ABSTRACT
A natural on sludge drying bed has resulted to a modified incorporating the compressibility coefficient. The equation was derived using the of a modified FMTLXLYLZ dimensional technique.
The equation was validated using experimental data from a pilot scale sand drying bed and there was a close agreement between theory and with a correlation coefficient ranging from 0.94 to 0.98.
The experimental slope and intercept was found to be (1260913.48 s/m6 , 4872.53 s/m3) (5359604.57 s/m6, 844882.56 s/m3), (112117050.4 s/m6, -2135816.16 s/m3), and (145562880 s/m6, -30497917.03 s/m3)
while the theoretical values of slopes and intercepts are (1257426.75 s/m6, 5270.26 s/m3),( 4579418.42 s/m6, 905658.24 s/m3), (112117075 s/m6, -21358166.74 s/m3),and (206699290.5 s/m6, – 4589555.58 s/m3) respectively.
TABLE OF CONTENT
Title page i
Certification ii
Dedication iii
Abstract iv
Acknowledgment v
List of Tables vi
List of figures vii
List of symbols viii
Table of content ix
CHAPTER ONE: INTRODUCTION 1
1.1 Sludge and sand drying bed
1.2 Research Problem 2
1.3 Objective of project 2
1.4 Justification of project 2
1.5 Scope of study 3
CHAPTER TWO: LITERATURE REVIEW
2.1 Sludge treatment process 4
2.1.1 Thickening 4
2.1.2 Stabilization 4
2.1.3 Conditioning 5
2.1.4 Disinfection 6
2.1.5 Dewatering 7
2.1.5.1 Vacuum filtration 7
2.1.5.2 Centrifuge 7
2.1.5.3 Belt filter press 8
2.1.5.4 Filter Press 8
2.1.5.5 Conventional sand drying bed 8
2.1.5.6 Paved drying bed 9
2.1.5.7 Artificial media drying beds 10
2.1.5.8 Vacuum-assisted drying bed 11
2.2 Drying 11
2.3 Definition of Terms 11
2.31 Specific Resistance 11
2.3.2 Compressibility coefficient 14
2.4 Limitation of Carman’s Equation 16
2.4.1 Variability of (R) during filtration process 17
2.4.2 The problem of variable hydrostatic head 17
2.4.3 Relationship between volume and time. 18
2.4.4 Relationship between volume and area of filtration 18
2.4.5 The concentration Term 18
2.4.6 Relationship between R and P 19
2.4.7 Area of filtration 19
2.5 Apparatus used in filtration experiment 19
2.6 Filtration Theories 21
2.6.1 Almy and Lewis (1912) 21
2.6.2 Sperry (1916) 21
2.6.3 Baker (1921) 22
2.6.4 Weber and Hershey (1926) 22
2.6.5 Carman (1934, 1938) 22
2.6.6 Ruth (1933, 1935) 23
2.6.7 Tiller (1953) 24
2.6.8 Grace (1953) 24
2.6.9 Rushton et al (1973) 25
2.6.10 Anazodo (1974) 25
2.6.11 Gale and White (1975) 26
2.6.12 Hemant (1981) 26
2.6.13 Ademiluyi jo , Anazodo and Egbuniwe (1982) 27
2.6.14 Ademiluyi (1984) 28
2.6.15 Ademiluyi et al (1982, 1987) 28
2.6.16 Agunwamba et al (1988) 29
2.6.17 Ademiluyi (1991) 30
CHAPTER THREE: RESEARCH METHODOLOGY
3.1 Study Area 31
3.2 Materials and Method 31
3.3 Dimensional analysis 33
3.4 Theory of Experiment 34
3.5 Method of evaluating filtration parameters 39
3.5.1 Initial solid content 39
3.5.2 The Area of filtration 39
3.5.3 The compressibility coefficient 39
3.5.4 Density of filtrate 39
3.5.5 Dynamic Viscosity 39
3.5.6 Weight of dry solid 40
3.5.7 Specific Resistance of sludge 40
3.5.8 Thickness of Dry sludge 40
3.5.9 Time of Filtration 40
3.5.10 Volume of Filtrate 40
3.5.11 Percentage of solid content expressed in decimal 40
CHAPTER FOUR: RESULTS AND DISCUSSIONS
4.1 Experimental validation of equation 41
4.2 The Effect of chemical conditioning on the specific resistance 44
4.3 Variation of Initial solid content with specific resistance 47
4.4 Variation of Hydrostatic pressure with specific resistance 47
CHAPTER FIVE: CONCLUSION AND RECOMMENDATION 48
REFERENCES 52
INTRODUCTION
1.1 Sludge and Sand Drying Bed Dewatering
Domestic wastewater result from the use of water in dwellings of all types and includes water after use and the various waste materials added: body waste, kitchen waste, household cleaning agents and laundry soap and detergents.
In contrast to the general uniformity of substances found in domestic waste water, industrial waste water show increasing variation as the complexity of industrial processes rises.
The character of these waste materials is such that they cause significant degradation of receiving waters and hence results to environmental health hazard and pollution. One of the steps in the control of pollution is the treatment of waste water before disposal.
In the process of treating waste water, sludge is generated and constitutes the most challenging problem facing the environmental engineer.
This sludge has high water content and is usually subjected to dewatering to reduce the moisture.
Sludge drying bed is one of the earliest processes used in the dewatering of sludge before the introduction of mechanical processes.
The waste can be dewatered in an open or covered sand bed which also requires a large amount of land for its operation.
REFERENCES
ADEMILUYI J.O (1986) development in the constant vacuum cake filtration theory.Proceedings of engineering section of science Association of Nigeria VOL 6 & 7.
ADEMILUYI J.O , ROMANUS M,EZE (1990), Improving the sludge conditioning potential of moringo seed: Environmental management VOL 14 NO 1 PP 125-129.
AGUNWAMBA J.C & ADEMILUYI J.O (1988), Coagulant mixes using linear programming; Nigerian journal of engineering NJE VOL 5 NO 2.
ADEMILUYI J.O ; EZE ROMANUS M , Modification of the sludge dewaterabilty number(SDN) equation Proceeding presented at the 2ND Uniben conference on engineering and technological development.
ADEMILUYI J.O AND EGBUNIWE N (1984), The relative effect on conditioners on the filterability of sewage sludge; Nigerian journal of engineering and thecnology,VOL7 N01.
ADEMILUYI J.O (1990) Effect of shear, filter medium ageing and sequence of chemical addition on sludge dewareability number (SDN) Afican journal of science and technology VOL 8 N0 2.
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