Hospital Wastewater Effluents Research Articles

Application of Fabric Phase Sorptive Extraction as a Green Method for the Analysis of 10 Anti-Diabetic Drugs in Environmental Water Samples

Due to the increased prevalence of diabetes, the consumption of anti-diabetic drugs for its treatment has likewise increased. Metformin is an anti-diabetic drug that is commonly prescribed for patients with type 2 diabetes and has been frequently detected in surface water and wastewaters, thus representing an emerging contaminant. Metformin can be prescribed in combination with other classes of anti-diabetic drugs; however, these drugs are not sufficiently investigated in environmental samples. Fabric phase sorptive extraction (FPSE) has emerged as a simple and green method for the extraction of analytes in environmental samples. In this study, FPSE coupled with a high-performance liquid chromatography diode array detector (HPLC-DAD) was employed for the simultaneous analysis of different classes of anti-diabetic drugs (metformin, dapagliflozin, liraglutide, pioglitazone, gliclazide, glimepiride, glargine, repaglinide, sitagliptin, and vildagliptin) in environmental water samples. Four different fabric membranes were synthesized but the microfiber glass filter coated with sol-gel polyethylene glycol (PEG 300) was observed to be the best FPSE membrane. The parameters affecting the FPSE process were optimized using a combination of one-factor-at-a-time processes and the design of experiments. The FPSE was evaluated as a green extraction method, based on green sample preparation criteria. The FPSE-HPLC-DAD method achieved acceptable validation results and was applied for the simultaneous analysis of anti-diabetic drugs in surface and wastewater samples. Glimepiride was detected below the quantification limit in both lake and river water samples. Dapagliflozin, liraglutide, and glimepiride were detected at 69.0 ± 1.0 μg·L−1, 71.9 ± 0.4 μg·L−1, and 93.9 ± 1.3 μg·L−1, respectively, in the city wastewater influent. Dapagliflozin and glimepiride were still detected below the quantification limit in city wastewater effluent. For the hospital wastewater influent, metformin and glimepiride were detected at 1158 ± 21 μg·L−1 and 28 ± 0.8 μg·L−1, respectively, while only metformin (392.6 ± 7.7 μg·L−1) was detected in hospital wastewater effluent.

Analysis of chlorhexidine, antibiotics and bacterial community composition in water environments from Brazil, Cameroon and Madagascar during the COVID-19 pandemic

The widespread of chlorhexidine and antibiotics in the water bodies, which grew during the global COVID-19 pandemic, can increase the dispersion of antibiotic resistance. We assessed the occurrence of these pharmaceutical compounds as well as SARS-CoV-2 and analysed the bacterial community structure of hospital and urban wastewaters from Brazil, Cameroon, and Madagascar. Water and wastewater samples (n = 59) were collected between January–June 2022. Chlorhexidine, azithromycin, levofloxacin, ceftriaxone, gentamicin and meropenem were screened by Ultra-High-Performance Liquid Chromatography coupled with mass spectrometer. SARS-CoV-2 was detected based on the nucleocapsid gene (in Cameroon and Madagascar), and envelope and spike protein-encoding genes (in Brazil). The total community-DNA was extracted and used for bacterial community analysis based on the 16S rRNA gene. To unravel likely interaction between pharmaceutical compounds and/or SARS-CoV-2 with the water bacterial community, multivariate statistics were performed. Chlorhexidine was found in hospital wastewater effluent from Brazil with a maximum concentration value of 89.28 μg/L. Additionally, antibiotic residues such as azithromycin and levofloxacin were also present at concentrations between 0.32–7.37 μg/L and 0.11–118.91 μg/L, respectively. In Cameroon, azithromycin was the most found antibiotic present at concentrations from 1.14 to 1.21 μg/L. In Madagascar instead, ceftriaxone (0.68–11.53 μg/L) and levofloxacin (0.15–0.30 μg/L) were commonly found. The bacterial phyla statistically significant different (P < 0,05) among participating countries were Proteobacteria, Patescibacteria and Dependentiae which were mainly abundant in waters sampled in Africa and, other phyla such as Firmicutes, Campylobacterota and Fusobacteriota were more abundant in Brazil. The phylum Caldisericota was only found in raw hospital wastewater samples from Madagascar. The canonical correspondence analysis results suggest significant correlation of azithromycin, meropenem and levofloxacin with bacteria families such as Enterococcaceae, Flavobacteriaceae, Deinococcaceae, Thermacetogeniaceae and Desulfomonilaceae, Spirochaetaceae, Methanosaetaceae, Synergistaceae, respectively. Water samples were also positive for SARS-CoV-2 with the lowest number of hospitalized COVID-19 patients in Madagascar (n = 7) and Brazil (n = 30). Our work provides new data about the bacterial community profile and the presence of pharmaceutical compounds in the hospital effluents from Brazil, Cameroon, and Madagascar, whose limited information is available. These compounds can exacerbate the spreading of antibiotic resistance and therefore pose a risk to public health.

