Page 43 - ACCB 2020

Nanotechnology for Combating Microbial Contamination. do Nascimento et al

Abstract

The water is a universal need that has been reported by the United Nations (UN) and World Health Organization
(WHO) as a priority. There is a pressing need for free access to drinking water for populations from developing
countries. Furthermore, the water sources of developed countries also require attention due to the presence of a
high level of emergent contaminants. Therefore, nanotechnology appears to be a powerful tool that could be used
as sensors, fi lters, antibacterial surfaces, and nanoantimicrobials. In this review, we have discussed the application
of nanoparticles and nanocomposites for water and wastewater treatment. Moreover, the impact of free-nanoparti-
cles as emergent contaminants in water treatment plants as well as groundwater warrants further studies.

Keywords: Water contaminants, nanotechnology, sensors, fi lters, antibacterial surfaces, nanoparticles, nanocom-
posites.

1. Introduction consumed by the industries. From UNESCO’s report,
Water is one of the most important compounds that it is clear that the withdrawal of freshwater was three
greatly infl uence life (1). Groundwater is used for do- times more in the last 50 years because the demand for
mestic, industrial, and also for irrigation purposes, all freshwater is increasing by 64 billion cubic meters a
over the world. Water also plays an important role in year (7). The possible reasons for an increase in global
shaping the land and regulating the climate. During the demand of freshwater are as follows: (i) the world’s po-
last few decades, there has been a tremendous increase pulation is growing by roughly 80 million people each
in the global demand for freshwater as well as sewa- year (ii) modifi cations in lifestyles and eating habits
ge treatment due to the rapid growth of population and in recent years need more water consumption per ca-
the accelerated pace of industrialization (2). Those de- pita (iii) the production of biofuels has also augmen-
mands also shed light on waterborne diseases that can ted abruptly in recent years, with substantial impact on
rapidly spread and affect several countries, as an exam- water demand. Between 1,000 and 4,000 liters of water
ple of last cholera outbreak(3). According to the report are required to produce a single liter of biofuel, and (iv)
of WHO, about 80% of all the diseases in human beings energy demand is also accelerating, with corresponding
are caused by waterborne pathogens. Considering that, implications for water demand (6).
once the groundwater is contaminated, its quality can-
not be restored easily(4). Considering the water and wastewater treatment pro-
blems, nanotechnology appears as an important tool to
The water quality index is one of the most effective improve water quality, quick detection of pollutants, as
tools to communicate information on the quality of well as to the removal of recalcitrant/emergent contami-
water to the concerned citizens and policymakers. Hen- nants from water and wastewater. Nanoparticles present
ce, analysis of the water quality is very important to unique properties that allow their application in several
protect citizen’s health, as well as to preserve the natu- areas. Along with this, we will discuss nanotechnolo-
ral ecosystems of each country(5). Besides that, reports gical solutions for water and wastewater treatment, as
from various agencies such as the United Nations (UN) well as some concerns related to the toxicity of nano-
and its other divisions (UNESCO, and FAO) provide the particles. To understand the main problems regarding
data on water consumption in the world. According to water and wastewater pollutants, this review also dis-
their reports, the distribution of available water world- cusses the source, environmental effects, and traditio-
wide can be 70% for agriculture, 20% for industry, and nal mechanisms for treatment and removal of aquatic
10% for domestic use. Providing high-quality water for pollutants.
agricultural use has been the major challenge due to the
increased production of industrial waste and chemicals 2. Main contaminants of water
released into the water bodies (6). It was reported that Clean potable water is one of the important fundamental
in developed countries having huge industrialization, requirements for a healthy human population. However,
more than half of the water available for human use is nowadays, the contamination of water resources repre-
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Rev. Asoc. Col. Cienc.(Col.), 2020; 32: 42-62.