Evaluation Of Waste Landfill Using 2-D Resistivity Imaging

Municipal solid waste disposal sites can be sources of groundwater contamination and the contamination problems are more likely to occur in humid areas, where the moisture available exceeds the ability of the waste pile absorb water. 2-D resistivity imaging has frequently been used in the subsurface pollution studies. The method maps the distribution of resistivity of subsurface materials. The 2-D resistivity image provides general information on subsurface stratification of buried waste and contaminated soil, as well the depth to the bedrock below the lines of traverse. Underground soil or water that has been contaminated by leachate usually has a significantly lower resistivity value. This paper discusses the results of the 2-D resistivity imaging which were conducted to identify and delineate the extent of contaminated soil and leachate plumes, as well as to assess the capability of the 2-D resistivity imaging as a pre-characterization tool for tracing the properties of disposed waste and its severity underneath a capped landfill sites.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

INTRODUCTION

• • BACKGROUND OF THE PROJECT

• • PROBLEM STATEMENT

• • OBJECTIVE OF THE PROJECT

• • SCOPE OF THE STUDY

• • SIGNIFICANCE OF THE STUDY

• • RESEARCH QUESTION

• • LOCATION AND GEOLOGY OF THE STUDY AREA

• • METHODOLOGY

• • PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

2.1      OVERVIEW OF THE STUDY

2.2      CONCEPTUAL FRAMEWORK

2.3      EFFECT OF LEACHATE ON THE SOIL

CHAPTER THREE

3.0      METHODOLOGY

CHAPTER FOUR

4.1      RESULT AND DISCUSION

4.2      DISCUSSION

CHAPTER FIVE

5.0      CONCLUSION AND RCOMMENDATION

• • CONCLUSION

• • RECOMMENDATION

5.3     REFERENCES

CHAPTER ONE

1.0                                          INTRODUCTION

1.1                            BACKGROUND OF THE STUDY

Recent studies have shown that the problem of environmental contamination and waste management is one of the main concerns of geoscientists and researchers from other related fields of science around the globe. Fast industrial development and the uncontrolled growth of the urban population result in the production of toxic solid wastes. Urban waste materials, mainly domestic garbage, are usually disposed of inadequately in waste disposal sites posing a high risk to the underground water resources, the environmental pollution, and the community health. Moreover, older waste sites often lack reliable geological or artificial barriers, so that leaching of pollutants into the groundwater is a concern. Contamination problems are particularly severe for waste dumped in abandoned gravel pits, many of which extend to below the groundwater table. Being small and unregulated, the exact location, structure, and contents of such landfills are either unknown or poorly documented. The solution to the day-to-day problems of modern urban societies demands fast and effective geophysical methods. One of the most frequent demands in metropolitan areas is to determine the landfill’s geological and geotechnical structure shape and extend, together with the excavation and dumping history [3]. Details on the contents of a landfill may be difficult to acquire but are essential for evaluating the level of risk associated with leaking pollutants. In such context, the integrated use of geophysical methods provides an essential tool in the characterization and evaluation of contaminants generated by urban residues (domestic and/or industrial) [8]. Among those geophysical methods, electrical resistivity tomography has been found very suitable for such kind of environmental studies, due to the conductive nature of most contaminants. The use of electrical resistivity tomography applied to environmental studies is well documented [11].

The management of solid waste landfills has been a major problem of our urban centers in Nigeria and other developing countries as well as the disposal of waste indiscriminately in rivers and landfills and mostly their proximity to the living quarters. The landfill constituents are predominately household waste. Other waste comes from shops, offices, and chemical and manufacturing industries. These wastes may contain toxic substances as they are decomposed or biodegraded, with the preference of infiltrating water, to produce organic liquid known as leachate.

Sometimes, especially during the peak of the raining season, the landfills are covered by flood water. This also contributes to the leachate plumes, which contains liquid that permeates into the solid and water system through the landfill. This result pollutant to load on the environment which depends on the quantity and quality of the water that percolates through the dumpsite and penetrates down to the ground water [12].

