EVALUATION OF BIOFILM IN WASTEWATER TREATMENT SYSTEM

ABSTRACT

Biofilm in waste water treatment system was evaluated. Slime (film) formers were isolated from water samples collected from treated waste water; from brewery and bottling company in Aba. Result obtained from the adherence slip culture show the presence of five bacteria isolates with ability to adhere strongly onto the cover slip in water. The isolates and occurance  were; Staphylococcus,  100%, Bacillus, 100%, Pseudomonas 80%, E.coli  40% and Listeria  50%. Further tests for confirmation of biofilm production was done using the congo red agar colorimetric method. Staphylococcus, Bacillus,  and Pseudomonas  showed positive biofilm production while  E.coli  and Listeria  did not produce slime in the culture. Also present of physico-chemical properties of the waste water samples indicates low quality with high BOD of 9.7mg/l to 22.5mg/l in the treated water bottling company waste water and from 9.67mg/l to 13.7mg/l. The COD range was 4.61mg/l to 8.06mg/l and from 2.75mg/l to 5.66mg/l in the two waste waters respectively. The pH ranged from 5.33 to 5.79 and from 5.43 to 6.23 in the water samples. The more variations in Temperature of the waters over the days as well as in the Total Solids and Total Suspended Solids content. The water was considered to be polluted by organic pollutant and unsuitable for domestic use as the biofilm can cause deliteries effects on utensils including corrosion and possible infections. 

TABLE OF CONTENTS

Title page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

Table of Contents ﾿ v

List of Tables ﾿ vii

List of  Figures ﾿ viii

Abstract ﾿ ix

CHAPTER ONE

1.1 ﾿ Introduction ﾿ 1

1.2 ﾿ Advantages and disadvantages of biofilm application ﾿ 2

1.3 ﾿ Aims and objectives ﾿ 3

CHAPTER TWO - LITERATURE REVIEW ﾿ 4

2.1 Wastewater and Its Treatment ﾿ 4

2.1.1 ﾿ Wastewater Components ﾿ 5

2.2  Biofilms ﾿ 7

2.2.1 ﾿ Development of formation of biofilm ﾿ 8

2.2.2 ﾿ Biofilm system in Wastewater ﾿ 11

2.2.3 ﾿ Comparison between suspended and fixed film ﾿ 12

2.2.4 ﾿ Sludge mechanisms ﾿ 13

2.2.5 ﾿ Wastewater and anaerobic treatment ﾿ 14

CHAPTER THREE - MATERIALS AND METHOD ﾿ 16

3.1 ﾿ Sources of Material ﾿ 16

3.2 ﾿ Sample and  Media Preparation. ﾿ 16

3.2.1 ﾿ Sample and Sampling ﾿ 16

3.2.2 ﾿ Media Preparations ﾿ 16

3.3 ﾿ Determination of Bacterial Load ﾿ 17

3.4 ﾿ Isolation of Biofilm Producing Bacteria ﾿   18

3.4.1 ﾿ Characterisation and Identification of Biofilm suspect isolates ﾿   19

3.5 ﾿ Determination of physiochemical properties of waste water samples. ﾿   20

3.5.1 ﾿ Determination of temperature ﾿   20

3.5.2 ﾿ Determination of pH ﾿   20

3.5.3 ﾿ Determination of total and suspended solids. ﾿   20

3.5.4 ﾿ COD determination ﾿    21

3.5.5 ﾿ Determination of BOD ﾿    21

3.6 ﾿ Determination of Biofilm formation of Isolates ﾿     22

CHAPTER FOUR – RESULTS ﾿        24

CHAPTER FIVE – DISCUSSION, CONCLUSION AND RECOMMENDATION      30

5.1 ﾿ Conclusion ﾿       31

5.2 ﾿ Recommendation ﾿       31

References

Appendixes