Removal of antibiotics, bacterial toxicity, and occurrence of antibiotic resistance genes in secondary hospital effluents treated with granular activated carbon and the impact of preceding chlorination

This comprehensive investigation highlighted the complex adsorption behaviors of antibiotics onto granular activated carbon (GAC), the effectiveness of this adsorption in reducing bacterial toxicity, and the reduction of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) in hospital wastewater (HWW) effluents. Six GACs were characterized for their physicochemical properties, and their ability to adsorb six antibiotics in the background matrix of actual HWW was evaluated. Coconut shell-derived GAC (Co-U), which had the highest hydrophobicity and lowest content of oxygen-containing acidic functional groups, demonstrated the highest adsorption capacities for the tested antibiotics. Bacterial toxicity tests revealed that GACs could eliminate the bacterial toxicity from antibiotic intermediates present in chlorinated HWW. By contrast, the bacterial toxicity could not be removed by GACs in non-chlorinated HWW due to the greater presence of intermediate components identified by LC-MS/MS. The intraparticle diffusion coefficient of antibiotics adsorbed onto Co-U could be calculated by adsorption kinetics derived from the linear driving force model and the homogenous intraparticle diffusion model associated with the linear adsorption isotherms (0–150 μg/L). Meropenem and sulfamethoxazole exhibited the highest adsorption capacities in a single-solute solution compared to penicillin G, ampicillin, cetazidime, and ciprofloxacin. However, the greater adsorption capacities of meropenem and sulfamethoxazole disappeared in mixed-solute solutions, indicating the lowest adsorption competition. GAC can eliminate most ARGs while also promoting the growth of some ARB. Chlorination (free chlorine residues at 0.5 mg Cl2/L) did not significantly affect the overall composition of ARGs and ARB in HWW. However, the accumulation of ARGs and ARB on GAC in fixed bed columns was lower in chlorinated HWW than in non-chlorinated HWW due to an increase in the adsorption of intermediates.

Natural clays as adsorbents for the efficient removal of antibiotic ciprofloxacin from wastewaters: Experimental and theoretical studies using DFT method

Natural clays were used as adsorbent to remove ciprofloxacin from aqueous solutions by adsorption. The textural, structural, and morphological properties were examined, finding low-moderate specific surface area values (9.9–50.1 m2g−1) and a structure coincident with the smectite phase. Adsorption kinetic studies revealed that clay 3 and 4 reached a CIP removal around 70–80 % in 7–8 h. Elovich and pseudo-second-order models were the most suitable to describe the kinetics. The highest equilibrium adsorption capacities (qe = 150.2–193.7 mg g−1) were obtained for clay 1, 3, and 4; the lowest (qe = 30.6 mg g−1) was found for clay 2, which showed the highest-ordered structure. The Freundlich adsorption model led to the best-fitting results. From pH studies, working at solution pH = 4.0 led to the best adsorption results. The estimated thermodynamic parameters suggested that the adsorption process can be considered of physical nature. It was found that the high concentration of CO32– salts in the hospital wastewater effluent enhanced the CIP adsorption capacity, showing a CIP removal of about 95 % for the clay 3. Therefore, the adsorbent with the greatest compromise situation among all the variables was clay 3, presenting the maximum CIP removal after 7 h at pH 4.0, 50 °C and real matrices. The reusability of natural clays can be successfully regenerated by NaOH treatment using the adsorption/desorption process, an indication of its excellent reusability and stability during the regeneration. Finally, DFT molecular studies were performed to clarify the particularities of the adsorption of CIP onto clays.

