Environmental Engineering Reference
In-Depth Information
FIGURE 31.3
Example of Nano-crystals.
31.4
MetaMateria Approach to Phosphorus Removal
MetaMateria Technologies utilizes proprietary process technology to prepare nanomate-
rials in the form of particles, whiskers, or platelets that can take advantage of the unique
properties afforded by these nanomaterials for removal of contaminants from drinking
water. For phosphorus removal, nano-iron oxyhydroxide (FeOOH) crystals are grown on
a novel high surface area porous ceramic structure.
31.4.1 Novel Porous Ceramic Composite
Figure 31.4 shows two examples of the highly porous ceramic composite used for phos-
phate removal. These contain alumino-silicate binders and iller materials, such as iron
or zeolite powder. They typically have >80% open interconnected porosity, a density of
0.4-0.6 g/cm
3
, and surface area of 15 m
2
/g (>700,000 m
2
/m
3
) but this can be higher.
The novel method used to prepare the porous ceramic substrate starts with slurries of
reactive materials, iller/aggregate materials, and surfactants/gas-forming agents. After
mixing, liquid is poured into molds to make shapes or into a mix chamber to make aggre-
gates. An alumino-silicate bonded matrix with interconnected porosity is formed during
gas expansion of liquid (three to four times) followed by solidiication due to chemical
reactions. The product then goes through a curing step and other postforming procedures
to prepare it for nanomodiication. The phosphorous media (Meta-PO4) is prepared using
FIGURE 31.4
Foamed ceramic shape examples.
