ABSTRACT
Physiochemical and bacteriological analyses of water samples from three different boreholes located close to a dumpsite at Owerri, Nigeria were carried out to evaluate the level of dumpsite pollution on underground water. Some soil hydraulic properties were analyzed to determine the penetration rate of leachate into the underground water. Borehole locations were at distances of 50m, 100m, and 500m respectively away from the dumpsite. The parameters determined included; turbidity, temperature, pH, chemical oxygen demand (COD), total dissolved solids (TDS), Total Hardness (TH), Total Iron, Nitrate, Nitrite, Chloride, Calcium and some metals such as Copper, Zinc and Lead using standard laboratory equipment and procedures. Most of these parameters indicated slight pollution but below the Nigerian Standard for Drinking water quality (NSDWQ) and World Health Organization (WHO) limits permissible for consumption. The pH and turbidity values of 6.95 and 3.5 NTU respectively were obtained indicating the presence of active microorganism. Temperature was peaked at 27.80C. The concentrations of COD, TDS, and TH were highest at 2.2mg/L, 352mg/L and 150mg/L respectively. The maximum observed concentrations of calcium, nitrate, nitrite and chloride were 75mg/L, 56mg/L, 1.1 mg/L and 193mg/L respectively. The metals iron, lead, zinc were peak at 4mg/L, 0.1 mg/L and 0.1mg/L respectively, while copper was only detected in one site with maximum value of 0.2mg/L. Bacteriological analysis ranged from 0-50/100ml MPN for all the boreholes. For soil hydraulic properties the maximum values obtained were as follows; soil infiltration rate (I.R) - 5.6 cm/hr., soil bulk density-1.2 g/cm3, cation exchange capacity (C.E.C.)-1.1% and effective porosity (E.P)-65%. Statistical analyses indicated significant differences in all the parameters tested for, in the samples at (p<0.05) compared to WHO and NSDWQ standards. The results showed that underground water from site 1 and 3 was slightly polluted but still require certain levels of treatment before use while that of site 2 at Aba road was highly polluted and such needed to be thoroughly treated before use. Therefore, the use of advanced water treatment technology and water purification methods such as sedimentation, filtration, distillation and chlorination of drinking water before consumption to prevent infections are recommended also adequate public enlightenment on proper waste disposal management, treatment and siting of boreholes far away from dump sites are encouraged.
TABLE OF CONTENTS
Title page i
Declaration ii
Certification iii
Dedication iv
Acknowledgements v
Table of contents vi
List of tables ix
List of figures x
List of abbreviations and
their meaning xi
Abstract xii
CHAPTER 1
INTRODUCTION
1.1
Background of the Study 2
1.2
Statement of Purpose 3
1.3
Aim of the Study 4
1.4
Objectives of the Study 4
1.5
Significance of the Study 4
1.6
Statement of Problem 5
1.7
Justification of the Study 6
CHAPTER
2
LITERATURE REVIEW
2.1
Aquifer in Ground Water Movement 7
2.1.1
Formation of aquifers
8
2.1.2
Types of aquifers 9
2.2 Formation
of Leachate 9
2.2.1 Physical
composition of leachate 9
2.2.2 Chemical
components of leachates 9
2.2.3 Bacteriological
components of leachate 9
2.3 Soil-Leachate
Interaction 9
2.4 Health
Impact of Turbidity 10
2.4.1 Causes
of turbidity 10
2.4.2 Consequences
of high turbidity 10
2.5 Health
Impact of Temperature 11
2.5.1 Cause
of increased water temperature 11
2.6 Health
Impact of pH 11
2.7 Health
Impact of Chemical Oxygen Demand 13
2.8 Health
Impact of Total Dissolved Solid 13
2.9 Health
Impact of Total Hardness 14
2.10 Health
Impact of Calcium 15
2.11 Health
Impact of Nitrate/Nitrite 15
2.12 Health
Impact of Chlorine 16
2.13 Health
Impact of Iron 17
2.14 Health
Impact of Lead 18
2.15 Health
Impact of Copper 19
2.16 Health
Impact of Zinc 20
2.16.1 Health
impact of Escherichia coli 20
2.16.2 Implications
of soil infiltration rate 21
2.17 Implications
of Soil Effective Porosity 22
2.17.1 Implications
of soil bulk density 22
2.17.2 Implications
of soil organic carbon 23
2.17.3 Implications
of cation exchange capacity 24
CHAPTER 3
