Hospital Wastewater Treatment Research Articles

Global techno-economic analysis of MBR for hospital wastewater treatment

This study comprehensively examines and characterizes global membrane bioreactor (MBR) practices for hospital wastewater treatment, focusing on development trends, technical performance (pollutant removal and carbon emissions), and economic costs, including both capital expenditures (CAPEX) for civil engineering and equipment procurement, and operational expenditures (OPEX) for electricity, membrane replacement, labor, and chemical costs, as well as system footprint. The results show that MBR has been widely used for hospital wastewater treatment for over two decades, with global applications and scales significantly increasing, especially after the COVID-19 pandemic. A notable shift in membrane types has occurred, with hollow fiber membranes dominating before 2010 and flat inorganic membranes gaining prominence after 2020. MBR not only effectively removes conventional pollutants but also greatly reduces pathogens, ARBs and ARGs before disinfection, thus alleviating the subsequent disinfection burden. In addition, MBR is a crucial step in the process of completely removing emerging contaminants (ECs) that pose significant environmental and health risks. The CAPEX of MBR has decreased at the technical level in recent years. MBR requires only 62 % and 21 % of footprint for conventional activated sludge (CAS) and biofilm-based processes, respectively. MBR's land-saving advantage offsets the CAPEX gap with CAS in high land-cost areas. From before 2010 to after 2020, membrane costs saw the largest reduction in OPEX, dropping by 71 %, while electricity consumption saw a 10.71 % reduction, now comparable to biofilm-based processes. Currently, MBR's OPEX (0.158 USD/m3) is only slightly higher than that of biological contact oxidation (0.138 USD/m3). MBR also minimizes sludge production, reducing both treatment costs and associated disposal risks. MBR exhibit minimal concerns of excessive carbon emissions, with a carbon emission intensity (1.11 kg CO2eq·m−3), only slightly higher than biofilm-based processes (0.92 kg CO2eq·m−3). This study demonstrates that MBR is the valuable and practical solution for hospital wastewater treatment, as well as a preferred choice for upgrading existing facilities.

Evaluation of the Cytotoxicity Effects of Bacteriophage VbɸPA-1 on the Virulent Pseudomonas aeruginosa, A375 Human Skin Melanoma Epithelial, and HFSF PI3 Human Skin Fibroblast Cells

Background: Gram-negative bacteria are the most common infectious bacteria and are life-threatening in burn patients. Phage therapy studies can help the hospital community eliminate these bacterial pathogens. Objectives: This study aimed to evaluate the effects of the isolated bacteriophages from hospital wastewater against Gram-negative pathogenic bacteria and investigate their cytotoxicity on two human skin cell lines. Methods: The bacterial strains were isolated from burn wound infections. Bacteriophages were isolated from the hospital wastewater treatment plant in Isfahan, Iran. Transmission electron microscopy, spot tests, and restriction enzyme digestion were considered for phage identification. Finally, the lactate dehydrogenase (LDH) and tetrazolium-based MTT assays were used to realize the cytotoxicity impacts of the isolated phages. The statistical analysis of cell viability was performed using a two-way analysis of variance (ANOVA). Results: The results showed that among the isolated strains, P. aeruginosa strain NEG_RA1300 (GenBank accession number: MW845642) was sensitive to the isolated phage VbɸPA-1. The TEM results showed a possible viral taxonomy of VbɸPA-1 based on its morphology, which belonged to the Myoviridae (T4-like phages). The MTT and LDH experiments showed no cytotoxicity of VbɸPA-1 on two tested cell lines. Conclusions: Based on the results, the inhibitory effect of isolated phage on P. aeruginosa isolated from burn wounds with no toxic effect on cell lines was very significant. This phage can also be an acceptable selection against burn wound infections.

Nanotechnology strategy for inhibition of PARP1 and IL-17A-associated with neurotoxicity in rats exposed to hospital wastewater.