Trochobanogous et al. [13] said that CO₂ and methane are the principal gases produced from the anaerobic decomposition of the biodegradable organic waste components in municipal solid waste. Because only limited amounts of oxygen are present in a landfill when methane concentrations reach this critical level, there is little danger that the landfill will explode. However, methane mixtures in the explosive range can form if landfill gas migrates off-site and mixes with air. This work is aimed to investigate the effects of waste landfill in abua–odual local government area of rivers state, Nigeria on groundwater by employing 2D electrical resistivity imaging in order to delineate the leachate plumes.

1.2                                   PROBLEM STATEMENT

Solid wastes are produced on daily basis as a result of direct consequence of inevitable human activities. The intensity of man’s activities has led to increasing volume of solid waste worldwide despite the current level of global technological advancement and industrialization. Landfill/ dumpsite serves as the ultimate recipient of municipal solid waste. It is a common waste management practice employed by many nations in many parts of the world. The waste dumped in this process causes various aesthetic and public health problems and also attracts insects, rodents and various disease vectors. The solid waste in this dumping process undergoes slow, anaerobic decomposition over a period of years and generate substantial amount of leachate with decomposing products such as leachate, landfill gas, heavy metals and varieties of hazardous pollutants which may seep from the landfill site into underground aquifers and thus polluting much needed urban water resources. Leachate is a liquid formed from decomposed waste and has higher conductivity due to the presence of dissolved salts. Geo-electrical surveys on dumpsite have been carried out by numerous researchers on leachate contamination of soil and groundwater. The 2D resistivity Imaging is used to estimate the depth to the groundwater table, identify and delineate the extent of contaminant leachate plume and migration paths below the surface around landfill

1.3                              OBJECTIVES OF THE STUDY

The main objective of this study is to detect the leachate plume zone in the crystalline basement area and delineate the level and extent of contamination caused by leachate derived from an opened waste disposal site. The use of resistivity imaging method will present detailed information about the delineation of contaminated zones of groundwater around the dumpsite.

1.4                                    SCOPE OF THE STUDY

Consequently, the electrical resistivity of leachate is often very much lower than natural groundwater. Pollutants or contaminants released into the environment rarely remains at the point of discharge. They are transported through the porous media by four basic mechanisms. These are advection, molecular diffusion, mechanical dispersion and adsorption. Adsorption is one of the most important transport mechanisms that affect the fate of chemicals in soils and determine their distribution in the soil water environment. Pollution of groundwater happens mostly due to percolation of fluvial water and infiltration of contaminants through the soil in waste disposal sites.

1.5                                 SIGNIFICANCE OF THE STUDY

This research will help to highlight the relationship between the physical state of an environment and the resultant health implications of mismanaging it. This will help physical planners and health workers coordinate their activities in relation to environmental health policy issues as well as to guide stakeholders on the environment, health water resources ministries, and community based organizations with best options for public campaign towards maintaining a clean environment.

In addition, it is also hoped that the research outcome will contribute to the existing body of knowledge on the subject matter.

1.7                                 RESEARCH QUESTION

During the survey conduct the following question were thrown to the respondent;

1. 1. Do solid waste properly disposed along drainage channels within the Local Government?

1. 1. Are there any benefits that can be derived from waste?

• • Does Solid waste a major environmental issue?

1. 1. Does the quality of waste disposal services satisfactory?

1. 1. Does method of waste adopted work for the resident living within the Local Government?

1. 1. Is it good to bury waste than to burn it?

1.6           LOCATION AND GEOLOGY OF THE STUDY AREA

The topographical map of the study area is shown in Figure 1. Abua–Odual is a Local Government Area in Rivers State, Nigeria. Its headquarters is located in Ayama/Abua CentralAbua. It has an area of 704 km² and a population of 282,988 at the 2006 census. GPS coordinates of Abua/Odual, Nigeria. Latitude: 4.8298 Longitude: 6.5674.

1.7                               RESEARCH METHODOLOGY

In the course of carrying this study, numerous sources were used which most of them are by visiting libraries, consulting journal and news papers and online research which Google was the major source that was used.

1.8                                                         PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work, chapter two presents the literature review of the study, chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.