MATERIALS AND METHODS
3.1 Materials 26
3.1.1 Apparatus 26
3.1.2 Parameters analyzed 31
3.2 Dumpsite Location and Sampling 31
3.2.1 Leachate collection 34
3.2.2 Water
sample collection 34
3.2.3 Soil sample collection 34
3.3 Methods 35
3.3.1 Preparation of solutions 35
3.3.2 Determination
of direction of flow of underground water 32
3.4 Physical
Parameters Analyzed 37
3.4.1 Determination of odour 37
3.4.2 Determination of taste 37
3.4.3 Determination of colour 37
3.4.4 Determination of turbidity 37
3.4.5 Determination of temperature 38
3.5 Chemical
Parameters Analyyzed 38
3.5.1 Determination of pH 38
3.5.2. Determination of chemical oxygen demand 39
3.5.3 Determination
of total dissolved solid 40
3.5.4 Determination
of total hardness 41
3.5.5 Determination
of calcium 42
3.5.6 Determination
of nitrate 43
3.5.7 Determination
of chlorine 44
3.5.8 Determination of iron 44
3.5.9 Determination
of lead 45
3.5.10 Determination of copper 45
3.6 Bacteriological
Analysis 46
3.6.1. Determination of E. coli 46
3.7 Soil
Analysis (hydraulic properties) 47
3.7.1 Determination
of soil infiltration rate 47
3.7.2 Determination
of soil effective porosity 47
3.7.3 Determination
of soil bulk density 48
3.7.4 Determination
of soil cation exchange capacity 48
3.7.5 Determination
of soil organic carbon 49
3.8 Statistical Analysis 50
CHAPTER 4
RESULTS AND
DISCUSSION
4.1 Results 51
4.2 Physiochemical and some Biological 51
(Turbidity,
Temperature and Bacteriological) Parameters in Site 1
4.3 Physiochemical and Some Biological 53
(Turbidity,
Temperature and Bacteriological) Parameters in Site 2
4.4
Physiochemical and some Biological 55
(Turbidity,
Temperature and Bacteriological) Parameters in Site 3
4.5 Some
Soil Hydraulic Parameters in All Sites 57
CHAPTER 5
CONCLUSION AND RECOMMENDATIONS
5.1 Discussion
58
5.1.1 Physical result analysis 58
5.1.2 Chemical result analysis 59
5.1.3 Bacteriological result analysis 62
5.1.4 Soil hydraulic properties analysis 63
5.2 Conclusion 64
5.3 Recommendations 64
References 66
Appendix
LIST OF TABLES
2.1: Common
water pH levels 12
4.1a: Physical analysis result for dumpsite 1 48
4.1b: Chemical analytes
result for borehole and leachate on dumpsite 1 48
4.1c: Bacteriological analysis result for dumpsite
1 48
4.2a: Physical analysis result for dumpsite 2 50
4.2b: Chemical analytes
result for borehole and leachate on dumpsite 2 50
4.2c: Bacteriological analysis result for dumpsite
2 50
4.3a: Physical analysis result for dumpsite 3 52
4.3b: Chemical analytes
result for borehole and leachate on dumpsite 3 52
4.3c: Bacteriological analysis result for dumpsite
3 52
4.4: Soil analysis result for all the dumpsites 53
LIST OF FIGURES
1: Map of site 1 (Imo ENTRACO dump site
along Port Harcourt road Owerri) 32
2: Map of site 2 (Mechanic village dump site along Aba road
Owerri) 33
3 Map of site 3 (Orji market dumpsite along Okigwe road Owerri) 33
4.1a: Graph of physical
analysis (Turbidity and Temperature) result for 72
Imo ENTRACO dumpsite along Port Harcourt road Owerri
4.1b: Graph of chemical
analysis result for Imo ENTRACO dumpsite along 72
Port
Harcourt road Owerri
4.2a: Graph of physical
analysis (Turbidity and Temperature) result 73
for
mechanic village dumpsite along Aba road Owerri
4.2b: Graph of chemical
analysis result for mechanic village dumpsite along 73
Aba road Owerri
4.3a: Figure of physical
analysis (Turbidity and Temperature) result for Orji 74
market
dumpsite along Okigwe road Owerri
4.3b: Graph of chemical
analysis result for Orji market dumpsite along Okigwe 74
road Owerri
4.4: Figure of soil analysis
result for all the sites 75
LIST OF ABBREVIATIONS
B.D. ---- Bulk Density
BOD----
Biochemical Oxygen Demand
C.E.C. ---- Cation
Exchange Capacity
Cmol/kg ---- Moles of
Electric Charge per Kilogram
COD----
Chemical Oxygen Demand
E.P. ---- Effective Porosity
[H+]-----Hydrogen Ion
Concentration
I.R---- Infiltration Rate
Mg/L ---- Milligram per Litre
ND----
Not Detected
NSQDW---- National
Standard Quality for Drinking Water
NTU----Nephelometric Turbidity Unit
pH ---Potential
of Hydrogen
PPM ---- Part per Million
TDH----
Total Dissolved Solid
TH-----
Total Hardness
S.O.C.
