This document discusses land reclamation and remediation techniques for contaminated sites. It begins with an introduction on land degradation and identifying contamination. It then covers risk assessment which involves identifying hazards, exposure pathways, and risk characterization. The main remediation methods discussed are in-situ, ex-situ, and bio-remediation techniques. In-situ methods include permeable reactive barriers, bioventing, and phytoremediation. Ex-situ techniques involve removing contaminated soil to bioreactors or bio-piles. The document concludes that identifying the appropriate remediation method is important to reduce threats from contaminants.

1. DEPARTMENT OF CIVIL ENGINEERING
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2. LAND RECLAMATION
(REMEDIATION TECHNIQUES)
PRESENTED BY:
HILAL BASHIR
M TECH 1ST YEAR
32212101
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3. contents
 Introduction
 Identifying Contamination
 Risk assessment
 Remediation methods for contaminated sites
 Conclusive remarks
 References
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4. Introduction
 Approximately 90.00% of the world’s population depends directly or
indirectly on land.
 The degradation of land or simply land degradation is one of the foremost
challenging issues most of which is a consequence of man’s continuous or
incessant exploration.
 The Department of the Environment (UK) has described contaminated land
as ‘land which represents an actual or potential hazard to health or the
environment as a result of current or previous use’.
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5. Identifying contamination.
 Contamination can create a range of hazards, depending on its
composition and nature. It may be present in solid, liquid or gas phases,
and may be physical, chemical or biological.so we need to identify the
contamination first.
 As Contamination may be hazards to:
• People
• Water resources
• Flora and fauna
• Foundations and structures
 The process of assessing whether the existence of contamination matters
is termed as risk assessment. This is discussed more fully in the next
section.
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6. Risk assessment.
 The process of risk assessment can be defined as simply ‘an evaluation of
the probability of harm and, in the context of contaminated land, is
concerned with gathering and interpreting information on the
characteristics of sources, pathways and receptors at a specific site and
understanding the uncertainties inherent to ensuring assessment of risk.
 The process of risk assessment can be viewed as consisting of four key
stages:
• hazard identification
• exposure assessment (what are the key environmental pathways and exposure routes by
which the toxic substances can reach the receptors)
• dose—response assessment (how potent are the toxic substances that can reach the
receptor).
• risk characterization (what level of risk can be assigned to each source—pathway—receptor
linkage).
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7. Remediation methods for
contaminated sites.
 Soil remediation is the application of proven technologies to mitigate and
manage risks from contaminated soils that could be harmful to human
health and the environment.
 In Remediation techniques, either the land is fully recovered from
contamination or the contamination is minimized to make the land useful
for different purposes.
 Soil remediation falls into three primary categories: In-situ, ex-situ and
other treatment. Under each category is a range of specialized technology
and methods that may be required for any given project.
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8. Different methods of soil remediation.
1. Physical and
chemical
remediation.
• Solidification and
stabilization.
• Removal to landfill.
• Washing and sorting
treatments.
• Chemical oxidation
2. Thermal soil
remediation.
• Steam Enhanced
Extraction (SEE).
• Electrical Resistance
Heating (ERH).
• Thermal Conduction
Heating (TCH).
3. Bio Remediation.
• Intrinsic
Bioremediation.
• Projected
Bioremediation.
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9. Bio Remediation:
 Bioremediation is the process by which living beings such as plants, algae
and microorganisms are used to remediate, reduce or remove
contamination from the environment.
 Bioremediation of soil uses living organisms to degrade the soil. In
essence, the biological activity removes or immobilizes soil pollutants.
 Most bioremediation projects require months or even years to complete
the treatment process.
 Costs related to biological remediation are generally lower than other
techniques.
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10. A). In situ Bioremediation:
 Permeable Reactive Barriers (PRBs):
• A permanent or semi-permanent reactive barrier composed mainly of iron
immersed in the contaminated groundwater stream.
• Remediate groundwater contaminated by many types of pollutants such as
chlorinated hydrocarbons and heavy metals.
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11.  Bio slurping:
• Remediation of
groundwater and
soil by indirect
O2 supply and
improve pollutant
degradation.
• Bio slurping is
unsuitable to treat
low permeable
soils.