Bioremoval and biodetoxification of ciprofloxacin from hospital wastewater effluent by the efficient and recyclable laccase@hercynite magnetic nanoparticles

Fluoroquinolones present in hospital wastewater potentially threaten human health security due to the development of antibiotic-resistant bacteria and genes. Today enzymatic treatments are known as a promising method for the removal of antibiotic residues from environmental waters. In the present study, laccase was adsorbed on the surface of hercynite (FeAl2O4) magnetic nanoparticles (MNPs) to remove ciprofloxacin from hospital wastewater (HWW) with high stability and efficiency. For this purpose, the hercynite MNPs were fabricated via the co-precipitation method, and their surface was subsequently modified by copper (II) ions to create coupling with the functional groups of the enzyme. The catalytic activity of laccase@Cu2+@hercynite•MNPs was preserved up to 50% of its initial activity after 13 cycles of reuse. The stability of the adsorbed enzyme was 2.2-fold and 4-fold higher than the free laccase after one month of storage at 4 °C and 25 °C, respectively. The immobilized laccase removed 85% of ciprofloxacin in HWW after 3 h incubation with 1 mM p-coumaric acid at 40 °C. The removal process involved defluorination, hydroxylation, and piperazine ring cleavage, which reduced the antibiotic toxicity against G+ and G– bacteria. Thus, laccase@Cu2+@hercynite•MNPs can be recommended for the bioremediation of micro-pollutants from hospital effluents.

Degradation of methotrexate by unactivated and solar-activated peroxymonosulfate in water: Moiety-specific reaction kinetics and transformation product-associated risks

Anticancer drugs have raised worldwide concern owing to their ubiquitous occurrence and ecological risks, necessitating the development of efficient removal strategies in water and wastewater treatment. Although peroxymonosulfate (PMS) is known to be a promising chemical in water decontamination, limited information is available regarding the removal efficiency of anticancer drugs by PMS and solar/PMS systems. This study first reports the moiety-specific reaction kinetics and mechanisms of methotrexate (MTX), an anticancer drug with widespread attention, by PMS (unactivated) and solar-activated PMS in water. It was found that MTX abatement by the direct PMS oxidation followed second-order kinetics, and the pH-dependent rate constants increased from 0.4 M−1 s−1 (pH 5.0) to 1.3 M−1 s−1 (pH 8.0), with a slight decrease to 1.1 M−1 s−1 at pH 9.0. The presence of chloride and bromide exerted no obvious influence on the removal of MTX by PMS. Furthermore, the chemical reactivity of MTX and its seven substructures with different reactive species was evaluated, and the degradation contributions of the reactive species involved were quantitatively analyzed in the solar/PMS system. The product analysis suggested similar reaction pathways of MTX by PMS and solar/PMS systems. The persistence, bioaccumulation, and toxicity of the transformation products were investigated, indicating treatment-driven risks. Notably, MTX can be removed efficiently from both municipal and hospital wastewater effluents by the solar/PMS system, suggesting its great potential in wastewater treatment applications. Overall, this study systematically evaluated the elimination of MTX by the unactivated PMS and solar/PMS treatment processes in water. The obtained findings may have implications for the mechanistic understanding and development of PMS-based processes for the degradation of such micropollutants in wastewater.

Detection of Multidrug-Resistant RND Efflux Pumps and Regulatory Proteins in Antibiotic-Resistant P. aeruginosa Recovered from Hospital Wastewater Effluent in the Eastern Cape Province of South Africa

P. aeruginosa (P. aeruginosa) is a problematic hospital agent that is a global challenge due to the ineffectiveness of some conventional antimicrobial therapies. Multidrug-resistant (MDR) P. aeruginosa has distinct action modes, including beta-lactamase production, porin gene repression, and efflux pump overexpression. This current research work focuses on efflux pumps (MexAB-OprM, MexCD-OprJ, MexXY-OprN) and their regulatory proteins (NfxB, MexR, MexZ, NalC, NalD) in MDR P. aeruginosa isolated from hospital wastewater effluent. The sequence analysis of the main transporter MexB was also performed. Following antibiotic resistance profiling and polymerase chain reaction (PCR) amplification of the efflux pump genes, the association of the efflux pump proteins with antibiotic resistance was investigated and analysed statistically. Fifty-seven (57) multidrug-resistant isolates were obtained from 81 PCR-confirmed P. aeruginosa isolates. Of the MDR P. aeruginosa isolates, the following rates were recorded: MexA (96.5%), MexB (100%), OprM (96.5%), MexC (100%), MexD (74.1%), OprJ (63.7%), MexX (89.6%), and OprN (51.7%). Additionally, the regulatory proteins had the following rates: NfxB (31.6%), NalC (15.8%), NalD (12.2%), MexZ (3.5%), and MexR (3.5%). The efflux pumps and regulatory proteins are strongly associated with antibiotic resistance, implying that P. aeruginosa antibiotic resistance is heavily influenced by these efflux pumps and regulatory genes. The MexB DNA sequences had numerous substitutions and poor alignment with divergent regions, and hence they have a possible role in increased antibiotic resistance. The absence of regulatory genes in most MDR P. aeruginosa isolates in the current research may have permitted transcription of the efflux pump operons, thus also increasing the antibiotic resistance burden.

