Filtration, Aeration, Constructed Wetlands

154 Pages·2015·3.39 MB·English

An Evaluation of Treatment Options for Dairy Farm Wastewaters:
Filtration, Aeration, Constructed Wetlands

by
Heather M. Bromley, B. Eng.

A Thesis
presented to
The University of Guelph

In partial fulfillment of requirements
for the degree of
Master of Science
In Environmental Sciences

Guelph, Ontario, Canada
© Heather M. Bromley, August, 2015
i
ABSTRACT
AN EVALUATION OF TREATMENT OPTIONS FOR DAIRY FARM WASTEWATERS:
FILTRATION, AERATION, CONSTRUCTED WETLANDS

Heather M. Bromley, B. Eng. Advisors:
University of Guelph, 2015 Dr. Robert J. Gordon and Chris Kinsley

Agricultural wastewaters are highly concentrated with contaminants. Economical, efficient solutions for
managing and disposing of agricultural wastewaters are soon to be required by Ontario legislation.
A constructed wetland was assessed on its treatment of dairy milk house washwater. Effluent water
quality evaluations revealed BOD concentration reductions of 90% during the summer and 82% during
5
the winter. The seasonal TSS removals were 83% during the summer and 79% during the winter.
Bench scale column tests determined that intermittent sand filters with gravel caps are appropriate pre-
treatment options. The sand columns removed 72% of TSS, and 54% of COD content. The gravel filter
columns removed 56% of TSS and 43% of COD content.

Complete mix aeration reactors were examined for their efficiency in the removal of COD and nutrients
from different types of dairy farm wastewaters. All reactors produced high quality effluent, and first order
kinetic rate constants were determined.
iii

Acknowledgements

I would like to take this opportunity to express my sincere appreciation to my advisor Dr. Robert
J. Gordon and my co-advisors Anna Crolla and Chris Kinsley for giving me this wonderful
opportunity to pursue a master’s degree. Their guidance, support, endless hours of help and
words of encouragement over the past few years truly inspired and pushed me to rise to every
challenge with excitement and perseverance.
I would like to thank my colleagues at the University of Guelph’s Campus D’Alfred for their
constant support, encouragement and time; those samples would have never gotten analysed
without your guidance.
I would like to thank my family for their unconditional love and support throughout not only this
experience but all other life changes and challenges. To my parents, David and Claire Bromley,
who were just as excited as I was when I decided to start on this crazy journey, and who wanted
to be filled in on every detail along the way; even if it was about cow manure. They have always
been my biggest fans, and taught me to always do my best, get back up when I fall and that
tomorrow is another day. To my sister, Emma Bromley, who always knew just what to say
during difficult times and never failed to bring a smile to my face. Thank you all for standing by
me through this process, and for you adventurous attitude when helping with wastewater
sampling.
To my fiancé, Justin Phillips, who tells me I can do anything, and means it. His support and
encouragement has been a steady constant, and knowing he is proud of what I have
accomplished is all the recognition I need.
To my friends who supported and understood that Saturday night was data entry night, and that I
would see them again in two years.
And finally to the calves at the dairy barns, you made sampling in - 40˚C a little easier.
Contents
Abstract ii
Acknowledgements iii
List of Figures vii
List of Tables ix
Abbreviations xi

1.0 Introduction 1
1.1 Objectives 2

2.0 Literature Review 4
2.1 Introduction 4
2.2 Dairy Farm Wastewaters 5
2.2.1 Dairy Milk House Washwater 5
2.2.2 Manure Runoff 7
2.2.3 Silage Leachate 8
2.2.4 Environmental Concerns of Dairy Wastewaters 9
2.2.5 Management Options for Dairy Wastewaters 10
2.3 Wetlands and Their Treatment Processes 12
2.3.1 Constructed Wetlands 12
2.3.2 Primary Treatment 14
2.3.3 Wetland Treatment Mechanics 14
2.3.3.1 Suspended Solids 14
2.3.3.2 Organics 15
2.3.3.3 Nutrient Removal 16
2.3.4 Constructed Wetland Design Considerations 18
2.4 Treatment Mechanics of Neutralization, Coagulation and Flocculation 20
2.4.1 Neutralization of Wastewater 20
2.4.2 Coagulation/Flocculation of Wastewater 20
2.4.3 Calcium Hydroxide for Stabilization 22
2.5 Treatment Mechanics of Sand Filtration 23
2.6 Treatment Mechanics of Aeration 25
2.7 Amendment to Ontario Regulation 27
2.8 Summary 29