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12.  Bioventing:
• Bioventing involves controlled stimulation of the air flow, providing oxygen to
increase microbial activity and, consequently, enhance bioremediation.
• This technique has been used successfully in the remediation of soils polluted by oil
products.
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13.  Biosparging:
• In bio sparging, air is introduced into the soil to promote the degradation
capacity of microorganisms. In contrast to bioventing, air is introduced
inside the saturated area, causing the upward movement of volatile
pollutants.
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14.  Phytoremediation:
• Phytoremediation refers to the use of plants in polluted sites to promote biological,
biochemical, physical, microbiological and chemical interactions to attenuate the toxicity of
contaminants.
• Elemental contaminants like heavy metals or radioactive elements are mainly extracted,
transformed and sequestered, while organic contaminants are eliminated mainly through
rhizodegradation, biodegradation, vaporization or stabilization.
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15. B). Ex situ bioremediation:
 The polluted material is removed and degraded in special facilities outside
the incident site.
 The selection of an ex-situ bioremediation technique is usually made on
the basis of the following aspects:
• Operating costs
• Extent and depth of contamination
• Type of contaminant
• Location and geological features of the contaminated site.
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16. Ex situ techniques:
 Bioreactors: Contaminants are kept in a containment container where, using various types
of devices to mix the sludge, a mixture (solid, liquid, gas) is obtained. The biofilm formed
stimulates the biodegradation of pollutants and increase the biomass level.
 Bio piles: Bioremediation through bio piles consists in the piling of contaminated soil and
subsequent aeration to promote biodegradation mainly by improving microbial activity.
 Compositing: Composting is an ex-situ aerobic process by which organic waste is
decomposed by thermophilic biological agents to obtain a humic amendment known as
composit, which is used as soil fertilizer.
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17. C). Surface enhanced soil bioremediation:
 The use of surfactants and bio surfactants may be an efficient option to
assist soil treatment.
 Synthetic surfactants: Synthetic surfactants include ionic and non-ionic surfactants. Both
have been used successfully to remove different types of toxic organic compounds as well as
heavy metals contaminating the soil.
 Biosurfactants: Biological counterpart of synthetic surfactants
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18. Conclusive Remarks:
 The primary aims of remediation of a contaminated site are either the
reduction of actual or potential environmental threat, or the reduction of
potential risks that are unacceptable to levels that are acceptable.
 Identifying the most appropriate remediation method is of prime
importance to reduce or remove the threat associated with the
contaminants.
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19. References:
 L. D. Hooper, F. W. Oehme and G. R. Krieger, in Hazardous Materials Toxicology, ed. J. B. Sullivan, Jr., and G.
R. Kreiger, Williams and Wilkins, Baltimore, 1992
 Department of the Environment (DoE), A Framework for Assessing the Impact of Contaminated Land on
Groundwater and Surface Water, CLR1, DoE, London, 1994, vols. 1 and 2.
 S. J. T. Pollard, D. O. Harrop, P. Crowcroft, S. H. Mallett, S. R. Jeffries and P. J. Young, J. Chart. Inst. Water
Environ. Manage., 1995.
 Martin and P. Bardos, A Review of Full Scale Treatment Technologies for the Remediation of Contaminated
Soil, BPP Publications, Richmond, 1996.
 Davis, E.L., 1997. How Heat Can Accelerate In-situ Soil and Aquifer Remediation: Important Chemical
Properties and Guidance on Choosing the Appropriate Technique. US EPA Issue Paper, EPA/540/S-97/502.
 Derby (2009). "In Situ Chemical Oxidation for Groundwater Remediation." SERDP/ESTCP Environmental
Remediation Technology (2011). Environment. Groundwater and Environmental Services, Inc., Web.
 Banerjee, A.; Roy, A.; Dutta, S.; Mondal, S. Bioremediation of hydrocarbon—A review. Int. J. Adv. Res. 2016.
 Saxena, G.; Bharagava, R.N. Bioremediation of Industrial Waste for Environmental Safety: Volume I:
Industrial Waste and Its Management; Saxena, G., Bharagava, R.N., Eds.; Springer: Singapore, 2020.
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20. THANK YOU
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