systems and aquatic environments. Furthermore, recreation activities such as swimming and other water sports can also contribute the personal care products’ contamination in water (Yang et al. 2017). Example list of pharmaceuticals and personal
care products with their physical and chemical properties is shown in Table 1.4.
The environmental contamination of pharmaceuticals and personal care products
is caused by both intentional and unintentional discharge from many sources,
including households, industries, hospitals, sewage treatment plants, livestock
farms, and landfill leachate. The effluent discharge from sewage treatment plants
and industries is identified to be the predominant sources (Awfa et al. 2018).
Pharmaceuticals and personal care products are usually synthesized to be persistent,
high chemical stability, and low biodegradability, which cannot be completely
removed by conventional treatment processes. Although the occurrence of pharmaceuticals and personal care products in surface water, groundwater, tap water, as well
as drinking water is frequently detected at a trace concentration (ranging from ng/L
up to μg/L), the continuous exposure to these compounds can significantly lead to
adverse effects on aquatic living organisms, terrestrial organisms, and balance of
ecosystem (Jamil et al. 2017).
Many pharmaceuticals and personal care products behave as antimicrobial
agents; thus the biological degradation processes that use microorganisms to break
down organic pollutants in water seem to be ineffective to remove them. Physical
treatment processes such as adsorption and membrane filtration can only transfer
pharmaceuticals and personal care products from one medium to another medium
without the destruction of them, leading to the formation of secondary contaminants
in the form of spent adsorbents and concentrated water, respectively (Awfa et al.
2018). Nowadays, the chemical oxidation processes especially advanced oxidation
processes, involving photo-Fenton, ozonation, UV/H 2 O 2 , and semiconductor
photocatalysis, are accepted as the most promising potential treatment method for
removals of pharmaceuticals and personal care products. Unfortunately, degradation
of pharmaceuticals and personal care products by photo-Fenton and ozonation can
form toxic by-products (Wang and Wang 2016). The low UV absorbance of
hydrogen peroxide and scavenging effects of
•
OH by H 2 O 2 are the main drawbacks,
leading to high operating costs in the UV/H 2 O 2 process (Guo et al. 2018). Semiconductor photocatalysis has been accepted as a cost-effective process for degradation and mineralization of pharmaceuticals and personal care products in water
because this process can be operated at ambient condition by using low-cost
available semiconductor photocatalysts and their modified forms, which can be
activated by UV light, visible light, as well as natural sunlight. Furthermore, the
immobilization of semiconductor photocatalysts on support material has been
proved as a promising way to enhance the recycling ability of them, resulting in
effective operating and maintenance cost (Klavarioti et al. 2009).
16
P. Kemacheevakul and S. Chuangchote
care products with their physical and chemical properties is shown in Table 1.4.
The environmental contamination of pharmaceuticals and personal care products
is caused by both intentional and unintentional discharge from many sources,
including households, industries, hospitals, sewage treatment plants, livestock
farms, and landfill leachate. The effluent discharge from sewage treatment plants
and industries is identified to be the predominant sources (Awfa et al. 2018).
Pharmaceuticals and personal care products are usually synthesized to be persistent,
high chemical stability, and low biodegradability, which cannot be completely
removed by conventional treatment processes. Although the occurrence of pharmaceuticals and personal care products in surface water, groundwater, tap water, as well
as drinking water is frequently detected at a trace concentration (ranging from ng/L
up to μg/L), the continuous exposure to these compounds can significantly lead to
adverse effects on aquatic living organisms, terrestrial organisms, and balance of
ecosystem (Jamil et al. 2017).
Many pharmaceuticals and personal care products behave as antimicrobial
agents; thus the biological degradation processes that use microorganisms to break
down organic pollutants in water seem to be ineffective to remove them. Physical
treatment processes such as adsorption and membrane filtration can only transfer
pharmaceuticals and personal care products from one medium to another medium
without the destruction of them, leading to the formation of secondary contaminants
in the form of spent adsorbents and concentrated water, respectively (Awfa et al.
2018). Nowadays, the chemical oxidation processes especially advanced oxidation
processes, involving photo-Fenton, ozonation, UV/H 2 O 2 , and semiconductor
photocatalysis, are accepted as the most promising potential treatment method for
removals of pharmaceuticals and personal care products. Unfortunately, degradation
of pharmaceuticals and personal care products by photo-Fenton and ozonation can
form toxic by-products (Wang and Wang 2016). The low UV absorbance of
hydrogen peroxide and scavenging effects of
•
OH by H 2 O 2 are the main drawbacks,
leading to high operating costs in the UV/H 2 O 2 process (Guo et al. 2018). Semiconductor photocatalysis has been accepted as a cost-effective process for degradation and mineralization of pharmaceuticals and personal care products in water
because this process can be operated at ambient condition by using low-cost
available semiconductor photocatalysts and their modified forms, which can be
activated by UV light, visible light, as well as natural sunlight. Furthermore, the
immobilization of semiconductor photocatalysts on support material has been
proved as a promising way to enhance the recycling ability of them, resulting in
effective operating and maintenance cost (Klavarioti et al. 2009).
16
P. Kemacheevakul and S. Chuangchote