The ability of biochars from cookstoves to remove pharmaceuticals and personal care products from hospital wastewater

Adequate treatment of wastewater to remove micropollutants constitutes a major concern globally. Despite this, large volumes of untreated wastewater are released into the environment, mainly due to the cost involved. Biochars have been suggested to have the potential to remove pharmaceuticals and personal care products (PPCP) from wastewater, but, adsorption potential needs to be investigated further. Production of biochars should also preferably be sustainable and based on low-cost materials. This study investigated the ability of nine biochars produced in three cookstoves and from three feedstocks. All biochars were characterized and then applied in adsorption experiments, based on authentic hospital effluent. Our analytical method included 32 pharmaceuticals and personal care products, and 28 of these were detected and quantified in hospital wastewater effluent samples. Some PPCP were present in relatively high concentrations (more than 24 µg/L). Adsorption experiments showed that the biochars used in the investigation had average removal rates (RR) ranging from 14.2% to 65.5%. Removal rates also varied between and within cookstoves and feedstock. Although cookstove biochars with a low surface area in this study generally showed lower removal rates, results from surface characterization were not detailed enough to correlate the physicochemical properties of the pollutants with the adsorption. Further characterizations are therefore needed to point out the most important parameters involved in PPCP adsorption on cookstove biochars.

Incidence and Virulence Factor Profiling of Vibrio Species: A Study on Hospital and Community Wastewater Effluents.

This study aimed to determine the incidence and virulence factor profiling of Vibrio species from hospital wastewater (HWW) and community wastewater effluents. Wastewater samples from selected sites were collected, processed, and analysed presumptively by the culture dependent methods and molecular techniques. A total of 270 isolates were confirmed as Vibrio genus delineating into V. cholerae (27%), V. parahaemolyticus (9.1%), V. vulnificus (4.1%), and V. fluvialis (3%). The remainder (>50%) may account for other Vibrio species not identified in the study. The four Vibrio species were isolated from secondary hospital wastewater effluent (SHWE), while V. cholerae was the sole specie isolated from Limbede community wastewater effluent (LCWE) and none of the four Vibrio species was recovered from tertiary hospital wastewater effluent (THWE). However, several virulence genes were identified among V. cholerae isolates from SHWE: ToxR (88%), hylA (81%), tcpA (64%), VPI (58%), ctx (44%), and ompU (34%). Virulence genes factors among V. cholerae isolates from LCWE were: ToxR (78%), ctx (67%), tcpA (44%), and hylA (44%). Two different genes (vfh and hupO) were identified in all confirmed V. fluvialis isolates. Among V. vulnificus, vcgA (50%) and vcgB (67%) were detected. In V. parahaemolyticus, tdh (56%) and tlh (100%) were also identified. This finding reveals that the studied aquatic niches pose serious potential health risk with Vibrio species harbouring virulence signatures. The distribution of virulence genes is valuable for ecological site quality, as well as epidemiological marker in the control and management of diseases caused by Vibrio species. Regular monitoring of HWW and communal wastewater effluent would allow relevant establishments to forecast, detect, and mitigate any public health threats in advance.

Antibiotic Resistance Patterns of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa Isolated from Hospital Wastewater

Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in treated hospital wastewater effluents constitute a major environmental and public health concern. The aim of this study was to investigate the antibiotic resistance patterns of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa isolated from wastewater effluent at the Benjamin Mkapa Hospital (BMH) in Dodoma, Tanzania. These bacteria were selected to represent the most prevalent gram-negative bacteria found in hospital wastewater, and they have the potential to generate resistance and spread resistance genes to antibiotics. The wastewater BMH is treated in a Constructed Wetland (CW) planted with Typha latifolia before being released into the environment. The bacteria were isolated from wastewater effluent collected at the outlet of the CW. Isolated bacteria were analyzed for antibiotic resistance by disc diffusion method. Molecular identification of bacterial species was performed by using 16S rRNA. The results show that Klebsiella ssp. was the most common isolate detected, with a prevalence of 39.3%, followed by E. coli (27.9%) and Pseudomonas ssp. (18.0%). Klebsiella ssp. were more resistant than Pseudomonas ssp. for Tetracycline, Gentamycin, Ciprofloxacin, and Sulfamethoxazole. Pseudomonas ssp. were more resistant than Klebsiella ssp. for Ceftriaxone and Azithromycin. Klebsiella ssp. harbored more resistance genes (40%), followed by Pseudomonas ssp. (35%) and E. coli (20%). The findings of this investigation indicate that the effluent from the CW requires additional treatment to reduce discharged ARB and ARGs in the receiving water bodies. As a result, the effluent quality of the CW should be continuously monitored and assessed, and further developments for treating the final effluent are necessary.

