Daily physicochemical, microbiological and ecotoxicological fluctuations of a hospital effluent according to technical and care activities

Characterization of bacterial resistance in treated hospital wastewater

This article seeks to characterize the bacterial profile of pediatric hospital wastewater samples collected at the outlet of a wastewater treatment plant, and to estimate their relative susceptibility to antimicrobial agents. A total of 64 strains were isolated in the wastewater samples, of which 49 were identified as belonging to different families: Enterobacteriaceae (e.g. Escherichia coli, Klebsiella sp., Citrobacter sp.) comprised 57.2% of the identified bacteria, non-Enterobacteriaceae (e.g. Aeromonas sp., Pseudomonas sp.) comprised 30.6%, and Streptococcaceae (e.g. Enterococcus sp.) comprised 12.2%. The tests of the susceptibility of the bacteria to the antimicrobial agents used in the hospital showed that 100% of the bacterial species found discharged in the hospital wastewater treatment system were resistant to one or more of the antimicrobial agents according to the criteria of the U.S. Clinical Laboratory Standards Institute/National Committee for Clinical Laboratory Standards. The antimicrobial agent tests showed that meropenem, norfloxacin, ciprofloxacin, levofloxacin, and cefepime were the most effective antimicrobials against bacteria of the Enterobacteriaceae family. For bacteria of the non-Enterobacteriaceae family, norfloxacin, ciprofloxacin, levofloxacin, and cefepime presented the most effective antimicrobial action, whereas for bacteria of the Streptococcaceae family, ampicillin, vancomycin, and gentamicin were the most effective antimicrobials. Hospital wastewater treatment plants could be considered as places of selection pressure for bacterial resistance because of the presence of antibiotic-resistant bacteria coming from sewers or created at the treatment plant.

Occurrence and risk assessment of pharmaceuticals in hospital wastewater in Costa Rica

This work aims to determine the occurrence, hazard and prioritization of pharmaceuticals from hospital wastewater in Costa Rica through the monitoring of 70 compounds and assessing their environmental risk through a hazard quotient approach (HQ). Moreover, the quantification of selected antibiotic resistance genes (ARGs) was conducted for the first time in this matrix in this geographical location. Thirty-four pharmaceuticals were detected, being caffeine, 1,7-dimethylxanthine, acetaminophen, ibuprofen, naproxen, ciprofloxacin and ketoprofen the most frequent (>50% of the samples). Eighteen pharmaceuticals exhibited high hazard (HQ ≥ 1), while five more showed medium hazard (1 > HQ ≥ 0.1). Prioritization, which also included frequency parameters, revealed caffeine, lovastatin, diphenhydramine, acetaminophen, ibuprofen, ciprofloxacin, and sildenafil as the compounds of major concern. Similarly, cumulative hazard per sample (ΣHQ) estimated high hazard towards aquatic organisms in every sample. All selected ARGs, except mcr-1 (polymyxin resistance), were detected. Among genes conferring resistance to beta-lactams, blaCTX-M and blaKPC were the most abundant, related to resistance to cephalosporins and carbapenems. Ecotoxicological evaluation showed mostly low toxicity towards Daphnia magna and Vibrio fischeri, contrary to the marked effect observed towards Lactuca sativa. These findings provide relevant and novel information on the risk posed by hospital wastewater and their pharmaceutical content in the Latin American environmental context.

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.

Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

This review aims to assess different technologies for the on-site treatment of hospital wastewater (HWW) to remove pharmaceutical compounds (PhCs) as sustances of emerging concern at a bench, pilot, and full scales from 2014 to 2020. Moreover, a rough characterisation of hospital effluents is presented. The main detected PhCs are antibiotics and psychiatric drugs, with concentrations up to 1.1 mg/L. On the one hand, regarding the presented technologies, membrane bioreactors (MBRs) are a good alternative for treating HWW with PhCs removal values higher than 80% in removing analgesics, anti-inflammatories, cardiovascular drugs, and some antibiotics. Moreover, this system has been scaled up to the pilot plant scale. However, some target compounds are still present in the treated effluent, such as psychiatric and contrast media drugs and recalcitrant antibiotics (erythromycin and sulfamethoxazole). On the other hand, ozonation effectively removes antibiotics found in the HWW (>93%), and some studies are carried out at the pilot plant scale. Even though, some families, such as the X-ray contrast media, are recalcitrant to ozone. Other advanced oxidation processes (AOPs), such as Fenton-like or UV treatments, seem very effective for removing pharmaceuticals, Antibiotic Resistance Bacteria (ARBs) and Antibiotic Resistance Genes (ARGs). However, they are not implanted at pilot plant or full scale as they usually consider extra reactants such as ozone, iron, or UV-light, making the scale-up of the processes a challenging task to treat high-loading wastewater. Thus, several examples of biological wastewater treatment methods combined with AOPs have been proposed as the better strategy to treat HWW with high removal of PhCs (generally over 98%) and ARGs/ARBs (below the detection limit) and lower spending on reactants. However, it still requires further development and optimisation of the integrated processes.

An assessment of hospital wastewater and biomedical waste generation, existing legislations, risk assessment, treatment processes, and scenario during COVID-19

Hospitals release significant quantities of wastewater (HWW) and biomedical waste (BMW), which hosts a wide range of contaminants that can adversely affect the environment if left untreated. The COVID-19 outbreak has further increased hospital waste generation over the past two years. In this context, a thorough literature study was carried out to reveal the negative implications of untreated hospital waste and delineate the proper ways to handle them. Conventional treatment methods can remove only 50%-70% of the emerging contaminants (ECs) present in the HWW. Still, many countries have not implemented suitable treatment methods to treat the HWW in-situ. This review presents an overview of worldwide HWW generation, regulations, and guidelines on HWW management and highlights the various treatment techniques for efficiently removing ECs from HWW. When combined with advanced oxidation processes, biological or physical treatment processes could remove around 90% of ECs. Analgesics were found to be more easily removed than antibiotics, β-blockers, and X-ray contrast media. The different environmental implications of BMW have also been highlighted. Mishandling of BMW can spread infections, deadly diseases, and hazardous waste into the environment. Hence, the different steps associated with collection to final disposal of BMW have been delineated to minimize the associated health risks. The paper circumscribes the multiple aspects of efficient hospital waste management and may be instrumental during the COVID-19 pandemic when the waste generation from all hospitals worldwide has increased significantly.

Anionic surfactants monitoring in healthcare facilities - a case of Belo Horizonte City, Brazil

Surfactants are substances that when in aquatic environments can cause negative impacts. Hospital effluents carry numerous chemicals daily, including surfactants, used in sanitization and disinfection procedures. These chemicals are found in the effluents and reach water bodies due to a lack of proper removal in the wastewater treatment plants. The present study investigated data about wastewater monitored from healthcare facilities located in the city of Belo Horizonte, Brazil, focusing on anionic surfactants. The results showed 72 establishments monitoring this parameter, resulting in a median concentration of 1 mg L^-1 and 2.49 mg L^-1 mean value of anionic surfactants, between 2007 and 2019. It is also observed in the correlation between surfactants and oils in all healthcare establishment sizes, except for the medium-sized. Although anionic surfactants are the most used in cleaning product formulations, cationic surfactants still do not have specific legislation in the studied country that dictates a limit for discharge into sewage; consequently, they are not routinely monitored in effluents. However, these compounds are used in the formulation of routine hospital products.

A multi-biomarker approach for the early assessment of the toxicity of hospital wastewater using the freshwater organism Daphnia magna

