**4. Determination of remediation options**

In carrying out decision-making process, a number of techniques could be utilised, for example, pairwise comparison chart, decision matrix, force field analysis, cost-benefit analysis, and HOQ. HOQ is used in this study among various available methods. This decision-making tool is considered as a simple decision mechanism with potential of implementation at various stages of advertising and product manufacturing. Function deployment instrument is required to develop the specifications into the product and organise customer requirements as well as enhance procedure of work. This decision-making tool needs to assign weight to each specification also; upon outlining personnel responsible for decision-making ought to outline weighted symbols among the progressions that constitute the interlink between the proposed processes and specifications and non-weighted symbols between the processes themselves. Towards the end, the sum of the product of the specified weight by the equivalent symbol weight is determined by calculating the accumulated score for each process. Moreover, HOQ provides assistance to engineers in focusing on specified needs and deciding on the best sequence in the case that the process goes ahead. Because of this, HOQ was employed for this project to incorporate the requirements of UNCC and KNFP and choose the best technique of remediation method for which the remediation process will proceed.

#### **4.1 Establishing house of quality**

Within this research, relationships were established between pre-set objectives outlined by UNCC and KNFP and various methods of remediation chosen by the team. In contrast to the numerical evaluation matrix, HOQ utilises symbols to demonstrate the relationship between objectives and alternatives in addition to the connection between alternatives themselves. In an effort to compare the proposed

methods of remediation, all the needs were incorporated and translated into engineering characteristics. This is beneficial in assessing the available remedial methods with the pre-set engineering characteristics and comparing them with one another. The detailed description of the UN requirements is described hereunder:


In an effort to weigh these criteria, Ejbarah et al. [35] carried out a series of discussions with consultants, environmental engineers, and scientists, and undertaking literature review, UN requirements were aimed to develop the weighted objective tree. Based upon the outcomes, weights are assigned to each objective creating the weighted objective, as listed in **Table 3**. The outcome of the study is utilised to distinguish, appraise various solutions, and determine the importance


**161**

**Table 4.**

*The Assessment Strategy for Selecting and Evaluating Geoenvironmental Remediation*

between the objectives listed. These engineering techniques are effective in removing potential risks posed by contaminants, require comparatively shorter duration

The "soil remediation" terminology relates to the efforts which seek to eradicate or reduce the risks connected to contaminated soil. Several soil remediation methods have been considered in an attempt to remove the impact of crude oil pollution on the environment. There are large variances in the biological, chemical, and physical characteristics of the contaminants, as well as a number of soil remediation methods are available in the market; selection of suitable and economical technology for the remediation of specific contaminants may not be an easy. In this study using a HOQ analysis system, only 10 remediation technologies have been considered: land farming, windrow, phytoremediation, vermiremediation, bioventing, soil washing, biopiles, electro-remediation, solidification/stabilisation, and thermal. These approaches have been selected in accordance with previous successful investigations into the remediation of hydrocarbon-contaminated soil. For each of

to operate, and can frequently be used extensively.

*Interrelationship matrix among several soil remediation methods.*

**4.2 Investigating alternative methods**

*DOI: http://dx.doi.org/10.5772/intechopen.88166*

#### **Table 3.**

*Weights of engineering characteristics (source: [34]).*

*The Assessment Strategy for Selecting and Evaluating Geoenvironmental Remediation DOI: http://dx.doi.org/10.5772/intechopen.88166*


#### **Table 4.**

*Geopolymers and Other Geosynthetics*

a.Remediating various contaminated soil.

c.Simple to operate and assemble.

environment.

e. Short time duration.

conditions of this claim.

methods of remediation, all the needs were incorporated and translated into engineering characteristics. This is beneficial in assessing the available remedial methods with the pre-set engineering characteristics and comparing them with one another. The detailed description of the UN requirements is described hereunder:

b.Operate with severe weather conditions (extreme temperature).

g.Previous success percentage in Kuwait or comparable conditions.

d.Produces least effect on groundwater, air, soil, employees, and neighbouring

f. In compliance with the requirements of Environmental Protection Agency (EPA).

h.The panel is of the opinion that remediation of oil-contaminated material by means of high-temperature thermal desorption is unjustifiable, given the