Hospital wastewater (HWW) poses a serious hazard to human health security concerning its high susceptibility to neurodegeneration. Water sources and ecosystems are exposed to a complicated pollution load from a variety of refractory organics and pharmaceutical active composites. This study evaluates the treated newly developed nanocomposite (NiFe2O4) HWW on the neural injury induced by HWW action in rats. Three groups of male Wistar rats were distributed, with eight rats in each: group I: tap water served as a control; group II: HWW; and group III: nano-HWW. Each group was intragastrical administrated with each type of water (2.5 ml/100 g b.wt/6 h) for 28 consecutive days. The open field test and Morris Water Maze assessed behavioral activity and spatial learning 2 days before the last day. The research demonstrated that HWW treated with nanocomposite (NiFe2O4) may exert decreased risks of the neural impairment effect of HWW. This improvement was achieved by reducing the neurotoxicity by lowering nitric oxide contents, lipid peroxidation, acetylcholinesterase, interleukin-17A (IL-17A), and poly(ADP-ribose) polymerase1(PARP1) while restoring the antioxidant biomarkers and neurotransmitter levels (β-endorphin, norepinephrine, dopamine, and serotonin) of the treated groups in the cortex and brainstem and enhancement of the histopathology of the cortex as well. In conclusion, this study introduced a newly developed nanotechnology application for treating HWW to protect from neural injury. The findings of this research have significant value for policymakers, Ministry of Health management, and environmental organizations in their selection of suitable techniques and procedures to optimize hospital wastewater treatment efficiency.

Evaluation of the Efficiency of Hospital Wastewater Treatment Systems and Stations in the Atlantic and Littoral Departments of Benin

Evaluation of the Efficiency of Hospital Wastewater Treatment Systems and Stations in the Atlantic and Littoral Departments of Benin

An innovative combination of anodic oxidation using Cu/SnO2–Sb2O5 rotating cylinder anode with TiO2 photocatalytic process for treating hospital wastewater

Treatment of hospital wastewater was achieved successfully using a novel combined process composed of an anodic oxidation with Cu/SnO2–Sb2O5 rotating cylinder anode and a photocatalysis process with titanium oxide nanoparticles. Cu/SnO2–Sb2O5 anode and TiO2 nanoparticles were characterized by x-ray diffractometer (XRD) and scanning electron microscopy (SEM). The feasibility of the combined process was evaluated using response surface methodology (RSM). Three operating factors were studied namely current density (10–20 mA/cm2), pH (4–8), and TiO2 dosage (0.3–0.7 g/L). Results showed that current density has the major effect on the COD removal with a contribution percent of 40 %. The optimal conditions were current density of 20 mA/cm2, pH of 4, and TiO2 dosage of 0.7 g/L in which COD removal of 91.2 % was achieved with claiming a total electrical energy (EECT) of 39.41 kWh/ m3. An interesting synergistic effect with a synergy of 21.26 % was recognized in the combined process due to the high productivity of hydroxyl radicals resulting from the interaction between the individual processes. Results confirmed that coupling anodic oxidation with photoctalysis is a promising method for treating hospital wastewater.

N-coordinated iron sites dispersed in porous carbon frameworks to activate peroxymonosulfate for efficient sulfisoxazole degradation and real hospital wastewater decontamination

Herein, an N-coordinated Fe site dispersed in porous carbon frameworks (Fe-NC) fabricated from zeolitic imidazolate frameworks encapsulated with iron acetylacetonate (Fe(acac)3 @ZIFs) was employed to activate peroxymonosulfate (PMS) for the attenuation of sulfisoxazole (SIZ) and treating real hospital wastewater. The constructed Fe-NC/PMS system exhibited good catalytic stability for SIZ degradation, maintaining excellent degradation performance over multiple cycles with virtually no leaching. The quenching experiments, electron paramagnetic resonance (EPR) capture analyses, and semi-quantitative measurements showed that singlet oxygen (1O2) and high-valent metal-oxo species were mainly responsible for SIZ degradation by Fe-NC/PMS. Significantly, ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) was used to trace 134 pharmaceutical contaminants in real hospital wastewater. Effective degradation was achieved for 87 % of the pharmaceutical contaminants by the Fe-NC/PMS process. Seventy-four pharmaceutical contaminants were eliminated. Taken together, this work successfully established the Fe-NC/PMS technology using the developed iron-based materials and explored its application to real hospital wastewater treatment, providing an eco-friendly and effective strategy for treating wastewater.

