Effect Of Waste Engine Oil Contamination On Geotechnical Properties Of Clay Soil

ABSTRACT

The effects of waste engine oil (WEO) contamination on geotechnical properties of  laterite  soil  was  investigated. Laboratory testing of clay soil from Eagle Island area of Port Harcourt was carried out. Tests carried out included Specific gravity, Atterberg properties, Compaction, California Bearing Ratio (CBR), Linear shrinkage and tri-axial compression in both clean and contaminated clay soils. Varying percentages of (0%, 3%, 6%, 9% and 12%) of WEO were mixed with clay soil as a simulation of the contamination. Results show that the Specific gravity and Plastic Limits (PL) decreased as the content of used engine oil increased. The values of the Linear Shrinkage, Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) increased as the content of the waste engine oil increased but experienced a decrease at 6% contamination. The values of Shear Strength and CBR decreased as the content of the contamination increased but experienced an increase at 9% WEO content, thereafter a decrease commenced again.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• AIM OF THE STUDY
• SCOPE OF THE STUDY
• LIMITATION OF THE STUDY
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• OVERVIEW OF LATERITE SOIL
• USES OF LATERITE SOILS
• REVIEW OF RELATED STUDIES

CHAPTER THREE

3.0      MATERIALS AND METHOD

• MATERIALS
• METHOD

CHAPTER FOUR

• RESULT AND DISCUSSIONS

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION

CHAPTER ONE

1.0                                                              INTRODUCTION

1.1                                                BACKGROUND OF THE STUDY

The indiscriminate location of auto maintenance workshops and operation of industrial and home generators has resulted in massive pollution of soils in such locations. The waste engine oil penetrate  deep  down affected soils by the effect of gravity. Several works have been carried out on WEO and crude oil contaminated soils.

Hashim, M.A. and Sabiu, A.F.(2013), investigated the effects of Crude Oil Low Point Pour Fuel Oil (LPFO) and Vacuum Gas  Oil  contamination on the geotechnical properties of sand, clay and lateritic soils. They established that shear strength of clay soil increased with LPFO contaminations at 2% and 4% LPFO, however, at 6% LPFO contamination and 2-6% LPFO contamination, the shear strength of clay increased.

The  CBR values for the clay soil  decreased with  LPFO contamination. Other deleterious changes included  an increase in consolidation settlement for LPFO contaminated laterite. The consolidation settlement of the contaminated clay soil generally decreased with all contaminants. Meegoda, N. J. and Ratanweera P. (1994), examined the compressibility of contaminated fine-grained soils by consolidation test.

Meegoda, N. J. and Ratanweera P. (1994), also carried out geotechnical investigation of oil contaminated Kuwaiti Sand as  a  result  of  the destruction of Kuwaiti’s oil production facilities at the end of the Gulf war. The results of their findings revealed a reduction in permeability and strength and an increase in compressibility with oil contamination.

Meegoda, N. J. and Ratanweera P. (1994), studied the effect of motor oil contamination duration  on over consolidated clay and reported decreases  in Atterberg properties, unconfined compression strength but increases in the permeability, compression and swell potential of the contaminated soil. Furthermore, they observed that  motor oil contamination  led  to  close packing of the clay particles.

Authors in [5] and [6] corroborated this view. They also concluded that the compression behaviour of montrmorillonite indicated that the particles tend to coagulate and to behave like granular materials in the presence of organic contaminants. [7], observed that Liquid Limit and consolidation parameters of highly plastic clay tend to decrease in the presence of organic pollutants.

The engineering properties of oil contaminated sand were investigated by [8]. They reported  decreasing values of strength, permeability, MDD, OMC and Atterberg Limits values with increase in contaminant content.

Tests to determine the geotechnical properties of oil contaminated sands were carried out by [9] and [10]. Results indicated that the compaction characteristics are influenced by oil contamination. The suitability of petroleum contaminated soils in road construction was studied by [11]. They found out that in construction application including stabilizing the soil with cement, mixing it with crushed stone aggregate for use in road bases or sub bases, and using it for as a fine aggregate replacement in hot mix asphalt concrete,  there  was good potential for use in road construction..

