Tratamento de efluentes

An Offshore proposal for Sewage Treatment in Victoria
Main considerations:
“ If nothing
has been done so far, anything we do to improve will be
better than this now” .
• The presented purpose is an technique alternative to prevent the disorder from the
installation of a sewage treatment plant related with the construction services and
environmental impact in the onshore nearby .
• This proposal despite bold look and to be a paradigm change for sewage treatment
environment , presents no technological challenge as it is based on classic sewage
treatment processes converted in submarine environment whose technology for
construction and subsea installation is now fully dominated by Petroleum offshore
industry.
• The presentation describes the basic concepts to be applied to the development of the
project, to be developed on the basis of information not provided yet.
• The results to be obtained for the specifications of the effluents to be discharged into the
ocean, can follow a schedule of progress according to the project evolution curve.
• We consider in order, the following factors are most striking in the deployment cost of this
offshore project when compared to onshore:
1- Depth determined for the subsea facilities.
2 - Meteorological window for service at sea.
Preliminary Data:
From the report of “ Responsible Sewage Treatment Victoria” RSTV.
Sewage flowrate:
Figures obtained from the CRD indicate 66,000 cubic meters or 66 Mega Liters
from Mac Caulay and 40,000 cubic meters or 40 Mega Liters from the Clover point
are discharged through the deep sea outfalls daily.
This totals 106 Million liters/ day or 4416m³/hr .
Contaminants ( From newspaper) :
Between tests in 2010 and 2013, the average fecal coliform count in Victoria's
wastewater pipes went from 5.3 and 5.7 million bacteria per 100 millilitres of
water up to 7.2 and 9.3 million bacteria per 100 millilitres of water.
For reference: B.C. guidelines peg safe levels at 200 fecal coliforms per 100
millilitres for recreational beaches, and 14 fecal coliforms per 100 millilitres for
shellfish harvesting.
Classic Sewage Treatment Process
The New Concept
The new proposal for the sewage outfalls is to simply adapt the subsea offshore
technology currently in use in the offshore oil industry.
Environmental safety is crucial for the offshore oil industry and necessarily to be certified by
current international regulations. Assurance of high quality standards is achieved by having the
entire project, construction and installation by a third party certification body.
All subsea operation can be monitored from onshore.
The cost for the installation, operation and maintenance in shallow offshore waters is not
very high, relative to the cost of a new onshore sewage treatment station, underground pipe
installation and mainly when we also take environment impact in consideration, like in Victoria.
All the construction and subsea installation technology
are fully developed and all ready in application in
many offshore facilities.
Exemple of offshore system in operation from others.
STATOIL
Sewage treatment stage to be done underwater
Submarine manifold system for aeration
The schematic System for the Outfalls Upgrade
Esquimalt and Clover Point
Areas
1MW Ozone Generator.
Air in let
Buoy system
Air inlet
Sea level
Pumping Room
sewage wate
To the open sea
Submarine Manifolds for air injetction using high
technologic ventury can be installed in specific
quantities all long the offshore discharge system.
Ozone injection
Treated water
Sewage Water
Additional Secondary Treatment System
After appropriate studies are completed and appropriate level of contaminants
removal is established, if necessary, complementary barges can be sunk into the sea
to work in the sewage treatment tanks. These barges/tanks will work with a ballast
system to rise and sink in accordance with the needs for maintenance and system
operation.
Specific pipeline can send the treated “solids” and/ “ mud” to be treated on shore
Exemple of the submarine sewage station in operation.
Accordingly with the project, only one tower will be visable at the sea level .
CRD
Possible cicles to improve aeration and/or Secondary Treatment
Desinfectant gases
or Chemicals Injection
Cicle 2
Cicle 1
(Sunk barge tanks)
(Manifold system)
Main flow of the sewage outfall
Phase of Seawage Treatment where the Sunk barges may be
Applied.
Submerged barges Tanks
To the Secondary Treatment improvement.
Air in let
Buoy system
Air inlet
Pumping Room
UV Room
Sea level
From stage 1
To open sea
Tank Barge for aeration
Submerged Barge with tanks for Denitrification and
Nitrification treatment to be installed in specific
quantities all long the offshore discharge system.
Sea botton
Treated water
Sewage Water
Alternative 2
Surface Air injection
with Venturi System
Secondary Flow
Underwater manifold
Venturi system
Main Water Flow by pump
Alternative engineering studies to drill the outfalls pipeline
Special gasket and reinforciment device for hot tape of existing outfalls pipeline
To be developed accordingly to the actual outfalls pipeline piping structure
For the flow rate of 4400m³/hr we consider 6 pumps as described bellow.
Barge Main Deck with Submarine manifold module
BSWMS ( Ballast and Sewage Water Management System)
Similar process is applied to the modern Ballast system.
Suspension and solid clean up process
Hi SEA technology
Complementary disinfection alternatives
Similar visual aspects for the UV room.
Los Angeles
Utraviolet disifection Facility
UV treatment unit
New Tecnology for Ozone Aplication
Submarine Sewage Master Basic Plan
1
Ativities
Sea bed topograph and research
FEED development
Documentation for BID
Licenses
BID and contract signature
Barge procurement
EPC for Barge
EPC for Modules
Main deck Integration
Barge transport for location and installation
New outfalls EPC
Submarine barge and pipeline integration services
Comissioning and pre-operation
2
Months
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7
8
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END