In an effort to weigh these criteria, Ejbarah et al. [35] carried out a series of discussions with consultants, environmental engineers, and scientists, and undertaking literature review, UN requirements were aimed to develop the weighted objective tree. Based upon the outcomes, weights are assigned to each objective creating the weighted objective, as listed in **Table 3**. The outcome of the study is utilised to distinguish, appraise various solutions, and determine the importance

**Engineering characterisation Assigned weight** 1. Reduction in major contaminants 0.36 2. Can be used in Kuwait's climatic conditions 0.18 3. Does not cause health problems to the worker 0.12 4. Simple to operate and assembly 0.07 5. Generates least residuals 0.03 6. Creates least equipment contaminants 0.03 7. The least pollution to air 0.027 8. Only small area needed 0.02 9. The least pollution to groundwater 0.018 10. Does not cause noise pollution 0.015 11. Requires shorter duration 0.01 12. In compliance with the requirements of EPA 0.06 13. Previous experience in Kuwait or similar surroundings 0.06 Total score 1

**160**

**Table 3.**

*Weights of engineering characteristics (source: [34]).*

*Interrelationship matrix among several soil remediation methods.*

between the objectives listed. These engineering techniques are effective in removing potential risks posed by contaminants, require comparatively shorter duration to operate, and can frequently be used extensively.

#### **4.2 Investigating alternative methods**

The "soil remediation" terminology relates to the efforts which seek to eradicate or reduce the risks connected to contaminated soil. Several soil remediation methods have been considered in an attempt to remove the impact of crude oil pollution on the environment. There are large variances in the biological, chemical, and physical characteristics of the contaminants, as well as a number of soil remediation methods are available in the market; selection of suitable and economical technology for the remediation of specific contaminants may not be an easy. In this study using a HOQ analysis system, only 10 remediation technologies have been considered: land farming, windrow, phytoremediation, vermiremediation, bioventing, soil washing, biopiles, electro-remediation, solidification/stabilisation, and thermal. These approaches have been selected in accordance with previous successful investigations into the remediation of hydrocarbon-contaminated soil. For each of

these techniques, the chosen methodology and theories are discussed in a comparative evaluation based on the specialised research conducted.

#### **4.3 Define the relationship symbol and weights**

The relationship between the characteristics and each remediation method was clarified in **Table 4**; the main target of this section is to find the appropriate remediation method among other alternative methods. The symbols used with their corresponding values are defined and listed below:

1.Strong positive ● with a weight of 7

2.Positive ○ with a weight of 3

3.Moderate ▽ with a weight of 1

The interrelationship symbols were set to identify the potential of implementing the selected remediation process in sandy soil. The symbols are used and listed below:

1.More suitable ▲ without problems

2.Suitable ◇ with a few concerns

3.Less suitable ▼ to work

#### **5. Results and discussion**

#### **5.1 Evaluating alternatives**

A range of remediation alternatives are briefly presented in **Table 4**, and it explains why it is the treatment alternative of choice for Kuwait's oil-contaminated sand. This chapter explains the decision-making process behind using soil washing and other remediation techniques. In order to choose the most appropriate method, an exhaustive list of each remediation option was reviewed. As shown in Section 2, each treatment was briefly described after thorough research in order to develop an interrelationship between these methods. As a result, the matrix was formulated and evaluated to show the interrelationship, although the requirements were assessed and ascertained against the alternatives and the weights. Therefore, weighted alternatives have been formulated. The process can be started by altering the set symbols to their corresponding values. The characteristic weight is multiplied by each value. This procedure was repeatedly employed for all the characteristics, and the total sum was kept at the last phase.

As seen in **Table 4**, the relative weight for biopiles is 7%; there is a similar weight score recorded among land farming, windrow, phytoremediation, bioventing, and vermiremediation; the outcome showed that the score of relative weight was about 8%. Similarly, the result also demonstrated that the scores of relative weight for thermal adsorption and soil washing were 14 and 18%, respectively, and that the score for both electro-remediation and solidification/ stabilisation was 9%.

Correspondingly, **Table 4** also showed that there were no real concerns for all the methods employed except for one: soil washing. From the results, soil washing

**163**

available approaches.

