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MERC ER01-10
2
generated automatically on demand and is matched to the ballast flow rate and the oxidant
demand of the ballast water. Initial oxidant concentration is dosed at 1.5 times the TOC
concentration, which remains effective for several days. To minimize potential regrowth of
(micro) organisms a background level of chlorine is maintained (1 mg/L) until discharge. To
eliminate the release of chlorine, sodium sulfite or bisulfite is added prior to discharge.
For this land-based test, the water is filtered through a 40 micron BallastSafe™ BSFc
Automatic Electric Filter, Model BSFc-V-1.6 prior to treatment. The sintered stainless steel
screen technology enables it to remove zooplankton. BallastSafe’s filter features continuous
cleaning of large volumes of dirt during ballasting without interruption, and a reversible screw
system for smooth, reliable and rapid cleaning of the entire screen surface.
All test facility equipment and instrumentation was operated by MERC personnel. The
ballast water treatment system was operated by STDN.
3. Summary of IMO Standards
This evaluation was designed to determine if the BalPure® BWMS could meet IMO D2
standards in accordance with both the IMO
Guidelines for Approval of Ballast Water
Management Systems (G8)
and the
Procedure for Approval of Ballast Water Management
Systems that make use of Active Substances (G9)
. The IMO Convention performance standard
states that ships must discharge:
1) Less than 10 viable organisms per m
3
, greater than or equal to 50 µm in minimum
dimension;
2) Less than 10 viable organisms per ml, less than 50 µm in minimum dimension and greater
than or equal to 10 µm in minimum dimension and
3) Less than the following concentrations of indicator microbes, as a human health standard:
1. Toxigenic
Vibrio cholerae
(serogroups O1 and O139), less than 1 colony forming unit
(cfu) per 100 ml
2.
Escherichia coli,
less than 250 cfu per 100 ml;
3. Intestinal Enterococci, less than 100 cfu per 100 ml.
4. Summary of Test Protocols
The following is a brief summary of the testing approach and methods. For complete
details on protocols, data management, and quality control / quality assurance procedures for this
MERC evaluation, please refer to the
Test Plan for the Performance Evaluation of the
Severn
Trent De Nora BalPure™ BP-1000
Ballast Water Management System
(August 2009), available
for download at www.maritime-enviro.org.
The protocols described below are based upon the IMO G8/G9 guidelines and the U.S.
Coast Guard supported ETV protocols under development. Any deviation from IMO G8/G9
guidelines or draft ETV protocols were explained and justified in the Test Plan. MERC
evaluated the biological efficacy of the STDN ballast water treatment system onboard the U.S.
Maritime Administration (MARAD) Ro-Ro vessel
MV Cape Washington
while docked in the
Port of Baltimore. The ballast system on
MV Cape Washington
was modified to allow for water
at a flow rate of 400m
3
/hr to be split equally at flow rates of 200 m
3
/hr. Just before this split,
challenge condition concentrations of total suspended solids (TSS) and particulate organic
carbon (POC)
were augmented by injecting a
concentrated slurry of Arizona test dust and humic