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Industrial Case Studies

Client Recovers $5 Million in coal after coal pile runoff pond volume reduction


The Client's Needs

Cole pile runoff
USA – A large American power company with about 6,800 megawatts of capacity, generating electricity from natural gas, western coal, and wind.

 
The Client had a need to treat and discharge coal pile runoff water containing high amounts of total suspended solids from its facility.
 
The Client had tried in the past several other technologies such as conventional clarification, DAF & compressible sponge-like media filters, developed by Veolia’s competition
with no satisfying result.
 
It led the Client to first contract Veolia for a four week pilot demonstration of the high-rate, sand ballasted clarification process, ACTIFLO®, to demonstrate the overall system performance with regards to the desired effluent quality (TSS < 30 mg/l and/or < 20 NTU with inlet of 100 – 1000 mg/l TSS and particles distribution of 0.5 – 10 micron in inlet ) and to confirm full-scale design parameters.
 
A year later the client experienced a significant rainfall. They had 13 inches in a month compared to their average of 4 inches which caused the level in the coal pile runoff pond,
usually maintained by evaporation rates, to rise up to the spillway.
 

The Solution


The Client contracted Veolia for the rental of an ACTIFLO® TURBO trailer (capable of 1200+ GPM) coupled with HYDREX™ chemicals. Veolia was also awarded an operations contract, offering the Client a hands-off approach.

Key to the overall success of the project, Hydrex™ chemicals supplied a blend of two coagulants and a flocculant / polymer needed with the microsand.
 

Key Facts
 

- Type of contract: Solutions & Operations

Key Facts
 

- 50 million gallons of water at instantaneous flow of 500-1000 GPM treated
- Processes: ACTIFLO® TURBO and Hydrex™ chemicals

 

ACTIFLO® TURBO process description and system performance

 
Coal pine runoff Actiflo Turbo

 
System Performance 
Flow Rate25-125 m3/h
Softening Mode (Actiflo Soft)40 m3/h
Typical Clarification Rate80 m3/h
Carbon Filtration Mode (Actifloc Carb)40 m3/h
System Dimensions 
Length13650 mm
Width2500 mm
Height4510 mm
System Connections 
Inlet ConnectionDN 150mm PN16
Outlet ConnectionDN 200mm PN16
Sludge ConnectionDN 80mm PN16
Electrical Supply 
Electrical Type125A ; 400V ; 3 phases + earth + neutral
 

Results
 

Veolia treated over 50 million gallons of water in clarification mode; at instantaneous flows of 500 – 1000 GPM. The pilot indicated rise rates > 40 GPM/ ft2 were achievable; however, in the full-scale, the client did not have a feed pump big enough to provide more than 30 GPM/ ft2 ~ 1000 GPM. The cost of treatment using ACTIFLO® rental, Hydrex™ chemicals and the operations, was similar to typical sewer rates in the US.

 

Benefits

  • Recovery of approximately $5,000,000 USD in coal from the basin / pond once the pond level was brought down.
  • Ensured compliance with the plant’s required effluent quality.