Risk Assessment of Hospital Waste Water Treatment Plant Operation – A Case Study of a Class B Hospital in Indonesia

Risk Assessment of Hospital Waste Water Treatment Plant Operation – A Case Study of a Class B Hospital in Indonesia

Antibiotic resistance genes and crAssphage in hospital wastewater and a canal receiving the treatment effluent

Hospital wastewater is a major hotspot for the spread of antimicrobial resistance (AMR) in aquatic ecosystems. This study aimed to investigate the prevalence of antibiotic resistance genes (ARGs) and their correlation with crAssphage in a hospital wastewater treatment plant (HWWTP) and a receiving canal. Water samples were analyzed for 94 ARGs and crAssphage relative to the 16S rRNA using high-throughput quantitative polymerase chain reaction (HT-qPCR). Subsequently, 7 ARGs and crAssphage were selected and quantified using qPCR. The results showed that the detected genes ranged from 79 to 93 out of 95 genes. The raw wastewater (WW) samples had the highest gene diversity compared to the upstream canal, which had less diversity than downstream samples, as determined by HT-qPCR. The blaGES was the most abundant in WW samples, while qacEΔ1, merA, IS6100, tnpA, and IS26 showed high prevalence throughout the treatment processes. The concentrations of intI1, sul1, blaTEM,blaNDM,blaVIM,tetQ, mcr-1, crAssphage, and 16S rRNA, measured using qPCR, were the highest in WW and significantly reduced in treated water samples. Although some water quality parameters, such as total suspended solids and dissolved oxygen, did not significantly differ before and after treatment, removal efficiency ranged from 0.60 to 3.23 log reduction values (LRV). The highest LRV was observed for the tetQ, whereas the mcr-1 had the lowest LRV. Strong positive correlations among the absolute concentrations of ARGs and crAssphage were observed (Spearman's rho = 0.6–1.0), and biochemical oxygen demand correlated with blaTEM and blaVIM (Spearman's rho = 0.6). These results indicate that crAssphage and water quality could reflect the distribution of other ARGs throughout the HWWTP. Further studies are needed to underscore the importance of monitoring ARGs and genetic markers such as crAssphage in HWWTPs and their receiving waters to enhance our understanding of ARG distribution.

Zn-Al@LDH infused hydrochar as cathode catalyst for upgrading tetracycline degradation and hospital wastewater treatment: A synergy of Fenton-like and bio-electrochemical systems

The present investigation proposed a “Bio-electro-Fenton like (BEFL)” approach for the treatment of antibiotic (tetracycline, TC) containing wastewater. The system is modified using a uniquely developed cathode catalyst Zn-Al@layered double hydroxide (LDH) supported by low-cost carbonaceous material hydrochar (i.e., Zn-Al@LDH/HC), derived from anaerobic digestate and electrocoagulation sludge (waste materials). The result revealed nearly 96.90 ± 0.25 % removal of 10 mg/L of TC as well as about 89.50 ± 0.45 % abatement of total organic carbon (TOC) during 240 min of treatment time using Zn-Al@LDH/HC based BEFL system. Simultaneously, the chemical oxygen demand (COD) abatement in the anodic chamber (with glucose as substrate having COD of 1000 mg/L) was observed to be 85.16 ± 0.50 %. In-situ hydrogen peroxide (46.2 ± 1.2 mg/L as mean 4 h concentration) generation capability of the Zn-Al@LDH/HC was responsible for the outstanding performance of BEFL system. Additionally, the BEFL was also proficient in generation of bioelectricity (1141 ± 25 mA/m2) via the microbial activity in the anodic chamber. Further, the technology was extended for TC degradation in presence of surfactants and real hospital wastewater to depict the effect of real field conditions on the performance of as-synthesized waste derived catalyst. Intermediate products formed, the mechanism of TC degradation, and the phytotoxicity assessment were also illustrated to confirm the negligible toxicity of the treated effluent. Overall, deriving the catalyst from waste materials would reduce the scale-up cost of the proposed technology, enhance environmental sustainability, and contribute to circular economy.

