Lecture #9: Sustainable Development with Dredged Sediments - - PowerPoint PPT Presentation

Welcome to CE488 Environmental Geotechnics

Lecture #9: Sustainable Development with Dredged Sediments

Department of Civil Engineering IIT Bombay

Po Ports

Port of Rotterdam, Netherlands

Layout of JNPT, Mumbai

Ai Airport rports

Artificial Island Chek Lap Kok, Hong Kong Kansai Airport, Japan

Artificial Islands

Construction of Palm Group of Islands, Dubai

“Dredging”

What is dredging?

“Under water excavation”

• Need for Dredging
• Maintenance/creation of navigable depth in channels and berths
• In rivers to avoid flooding.
• Lake restoration projects
• Desiltation of water treatment plans

Dr Dredgi edging ng activity activity

• Pre‐Survey
• Drilling and Blasting
• Dredging
• Types of Dredgers

Materials

• Trailing Suction Hopper Dredger

sand/silt/soft clays.

• Cutter Suction Dredger

medium‐stiff clay/soft rocks.

• Back‐hoe Dredger

usually used to dredge out rocks.

• Post‐Survey

Dredged Sediments

10

What is the need for utilization? Depleting natural resource Cost of disposal

SUSTAINABILITY

Steps in Utilization

11

Characterization Utilization Challenges Solutions Issues in utilization?

• Infrastructure sector
• Agriculture activities
• Habitat restoration
• Beach

replenishment

12

Strength and durability Handling and storage Contamination (organic and Inorganic) Vulnerability to microbial attack Policies on beneficial usage

ISSUES

Re Remediation

• Physical Separation & Mechanical Process
• Density separation
• Filter‐press methods
• Thermal Process
• Incineration
• Chemical process
• Chelant Extraction
• Electro‐kinetic remediation
• Bio‐remediation
• Use of reducing/oxidizing bacteria

Ty Typical dr dredged edged mater material als and and their their bene benefi fici cial al uses… uses…

Table Source: USEPA Manual on ‘Beneficial Use of Dredge Material’