Microbiological And Physicochemical Characteristics Of Soil Contaminated With Petroleum In Umuahia, Abia State.

ABSTRACT

The microbiological and physicochemical characteristics of soil contaminated with petroleum products were carried out. A total of 3 sampling sites ( Filling station, mechanic workshop and areas around power generating plant) were investigated. The media used were Nutrient agar, Sabouraud dextrose agar, Mineral salt agar for Isolation of total heterotrophic bacteria and fungi and hydrocarbon-utilizing bacteria and fungi, respectively. The pour plate method is used for the isolation of microorganisms. The total heterotrophic bacterial count ranged from 1.4×107±0.36 - 1.7×108±0.06 cfu/g, while the total heterotrophic fungal count ranged from 6.0×105±0.63 - 9.0×106±4.0 cfu/g. The hydrocarbon-utilizing bacterial count ranged from 3.0×105±0.81 - 2.3×106±0.17 cfu/g, while hydrocarbon-utilizing fungal count ranged from 1.0×106±0.2 - 1.4×106±0.2 cfu/g. The microorganisms isolated were Bacillus species, Escherichia coli, Staphylococcus species, Klebsiella species, Micrococcus species, Penicillium species, Aspergillus species, Rhizopus species and Mucor species. The result of the physicochemical parameters ranged as follows: Oil and grease, 520mg/kg to 615mg/kg; total organic carbon, 22.10% to25.65%; pH, 3.8 to 4.3; Conductivity, 129µS/cm to 134µS/cm; Phosphate, 1.92 mg/kg to 2.26 mg/kg; Sulphate, 12.70mg/kg to 16.30mg/kg; Nitrate, 1.72mg/kg to 2.19mg/kg; Total Iron, 39.5mg/kg to 53.4mg/kg; Copper, 1.92mg/kg to 2.26mg/kg; Nickel, 0.081mg/kg to 0.102mg/kg; Cadmium, 0.049mg/kg to 0.085mg/kg, Barium, 0.034mg/kg to 0.046mg/kg; Manganese, 7.08mg/kg to 9.47mg/kg; Sodium, 13.7mg/kg to 18.4mg/kg; Magnesium, 1.86mg/kg to 3.72mg/kg; Potassium, 4.11mg/kg to 5.21mg/kg; and Calcium, 129mg/kg to 169mg/kg. It has been observed that the used petroleum had impacted negatively on the soil within the vicinity of the polluted sites and could affect vegetation around the area.

TABLE OF CONTENTS

Title page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

Table of Contents ﾿ v

List of Tables ﾿ x

Abstract ﾿ ix

CHAPTER ONE: INTRODUCTION ﾿ 1

1.1  Aims and objectives ﾿ 3

CHAPTER TWO: LITERATURE REVIEW ﾿ 4

2.1  The Biology of Soil ﾿ 4

2.2  Petroleum and its Derivatives ﾿ 5

2.3  Environmental contamination of soil ﾿ 6

2.4  Sources of Petroleum contamination in soil ﾿ 6

2.5  Effect of petroleum contamination ﾿ 6

2.6  Effect of soil contamination on ecosystem ﾿ 7

2.7  Clean up of soil ﾿ 7

2.7.1 Bioremediation of sites contaminated by petroleum derivatives ﾿ 10

2.8  The physical characteristics of soil ﾿ 11

1.8.1 Soil texture ﾿ 11

1.8.2 Soil structure ﾿ 12

1.8.3 Soil tilth ﾿ 13

1.8.4 Soil water ﾿ 13

1.8.5 Soil organic matter ﾿ 14

1.9  Chemical properties of soil ﾿ 14

1.9.1 Cat ion exchange ﾿ 14

1.9.2 Soil pH ﾿ 15

1.9.3 Soil salinity ﾿ 16

1.9.4 Heavy metals ﾿ 16

CHAPTER THREE: MATERIALS AND METHODS ﾿ 19

3.1 Study area ﾿ 19

3.2 sample collection ﾿ 19

3.3 Microbiological methods ﾿ 19

3.3.1 Media ﾿ 19

3.4  Enumeration of Total Heterotrophic Bacteria and Fungi ﾿ 20

3.5  Enumeration of hydrocarbon-utilizing Bacteria and Fungi ﾿ 20

3.6  Characterization and identification of Hydrocarbon utilizing isolates ﾿ 21

3.6.1 Macroscopic Examination ﾿ 22

3.6.2 Microscopic Examination ﾿ 22

3.6.3 Gram staining ﾿ 22

3.6.4 Lacto phenol cotton blue ﾿ 22

3.6.5 Spore Staining ﾿ 23

3.6.6 Motility Test ﾿ 23

3.7  Biochemical Tests ﾿ 24

3.7.1 Catalase test ﾿ 24

3.7.2 Citrate test ﾿ 24

3.7.3 Oxidase test ﾿ 24

3.7.4 Indole test ﾿ 24

3.7.5 Urease test ﾿ 25

3.7.6 Coagulase test ﾿ 25

3.7.7 Methyl red- Voges proskquer test ﾿ 25

3.7.8 Triple Sugar Iron Agar (TSIA) Test ﾿ 25

3.7.9 Starch Hydrolysis Test ﾿ 26

3.7.10 Sugar Fermentation Test ﾿ 26

3.8  Determination of physicochemical parameters ﾿ 27

3.8.1 pH Determination ﾿ 27

3.8.2 Electrical Conductivity ﾿ 27

3.8.3 Determination of sulphates ﾿ 27

3.8.4 Determination of nitrates ﾿ 28

3.8.5 Determination of phosphates ﾿ 28

3.8.6 Heavy metal Analysis ﾿ 29

3.8.7 Determination of oil and grease and Total Petroleum Hydrocarbon(TPH) ﾿ 29

3.8.8 Determination of Total Organic Carbon ﾿ 29

3.8.9 Determination of Exchangeable Cat ions ﾿ 30

CHAPTER FOUR: RESULTS ﾿ 31

CHAPTER FIVE: DISCUSSION, CONCLUSION, RECOMENDATION ﾿ 41

5.1  Discussion ﾿ 41

5.2  Conclusion ﾿ 44

5.3  Recommendation ﾿ 44

References ﾿

Appendix ﾿