antibiotic-resistance bacteria (Jia et al. 2012; Michael et al. 2013; Rizzo et al. 2013).
In South China, the removal efficiency of eleven classes of pharmaceutical compounds in WWTPs in Guangdong varied and ranged from 21 to 100% (Zhou et al.
2013). Furthermore, sulfonamide has gained more attention due to its distribution
pattern between water and sediments. Although it was detected significantly in
sludge and wastewater, many studies refer to its occurrence in the outlet of sediment
and agriculture. This is due to low water distribution coefficient (K d ), which poses
the low sorption affinity to water and sediment particles (Thiele-Bruhn 2003). In
China, the most common antibiotic used for human and animal body is
fluoroquinolones, which can enter the aquatic system via urine and ultimately the
environment though wastewater (Renew and Huang 2004). The massive consumption of fluoroquinolones resulted in development of fluoroquinolone-resistance
bacteria initiated from livestock to wastewater and from municipal STPs, hospitals,
and rivers to effluent and sewage sludge (Reinthaler et al. 2003; Polk et al. 2004; Hu
et al. 2008; Taylor et al. 2008).
In WWTPs, the combined sewage from hospitals and other places is subjected to
several biological and physicochemical processes for biodegradation, where the
number of pathogens is reduced, and nitrogen and phosphorous are removed prior
to discharge in surface water; however, sewage acting as a special nutrient-rich
environment, with high bacterial density, antibiotics, boosts the antibiotic resistance
in bacteria, and antibiotic-resistance genes (Szczepanowski et al. 2009; Ju et al.
2019). As a consequence, sewage is considered as an initiator for development,
recombination, and distribution of antibiotic resistance (Rizzo et al. 2013). Furthermore, WWTPs are not particularly designed to eliminate antibiotic-resistance genes,
although the biomass of pathogens is decreased through WWTPs, and strong
selection for antibiotics may occur during treatment processes, which may eventually increase the fraction of resistant pathogens (Hocquet et al. 2016; Bürgmann et al.
2018). The richness of antibiotic-resistance bacteria and antibiotic-resistance genes
is highly reduced in the water portion of sewage, whereas their abundance is more in
biosolids used as a fertilizer for crops (Munir et al. 2011; Chen and Zhang 2013;
Yang et al. 2014). Most notably the different kinds of sewage treatments employed
in WWTPs, such as anaerobic digestion, drying, and application to agricultural soils,
may limit the abundance of antibiotic-resistance genes in both effluent and biosolids
to some extent (Diehl and Lapara 2010).
3.4.4 Occurrence in Groundwater
The ground water bodies are exposed to antibiotic contamination by artificial
man-made activities. Soil acts as a natural barrier to curb the contaminant into the
subsurface water; however, if the contamination occurs, it is difficult to suppress its
impact. Pollutants could be administered to the groundwater by many sources, such
as infiltration of wastewater, natural bank filtration, water supply pipes, and rainfall.
In Spain, chemical pollutant in the aquifers of rural and urban area was examined
52
H. H. Al-Haideri et al.
In South China, the removal efficiency of eleven classes of pharmaceutical compounds in WWTPs in Guangdong varied and ranged from 21 to 100% (Zhou et al.
2013). Furthermore, sulfonamide has gained more attention due to its distribution
pattern between water and sediments. Although it was detected significantly in
sludge and wastewater, many studies refer to its occurrence in the outlet of sediment
and agriculture. This is due to low water distribution coefficient (K d ), which poses
the low sorption affinity to water and sediment particles (Thiele-Bruhn 2003). In
China, the most common antibiotic used for human and animal body is
fluoroquinolones, which can enter the aquatic system via urine and ultimately the
environment though wastewater (Renew and Huang 2004). The massive consumption of fluoroquinolones resulted in development of fluoroquinolone-resistance
bacteria initiated from livestock to wastewater and from municipal STPs, hospitals,
and rivers to effluent and sewage sludge (Reinthaler et al. 2003; Polk et al. 2004; Hu
et al. 2008; Taylor et al. 2008).
In WWTPs, the combined sewage from hospitals and other places is subjected to
several biological and physicochemical processes for biodegradation, where the
number of pathogens is reduced, and nitrogen and phosphorous are removed prior
to discharge in surface water; however, sewage acting as a special nutrient-rich
environment, with high bacterial density, antibiotics, boosts the antibiotic resistance
in bacteria, and antibiotic-resistance genes (Szczepanowski et al. 2009; Ju et al.
2019). As a consequence, sewage is considered as an initiator for development,
recombination, and distribution of antibiotic resistance (Rizzo et al. 2013). Furthermore, WWTPs are not particularly designed to eliminate antibiotic-resistance genes,
although the biomass of pathogens is decreased through WWTPs, and strong
selection for antibiotics may occur during treatment processes, which may eventually increase the fraction of resistant pathogens (Hocquet et al. 2016; Bürgmann et al.
2018). The richness of antibiotic-resistance bacteria and antibiotic-resistance genes
is highly reduced in the water portion of sewage, whereas their abundance is more in
biosolids used as a fertilizer for crops (Munir et al. 2011; Chen and Zhang 2013;
Yang et al. 2014). Most notably the different kinds of sewage treatments employed
in WWTPs, such as anaerobic digestion, drying, and application to agricultural soils,
may limit the abundance of antibiotic-resistance genes in both effluent and biosolids
to some extent (Diehl and Lapara 2010).
3.4.4 Occurrence in Groundwater
The ground water bodies are exposed to antibiotic contamination by artificial
man-made activities. Soil acts as a natural barrier to curb the contaminant into the
subsurface water; however, if the contamination occurs, it is difficult to suppress its
impact. Pollutants could be administered to the groundwater by many sources, such
as infiltration of wastewater, natural bank filtration, water supply pipes, and rainfall.
In Spain, chemical pollutant in the aquifers of rural and urban area was examined
52
H. H. Al-Haideri et al.