Hospital wastewater (HWW) contains different hazardous substances resulting from a combination of medical and non-medical activities of hospitals, including pharmaceutical residues. These substances may represent a threat to the aquatic environment if they do not follow specific treatment processes. Therefore, we aimed to investigate the effects of the untreated effluent collected from a general hospital in Mahdia City (Tunisia) on neonatal stages of the freshwater crustacean Daphnia magna. Test organisms were exposed to three proportions (3.12%, 6.25%, and 12.5% v/v) of HWW. After 48 h of exposure, a battery of biomarkers was measured, including the quantification of antioxidant enzymes [catalase (CAT) and total and selenium-dependent glutathione peroxidase (total GPx; Se-GPx)], phase II biotransformation isoenzymes glutathione-S-transferases (GSTs), cyclooxygenases (COX) involved in the regulation of the inflammatory process, and total cholinesterases (ChEs) activities. Lipid peroxidation (LPO) was measured to estimate oxidative damage. The here-obtained results showed significant decreases of CAT and GSTs activities and also on LPO content in daphnids, whereas Se-GPx activity was significantly increased in a dose-dependent manner. Impairment of cholinesterasic and COX activities were also observed, with a significant decrease of ChEs and an increase of COX enzymatic activities. Considering these findings, HWW was capable of inducing an imbalance of the antioxidant defense system, but without resulting in oxidative damage in test organisms, suggesting that peroxidases and alternative detoxifying pathways were able to prevent the oxidant potential of several drugs, which were found in the tested effluents. In general, this study demonstrated the toxicity of hospital effluents, measured in terms of the potential impairment of key pathways, namely neurotransmission, antioxidant defense, and inflammatory homeostasis of crustaceans.

Dynamic and quantitative characterization of antagonism within disinfectant mixtures by a modified area-concentration ratio method

The coexistence of various typical disinfectant pollutants has the potential to produce toxicity interaction towards organisms in the environment. A suitable model is necessary to evaluate the interaction quantitatively. Hence, the area-concentration ratio (ACR) method was modified (MACR) by combing confidence intervals to dynamically and quantitatively evaluate the toxicity interactions within disinfectant mixture pollutants. Disinfectant mixtures were designed by the direct equipartition design ray method using three guanidine disinfectants, chlorhexidine diacetate (CD), chlorhexidine (CHL), and polyhexamethylene biguanidine (POL) and one chlorine-containing disinfectant calcium hypochlorite (CAL). The toxicities of the four disinfectants and their mixtures towards Vibrio qinghaiensis sp.-Q67 (Q67) were determined by the time-dependent toxicity microplate analysis method. And the toxicity mechanism was analyzed by determining the effects of four disinfectants and their binary mixtures on the structure of cell, DNA and proteins (Pro) for Q67. The results show that the toxicities of CD and CHL to Q67vary little with time, but POL and CAL show the obvious time-dependent toxicity. The toxicities of CD, CHL and POL to Q67 are significantly stronger than that of CAL at the same exposure time. The toxicities of three binary mixture systems don't have significant difference in different exposure time. MACR can dynamically, quantitatively and accurately characterize toxicity interactions compared with ACR. According to MACR, the antagonism intensity dynamically changes with the prolongation of exposure time for binary mixture rays of three guanidine disinfectants and CAL, and linearly correlates with the components' concentration ratios. Four disinfectants all can destroy cell membrane and cause desaturation DNA of test organism, and CAL even can destroy the structure of DNA and protein. The probably reason for the antagonism within binary mixtures is the reaction between guanidine group and ClO^-, which is called chemical antaogism.

A comparative study among catalytic wet air oxidation, Fenton, and Photo-Fenton technologies for the on-site treatment of hospital wastewater

The feasibility of catalytic wet air oxidation, intensified homogeneous Fenton and heterogeneous Photo-Fenton systems for the treatment of real hospital wastewater has been investigated. Wastewater samples were collected from a hospital sewer, during a weekly monitoring program, and fully characterized. Up to seventy-nine pharmaceuticals, including mostly parent compounds and some of their transformation products, were analyzed. Catalytic wet air oxidation allowed the complete removal of several pharmaceutical groups, but it did not allow to eliminate analgesics/anti-inflammatories and antibiotics, whose average removal was around 85%. Intensified Fenton oxidation was the most efficient process for all the drugs removal with an almost complete reduction of the initial pharmaceutical load (99.8%). The heterogeneous Photo-Fenton system reached a 94.5% reduction of the initial pharmaceutical load. The environmental risk of the treated samples by the hazard quotient (HQ) method was also evaluated. Fenton oxidation was the most effective system with a final ∑HQ of 5.4. Catalytic wet air oxidation and Photo-Fenton systems achieved total ∑HQ values of 895 and 88, respectively. This fact was related to the presence of refractory antibiotics in the treated catalytic wet air oxidation samples. On the opposite, the Photo-Fenton system provided the elimination of most pharmaceutical pollutants that pose a high environmental risk such as antibiotics. Simplified cost estimation was finally performed as a preliminary approach of the economy of the three oxidation processes for the hospital wastewater treatment.