Exploring the adsorptive potential of chemically activated Nanoporous carbons derived from invasive goat weed for treatment of hospital wastewater

Nanoporous activated carbons synthesized from goat-weed (Ageratum Conyzoides) using single-step pyrolytic chemical-activation with ZnCl2 and H3PO4 at various ratios. Nano-textural properties of samples assessed through N2 adsorption/desorption, XRD, SEM, and FTIR. ZnCl2 activation led to a high microporosity and maximum surface-area of 1699 m2·g−1 and total pore-volume of 1.23 cm3·g−1 (Zn/biomass ratio 1:1), while H3PO4 activation yielded 866 m2·g−1 and 1.24 cm3·g−1, respectively (P/biomass ratio 1.5:1). The adsorption capacity of samples follows surface-area variations of samples. During treatment of hospital wastewater, ZnCl2-activated carbon removed 90–93 % of pollutants, comparable to commercial carbon, while H3PO4-activated carbon removed 85–88 %. The adsorption mechanism of carbons during interaction with HWW contaminants was discussed to explain variation in removal efficiency.

Surveillance of influenza A and B viruses from community and hospital wastewater treatment plants.

Influenza virus is a well-known pathogen that can cause epidemics and pandemics. Several surveillance methods are being followed to monitor the transmission patterns and spread of influenza in the community. Wastewater-based Epidemiology (WBE) can serve as an additional tool to detect the presence of influenza viruses. The current study primarily focuses on surveillance of Influenza A and Influenza B in wastewater treatment plant (WWTP) samples. A total of 100 wastewater samples were collected in July (n = 50) and August (n = 50) 2023 from four different WWTPs in Manipal and Udupi, district of Karnataka, India. The WWTP samples were processed and tested by Real-Time reverse transcriptase PCR (RT-PCR). The data generated was analysed in comparison with the clinical Influenza cases. Of the 100 samples, 18 (18%) tested positive for Influenza A virus and 2 (2%) tested positive for Influenza B virus, with a viral load ranging 1.4 x 102-2.2 x 103 gc/L for influenza A virus and 5.2 x 103-7.7 x 103gc/L for influenza B virus. On correlating the WWTP positivity with clinical case, it was found that influenza clinical cases and virus positivity in wastewater increased simultaneously, emphasizing WBE as a concurrent method for monitoring influenza virus activity.

On-Site Inactivation for Disinfection of Antibiotic-Resistant Bacteria in Hospital Effluent by UV and UV-LED.

The problem of antimicrobial resistance (AMR) is not limited to the medical field but is also becoming prevalent on a global scale in the environmental field. Environmental water pollution caused by the discharge of wastewater into aquatic environments has caused concern in the context of the sustainable development of modern society. However, there have been few studies focused on the treatment of hospital wastewater, and the potential consequences of this remain unknown. This study evaluated the efficacy of the inactivation of antimicrobial-resistant bacteria (AMRB) and antimicrobial resistance genes (AMRGs) in model wastewater treatment plant (WWTP) wastewater and hospital effluent based on direct ultraviolet (UV) light irradiation provided by a conventional mercury lamp with a peak wavelength of 254 nm and an ultraviolet light-emitting diode (UV-LED) with a peak emission of 280 nm under test conditions in which the irradiance of both was adjusted to the same intensity. The overall results indicated that both UV- and UV-LED-mediated disinfection effectively inactivated the AMRB in both wastewater types (>99.9% after 1-3 min of UV and 3 min of UV-LED treatment). Additionally, AMRGs were also removed (0.2-1.4 log10 for UV 254 nm and 0.1-1.3 log10 for UV 280 nm), and notably, there was no statistically significant decrease (p < 0.05) in the AMRGs between the UV and UV-LED treatments. The results of this study highlight the importance of utilizing a local inactivation treatment directly for wastewater generated by a hospital prior to its flow into a WWTP as sewage. Although additional disinfection treatment at the WWTP is likely necessary to remove the entire quantity of AMRB and AMRGs, the present study contributes to a significant reduction in the loads of WWTP and urgent prevention of the spread of infectious diseases, thus alleviating the potential threat to the environment and human health risks associated with AMR problems.