Escherichia coli high-risk clone ST410 harboring blaNDM-13 isolated from hospital wastewater in China

A carbapenem-resistant Escherichia coli strain C-SRM-3 was isolated from hospital wastewater effluent in Hangzhou city, China in March 2022. Analysis of the whole genome sequence showed that this blaNDM-13-positive strain belonged to an internationally recognized high-risk clone ST410 responsible for the dissemination of carbapenem resistance in E. coli. This isolate displayed a multidrug-resistant phenotype and carried a cassette of antibiotic-resistant genes. blaNDM-13 gene was successfully transferred to the recipient E. coli C600 via conjugation. WGS results revealed that blaNDM-13 gene was located on an IncI1 type plasmid replicon. The phylogenetic reconstruction showed that wastewater-sourced C-SRM-3 strain was located in a single branch, far removed from human-derived and animal-sourced isolates. The detection of blaNDM-13 in hospital wastewater suggests that continuous monitoring of antibiotic-resistant genes in the environment is critical for the prevention of carbapenem-resistant bacteria spreading.

Molecular Characterization of Antibiotic Resistance Determinants in Klebsiella pneumoniae Isolates Recovered from Hospital Effluents in the Eastern Cape Province, South Africa.

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic bacteria responsible for many nosocomial and community-acquired infections. The emergence and spread of antibiotic resistances have resulted in widespread epidemics and endemic dissemination of multidrug-resistant pathogens. A total of 145 K. pneumoniae isolates were recovered from hospital wastewater effluents and subjected to antibiogram profiling. Furthermore, the antibiotic resistance determinants were assessed among phenotypic resistant isolates using polymerase chain reaction (PCR). The isolates showed a wide range of antibiotic resistance against 21 selected antibiotics under 11 classes, with the most susceptible shown against imipenem (94.5%) and the most resistant shown against ampicillin (86.2%). The isolates also showed susceptibility to piperacillin/tazobactam (89.0%), ertapenem (87.6%), norfloxacin (86.2%), cefoxitin (86.2%), meropenem (76.6%), doripenem (76.6%), gentamicin (76.6%), chloramphenicol (73.1%), nitrofurantoin (71.7%), ciprofloxacin (79.3%), amikacin (60.7%), and amoxicillin/clavulanic acid (70.4%). Conversely, resistance was also recorded against tetracycline (69%), doxycycline (56.6%), cefuroxime (46.2%), cefotaxime (48.3%), ceftazidime (41.4%). Out of the 32 resistance genes tested, 28 were confirmed, with [tetA (58.8%), tetD (47.89%), tetM (25.2%), tetB (5.9%)], [sul1 (68.4%), sul1I (66.6%)], and [aadA (62.3%), strA (26%), aac(3)-IIa(aacC2)a (14.4%)] genes having the highest occurrence. Strong significant associations exist among the resistance determinants screened. About 82.7% of the K. pneumoniae isolates were multidrug-resistant (MDR) with a multiple antibiotics resistance index (MARI) range of 0.24 to 1.0. A dual presence of the resistant genes among K. pneumoniae was also observed to occur more frequently than multiple presences. This study reveals a worrisome presence of multidrug-resistant K. pneumoniae isolates and resistance genes in hospital waste effluent, resulting in higher public health risks using untreated surface water for human consumption. As a result, adequate water treatment and monitoring initiatives designed to monitor antimicrobial resistance patterns in the aquatic ecosystem are required.

Machine learning-guided determination of Acinetobacter density in waterbodies receiving municipal and hospital wastewater effluents