Antibiogram profile and virulence signatures of Pseudomonas aeruginosa isolates recovered from selected agrestic hospital effluents

Hospital wastewater (HWW) harbours diverse microbial species and a miscellany of genome that would facilitate the emergence of novel pathogen upon genome integration that manifests novel traits in infectious pathogens. The study aimed to determine the antibiogram, and virulence signatures of Pseudomonas aeruginosa (P. aeruginosa) recovered from selected agrestic hospital effluents in Eastern Cape, South Africa. Thirty-six (36) wastewater samples were collected from selected hospital drains between February 2018 and April 2018, processed and analyzed by culture-dependent methods for the isolation of P. aeruginosa. The identity confirmation of isolates was achieved by amplification of oprl and oprL genes. Antibiogram was done using standard disk diffusion technique of Kirby-Bauer as approved by CLSI 2018 guidelines. Virulence signatures (lasA, lasB, toxA, popB) among isolates were analysed using polymerase chain reaction. A total of 54 P. aeruginosa isolates were confirmed by amplification of oprl and oprL genes in the hospital wastewater effluent samples. The isolates showed a 100% susceptibility to gentamicin, amikacin and imipenem antimicrobial agents. Ceftazidime recorded the most resistance (63%) against the isolates studied. Other antibiotics had a resistance range of 7% and 35%. The MAR index among the isolates revealed a range of 0.23 and 0.38. ToxA virulence gene was detected in all isolates while popB, lasB, lasA were detected in 82%, 75% and 54% of the isolates. This study reveals P. aeruginosa isolates with virulence traits and some strains showing multiple antibiotic resistance. The multiple antibiotic resistance index (MARI) of ≥ 0.2 indicates that the some isolates may have emerged from high-risk sources, thus projecting a risk to public health. However, with the high sensitivity pattern observed among the studied isolates, most of the antibiotics used in the susceptibility tests are not at peril. Hence, the use of these antibiotics is encouraged for treatment of infection attributed to P. aeruginosa. It is also pertinent to initiate strict control and rigid antibiotics therapeutic policy with surveillance programmes for multidrug-resistant pathogens to forestall the development and transmission of resistance traits in the pathogens.

A review on hospital wastewater treatment: A special emphasis on occurrence and removal of pharmaceutically active compounds, resistant microorganisms, and SARS-CoV-2

The hospital wastewater imposes a potent threat to the security of human health concerning its high vulnerability towards the outbreak of several diseases. Furthermore, the outbreak of COVID-19 pandemic demanded a global attention towards monitoring viruses and other infectious pathogens in hospital wastewater and their removal. Apart from that, the presence of various recalcitrant organics, pharmaceutically active compounds (PhACs), etc. imparts a complex pollution load to water resources and ecosystem. In this review, an insight into the occurrence, persistence and removal of drug-resistant microorganisms and infectious viruses as well as other micro-pollutants have been documented. The performance of various pilot/full-scale studies have been evaluated in terms of removal of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), PhACs, pathogens, etc. It was found that many biological processes, such as membrane bioreactor, activated sludge process, constructed wetlands, etc. provided more than 80% removal of BOD, COD, TSS, etc. However, the removal of several recalcitrant organic pollutants are less responsive to those processes and demands the application of tertiary treatments, such as adsorption, ozone treatment, UV treatment, etc. Antibiotic-resistant microorganisms, viruses were found to be persistent even after the treatment of hospital wastewater, and high dose of chlorination or UV treatment was required to inactivate them. This article circumscribes the various emerging technologies, which have been used to treat PhACs and pathogens. The present review also emphasized the global concern of the presence of SARS-CoV-2 RNA in hospital wastewater and its removal by the existing treatment facilities.