Solar powered membrane bioreactor (MBR) treating wastewater for reuse at a hospital in Kampala, Uganda – Results of pilot-scale trials

A robust and cost-effective pilot solar-powered membrane bioreactor (MBR) with downstream granular activated carbon (GAC) filter hospital wastewater treatment was developed for the Lubaga hospital in Kampala, Uganda. The MBR-GAC pilot included a 25 m2 ultrafiltration (UF) module, a 100 kg GAC filter, 20 photovoltaic panels totaling 7 kWp and a 3.55 kWh supercapacitor energy storage unit to produce non-potable and reusable water for toilet flushing, cleaning and irrigation. The pilot operated with 43% clean energy autonomy with grid and diesel generator backup for power outages of more than 1 hour. The MBR pilot produced an average flux of 10–15 L m–2 h–1 with 50% total organic carbon (TOC) removal. The nitrification, denitrification and filtration tanks were separated to achieve a nitrification of 80% and denitrification of 20%. The removal of typical hospital pharmaceutical residues that could not be reduced by the MBR increased to approximately 90% after the downstream GAC filter was upgraded. The removal efficiency of the GAC decreased to approximately 25% at 4,290 bed volume (BV). The significant increase of 75% in the removal efficiency of diclofenac in the MBR was attributed to the acclimation of the activated sludge. The quality of the treated wastewater from the pilot plant was sufficient for reuse by irrigation of the hospital garden, toilet flushing and cleaning. Finally, the study discussed ways to optimize the design and operation of the plant. The pilot is scalable to be replicated elsewhere and adapted in an efficient and cost-effective manner in sub-Saharan countries in Africa.

Unveiling the genomic diversity and ecological impact of phage communities in hospital wastewater

Phages are pivotal in shaping microbial communities and biogeochemical cycles, while our understanding of the diversity, functions potential, and resistance gene carriage of phages in hospital wastewater (HWW) remains limited. We collected influent and effluent samples from the 3 hospital wastewater treatment plants (HWTPs) to assess the diversity and fate of phages, the interactions between phages and hosts, and the presence of resistance genes and auxiliary metabolic genes (AMGs) encoded by phages. Compared to influent, effluent showed reduced phage abundance and altered composition, with decreases in Microviridae and Inoviridae. The gene-sharing network highlights that many phages in HWW are not classified in known viral genera, suggesting HWW as a rich source of new viruses. There was a significant association between phages and microorganisms, with approximately 32.57 % of phages expected to be capable of infecting microbial hosts, characterized primarily by lytic activity. A total of 8 unique antibiotic resistance genes, 13 unique metal resistance genes, and 5 mobile genetic elements were detected in 3 HWTPs phageomes. Phage AMGs have the potential to influence carbon, nitrogen, phosphorus, and sulfur metabolism, impacting biogeochemical cycles. This study reveals the genomic diversity and ecological role of phages in HWTPs, highlighting their environmental and ecosystem impact.