A smart artificial intelligent system (SAIS) for Acinetobacter density (AD) enumeration in waterbodies represents an invaluable strategy for avoidance of repetitive, laborious, and time-consuming routines associated with its determination. This study aimed to predict AD in waterbodies using machine learning (ML). AD and physicochemical variables (PVs) data from three rivers monitored via standard protocols in a year-long study were fitted to 18 ML algorithms. The models’ performance was assayed using regression metrics. The average pH, EC, TDS, salinity, temperature, TSS, TBS, DO, BOD, and AD was 7.76 ± 0.02, 218.66 ± 4.76 µS/cm, 110.53 ± 2.36 mg/L, 0.10 ± 0.00 PSU, 17.29 ± 0.21 °C, 80.17 ± 5.09 mg/L, 87.51 ± 5.41 NTU, 8.82 ± 0.04 mg/L, 4.00 ± 0.10 mg/L, and 3.19 ± 0.03 log CFU/100 mL respectively. While the contributions of PVs differed in values, AD predicted value by XGB [3.1792 (1.1040–4.5828)] and Cubist [3.1736 (1.1012–4.5300)] outshined other algorithms. Also, XGB (MSE = 0.0059, RMSE = 0.0770; R2 = 0.9912; MAD = 0.0440) and Cubist (MSE = 0.0117, RMSE = 0.1081, R2 = 0.9827; MAD = 0.0437) ranked first and second respectively, in predicting AD. Temperature was the most important feature in predicting AD and ranked first by 10/18 ML-algorithms accounting for 43.00–83.30% mean dropout RMSE loss after 1000 permutations. The two models' partial dependence and residual diagnostics sensitivity revealed their efficient AD prognosticating accuracies in waterbodies. In conclusion, a fully developed XGB/Cubist/XGB-Cubist ensemble/web SAIS app for AD monitoring in waterbodies could be deployed to shorten turnaround time in deciding microbiological quality of waterbodies for irrigation and other purposes.

Antibiotic-resistant bacteria in hospital wastewater treatment plant effluent and the possible consequences of its reuse in agricultural irrigation.

Wastewater from hospitals should be monitored precisely and treated properly before discharge and reuse to avoid epidemic and pandemic complications, as it contains hazardous pollutants for the ecosystem. Antibiotic residues in treated hospital wastewater effluents constitute a major environmental concern since they resist various wastewater treatment processes. The emergence and spread of multi-drug-resistant bacteria, that cause public health problems, are therefore always a major concern. The aims and objectives of this study were mainly to characterize the chemical and microbial properties of the hospital effluent of wastewater treatment plant (WWTP) before discharge to the environment. Special attention was paid to the presence of multiple resistant bacteria and the effects of hospital effluent reuse in irrigation on zucchini as an economically important plant. The risk of cell-free DNA carrying antibiotic resistance genes contained in the hospital effluent as a long-lasting hazard had been discussed. In this study, 21 bacterial strains were isolated from the effluent of a hospital WWTP. Isolated bacteria were evaluated for multi-drug resistance ability against 5 antibiotics (Tetracycline, Ampicillin, Amoxicillin, Chloramphenicol, and Erythromycin) at a concentration of 25 ppm. Out of them, three isolates (AH-03, AH-07, and AH-13) were selected because they recorded the highest growth in presence of tested antibiotics. Selected isolates were identified using 16S rRNA gene sequence homology as Staphylococcus haemolyticus (AH-03), Enterococcus faecalis (AH-07), and Escherichia coli (AH-13). Their susceptibility to ascending concentrations of tested antibiotics indicated that they were all susceptible at a concentration above 50 ppm. Results of the greenhouse experiment regarding the effect of hospital WWTP effluent reuse on zucchini plant fresh weights compared to that irrigated with fresh water indicated that the former recorded a limited increase in total fresh weights (6.2 g and 5.3 g/plant, respectively). Our results demonstrated the low impact of the reuse of Hospital WWTP effluent in agriculture irrigation compared to its greater risk in transferring multiple antibiotic bacteria and antibiotic resistance genes to soil bacteria through natural transformation.

Antibiotic resistance, pathotypes, and pathogen-host interactions in Escherichia coli from hospital wastewater in Bulawayo, Zimbabwe.

This study aimed to characterise E. coli strains isolated from hospital wastewater effluent in Bulawayo, Zimbabwe, using both molecular and cytological approaches. Wastewater samples were aseptically collected from the sewerage mains of a major public referral hospital in Bulawayo province weekly for one month. A total of 94 isolates were isolated and confirmed as E. coli through biotyping and PCR targeting the uidA housekeeping gene. A total of 7 genes (eagg, eaeA, stx, flicH7, ipaH, lt, and st genes) coding for virulence in diarrheagenic E. coli were targeted. Antibiotic susceptibility of E. coli was determined against a panel of 12 antibiotics through the disk diffusion assay. The infectivity status of the observed pathotypes was investigated using HeLa cells through adherence, invasion, and intracellular assay. None of the 94 isolates tested positive for the ipaH and flicH7genes. However, 48 (53.3%) isolates were enterotoxigenic E. coli (ETEC) (lt gene positive), 2 (2.13%) isolates were enteroaggregative E. coli (EAEC) (eagg gene), and 1 (1.06%) isolate was enterohaemorrhagic E. coli (EHEC) (stx and eaeA). A high level of sensitivity was observed in E. coli against ertapenem (98.9%), and Azithromycin (75.5%). The highest resistance was against ampicillin (92.6%) and sulphamethoxazole-trimethoprim (90.4%). Seventy-nine (84%) E. coli isolates exhibited multidrug resistance. The infectivity study results indicated that environmentally isolated pathotypes were as infective as the clinically isolated pathotypes for all three parameters. No adherent cells were observed using ETEC, and no cells were observed in the intracellular survival assay using EAEC. This study revealed that hospital wastewater is a hotspot for pathogenic E. coli and that the environmentally isolated pathotypes maintained their ability to colonise and infect mammalian cells.

