biopolymer flocculants for sediment control in effluent ... · biopolymer flocculants for sediment...
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Biopolymer flocculants for sediment control in effluent from tunnel excavation in an ecologically
sensitive environment
F. Kneib1, N. Araujo2, A. Saborío Rojas3, J. I. Santiago1, y J. F. Williams1
A discovery: Biopolymer interactions cause ‘unexpected’ aggregations
Trapped contaminants in fibrillar masses can be : • Suspended solids/sediment • Microorganisms (ie.bacteria,
cysts, viruses) • Microalgae • Coal fines, mining tailings • Metal oxides • PAC-bound hydrocarbons, PCB’s, hydrophobic organics
Putting the discovery to work: Proyecto Hidroeléctrico Balsa Inferior ( Aerial View and Location of PHBI)
Pititoy Solitaria (Tringa solitaria)
Laguna artificial del Polvorín.
Ranita de vidrio (Cochranella granulosa)
Humedal Remanente Orquídeas.
Casa Maquinas.
Tortuga negra (Rhinoclemmys funerea) Quebrada la Cangreja.
Central Construction Site PHBI, Costa Rica
Tunneling Operations
•Solids •Storm/Ground Water
Traditional Sedimentation Control System
Routine Sediment Control System Maintenance
with Large Pumps and Dump Trucks
Environmental Discharge: Traditional Sediment Control System
Complementary biopolymer flocculants: turbo charging the aggregative efficacy
High mag microscopic view of fibrillar aggregates and trapped particles
Faster Sedimentation Rate of Suspended Solids
Control - Treated 1 second 3 seconds 10 seconds
Sediment Control Systems
Passive Sediment Control Systems : options
Turbulent Flow in Corrugated Pipe
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Daily TSS Reduction of Sediment Control System #1 February 2012 (Inhoff Cones)
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Sediment Control Systems Maintenance/Cleanup
Central & End of Tunnel
TSS Reductions on PHBI Waste
Streams August-
September 2012
Evaluation @ PHBI
BMP Improvements
•Employee Training •Daily Maintenance •Data Collection:
•pH •Temperature •Conductivity •TSS Reduction •Cleanup Volume
•Systems’ Optimization
Rio Balsa now