Environmental Engineering Reference
In-Depth Information
Effect of reuse on product cost
120
100
80
60
40
20
0
0
5
10 15
No. of uses
20
25
FIGURE 31.14
Effect of reuse on product cost.
which have a relatively low cost. Meta-PO4 media provides a simpler removal approach
with much lower capital cost.
The cost to remove phosphorous depends on the initial cost of the media but primar-
ily on the number of times the media can be reused and whether regeneration is done on
site. Figure 31.14 illustrates how important regeneration affects average product cost, when
regeneration is done on site. With ive reuses, the average cost drops 80%, and 95% if media
can be used 20 times.
The capital cost for a system containing Meta-PO4 media is expected to be modest,
primarily consisting of containers, pumps/valves, monitoring/control, and a system for
regeneration.
Media costs are usually expressed as [$/kg-media] or [$/kg-P removed]. Cost depends
on the volume of water being processed, the number of times the media is reused, and the
amount of phosphorus that must be removed. It can be as low as $10-$20/kg-P for larger
operations and higher phosphorus concentrations (>50 mg/L). However, cost to remove
phosphorous from water will be comparable and often lower than other alternatives owing
to a higher capacity and the reuse characteristics of the media.
31.7 Conclusion
For phosphorous removal from water, nanomaterials provide exceptional performance
compared with naturally occurring minerals and most manufactured sorbents. A high con-
centration of phosphorous can be adsorbed by nanoenhanced media. A key to high perfor-
mance is the use of a highly porous ceramic substrate to support the active nanomaterials.
The hierarchical interconnected porosity allows for easy water low into and through the
media, bringing phosphorus ions into contact with the nanomaterials. Being able to lower
phosphorus to <0.01 mg/L has been shown, which is otherwise costly using chemicals.
Reuse of media after phosphorous removal provides a signiicant economic beneit and
is an alternative for many chemical precipitation applications. Phosphorous can be recov-
ered from the regeneration liquids by precipitation as a useful commercial phosphate
compound, such as calcium phosphate. Given the increasing scarcity of phosphate rock,
the principal source of phosphorous, and the increasing needs of phosphorus for food
and industrial production, media containing nanomaterials represents an economic and
“green” long-term worldwide approach to supplying additional phosphorus.