---- Soil Organic Carbon
WHO ----- World Health Organization
µg/dL ---- Microgram per
Decilitre
CHAPTER 1
INTRODUCTION
A
leachate is any liquid that, in the course of passing through matter, extracts
soluble or suspended solids, or any other component of the material through
which it has passed.
Groundwater pollution is
mainly
due to anthropogenic activities and the presence of contaminants, organic and inorganic compounds which
has infiltrated through the top soil to depth beneath the earth surface. The
rate of percolation is relative to various soil parameters such as soil
infiltration rate, soil porosity, cation exchange capacity, the solubility of
the pollutants and the direction of underground water flow. In recent times, the impact of leachate on underground water quality and other water resources
has raised concern because of the
complexity and high volume of waste
generated as a result of industrialization and urbanization; once in contact with decomposing solid waste, the percolating
water becomes contaminated, and if it then flows out of the waste material it
is termed leachate, additional leachate volume is produced during the
decomposition of carbonaceous materials such as; methane, carbon (iv) oxide and
complex mixture of acids, aldehydes alcohols and simple sugars (Akinbile, 2011).
When
water percolates through waste and other particle, it induces, promotes and assists
the process of biodegradation by bacteria and fungi. These processes in turn
releases intermediates like ethanol, acetate, lactate, methane etc. This may
rapidly lead to biotransformation of any available oxygen, creating an anoxic
environment. In actively decomposing dumpsites or landfills,
the release of pollutants from sediments
(under certain conditions) poses a high risk to groundwater resources if not adequately managed (Yusoff, 2011). Protection of groundwater is a major environmental issue since the importance
of
water quality on human health has attracted a great
deal of interest
lately. Assessing groundwater quality and developing strategies
to protect aquifers from contamination are necessary
for planning and designing water resources. Open dumps are the oldest and most common way
of disposing wastes, although in
recent years, thousands have been closed,
many are
still being used .Waste management has become increasingly
complex
due to the increase in human population, industrial, technological revolutions and the processes that control the fate of wastes in the soil. Issues such as nutrients
release rate, high activities of anaerobes, leaching of metals through macro
pores as suspended solids and sludge organic
matter on degradation are
often of great threat. Toxic chemicals that have high
concentration of nitrate and phosphate derived from waste in the soil can
filter through a dump and contaminate both underground and surface water (Akinbile and Yusoff, 2011). Bacteria, pathogens, insects, rodents, snakes and scavenger birds, dust, noise, are some
of the opportunistic inhabitants of
most of the open dumpsites.
1.1 BACKGROUND OF THE STUDY
Owerri has a population of approximately
150,000 people according to 2006 population census with area of 134km2.
It is located between latitude 4o45N and 5o50N and
longitude 6o32E and 7o30E. It experiences heavy rainfall with
annual rainfall of about 2000-2400mm/yr. having bimodal superficial rainfall
distribution with peaks in July and September and a little break in august. The
climate is humid semi-hot equatorial type with relative humidity that oscillates
between 75% and 90% in rainy and dry season respectively and average
temperature of 20oC. There is rapid urbanization witnessed by
continuous expansion of the city and development of sites, also the high influx
of tourists orchestrated by lots of tourist sites, especially in the
hospitality industry leading to the generation of large volume of waste
materials which eventually find their way in the dumpsites. There are several
of such dumpsites located at various spots in the city which is a hub of
industrial activities in the state and as such portends health danger to the
adults, children and unborn babies if not properly checkmated (Encyclopedia
Britannica 2009).
1.2 STATEMENT
OF PURPOSE
In recent years it has been observed
that indiscriminate dumping of refuse leads to environmental pollution hence;
the contaminated sites through infiltration of the contaminants find their way
into the underground water. Owerri located in south eastern part of the country
over time has experienced exponential increase in the volume of waste
generated, which when disposed in the open dumpsites has the tendencies to
contaminate the underground water bodies which will indirectly lead to increase
in the rate of water borne diseases like cholera, typhoid and have other health
impacts like cardiovascular diseases, liver and kidney dysfunction. The
presence of such dump sites which are mostly located around residential areas
attracts various active microorganism especially the coliform bacteria, such
that in the process of survival of such organisms, it further leads to the contamination
of the environment. Furthermore, the by-products of biotransformation of some
compounds are harmful to humans if consumed, because most of those dumpsites
have no cemented barriers therefore leading to percolation of the leachates
until they get to the underground water. As a result of the alarming level of
water contamination in the city it has resulted to the increase in the rate of
infections related to water borne diseases such as cholera, especially among
children in Owerri as contained in the UNICEF report of 2018 on infant
mortality rate in Imo state. Hence the need to carry out this research to
ascertain the level of contamination of underground water and its health impact
on the residents by evaluating the physiochemical and bacteriological components
of the water located close to some of those dumpsites in Owerri municipalities
with emphasis on the proximity of the dumpsite to the source of drinking water
in the metropolis also suggesting better ways of managing waste disposal and
provision of safe drinking water.
