the IHS Ballast Water Guide - RWO Marine Water Technology

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micro-organisms. In addition, the electrolysis
cell’s special coating ensures sufficient
chlorine concentration.
During deballasting, residual chlorine
is neutralised by the addition of sodium
bisulphite solution. Great emphasis has been
placed on monitoring and control to ensure
proper operation and effective neutralisation
of treated ballast water prior to discharge to
sea. The control unit logs the status of the
system, operation, electrolytic cell, selfcleaning
filter and cyclonic separator. ar arator or or. or or.
BallastMaster
GEA Westfalia
2 7
Its maker maintains that the BallastMaster
system requires low amounts of energy and
has a neutral effect on the environment.
BallastMaster operates in three stages.
First, during the filtration phase, ballast water
is taken on board and passed through a backflush
cartridge filter that removes particles
larger than 40µm at up to 1,000m 3 /h. In the
second stage, disinfection, an active substance
is added directly into the pipe leading to the
ballast tank.
An oxidate created on board using
electrolysis is used as a disinfectant. This
is produced from a simple sodium chloride
solution, consisting of common salt and
freshwater, and is added to the ballast water
that has been taken on board.
The oxidate breaks down into its original
ingredients when exposed to ultraviolet
radiation, which makes the substance
inactive. Any possible after-effect of the
processing is counteracted in the third
stage, neutralisation. As the ballast water is
discharged, a sulphur-based neutralisation
agent is added, if required, to reduce the total
residual oxidants (TRO) content to below
the level of 0.2ppm specified by the IMO.
An important point is that the system
works with low energy and operating costs.
The installation of a plant with a capacity of
500m3 /h is said to require an electrical current
of less than 8kW, most of which appears to be
required for the electrolysis of the he dis disinfectant. is isinfe fectan an ant.
SEDNA
Hamann
2 1
The SEDNA system developed in Germany
by Hamann was one of the first systems to be
given full approval in 2008.
Physical separation is in two stages: a
hydrocyclone followed by a compact, selfcleaning
filter with 50µm meshes. The
cleaning of the filter is triggered by the
differential pressure. During backflushing the
filter elements are cleaned one by one with
seawater without addition of any cleaning
substances. When backflushing the ballast
water operation continues at a slightly
reduced flow rate.
The system can be adapted to different
ballast water pump capacities, ranging in size
from 200m 3 /h to 1,000m 3 /h for individual
installations. Ballast water pump capacities in
excess of 1,000m 3 /h are said to be possible.
In addition to physical treatment, the
system makes use of Peraclean Ocean (a
chemical substance developed by Evonik-
Degussa). This substance has created problems
for the system because although it performs
as expected under most circumstances,
at extremely low sea temperatures and in
freshwater it does not degrade and so can
remain active in the environment.
The fully approved ballast water treatment
system was withdrawn from the market
after concerns were expressed that the active
substance it uses could remain toxic after
discharge. Under pressure from the German
authorities, further tests were carried out
18 © IHS Global Limited 2012
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