*The Assessment Strategy for Selecting and Evaluating Geoenvironmental Remediation*

appears to be the best method in view of their total score, while thermal cannot be employed based on UN requirements. This method was the most appropriate and hence employed in selecting an optimised treatment method to match the conditions under study. Each of the remedial methods was assessed against the set requirements, and their capability to treat sandy soil was investigated. The results obtained in this study showed that the soil washing was the best method to meet the objectives of the project. This method can be employed on its own or performed in series. The selection of the method for remediation is also essential for subsequent soil or site use. Later restrictions of land use may be as a result of groundwater pollution from the application of nitrates and due to the nitrogen release from the endogenous decomposition of microorganism [36]. Using (ex situ) techniques for soil washing, the coarser material which has been cleaned is without any clay or organic materials, which can be used for construction use such as subgrade fill or backfill. The major change in the soil materials takes place during the thermal treatment. Usually, high-temperature procedures damage the organic compounds and clay minerals; hydroxides are being transformed into oxides, and main minerals are changed to fines. For thermally treated soils which are transformed to slurry, their values of pH are quite high (pH 11); therefore the products are not ideal for future use; however, the UN requirement does not allow to use it for remediation of Kuwait's oil lakes. In addition, compared with other thermal and bioremediation technologies, soil washing method has some major benefits. Some of the benefits are their cost-effectiveness, scalability, and exceptional ability to remove oil from contaminated soil in short time. Limited successes have been reported with different remediation process. Thus it encourages researchers to develop and enhance the selected techniques of soil washing, so as to make it cost-effective, environmentally friendly, and effectiveness. The standard removal efficiency of TPH shall be tested and observed over a period of time. This involves developing methods for extrac-

A large number of remediation methods have been designed in an attempt to reduce the effects of petroleum pollution on the environment. Due to the large differences in the physical, chemical, and biological characteristics of the contaminants, as well as the large number of soil remediation methods available, selection of an appropriate and economical technology for the remediation of particular contaminants can be difficult. In this study using a multi-criterion analysis system, only nine remediation technologies have been considered: land farming, windrow, phytoremediation, vermiremediation, bioventing, soil washing, biopiles, electro-remediation, and solidification/stabilisation. Various criteria were evaluated and assessed to select appropriate methods such, soil constraints, implement in surface soil, if any further treatment is required when the remediation process is completed, which compounds can be removed, time for clean-up and cost. Among others, the ability of wastewater treatment was investigated. The evaluation study shows that bioventing, electro-remediation, and the solidification/stabilisation approaches are not applicable for use in sandy soil, once the bioventing required low permeable soil, while electro-remediation needs saturated soil with water. Furthermore, solidification/stabilisation is used at the subsurface soil. Solidification/stabilisation, electro-remediation, bioventing, and biopiles are generally considered to be the most expensive treatments. However, land farming and bioventing need around 2 years to complete the remediation process and were not effective for HMW. In this study, soil washing techniques were selected as well. It has less profound side effects, while removal of contaminants can be controlled by enhancing washing factors. The selected techniques require 1 year or less to achieve the remediation target and are the cheapest of the

*DOI: http://dx.doi.org/10.5772/intechopen.88166*

tion of TPH from soil samples.

#### *The Assessment Strategy for Selecting and Evaluating Geoenvironmental Remediation DOI: http://dx.doi.org/10.5772/intechopen.88166*

appears to be the best method in view of their total score, while thermal cannot be employed based on UN requirements. This method was the most appropriate and hence employed in selecting an optimised treatment method to match the conditions under study. Each of the remedial methods was assessed against the set requirements, and their capability to treat sandy soil was investigated. The results obtained in this study showed that the soil washing was the best method to meet the objectives of the project. This method can be employed on its own or performed in series. The selection of the method for remediation is also essential for subsequent soil or site use. Later restrictions of land use may be as a result of groundwater pollution from the application of nitrates and due to the nitrogen release from the endogenous decomposition of microorganism [36]. Using (ex situ) techniques for soil washing, the coarser material which has been cleaned is without any clay or organic materials, which can be used for construction use such as subgrade fill or backfill. The major change in the soil materials takes place during the thermal treatment. Usually, high-temperature procedures damage the organic compounds and clay minerals; hydroxides are being transformed into oxides, and main minerals are changed to fines. For thermally treated soils which are transformed to slurry, their values of pH are quite high (pH 11); therefore the products are not ideal for future use; however, the UN requirement does not allow to use it for remediation of Kuwait's oil lakes. In addition, compared with other thermal and bioremediation technologies, soil washing method has some major benefits. Some of the benefits are their cost-effectiveness, scalability, and exceptional ability to remove oil from contaminated soil in short time. Limited successes have been reported with different remediation process. Thus it encourages researchers to develop and enhance the selected techniques of soil washing, so as to make it cost-effective, environmentally friendly, and effectiveness. The standard removal efficiency of TPH shall be tested and observed over a period of time. This involves developing methods for extraction of TPH from soil samples.