3.0 Neutralization and Aeration of Dairy Farm Wastewater as Pre-treatment
Options 30
3.1 Introduction 30
3.2 Pre-Treatment of Silage Leachate vie Hydrated Lime Addition 30
3.3 Pre-Treatment of Dairy Wastewaters via Complete Mix Reactor Aeration 32
3.4 Materials and Methods 33
3.4.1 Neutralization and Coagulation/Flocculation Bench Test 33
3.4.1.1 Silage Leachate Collection 33
3.4.1.2 Bench Scale Neutralization and Stabilization Jar Test 34
3.4.1.3 Hydrated Lime Addition – Preliminary Experiment 34
iv
3.4.1.4 Bench Scale Neutralization with Possible
Coagulation/Flocculation of Silage Leachate Jar Test 35
3.4.2 Bench Scale Reactor Kinetic Determination 37
3.4.2.1 Wastewaters Components 39
3.4.2.2 Preparation of Reactors 40
3.4.2.3 Reactor for Kinetic Determination 41
3.4.2.3.1 Hydraulic Retention Time 41
3.4.2.3.2 Pump Calibrations 42
3.4.2.3.3 Reactor Sampling 43
3.4.2.3.4 Kinetic Determinations 44
3.4.2.3.5 Statistical Analyses 46
3.5 Results and Discussion 46
3.5.1 Silage Leachate Characteristics 46
3.5.2 Neutralization of Silage Leachate 48
3.5.2.1 Preliminary Jar Test 48
3.5.2.2 Coagulation/Flocculation of Silage Leachate 48
3.5.3 Bench Scale Reactor Performances 51
3.5.3.1 Influent Wastewater Characteristics 51
3.5.3.2 Reactor Performance 53
3.5.3.2.1 Reactor Observations 53
3.5.3.2.2 Performance of COD Removal 55
3.5.3.2.3 Performance of Nutrient Removal 59
3.5.3.2.4 Reactor Kinetics Determination 64
3.6 Conclusions 69
3.6.1 Neutralization of Silage Leachate Conclusions 69
3.6.2 Kinetics Determination Conclusions 69

4.0 Evaluation of Two Filter Medias for the Pre-Treatment of Dairy Washwater 71
4.1 Introduction 71
4.2 Materials and Methods 72
4.2.1 Statistical Analyses 75
4.3 Results and Discussion 76
4.3.1 Column Performance of TSS Removal 77
4.3.2 Column Performance of COD Removal 81
4.4 Conclusions 84

5.0 Evaluation of the Performance of a Horizontal Subsurface Flow Constructed
Wetland with Pre-Treatment at an Ontario Dairy Farm 86
5.1 Introduction 86
5.2 Materials and Methods 88
5.2.1 Statistical Analyses 92
5.3 Results and Discussion 92
5.3.1 Performance of Pre-Treatment and HSFCW Treating Dairy
Milk House Washwater 92
5.3.2 Seasonal Performance of HSFCW 99
5.3.3 Kinetic Determination Based on System Performance 102
5.3.3.1 Aeration Chamber Kinetics 102
5.3.3.2 Wetland Kinetics 104
5.4 Conclusions 106

6.0 Conclusions 107
v
7.0 Appendices
A Reactor Wastewater Quality Raw Data 111
B Kinetic Determination 118
B.1 Linearized First Order Kinetic Rate Constant Method
– Complete Mix Reactor 118
C Filter Media Raw Data 121
D Wetland Water Quality Raw Data 124
E Sample Calculations 133
E.1 Percent Removal 133
E.2 Kinetics – Twin Hills Wetland 134
E.2.1 Complete Mix Reactor 134
E.2.2 Plug Flow Wetland 135
E.3 Nutrients 136
E.3.1 TN Determination 136
E.3.2 Organic N Determination 136

