the other hand, indirect sources are those in which the pollutant comes into contact
with water through leaching, draining and dilutions. It seems that the impact of a
pollutant directly affects the place where it originated; however, several studies
indicate that there may be a contact of a pollutant that originated thousands of
kilometres from the body of water due to the transport of goods within the commercial and production supply chains (Mekonnen and Hoekstra 2015).
Pollutants can be classified according to their nature in physical, biological or
chemical, being the chemical type pollutants one of the most common agents presents in contaminated bodies of water. Chemical contaminants represent a serious
problem within water bodies, since most of these are usually outside any biogeochemical and metabolic cycle, so finding techniques for their removal is of the most
importance. Normally, chemical contaminants are dissolved or suspended (Goel
2006), and therefore, the techniques for their elimination must be very specific
taking into account the physical and chemical characteristics of the polluting
agent. Both the impact and the level of contamination of chemical agents will depend
on the characteristics of the contaminant as well as the type of body of water, its
location and the types of beneficial uses it supports (Schweitzer and Noblet 2018).
Among the pollutants of a chemical nature, there are some that due to their
persistence and their serious harmful effect on human beings and the environment
are classified as “priority pollutants”. The damages that these could cause are very
diverse, in the environment they can cause from eutrophication to sterility of waters
(SA’AT SKBM 2006); while the effects on humans range from carcinogenicity,
mutagenicity, teratogenicity or acute toxicity (Sciortino et al. 1999). These pollutants
were first classified by the Environmental Protection Agency of the United States in
1976, having a list of 129 compounds of different chemical nature, which can be
subdivided into nine large groups (Keith and Telliard 1979): metals, asbestos, total
cyanides, pesticides, compounds extracted under acidic conditions, compounds
extracted under alkaline conditions, neutrally removable compounds, total phenols
and purgeable compounds.
For its part, the European Union also has a similar list which was updated in 2013,
with 45 substances, some grouped by their chemical characteristics (Ue et al. 2013).
Both the American and European lists have to be continually updated due to the
presence of “emerging contaminants”, which are organic substances that are the
subject of great concern among the scientific community due to their frequent
detection in aquatic environments. Highlights pharmaceutical or personal care
products that are highly consumed by modern society (Bueno et al. 2012). In this
way, the spectrum of priority chemical pollutants present in the water is defined;
however, it increases as the presence of new compounds is observed and the
damages that these could cause are not completely known.
5.2.1 Priority Organic and Inorganic Pollutants
The growing development of agricultural and industrial activities has resulted in the
synthesis of various organic and inorganic substances that lack studies on their
5 Removal of Priority Water Pollutants Using Adsorption and Oxidation. . .
119
with water through leaching, draining and dilutions. It seems that the impact of a
pollutant directly affects the place where it originated; however, several studies
indicate that there may be a contact of a pollutant that originated thousands of
kilometres from the body of water due to the transport of goods within the commercial and production supply chains (Mekonnen and Hoekstra 2015).
Pollutants can be classified according to their nature in physical, biological or
chemical, being the chemical type pollutants one of the most common agents presents in contaminated bodies of water. Chemical contaminants represent a serious
problem within water bodies, since most of these are usually outside any biogeochemical and metabolic cycle, so finding techniques for their removal is of the most
importance. Normally, chemical contaminants are dissolved or suspended (Goel
2006), and therefore, the techniques for their elimination must be very specific
taking into account the physical and chemical characteristics of the polluting
agent. Both the impact and the level of contamination of chemical agents will depend
on the characteristics of the contaminant as well as the type of body of water, its
location and the types of beneficial uses it supports (Schweitzer and Noblet 2018).
Among the pollutants of a chemical nature, there are some that due to their
persistence and their serious harmful effect on human beings and the environment
are classified as “priority pollutants”. The damages that these could cause are very
diverse, in the environment they can cause from eutrophication to sterility of waters
(SA’AT SKBM 2006); while the effects on humans range from carcinogenicity,
mutagenicity, teratogenicity or acute toxicity (Sciortino et al. 1999). These pollutants
were first classified by the Environmental Protection Agency of the United States in
1976, having a list of 129 compounds of different chemical nature, which can be
subdivided into nine large groups (Keith and Telliard 1979): metals, asbestos, total
cyanides, pesticides, compounds extracted under acidic conditions, compounds
extracted under alkaline conditions, neutrally removable compounds, total phenols
and purgeable compounds.
For its part, the European Union also has a similar list which was updated in 2013,
with 45 substances, some grouped by their chemical characteristics (Ue et al. 2013).
Both the American and European lists have to be continually updated due to the
presence of “emerging contaminants”, which are organic substances that are the
subject of great concern among the scientific community due to their frequent
detection in aquatic environments. Highlights pharmaceutical or personal care
products that are highly consumed by modern society (Bueno et al. 2012). In this
way, the spectrum of priority chemical pollutants present in the water is defined;
however, it increases as the presence of new compounds is observed and the
damages that these could cause are not completely known.
5.2.1 Priority Organic and Inorganic Pollutants
The growing development of agricultural and industrial activities has resulted in the
synthesis of various organic and inorganic substances that lack studies on their
5 Removal of Priority Water Pollutants Using Adsorption and Oxidation. . .
119