1.3 AIM OF THE STUDY
The aim of the study is to evaluate
the impact of leachate on underground water quality around three dumpsites in
Owerri municipalities, in Imo state of Nigeria.
1.4
OBJECTIVES
OF THE STUDY
2.
To evaluate the
appropriate physiochemical characteristics of the leachate from dumpsites.
3.
To determine the level of
pollution caused by dumpsites in Owerri.
4.
To determine the level of
contamination by microbial activities in dumpsites.
5.
Evaluate the biophysical
and related soil parameters within the change in season samples to level of
pollution in the underground water and various aquifers
6.
To suggest possible
prevention methods for the leachates infiltrating into underground water.
7.
To suggest water
treatment methods to adopt in the treatment of polluted underground water.
1.5 SIGNIFICANCE
OF THE STUDY
1.
Harness soil and biophysical
considerations for contaminated underground water treatment considerations.
2.
Proffer borehole citing criteria
in proximity to the dumpsites and household neighbours.
3.
Creates insight on plausible
update as requirements for safe households’ water quality and management of
water borne infections.
4. Relates soil qualities as critical
pollution parameter.
The study will help to encourage people to analyze the
quality of water before drinking not just by mere physical evaluation as the
chemical and bacteriological constituent of the water could portend more health
risk. It will help in providing template for the individuals, government and
organizations on waste disposal management in avoiding underground water
pollution. It will also help in proffering treatment measures to be adopted in
purification of contaminated water before drinking thereby helping in preventing
high rate of diseases being contacted through drinking polluted water. It will
further help in the planning and provision of portable drinking water to Imo
state citizens and its environment and suggesting lasting measures and
conditions in the citing of boreholes around the municipality. The study will
also suggest the minimum distance in citing a dump site close to borehole and
encourage individuals, town planners and corporate bodies to carry out soil
analysis test before citing a dump site as well as drilling a borehole
1.6 STATEMENT OF PROBLEM
According to the sustainable
development goal (SDG) of United Nations general assembly of 2015, goal number
6 which is provision of clean portable water and sanitation before the end of
the year 2030 because according to the report, 6 out of 10 people lack safely
managed sanitation services, and 3 out of 10 lack safely managed water
services. Safe drinking water and hygienic toilets protect people from diseases
and enables the societies to be more productive economically. Water sources are
better preserved if open defecation and indiscriminate dumping of refuse are
ended and sustainable sanitation systems are implemented. Therefore the
provision of clean and portable water is not negotiable in Owerri Municipalities
and its environment to mitigate the level of disease contamination (United Nations,
2016). Owing to flagrant disregard for town planning templates by successive
government by way of funding and supervision. This conversion of mapped out
sites for dumpsites into building structures, over time, has led to poor
management of refuse. In most cases open dumpsites are indiscriminately cited
without proper planning which by way of leaching find their way into
underground water causing pollution to aquifers. This has negative health impact
in the populace that primarily depends on underground water for the source of drinking
water. Furthermore, climatic changes have further elevated the percolation rate
of the leachate through increased exerting hydraulic pressure and rise in
temperature (APHA, 2005). Also the steady decrease in underground water level
and rise in temperature has encouraged the breeding of new strains of
microorganism that causes various diseases. This may soon lead to epidemic if
adequate measures are not taken to mitigate this health challenge (Udosoro, et al., 2004). Hence the need for this
research to evaluate the associated health impact of leachate in underground
water quality.
1.7 JUSTIFICATION
OF THE STUDY
According to Imo city
watch 2007, the volume of solid waste generated in Owerri, in Imo state south
eastern Nigeria increased significantly over time from estimated quantity
70,000 metric tons per year in 2006 to 100,000 metric tons in 2016 because of
the increasing population, industrial and economic development especially in
construction and hospitality sector also the proliferation of indiscriminate
dumpsites all over the state is quite alarming. The total assessment revealed
that about 40% of the waste is organic in nature, plastics/bottles 20%, metal
scraps 20%, building materials 15%, other 5% and all these waste end up in
dumpsites which when leached through the soil leads to underground water
pollution hence the need to provide clean and portable water free from
suspended particles and germs as prolong consumption of these contaminated
water over time has alarming health impact leading to the loss of life and resources in
treatment of diseases if not properly managed (City Watch Population,2006)
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