Comparative analysis of bioaerosol emissions: Seasonal dynamics and exposure risks in hospital vs. municipal wastewater treatment systems

Hospital wastewater is known to contain various pathogenic microorganisms and harmful substances. During the hospital wastewater treatment process, the bioaerosols released may encapsulate these pathogens, leading to human infection. This study undertook an investigation to compare the dispersion characteristics and seasonal variations of bioaerosols from hospital and municipal sewage. The results indicated that the airborne bacterial concentration from hospital sewage (119 ± 118 CFU/m3) was higher than municipal sewage (46 ± 19 CFU/m3), with the highest concentration observed in summer. The dominant bacterial genera present in bioaerosols from both sewages were alike, with the proportions varied by sewage types and the structure mainly influenced by seasonal factors. Bacteroides, Escherichia-Shigella and Streptococcus were identified as the most prevalent pathogenic genera in spring, summer and winter bioaerosols, respectively, while Pseudomonas and Acinetobacter were abundant in autumn. Although the non-carcinogenic risk associated with bioaerosols was low (<1), the presence of pathogenic species and their potential synergistic interactions elevated the overall exposure risk. The diffusion modeling results demonstrated that bioaerosol emissions from the surface of hospital sewage can reach up to 10570 CFU/m3 in summer and can spread more than 300 m downwind. The potential pathogenicity of bioaerosols was also highest in summer, which may pose a health hazard to populations located downwind. Therefore, the management and control of bioaerosols from sewage should be strengthened, especially in summer.

Drugs Removal from Wastewater with Activated Carbon from Coffee Waste

Today, pharmaceutical residues constitute most of the problem in the water contamination because they are active principles which are able to act at low quantities, and they are usually recalcitrant to the conventional wastewater treatment. Hospital effluent is the main source of the environmental contamination by pharmaceuticals due to their excessive use in medical establishments. In our study, we collected the coffee grounds from Dubai cafes which was washed and then carbonized, and this carbonized product will be cooled and sieved. We will evaluate the ability of this unique activated carbon in decontaminating hospital effluents and eliminating pharmaceutical compounds. This filtration is carried out by the adsorption process on the pores generated by the activation of carbon in a prototype designed for this purpose. The chromatographic analysis will confirm the expected results. In fact, many pharmaceuticals were completely disappeared from hospital effluent after the treatment with coffee grounds and for other drugs the removal of the chemical compounds exceeded 90%. The developed technique which is based on the production of activated carbon from coffee grounds can have two major advantages: the recovery of one waste (coffee grounds) for the treatment of another waste hospital wastewater and completely clear of pharmaceuticals.

Microbiological Surveillance of Salmonella Strains in the Effluents of the Teaching Hospital (CHU) of Yopougon and Cocody, Côte d'Ivoire

Diarrhoeal diseases are a major public health problem worldwide, with salmonellosis being a leading cause of foodborne illness in humans. Environmental pollution from healthcare activities, particularly from the discharge of hospital effluent into urban sewer systems, poses a significant threat. These effluents can carry microorganisms, antibiotic residues and detergents that contribute to the development and spread of bacterial multiresistance. In Abidjan, the capital of Côte d'Ivoire, hospital wastewater is not treated before being discharged into the sewer system. This untreated wastewater eventually flows into the Ebrié lagoon, a critical water source for many local communities. The dependence of the lagoon's population on these waters raises significant public health concerns, particularly with regard to potential contamination with pathogenic bacteria such as Salmonella. The aim of this study was to assess the presence of Salmonella in hospital wastewater to understand the risk of contamination and to inform potential mitigation strategies. A total of 60 wastewater samples were collected: 30 from the teaching hospital (CHU) of Yopougon and 30 from Cocody. Upon analysis, no Salmonella sp strains were detected in any of the samples. However, 28 bacterial strains exhibiting characteristics similar to Salmonella were isolated, suggesting the presence of potentially virulent pathogens. In Yopougon's samples, 14 strains of Proteus mirabilis and 2 strains of Klebsiella sp were identified. In Cocody 's samples, 12 strains of Citrobacter freundii sp were isolated. These findings highlight the importance of monitoring and treating hospital wastewater to prevent the spread of potentially harmful bacteria into the environment.

Presence and Persistence of ESKAPEE Bacteria before and after Hospital Wastewater Treatment.

