260
ion oxide, and polymeric nanofibers. There are currently two approaches to address
the cost issue. One proposed approach is to use low-purity nanomaterials without
significantly compromising efficiency as much of the production cost is related to
separation and purification [267]. Alternatively, the cost- effectiveness can be
improved by retaining and reusing nanomaterials. Nanomaterials possess unique
challenges for risk assessment and management as they are small particles instead of
molecules or ions for which risk assessment framework and protocols are already in
place. Better understanding and mitigating of potential hazards associated with the
use of nanomaterials in water and wastewater treatment will lead to broader public
acceptance, which is crucial for new technology adoption. The compatibility between
aforementioned nanotechnologies and current water and wastewater treatment
processes and infrastructure also needs to be addressed. Most treatment plants and
distribution systems in developed countries are expected to remain in place for
decades to come. As a result, it is important to be able to implement nanotechnology
with minimal changes to existing infrastructure in the near term. In the meantime,
nanotechnology-enabled treatment processes can be employed in places where water
treatment infrastructure does not exist or in POU devices.
Conclusions
Nanotechnology for water and wastewater treatment is gaining momentum globally.
The unique properties of nanomaterials and their convergence with current treatment technologies present great opportunities to revolutionize water and wastewater
treatment. Although many nanotechnologies highlighted in this review are still in
the laboratory research stage, some have made their way to pilot testing or even
commercialization. Among them, three categories show most promise in full-scale
application in the near future based on their stages in research and development,
commercial availability and cost of nanomaterials involved, and compatibility with
the existing infrastructure: nano-adsorbents, nanotechnology-enabled membranes,
and nanophotocatalysts. All three categories have commercial products, although
they have not been applied in large-scale water or wastewater treatment. Several
other water treatment nanotechnologies have found their niche applications in POU
systems.
The challenges faced by water/wastewater treatment nanotechnologies are
important, but many of these challenges are perhaps only temporary, including technical hurdles, high cost, and potential environmental and human risk. To overcome
these barriers, collaboration between research institutions, industry, government,
and other stakeholders is essential. It is our belief that advancing nanotechnology by
carefully steering its direction while avoiding unintended consequences can continuously provide robust solutions to our water/wastewater treatment challenges,
both incremental and revolutionary.
13 Wastewater
ion oxide, and polymeric nanofibers. There are currently two approaches to address
the cost issue. One proposed approach is to use low-purity nanomaterials without
significantly compromising efficiency as much of the production cost is related to
separation and purification [267]. Alternatively, the cost- effectiveness can be
improved by retaining and reusing nanomaterials. Nanomaterials possess unique
challenges for risk assessment and management as they are small particles instead of
molecules or ions for which risk assessment framework and protocols are already in
place. Better understanding and mitigating of potential hazards associated with the
use of nanomaterials in water and wastewater treatment will lead to broader public
acceptance, which is crucial for new technology adoption. The compatibility between
aforementioned nanotechnologies and current water and wastewater treatment
processes and infrastructure also needs to be addressed. Most treatment plants and
distribution systems in developed countries are expected to remain in place for
decades to come. As a result, it is important to be able to implement nanotechnology
with minimal changes to existing infrastructure in the near term. In the meantime,
nanotechnology-enabled treatment processes can be employed in places where water
treatment infrastructure does not exist or in POU devices.
Conclusions
Nanotechnology for water and wastewater treatment is gaining momentum globally.
The unique properties of nanomaterials and their convergence with current treatment technologies present great opportunities to revolutionize water and wastewater
treatment. Although many nanotechnologies highlighted in this review are still in
the laboratory research stage, some have made their way to pilot testing or even
commercialization. Among them, three categories show most promise in full-scale
application in the near future based on their stages in research and development,
commercial availability and cost of nanomaterials involved, and compatibility with
the existing infrastructure: nano-adsorbents, nanotechnology-enabled membranes,
and nanophotocatalysts. All three categories have commercial products, although
they have not been applied in large-scale water or wastewater treatment. Several
other water treatment nanotechnologies have found their niche applications in POU
systems.
The challenges faced by water/wastewater treatment nanotechnologies are
important, but many of these challenges are perhaps only temporary, including technical hurdles, high cost, and potential environmental and human risk. To overcome
these barriers, collaboration between research institutions, industry, government,
and other stakeholders is essential. It is our belief that advancing nanotechnology by
carefully steering its direction while avoiding unintended consequences can continuously provide robust solutions to our water/wastewater treatment challenges,
both incremental and revolutionary.
13 Wastewater