Asd of Engineering

Contaminant Hydrogeology ENEN90030 CONTAMINATION REMIDIATION LECTURE - 7 Dr. Meenakshi Arora

Groundwater contamination
• Groundwater Contaminants - Organic contaminants - Inorganic contaminants - Radio nuclides • Contaminant Transport - Conservative - Non-conservative (Retardation and Decay) • Site Remediation - Source Control - Pump and Treat - Sorption - Membrane Treatment - In situ Bioremediation, NAPL Recovery - Permeable Reactive Barrier - Contaminated Land Cleanup

Dr. Meenakshi Arora ENEN90030 Contaminant Hydrogeology

Remediation Techniques: Recap so far
 Source control
◦ Removal and disposal ◦ Physical Containment ◦ Hydrodynamic isolation ◦ Target the plume ◦ Usually in combination with source control
 Sorption
◦ Adsorption, Absorption, Ion exchange ◦ Isotherms ◦ Breakthrough curves

 Pump and Treat

 Membranes
◦ Types of Membranes ◦ Membrane selection ◦ Fouling and Cleaning

 In Situ Treatment
Dr. Meenakshi Arora ENEN90030 Contaminant Hydrogeology

In-situ Treatment
• Very low concentrations of contaminants over wide area (Bioremediation). • Post treatment (to safeguard against retarded solutes). • If soil is contaminated too and removal and disposal is not feasible (minimal disruption and/or disturbance to on-going site activities). • Cost • Bioremediation • Permeable Reactive barriers
Dr. Meenakshi Arora ENEN90030 Contaminant Hydrogeology

Bioremediation
• organic wastes are biologically degraded by the microorganisms into relatively harmless byproducts, such as carbon dioxide and water. • Contaminants destroyed or transformed in harmless substances. • Low technological requirements, Low maintenance. • No additional disposal costs • Does not create an eyesore • Can be performed on-site

Dr. Meenakshi Arora ENEN90030 Contaminant Hydrogeology

Bioremediation
 Useful where physical removal not practical  Can be enhanced through Aeration by sparging and supply of nutrients via injection wells  Lab investigation