GE ENErGy - Frank Farnel

600
Number of ZeeWeed
plants installed,
including some of the
world’s largest
42
Number of countries
where ZeeWeed
has been installed
0.02 µ
Average pore diameter,
thousands times
smaller than a human
hair, and much smaller
than most bacteria,
viruses and suspended
particles
The qinghe wastewater
plant in beijing.
a higher level of public health and environmental
protection and can be used safely for a wider range
of purposes. Plant footprint is particularly important
in densely populated areas, where water treatment
is in great demand but there is a shortage of real
estate to meet the need.
“A lot of plants are in very tight areas where population
density is very high,” Singh says. “A new Zee-
Weed plant is usually half or a third the size of a comparable
conventional alternative. We can also retrofit
existing conventional plants, increasing both treatment
capacity and performance. We use the same
tanks and basins, we put in our membranes and we
can treat several times the water that conventional
technology can treat.”
Cleaner effluent
Chesapeake bay on the US Atlantic coast, North
America’s largest and most biologically diverse estuary,
has a history of environmental damage brought
about by increasing municipal and industrial effluent
discharges. Thanks to a ZeeWeed membrane
bioreactor system at the new broad run Water reclamation
Facility, the plant releases treated effluent
into one of the bay’s tributary rivers that is actually
cleaner than the water drawn from it. The high-qual-
ity effluent released from this plant and from several
other ZeeWeed plants in the watershed plays a critical
role in a massive effort to restore the environmental
health of the bay.
pressurized option
The latest asset in the ZeeWeed lineup is the Zee-
Weed 1500 Pressurized Ultrafiltration Membrane.
The ZeeWeed 1500 is an enclosed system that uses
pressure to force water through the pores, rather
than the traditional suction system of the other Zee-
Weed products. Pressurized systems offer operational
and cost advantages for smaller plants that
treat less than 25 million gallons of water per day. For
larger plants, the immersed ZeeWeed membranes
are still the right choice. Pressurized systems are
also ideal for industrial processes such as food and
beverage manufacturing. With a closed, pressurized
system, process water is never exposed to the plant
environment. An added advantage of the ZeeWeed
1500 system is that it can be built in the factory and
installed more quickly.
The ZeeWeed 1500 leverages the proven performance
and reputation that the ZeeWeed range
has established in a wide range of roles around the
world.
aBMet
THE SELENIUM
SOLUTION
industries such as coal-fired
power generation, mining and
petroleum refining produce
wastewater streams that contain
various dissolved contaminants
– many of them metals – including
mercury, arsenic and one of the
most difficult-to-treat dissolved
metals of all, the chemical element
selenium.
Selenium is of particular
environmental concern precisely
because it dissolves in water
so well, making it difficult to
effectively treat with conventional
chemical wastewater-treatment
countermeasures.
To meet increasingly stringent
water-quality regulations for
selenium levels, a new advanced
technology is required, such
as ge’s advanced Biological
Metals removal, or aBMet.
aBMet is a simple, low-energy
system that uses ordinary
bacteria to remove selenium.
it has biofilters seeded with
selected strains of naturally
occurring, non-toxic and nonpathogenic
microorganisms
to biochemically reduce selenium
and remove it from the water.
aBMet has been employed at
a number of mining and power
plants in north america.
for example, four power plants
in north Carolina owned by Duke
energy and progress energy
have employed aBMet biological
technology for removal of
contaminants from the wastewater
of their wet flue-gas desulfurization
processes, achieving an average
selenium removal efficiency
of better than 99%.
The aBMet system offers low
operating costs, cuts selenium
to very low levels and it also
removes nitrates completely.
aBMet is the first proven biological
technology to cost-effectively
treat wastewater in compliance
with today’s strict regulations for
selenium.
Number 3 l October 2009 CONNEXION l 13