340
R. Kumar et al.
method quantification limit (
It is notable that many ARGs, viz., bla SHV , sul1, bla KPC , ermB, intI1, bla NDM and
tetO, were present in the secondary effluent at significant levels (average concentration ~103 copies/mL). Predominantly, MBRs mitigated the ARGs with better
removal efficiencies than other processes. Xu et al. (2019) investigated the prevalence
of nine compounds classified under three clusters of frequently applied veterinary
antibiotics, viz., sulfonamides, tetracyclines and fluoroquinolones. The obliteration
of these antibiotics by sequencing-batch membrane bioreactor (SMBR) was investigated and found that the tetracyclines, and the sulfonamides were effectively reduced
by SMBR (>90%), while the removal efficiency of fluoroquinolones was <70%. Mass
balance analysis was done to substantiate the underlying mechanism, i.e., biodegradation/biotransformation. Besides, membrane retention and sludge adsorption was
also contributing factors for the antibiotic removal. It was adumbrated that out of
these three domains of antibiotics, fluoroquinolones and tetracyclines were more
susceptible to accrued in biosolids. Moreover, antibiotics were found to temporarily
perturb SMBR efficiency by restricting sludge growth and activity. The amount of
microbial by-products (soluble) and EPS in the slurry was also found to be elevated.
Nonetheless, swine wastewater was remediated with >60% obliteration of nutrients and organic matter by SMBR systems. Noticeably, the most persistent ARGs
in influents, like the macrolide resistance gene ermB, sul1 and int1 (concentrations
106.39–107.79 copies/mL), were profoundly depleted by MBR systems (1.5–7.3 log
removal) than conventional techniques such as sequencing batch reactor or oxidation
ditch (0.8–3.4 log removal) (Li et al. 2019). In conclusion, MBR eclipsed CAS in
the abrogating antibiotics, ARBs and target ARGs.
14.4 Conclusions
Comprehensive study of the underlying principal of AR removal in WWTPs and their
transport and persistence in drinking water and in the environment as such is of crucial importance for human health risk assessment. A number of latest techniques has
been engineered and are presently employed for water treatment (e.g., advanced oxidation processes, adsorption, micro- and ultra-filtration, nano-filtration, membrane
filtration, etc.), but their efficiency in AR removal and persistency is still poorly
understood. Also, strict guidelines, standards and permissible limits of wastewater
treatment plant effluents should be tabulated and followed to minimize the future
uncertainty of hazards related to AR. Thorough monitoring should be performed
on the excessive production and unethical disposal of surplus and expired antibiotics. In underdeveloped/developing countries, cost-effective cheap water treatment
techniques) are applied rather than traditional and super advanced wastewater treatment methods. Although, the effectiveness of cost-effective water treatment systems
on AR removal is scarcely perceived, may be due to lack of research, techniques
and analysis equipment in the poor countries. International collaborations between
researchers/institutes and companies from developing and developed countries will
R. Kumar et al.
method quantification limit (
It is notable that many ARGs, viz., bla SHV , sul1, bla KPC , ermB, intI1, bla NDM and
tetO, were present in the secondary effluent at significant levels (average concentration ~103 copies/mL). Predominantly, MBRs mitigated the ARGs with better
removal efficiencies than other processes. Xu et al. (2019) investigated the prevalence
of nine compounds classified under three clusters of frequently applied veterinary
antibiotics, viz., sulfonamides, tetracyclines and fluoroquinolones. The obliteration
of these antibiotics by sequencing-batch membrane bioreactor (SMBR) was investigated and found that the tetracyclines, and the sulfonamides were effectively reduced
by SMBR (>90%), while the removal efficiency of fluoroquinolones was <70%. Mass
balance analysis was done to substantiate the underlying mechanism, i.e., biodegradation/biotransformation. Besides, membrane retention and sludge adsorption was
also contributing factors for the antibiotic removal. It was adumbrated that out of
these three domains of antibiotics, fluoroquinolones and tetracyclines were more
susceptible to accrued in biosolids. Moreover, antibiotics were found to temporarily
perturb SMBR efficiency by restricting sludge growth and activity. The amount of
microbial by-products (soluble) and EPS in the slurry was also found to be elevated.
Nonetheless, swine wastewater was remediated with >60% obliteration of nutrients and organic matter by SMBR systems. Noticeably, the most persistent ARGs
in influents, like the macrolide resistance gene ermB, sul1 and int1 (concentrations
106.39–107.79 copies/mL), were profoundly depleted by MBR systems (1.5–7.3 log
removal) than conventional techniques such as sequencing batch reactor or oxidation
ditch (0.8–3.4 log removal) (Li et al. 2019). In conclusion, MBR eclipsed CAS in
the abrogating antibiotics, ARBs and target ARGs.
14.4 Conclusions
Comprehensive study of the underlying principal of AR removal in WWTPs and their
transport and persistence in drinking water and in the environment as such is of crucial importance for human health risk assessment. A number of latest techniques has
been engineered and are presently employed for water treatment (e.g., advanced oxidation processes, adsorption, micro- and ultra-filtration, nano-filtration, membrane
filtration, etc.), but their efficiency in AR removal and persistency is still poorly
understood. Also, strict guidelines, standards and permissible limits of wastewater
treatment plant effluents should be tabulated and followed to minimize the future
uncertainty of hazards related to AR. Thorough monitoring should be performed
on the excessive production and unethical disposal of surplus and expired antibiotics. In underdeveloped/developing countries, cost-effective cheap water treatment
techniques) are applied rather than traditional and super advanced wastewater treatment methods. Although, the effectiveness of cost-effective water treatment systems
on AR removal is scarcely perceived, may be due to lack of research, techniques
and analysis equipment in the poor countries. International collaborations between
researchers/institutes and companies from developing and developed countries will