8.0 References 137

vi
List of Figures

2.1 Typical HSFCW Schematic 19
3.1 Schouten Cornerview Farms Square Silo for Silage Storage 33
3.2 Bench Scale Jar Test Set-up for Silage Leachate Neutralization 36
3.3 Schematic of Complete Mix Reactor for Bench Scale Experiment 37
3.4 Drums Containing Wastewater Mixtures for Reactor Bench Scale Experiment 38
3.5 Schematic of Complete Mix Reactor Set-up for Bench Scale Experiment 39
3.6 Overview Schematic of Complete Mix Reactor Set-up, with Three Systems 41
3.7 Silage Leachate Production and BOD Concentration over Sampling
5
Period 47
3.8 Silage Leachate with 20g Hydrated Lime, 400mL Sludge after 18 hr Settling 48
3.9 Summary of TS, VS and pH After Lime Addition to Silage Leachate 49
3.10 Beaker 3 with 12.5 g of Hydrate Lime After 16 hr and 24 hr of Settling. 50
3.11 Summary of Average COD Effluent Concentrations from R-MW and R-MWMR 56
3.12 Time Series of COD Effluent Concentrations of R-MMSL 57
3.13 Summary of Average Nutrient Effluent Concentrations over time in R-MW 59
3.14 Summary of Average Nutrient Effluent Concentrations over time in R-MWMR 61
3.15 Summary of Average Nutrient Effluent Concentrations over time in R-MMSL 63
3.16 Average BOD Removal Efficiency and F/M ratio of R-MW 67
5
3.17 Average BOD Removal Efficiency and F/M ratio of R-MWMR 68
5
3.18 Average BOD Removal Efficiency and F/M ratio of R-MMSL 68
5
4.1 Schematic of Sand and Gravel Filter Columns 73
4.2 Filter Column Bench Scale Set-up 74
4.3 Summary of Average TSS Influent and Effluent Concentrations during Daily Dosage
Change for the Sand Filter Column Triplicates 77
4.4 Summary of TSS Influent Concentrations and Average TSS Effluent Concentrations
Over Time for the Sand Filters with Dosage Change 78
4.5 Summary of Average TSS Influent and Effluent Concentrations during Daily Dosage
Change for the Gravel Filter Column Triplicates 79
4.6 Summary of TSS Influent Concentrations and Average TSS Effluent Concentrations
Over Time for the Gravel Filters with Dosage Change 80
4.7 Summary of Average Influent and Effluent TSS Concentrations for Sand and Gravel
Filter Column Triplicates 81
4.8 Summary of Average COD Influent and Effluent 1 & 2 Daily Dose of Filter
Column Triplicates 81
4.9 Summary of COD Influent Concentrations and Average COD Effluent Concentrations
Over Time for the Sand Filters with Dosage Change 82
4.10 Summary of COD Influent Concentrations and Average COD Effluent Concentrations
Over Time for the Gravel Filters with Dosage Change 83
5.1 Aerial View of Twin Hills Farm and Treatment System 88
5.2 Overview of Treatment System at Twin Hills Farm 89
5.3 Top View of Sampling Points throughout Treatment System at Twin Hills Farm 90
5.4 HSFCW at Twin Hills Farm Summer 2014 90
5.5 Summary Over Time of Temperature across the Treatment System, Air Temperature
and Precipitation 94
5.6 HSFCW at Twin Hills Dairy Farm, Winter 2013 95

vii
5.7 Summary of Sludge and Scum Accumulation (% Volume of Septic Tank)
Within Second Chamber of Septic Tank at Twin Hills Farm 96
5.8 Summary of the Seasonal Average BOD Concentrations across Wetland 99
5
5.9 Summary of the Seasonal Average TSS Concentrations across the Wetland 100
5.10 Summary of Seasonal Average TKN Concentrations across Wetland 101