A large number of remediation methods have been designed in an attempt to reduce the effects of petroleum pollution on the environment. Due to the large differences in the physical, chemical, and biological characteristics of the contaminants, as well as the large number of soil remediation methods available, selection of an appropriate and economical technology for the remediation of particular contaminants can be difficult. In this study using a multi-criterion analysis system, only nine remediation technologies have been considered: land farming, windrow, phytoremediation, vermiremediation, bioventing, soil washing, biopiles, electro-remediation, and solidification/stabilisation. Various criteria were evaluated and assessed to select appropriate methods such, soil constraints, implement in surface soil, if any further treatment is required when the remediation process is completed, which compounds can be removed, time for clean-up and cost. Among others, the ability of wastewater treatment was investigated. The evaluation study shows that bioventing, electro-remediation, and the solidification/stabilisation approaches are not applicable for use in sandy soil, once the bioventing required low permeable soil, while electro-remediation needs saturated soil with water. Furthermore, solidification/stabilisation is used at the subsurface soil. Solidification/stabilisation, electro-remediation, bioventing, and biopiles are generally considered to be the most expensive treatments. However, land farming and bioventing need around 2 years to complete the remediation process and were not effective for HMW. In this study, soil washing techniques were selected as well. It has less profound side effects, while removal of contaminants can be controlled by enhancing washing factors. The selected techniques require 1 year or less to achieve the remediation target and are the cheapest of the available approaches.

*Geopolymers and Other Geosynthetics*

these techniques, the chosen methodology and theories are discussed in a compara-

The relationship between the characteristics and each remediation method was clarified in **Table 4**; the main target of this section is to find the appropriate remediation method among other alternative methods. The symbols used with their

The interrelationship symbols were set to identify the potential of implementing the selected remediation process in sandy soil. The symbols are used and listed

A range of remediation alternatives are briefly presented in **Table 4**, and it explains why it is the treatment alternative of choice for Kuwait's oil-contaminated sand. This chapter explains the decision-making process behind using soil washing and other remediation techniques. In order to choose the most appropriate method, an exhaustive list of each remediation option was reviewed. As shown in Section 2, each treatment was briefly described after thorough research in order to develop an interrelationship between these methods. As a result, the matrix was formulated and evaluated to show the interrelationship, although the requirements were assessed and ascertained against the alternatives and the weights. Therefore, weighted alternatives have been formulated. The process can be started by altering the set symbols to their corresponding values. The characteristic weight is multiplied by each value. This procedure was repeatedly employed for all the characteris-

As seen in **Table 4**, the relative weight for biopiles is 7%; there is a similar weight score recorded among land farming, windrow, phytoremediation, bioventing, and vermiremediation; the outcome showed that the score of relative weight was about 8%. Similarly, the result also demonstrated that the scores of relative weight for thermal adsorption and soil washing were 14 and 18%, respectively, and that the score for both electro-remediation and solidification/

Correspondingly, **Table 4** also showed that there were no real concerns for all the methods employed except for one: soil washing. From the results, soil washing

tive evaluation based on the specialised research conducted.

**4.3 Define the relationship symbol and weights**

corresponding values are defined and listed below:

1.Strong positive ● with a weight of 7

2.Positive ○ with a weight of 3

below:

3.Moderate ▽ with a weight of 1

1.More suitable ▲ without problems

tics, and the total sum was kept at the last phase.

2.Suitable ◇ with a few concerns

3.Less suitable ▼ to work

**5. Results and discussion**

**5.1 Evaluating alternatives**

**162**

stabilisation was 9%.
