the IHS Ballast Water Guide - RWO Marine Water Technology

Sponsored by IHS Fairplay Solutions Guide to Ballast Water Treatment Systems
sizes ranging from 40m 3 /h to 5,400m 3 /h.
For the basic BWTS 300-P30 system
configuration, where space is a limiting factor,
a pressurised filter is fitted with a mesh, of
pore size 30µm, which removes particles
in order to secure the efficiency of the
succeeding disinfection step.
In the second step, water flows through the
UV unit and is thereby exposed to a high dose
of UV-C irradiation from low-pressure UVlamps
to inactivate organisms smaller than
30µm. The UV lamp units generate photolytic
inactivating light and photochemical ozone
generating light. Each unit is capable of
treating 100m³ of ballast water per hour.
The UV unit also generates ozone, which
is used in the third step of the treatment
process, in which the water passes a venturi
injector. The vacuum created by the venturi
injector sucks dry compressed air through
the ozone generating components via a
pipeline to the injector for mixing into the
main ballast water stream. Finally, the treated
water is directed to the ballast tanks.
The system is controlled via a touch screen
and mimic pictures which provide an overview
of the system. Ocean Guard automatically logs
all events, alarms, and so forth.
The system has a capacity of treating
300m 3 /h, but it can be scaled up to process at
least 3,000m 3 /h in total.
ES
Ecochlor 2 2
The ballast water treatment system from
Ecochlor of Maynard, Massachusetts, uses
chlorine dioxide (ClO2) technology.
The BWMS from the US-based
manufacturer uses filtration followed by the
injection of a chlorine dioxide solution. The
ClO2 solution is created by chemical reaction
from mixing precise amounts of purate, which
is a powder formed of sodium chlorate, with
hydrogen peroxide and sulphuric acid supplied
by chemical pumps.
The ClO2 is drawn into a venturi by the
vacuum created by the flow of freshwater or
seawater. The filters must be located close to
the ballast water pumps, but the module for
the generation of this solution can be located
at a convenient place on board.
Ecochlor is reportedly concentrating on the
bigger vessels and flow rates. The system is
said to be able to treat from 1,000 to 10,000
tonnes of ballast water per hour.
Type approval was granted to the
Ecochlor system at the North Sea Ballast
Water Conference at Europort 2011 on 8
November 2011 by the Federal Maritime and
Hydrographic Agency (BSH) of Germany.
Ecochlor has been accepted into the US
Coast Guard’s STEP programme.
Erma First ESK
Engineering
Solutions 2 1 7
Developed by Greece-based Erma First ESK
Engineering Solutions, the Erma First BWTS
is described as a robust integrated system
with low energy consumption and a small
footprint. It consists of individual modules
each with a treatment capacity of 100m³/h.
Treatment is in two stages.
First, suspended materials and larger
organisms are removed by means of prefiltration
and an advanced cyclonic separator.
Then, during ballasting, electrolysis is used
to generate active chlorine. Here, residual
oxidants disinfect any harmful organisms that
may have been taken on board.
The levels of chlorine are controlled so that
even in waters where suspended sediment is
high, the efficient cyclonic units ensure low
chlorine demand for the disinfection of the
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