B.1 Kinetic Determination of R-MW, Trial 1, Complied with Data from Table B.2 & B.3 120

viii
List of Tables
2.1 Typical Milk House Washwater Characteristics 6
2.2 Milk House Washwater Production of Different Milking Systems 7
2.3 Typical Dairy Manure Runoff Characteristics 7
2.4 Typical Silage Leachate Characteristics 8
2.5 Leachate Production Based on Percent Dry Matter of Silage 9
3.1 Summary of Measured Parameters of Silage Leachate Analyzed at ORWC Labs
According to Standard Methods 34
3.2 pH Change of Silage Leachate due to Lime Addition 35
3.3 Lime Addition to Silage Leachate to Cause Neutralization, Coagulation/Flocculation 36
3.4 Hydraulic Retention Times used for all Three Reactors 42
3.5 Total Pump Run Times 42
3.6 Pump Run Time Based on HRT and 8 Programs 43
3.7 Summary of Measured Parameters of Wastewater Mixtures Analyzed at ORWC Labs
According to Standard Methods 44
3.8 Step One of Kinetic Determination 44
3.9 Step Two of Kinetic Determination 45
3.10 Step Three of Kinetic Determination 45
3.11 Summary of Average Parameters of Silage Leachate 47
3.12 Resultant Sludge from Hydrated Lime Addition 50
3.13 Parameter Ranges of Dairy Farm Wastewater Influent Components 51
3.14 Parameter Ranges of Dairy Farm Wastewater Mixtures - Reactor Influent 52
3.15 Summary of Average COD Concentrations of R-MW and R-MWMR 55
3.16 Summary of Average COD Concentrations of R-MMSL 58
3.17 Summary of Average Nutrient Concentrations and Removals in R-MW for
Trial 1 and Trial 2 60
3.18 Summary of Average Nutrient Concentrations and Removals in R-MWMR for
Trial 1 and Trial 2 62
3.19 Summary of Average Nutrient Concentrations and Removals in R-MMSL for
Trial 1 and Trial 2 64
3.20 Summary of Kinetic Coefficients for each Complete Mix Reactor -
Calculated Based on BOD 65
5
3.21 Summary of Kinetic Coefficients for each Complete Mix Reactor –
Calculated Based on TKN 66
4.1 Summary of Average Sand and Gravel Influent and Effluent TSS and COD, for
each Tirplicate Filter Column 76
5.1 Summary of Measured Parameters of Dairy House Washwater from Twin Hills
Farm Analyzed at ORWC Labs According to Standard Methods 91
5.2 Summary of Averages of Analyzed Washwater Parameters 93
5.3 Summary of Average Dairy Washwater Parameters at Different Stages
of Treatment Process 97

A.1 Water Quality Raw Data R-MW – Dairy Milk House Washwater 111
A.2 Water Quality Raw Data R-MWMR– Dairy Milk House Washwater +
Manure Runoff 113
A.3 Water Quality Raw Data R-MMSL– Dairy Milk House Washwater +
Manure Runoff + Silage Leachate 115

A.4 Drum 1 Influent Raw Data 116
ix
A.5 Drum 2 Influent Raw Data 116
A.6 Drum 3 Influent Raw Data 117
B.1 Complied Data for R-MW 119
B.2 Data Complied to Linearize Equation B-1 119
B.3 Data Complied to Linearize Equation B-2 119
B.4 Results of Kinetic Determination for R-MW and R-MWMR 120
C.1 Influent and Effluent TSS Raw Data 121
C.2 Influent and Effluent COD Raw Data 122
D.1 Raw pH Data from Twin Hills Wetland 124
D.2 Raw TSS Data from Twin Hills Wetland 125
D.3 Raw BOD Data from Twin Hills Wetland 126
5
D.4 Raw TKN Data from Twin Hills Wetland 127
D.5 Raw NO - Data from Twin Hills Wetland 128
3
D.6 Raw NH + Data from Twin Hills Wetland 129
4
D.7 Raw TP Data from Twin Hills Wetland 130
D.8 Raw O-PO Data from Twin Hills Wetland 130
4
D.9 Raw Temperature Data from Twin Hills Wetland 131
D.10 Raw Septic Sludge and Scum Data from Twin Hills Wetland 132

x