Feature
The latter differs from Ostara and Multiform Harvest in
that, rather than creating fertilizer pellets, Crystalactor
— licensed through Procorp Enterprises in the U.S.
— crystallizes phosphate on fine grain sand and has
thus far been used solely for industrial wastewater
treatment.
Here And Now: Turning Phosphorus Into Fertilizer
A number of companies are precipitating phosphorus
from the sidestream through fluidized-bed reactor
processes and recovering it as struvite, or magnesium
ammonium phosphate. While this practice is more
easily adopted by WWTPs that feature biological
phosphorus removal and anaerobic
digestion, it can also be installed
(less seamlessly) at plants using
chemical phosphorus removal.
The recovered struvite is turned
into and then sold as a slowrelease fertilizer. This offsets the
capital and operational costs of
the process, while also reducing
or eliminating disposal costs. By
contrast, chemical phosphorus
precipitation creates waste sludge
that has little value as a fertilizer
and is most often hauled off at
the expense of the municipality.
Furthermore, unrecovered struvite
forms as scale in pipes and can
reduce system capacity.
The
leading
company
in
extracting struvite and turning it
into profit, as measured by WWTP
installations, is Ostara Nutrient
Recovery Technologies. Oregon's
Clean Water Services was among
the first to take the plunge at their
Durham Advanced Wastewater
Treatment Facility near Portland,
and the success prompted them to
also incorporate the technology at
its Rock Creek facility in Hillsboro.
Hampton
Roads
Sanitation
District's Nansemond Treatment
Plant in Suffolk, VA, has also
taken advantage, as has the City of
York (PA) Treatment Plant. Carried
out as public-private partnerships,
Ostara garners service fees and
a portion of fertilizer profits to
pay back the costs of installation,
which can be repaid in as little as
five years.
Other companies extracting
struvite to make fertilizer include
Multiform Harvest, employed by
the City of Boise at the West Boise
Wastewater Treatment Facility, and
Netherlands-based DHV Water
with its Crystalactor technology.
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Water Online The Magazine
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