[12], investigated the effect of waste engine oil contamination on the plasticity, strength and permeability of lateritic clay. They concluded that (i) contamination of the lateritic clay with increasing percentage of waste engine oil resulted in progressive increase in plasticity index of the soil, thus making the soil less workable,

• Optimum Moisture Content and Maximum Dry Density, unit weight of the contaminated soil decreased with increasing percentage of waste engine oil in the
• Surprisingly, CBR (soaked and un-soaked) values of the contaminated soil were  greater  than those  of the uncontaminated soil.
• The permeability of the soil decreased with increasing content of the waste engine oil.
• They recommended stabilizing the waste engine oil contaminated lateritic clay before using it for construction

Also, authors in [10] – [13] also studied the effect of waste engine oil contamination on different types of soil. [10] concluded that the Atterberg Limits of unconfined compressive strength of an over  consolidated  clay decreased  while the coefficient of permeability increased with increasing motor oil content.[13] found out that the OMC, MDD and unconfined compressive strength and CBR of a lateritic soil decreased with the waste engine oil content of the soil.

• , investigated the effect of crude oil polluted soils and concluded that the Shear strength,  permeability  and OMC and MDD of the crude oil polluted soils decreased as the content of the crude oil increased. However, the CBR increased as the crude oil content increased. Therefore crude oil polluted   soils can be used as base and sub base for roads and air-field
• , investigated the geotechnical properties of waste engine oil contaminated laterites. The result showed a general decrease in OMC, Liquid limits and Permeability. They observed an increase in shear strength, MDD and

This study investigated the effects of waste engine oil on geotechnical properties of clay soils.

1.2                                          AIM OF THE STUDY

This paper entails experimental investigation of the effects of waste engine oil contamination of a lateritic clay soil on its plasticity, compaction characteristics, strength and permeability.

1.3                                       SCOPE OF THE STUDY

AN estimated 200,000 m³ of waste engine oil is annually generated in Nigeria. It is sometimes reused for suppressing dust, wood preservation, automobile spare-parts’ rust prevention, lubricating formwork and mould; as fuel for industrial boilers, fuel for bakery furnace, weed killer, hydraulic oil and as gear oil – when mixed with grease [1]. Despite these areas of application, more waste engine oil is still indiscriminately disposed on land. This is of major environmental concern because such disposal has the potential to pollute groundwater, surface water, reduce soil nutrients available to plants and alter the structural behaviour of the soil on which they are disposed.

1.4                                   LIMITATION OF THE STUDY

The experiment was carried out by Varying percentages of (0%, 3%, 6%, 9% and 12%) of WEO were mixed with clay soil as a simulation of  the  contamination, which was used to determine the specific gravity, plastic limit, optimum moisture content, maximum dry unit weight,  and permeability of the soil

1.5                                             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.

CHAPTER FIVE

5.1                                                                                                                                                                                              CONCLUSION

From the above discussions, the following conclusions can be drawn.

1. The specific gravity of the clay soil decreased with an increase in WEO content.
2. Contamination of the clay soil with increasing percentage of WEO resulted in progressive increase of Liquid Limit and Plasticity Index up to 3% contamination. Between 3 – 6% WEO contaminations, the trend is reversed with Liquid Limit and Plasticity Index decreasing, while the Plastic Limit starts to increase. This implies that an increase in WEO contamination between 3-9% resulted in an increase in the soil cohesion to working and also reduction in adsorbed water [15].

• The shrinkage limit increases as the WEO content is increased up till 6% WEO content, thereafter the Shrinkage Limit starts to

1. The MDD values of the WEO contaminated clay increases between 6-9% WEO content, prior to 6% WEO content, there was no improvement in the
2. The shear strength and stress at failure of the clay soil decreased as the WEO content is increased up till 6% WEO content. Thereafter, it starts to increase as the WEO content is increased up till 9 % when it commences a decrease again. This implies that between 6-9% WEO contaminations, such contaminated soils can be used in engineering works to
3. Between 6-9% WEO contamination, the OMC reduced for all the samples. This is as a result of  the lubrication ability of the WEO [15].

• Between 0-6% WEO content, unsoaked and soaked CBR values decrease as the WEO content is increased. From 6% WEO content, the CBR values start to increase as the WEO content is increased. The decrease in the soaked and unsoaked CBR between All dosages between (0-3%) of the WEO contaminants used with clay should clearly be avoided  in road construction unless stabilization of the contaminated soil will prove worthwhile [1].
• Any structure to be built near WEO contaminated clay soils should be adequately investigated as  a result of the large variations in clay soil properties at various degrees of

5.2                                         RECOMMENDATION

0 – 3% WEO contamination will need to be investigated further since the result is not consistent with results   of previous study.