, EPA/600/3-87-039
American Public Health Association (APHA), American Water Works Association (AWWA), and Water Environment Federation (WEF). 1995. Standard methods for the examina tion of water and wastewater, 19th edn. Washington, DC: American Public Health Association.
American Society of Civil Engineering Committee on Sanitary Engineering Research.1960. Solubility of atmospheric oxygen in water. J. Sanitary Eng. Div. 86(7): 41–53.