ABSTRACT

This research is the assessment of microbiological quality of Onu Imo River. The aim of the research was to evaluate the microbial contaminants of water. Samples of this research were collected at three strategic points for five days intervals. The standard microbiological method used was pour plate technique; standard analytical method was used to determine the physiochemical analysis. The research identified five bacteria isolates, Echerichia coli, Pseudomonas aeroginosa, Salmonella spp. Enterobacter aerogenes, Streptococus faecalis. On the first, second, third and fifth day the heterotrophic count observed and recorded. It was recorded that on the fifth day the heterotrophic count was lower than the first day. The result of this analysis indicated that the water quality is unsatisfactorily at all sampling sites. 

TABLE OF CONTENTS Page

Title Page i

Certification ii

Dedication iii

Acknowledgement iv

Table of Contents v

Abstract x

CHAPTER ONE

1.0 INTRODUCTION 1

1.1         Scope of Study  3

1.2 Justification 3

1.3 Aims and Objectives of the Study 3

CHAPTER TWO 

2.0 LITERATURE REVIEW 5

2.1 Water 5

2.2 Sources of Water 5

2.3 Surface Water 6

2.3.1 Sources of Surface Water Pollution 6

2.3.2 Survival of pathogens in surface water (Rivers) 8

2.3.3 Transport in Surface Water (river) 8

2.3.4 Evaluating the Growth Potential of Pathogenic Bacteria in Surface Water (River) 10

2.4 Bacteriological Analysis of Water (e.g. river) 11

2.5 Microbiological Analysis of Water 11

2.6 Indicator Organisms 13

2.6.1 Coliforms 13

2.6.1.1  Faecal coliforms 15

 2.6.1.2  Escherichia coli 15

2.6.1.3 Faecal streptococci 18

2.6.1.4 Clostridium perfringes 19

2.7 Other indicators 20

2.8 Methods of Assessing Microbial Quality of Water 21

2.8.1 Most Probable Number Technique (MPN) 21

2.8.2 Membrane Filtration Method 23

2.8.3 Presence – Absence Tests 24

2.8.4 Colilert Defined Substrate Test 24

2.8.5 Molecular Techniques 25

2.8.6 Choice of method 25

2.8.7 Multiple Tube (Most Profitable Number) Tests 27

2.9 Contaminants in Water 28

2.9.1 Waterborne Pathogens/Microbial contaminants 29

2.9.2 Radiological Contaminants 30

2.9.3 Organic Chemical Contaminants 31

2.9.4 Inorganic contaminants 32

2.10 Water Treatment and Purification 33

2.10.1 Sedimentation 34

2.10.2 Aeration 34

2.10.3 Coagulation/Flocculation 34

2.10.4 Softening 35

2.10.5 Filtration 35

2.10.6 Adsorption 35

2.10.7 Chlorination 35

2.10.8 Ozonation (Ozone Oxidation) 36

2.11 Sources of Microbial Growth in Water 36

2.12 Risks of Microorganism to Human Health 37

2.13 Examples of At-risk Concentration Levels 38

CHAPTER THREE 

3.0 MATERIALS AND METHODOLOGY 40

3.1 Background of Study 40

3.2 Sample Collection 40

3.3 Microbiological Methods 40

3.3.1 Media preparation 40

3.3.2 Nutrient Agar (NA) 41

3.3.3 MacConkey Agar (MCA) 41

3.3.4 Inoculation 41

3.3.5 Incubation 42

3.4 Enumeration of Fungi and bacteria 42

3.5 Determination of Bacterial and Fungal Flora of the Water Samples 43

3.5.1 Isolation 43

3.5.2 Identification and characteristics of Isolates 43

3.5.3 Cultural examination 43

3.5.4 Microscope examination 44

3.5.5 Gram Staining 44

3.5.6 Lactophenol Cotton Blue Stain 44

3.5.7 Test for Motility (Stab Culture Technique) 44

3. 5.8 Catalase Production Test 45

3.5.9 Oxidase Test 45

3.5.10 Coagulase Test 45

3.6 Test for Coliforms 46

3.6.1 (Multiple Tube Technique/Most Probable Number) 46

3.6.2 Presumptive test 46

3.6.3 Confirm Test 47

3.6.4 Complete Test 47

3.7 Methods for the Physio-Chemical Analysis of Water 47

3.7.1 pH 47

3.7.2 Determination of conductivity 48

3.7.3 Determination Dissolved Oxygen 48

3.7.4 Determination of Calcium 48

3.7.5 Determination of Acidity 48

3.7.6 Determination of Chloride 49

3.7.7 Determination of Sulphate 49

3.7.8 Determination of Nitrate 50

CHAPTER FOUR 

4.0 RESULTS AND DISCUSSION 51

4.1 Results 51

4.2 Discussion

CHAPTER FIVE 

5.0 CONCLUSION AND RECOMMENDATION

5.1 Conclusion 

5.2 Recommendation 

References