N-doped TiO2 nano particles for photocatalytic degradation of coliform and fecal coliform from hospital wastewater effluent

&lt;p&gt;The photocatalytic process as an advanced oxidation process (AOP) has gained worldwide attention in the water and wastewater industry. The photocatalytic process can be used for water and wastewater disinfection. The aim of this study was to remove coliforms and faecal coliforms from real hospital wastewater using UV and UV/N doped TiO2 photocatalytic process. Secondary wastewater samples were collected from Ali-ebne Abitaleb Hospital, Zahedan. The real wastewater samples containing N-doped TiO2 nanoparticles were exposed to UV light in a reactor. Multi-tube fermentation method (MPN/100ml) was used to count the coliform and faecal coliform bacteria and evaluate the process efficiency. The results showed that the mechanism of inactivation of coliforms and faecal coliforms by N-doped TiO2 nanoparticles and UV light followed the first-order equation, and the simultaneous application of N-doped TiO2 nanoparticles and UV light (N-doped TiO2/UV) increased the efficiency of the photocatalytic process and completely inactivated the coliforms and faecal coliforms in 10 minutes. The results of this study also showed that with increasing contact time, the removal efficiency of coliforms and faecal coliforms increased in the presence of UV light. The highest efficiency of the nanoparticles in bacterial inactivation was achieved at a dose of 120 mg/l in the presence of UV light and was 100%. The nano-photocatalytic process can be used as an efficient method to remove coliforms and faecal coliforms from hospital wastewater, and the N-doped TiO2/UV process is a reliable antibacterial method for water and wastewater disinfection.&lt;/p&gt;&#x0D;

Photocatalytic Degradation of Psychiatric Pharmaceuticals in Hospital WWTP Secondary Effluents Using g-C3N4 and g-C3N4/MoS2 Catalysts in Laboratory-Scale Pilot

Today, the pollution caused by a multitude of pharmaceuticals used by humans has been recognized as a major environmental problem. The objective of this study was to evaluate and compare the photocatalytic degradation of ten target psychiatric drugs in hospital wastewater effluents using g-C3N4 and 1%MoS2/g-C3N4 (1MSCN) as photocatalytic materials. The experiments were performed using real wastewater samples collected from hospital wastewater treatment plant (WWTP) secondary effluent in spiked and inherent pharmaceutical concentration levels. The photocatalytic experiments were performed in a laboratory-scale pilot plant composed of a stainless-steel lamp reactor (46 L) equipped with ten UVA lamps and quartz filters connected in series with a polypropylene recirculation tank (55–100 L). In addition, experiments were carried out in a solar simulator apparatus Atlas Suntest XLS+ at a 500 Wm−2 irradiation intensity. The analysis of the samples was accomplished by solid-phase extraction, followed by liquid chromatography-Orbitrap high-resolution mass spectrometry. Results showed that the photocatalytic degradation of pharmaceutical compounds followed first-order kinetics. In all cases, 1MSCN presented higher photocatalytic performance than g-C3N4. The removal rates of the pharmaceutical compounds were determined above 30% and 54% using g-C3N4 and 1MSCN, respectively. Parallel to kinetic studies, the transformation products (TPs) generated during the treatment were investigated.