The metagenomic surveillance of antimicrobial resistance in wastewater has been suggested as a methodological tool to characterize the distribution, status, and trends of antibiotic-resistant bacteria. In this study, a cross-sectional collection of samples of hospital-associated raw and treated wastewater were obtained from February to March 2020. Shotgun metagenomic sequencing and bioinformatic analysis were performed to characterize bacterial abundance and antimicrobial resistance gene analysis. The main bacterial phyla found in all the samples were as follows: Proteobacteria, Bacteroides, Firmicutes, and Actinobacteria. At the species level, ESKAPEE bacteria such as E. coli relative abundance decreased between raw and treated wastewater, but S. aureus, A. baumannii, and P. aeruginosa increased, as did the persistence of K. pneumoniae in both raw and treated wastewater. A total of 172 different ARGs were detected; blaOXA, blaVEB, blaKPC, blaGES, mphE, mef, erm, msrE, AAC(6'), ant(3″), aadS, lnu, PBP-2, dfrA, vanA-G, tet, and sul were found at the highest abundance and persistence. This study demonstrates the ability of ESKAPEE bacteria to survive tertiary treatment processes of hospital wastewater, as well as the persistence of clinically important antimicrobial resistance genes that are spreading in the environment.

Impact of health index and hospitals on dissemination of antibiotic resistance in two sewersheds of the third largest metropolitan region of Brazil

Antimicrobial resistance (AMR) stands as a critical threat to global public health. Wastewater-based epidemiology (WBE) provides health data within communities via sewage analysis. This study delved into antibiotic resistance prevalence across two sewersheds in Belo Horizonte, each with distinct health vulnerability indexes (HVI) and number of hospitals. Bacteria resistant (ARB) to amoxicillin, azithromycin, cephalexin, sulfamethoxazole + trimethoprim, meropenem and ARGs (Intl1, sul1, blaTEM, blaKPC) were quantified in sewage from the two sewersheds over the years from 2020 to 2023. Statistical analysis revealed no significant differences in median concentrations of ARBs between sewersheds, except for bacteria resistant to meropenem. ARGs Investigated exhibited similar patterns, with blaKPC showing statistical significant difference. This suggests that hospital density within a sewershed exerts a more pronounced influence on AMR dissemination than HVI. The difference found in meropenem-resistant bacteria, a hospital-prescribed carbapenem, and blaKPC concentrations underscores the impact of hospital antibiotic usage. Thus, the presence and number of hospitals emerges as a pivotal factor in AMR spread, emphasizing the need for specific treatment and management of hospital wastewater to curb antimicrobial resistance.

Dynamics of antimicrobial resistance and susceptibility profile in full-scale hospital wastewater treatment plants.

Drug resistance has become a matter of great concern, with many bacteria now resist multiple antibiotics. This study depicts the occurrence of antibiotic-resistant bacteria (ARB) and resistance patterns in five full-scale hospital wastewater treatment plants (WWTPs). Samples of raw influent wastewater, as well as pre- and post-disinfected effluents, were monitored for targeted ARB and resistance genes in September 2022 and February 2023. Shifts in resistance profiles of Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii antimicrobial-resistant indicators in the treated effluent compared to that in the raw wastewater were also worked out. Ceftazidime (6.78 × 105 CFU/mL) and cefotaxime (6.14 × 105 CFU/mL) resistant species showed the highest concentrations followed by ciprofloxacin (6.29 × 104 CFU/mL), and gentamicin (4.88 × 104 CFU/mL), in raw influent respectively. WWTP-D employing a combination of biological treatment and coagulation/clarification for wastewater decontamination showed promising results for reducing ARB emissions from wastewater. Relationships between treated effluent quality parameters and ARB loadings showed that high BOD5 and nitrate levels were possibly contributing to the persistence and/or selection of ARBs in WWTPs. Furthermore, antimicrobial susceptibility tests of targeted species revealed dynamic shifts in resistance profiles through treatment processes, highlighting the potential for ARB and ARGs in hospital wastewater to persist or amplify during treatment.