Benefits of Nanotechnology for the Environment - Nanotechnology and Human Health - page 144

TABLE 7.4
Comparison among Nanofilters (Including CNMs) and Alternative Water
Treatment Technologies in Terms of Contaminant Removal

Contaminants Removed

Type of
Technology Inorganic Organic Biological

Conventional Treatment Technologies
Coagulation-
flocculation

Arsenic, asbestos, cadmium,
chromium, selenium

No Bacteria, fecal

coliform, viruses

Chemical
disinfection

No No Bacteria, coliform,

fecal coliform, viruses

Distillation All a No Bacteria, cysts,

viruses

UV radiation No No Bacteria, spores,

coliform, viruses

Nanofiltration Technologies
Carbon nanotube
(CNT) membranes

Salts, arsenic, cadmium,
mercury, selenium

All b All c

Nanofibrous filters Sea salt, arsenic, chromium,

lead, radionuclides, etc.

Unspecified All c

SAMMS Arsenic, cadmium,

chromium, lead, mercury,
radionuclides

Dep. on
SAMMS
type

Unspecified

a Inorganic contaminants: that is, heavy metals, nitrites, salts, asbestos, radionuclides, calcium,
magnesium, and others.
b Organic contaminants: that is, pesticides, herbicides, insecticides, industrial effluents, MTBE,
PAHS, PCBs, VOCs, and others.
c Biological contaminants: that is, bacteria, bacterial spores, Giardia and Cryptosporidium cysts,
coliform, fecal coliform, DNA and RNA, fungi, mold, parasites, protozoa, and viruses.

7.4.2.2 Nanomembranes for Carbon Dioxide Removal

Industrial emissions of CO 2 contribute to global warming. Around the globe,
seasons are shifting, temperatures are climbing, and sea levels are rising.
Climate change permanently alters the lands and waters we all depend on
for survival. Some expected impacts associated with the greenhouse effect
are more heat-related diseases and increased risk of storms, drought, fire,
and floods in some regions, which threaten the lives and wellbeing of many
people.
Some authors consider the storage CO 2 in empty gas fields or aquifers a
potential solution to the problem on how to mitigate the effects caused by
industrial CO 2 emissions [46-49]. In order to store CO 2 in the underground,
however, it should be captured first. Novel nanostructured membranes
might potentially offer an efficient and cost-effective way of separating CO 2
from industrial effluents.