Treatment of hospital wastewater by potassium ferrate

It has been investigated how well potassium ferrate (K2FeO4) treats hospital wastewater effluents. In the treatment of water and wastewater, potassium ferrate serves as an oxidant, disinfectant, and coagulant with several functions. The effects of combining the oxidation and coagulation processes on features have not been extensively studied. The objective of this study is to evaluate the oxidation and coagulation effects of potassium ferrate treatment methods. An optimization technique based on response surface mythology (RSM) and Box-Behnken design was utilized to identify the ideal conditions for increased removal efficiency of chemical oxygen demand COD.. Potassium ferrate has a significant impact, according to experiments. With a COD of 790 ppm as the starting point, the effects of oxidation time (30-90 minutes), potassium ferrate concentration (20-100 ppm), pH (3-9), and process stirring speed (100-400 rpm) on COD removal efficiency were examined. To find the best COD removal efficiency, it also used an optimization strategy based on Box-Behnken design via the Surface Response Method (RSM). According to the findings, time, mixing speed, and pH are the factors that have the highest impact on the effectiveness of COD removal.. Based on the study of the Minitab-19 program, Regression analysis results revealed that a Fisher value of 13.68. pH value 3, oxidation time of 62 minutes, mixing speed of 300 rpm, and potassium ferrate content of 92 ppm were discovered to be the optimal operating parameters. Based on this ideal scenario, the final concentration reached had a COD elimination effectiveness of 98 percent.

Fate of selected pharmaceuticals in hospital and municipal wastewater effluent: occurrence, removal, and environmental risk assessment.

The concentrations and distribution of β-blockers, lipid regulators, and psychiatric and cancer drugs in the influent and effluent of the municipal wastewater treatment plant (WWTP) and the effluent of 16 hospitals that discharge into the wastewater treatment plant mentioned in this study at two sampling dates in summer and winter were examined. The pharmaceutical contribution of hospitals to municipal wastewater was determined. The removal of target pharmaceuticals was evaluated in a WWTP consisting of conventional biological treatment using activated sludge. Additionally, the potential environmental risk for the aquatic receiving environments (salt lake) was assessed. Beta-blockers and psychiatric drugs were detected in high concentrations in the wastewater samples. Atenolol (919 ng/L) from β-blockers and carbamazepine (7008 ng/L) from psychiatric pharmaceuticals were detected at the highest concentrations in hospital wastewater. The total pharmaceutical concentration determined at the WWTP influent and effluent was between 335 and 737 ng/L in summer and between 174 and 226 ng/L in winter. The concentrations detected in hospital effluents are higher than the concentrations detected in WWTP. The total pharmaceutical contributions from hospitals to the WWTP in summer and winter were determined to be 2% and 4%, respectively. Total pharmaceutical removal in the WWTP ranged from 23 to 54%. According to the risk ratios, atenolol could pose a high risk (risk quotient > 10) for fish in summer and winter. There are different reasons for the increase in pharmaceutical consumption in recent years. One of these reasons is the COVID-19 pandemic, which has been going on for 2 years. In particular, hospitals were operated at full capacity during the pandemic, and the occurrence and concentration of pharmaceuticals used for the therapy of COVID-19 patients has increased in hospital effluent. Pandemic conditions have increased the tendency of people to use psychiatric drugs. It is thought that beta-blocker consumption has increased due to cardiovascular diseases caused by COVID-19. Therefore, the environmental risk of pharmaceuticals for aquatic organisms in hospital effluent should be monitored and evaluated.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-21131-y.

Enhanced removal of neonicotinoid pesticides present in the Decision 2018/840/EU by new sewage sludge-based carbon materials

Due to the increasingly strict legislation about the disposal of sewage sludge, it is necessary to find sustainable solutions to manage this waste at low-cost conditions. In addition, priority contaminants are now attracting much attention since they are usually detected in WWTP effluents. In this work, five sludge have been used as precursors for the synthesis of activated carbons subsequently tested in the removal by adsorption of three neonicotinoid pesticides listed in the EU Watch List: acetamiprid (ACT), thiamethoxam (THM), and imidacloprid (IMD). Generally, the activated carbons were prepared by chemical activation using ZnCl2 as an activating agent and then the resulting materials were pyrolyzed at 800 °C for 2 h. The synthesized activated carbons showed different textural properties; thus, the best adsorption results were found for AC-Industrial activated carbon, obtained from an industrial origin sewage sludge, with high equilibrium adsorption capacities (qe = 104.2, 137.0, and 119.9 mg g−1), for ACT, THM, and IMD, respectively. Furthermore, it was elucidated that the use of CO2 in the synthesis generated an opening, followed by widening, of the narrowest microporosity, increasing the specific surface area of the carbon materials. The kinetic and isotherm adsorption experimental data were obtained for each of the pesticide-activated carbon systems; thus, the kinetic curves were well-fitted to the pseudo-second-order kinetic model, as well as, Freundlich and Guggenheim-Anderson-de Boer (GAB) empirical models were used for the fitting of the equilibrium adsorption isotherms, finding that GAB model best fitted the experimental data. Additionally, the regeneration of the activated carbons using methanol as a regenerating agent and the single and simultaneous adsorption of a hospital wastewater effluent, fortified with the three studied pesticides have been explored.