Medical laboratory wastewater treatment by electro-fenton process: Modeling and optimization using central composite design

Medical laboratory wastewaters arising from diagnosis and examination units show highly toxic characteristic. Within the scope of the study, removal of the wastewater's toxicity and increasing BOD₅ /COD ratio of the medical laboratory wastewaters through electro-Fenton (EF) process were investigated. In the study, central composite design was applied to optimize the process parameters of EF for COD, BOD₅ , and toxicity unit (TU) removal. Based on ANOVA, H₂ O₂ /COD was found to be significant parameter for COD removal, whereas current, reaction time, and H₂ O₂ /COD were determined to be significant parameters for BOD₅ and TU removal. Optimum conditions (pH value of 3.4, current 3 A, reaction time 33.9 min, and H₂ O₂ /COD of 1.29) were determined, and predicted removals of COD, BOD_5, and TU were found to be 55.1%, 42.5%, and 99.7% and experimental removals were found to be 53.4%, 41.2%, and 99.5%, respectively. TU value of the wastewater decreased from the value of 163-0.815, and BOD₅ /COD value increased from the value of 0.32-0.39. The results of the study indicate that EF process is an effective treatment option for COD, BOD_5, and especially toxicity removal from medical laboratory wastewater. PRACTITIONER POINTS: Electro-Fenton process was applied medical laboratory wastewater with highly toxic characteristic. Response surface methodology approach using central composite design was employed for modeling. 53.4%, 41.2%, and 99.5% of COD, BOD_5, and toxicity removals were achieved under statistically optimized conditions. TU value of the wastewater decreased from the value of 163-0.815. BOD₅ /COD value increased from the value of 0.32-0.39.

Terrestrial solar radiation driven photodecomposition of ciprofloxacin in clinical wastewater applying mesostructured iron(III) oxide

Cationic cylindrical polymer brushes based on polybutadiene-block-poly(2-vinylpyridine) were applied as structure-directing agent for mesostructuring Fe₂O₃ nanoparticles into nanotubes. After temperature-controlled template removal, the obtained non-woven catalysts were tested for the photodegradation of ciprofloxacin under terrestrial solar radiation. At a slightly basic pH value, as typically encountered in clinical wastewaters, the mesostructured Fe₂O₃ shows a 4.5 times faster degradation of ciprofloxacin than commercial Aeroxide® TiO₂ P25. Even wide-bandgap ZnO, mesostructured in the same way, is 1.6 times slower. Moreover, the non-woven-like structure of the catalyst allows for easy recovery of the catalyst and operation in a continuous flow reactor. Graphical abstract.

Sensitivity of Zebrafish (Danio rerio) Embryos to Hospital Effluent Compared to Daphnia magna and Aliivibrio fischeri

The Fish Embryo Acute Toxicity (FET) Test was adopted by the Organisation for Economic Co-operation and Development as OECD TG 236 in 2013. The test has been designed to determine acute toxicity of chemicals on embryonic stages of fish and proposed as an alternative method to the Fish Acute Toxicity Test performed according to OECD TG 203. In recent years fish embryos were used not only in the assessment of toxicity of chemicals but also for environmental and wastewater samples. In our study we investigated the acute toxicity of treated wastewater from seven hospitals in the Czech Republic. Our main purpose was to compare the suitability and sensitivity of zebrafish embryos with the sensitivity of two other aquatic organisms commonly used for wastewater testing – Daphnia magna and Aliivibrio fischeri. For the aim of this study, in addition to the lethal endpoints of the FET test, sublethal effects such as delayed heartbeat, lack of blood circulation, pericardial and yolk sac edema, spinal curvature and pigmentation failures were evaluated. The comparison of three species demonstrated that the sensitivity of zebrafish embryos is comparable or in some cases higher than the sensitivity of D. magna and A. fischeri. The inclusion of sublethal endpoints caused statistically significant increase of the FET test efficiency in the range of 1-12 %. Based on our results, the FET test, especially with the addition of sublethal effects evaluation, can be considered as a sufficiently sensitive and useful additional tool for ecotoxicity testing of the acute toxicity potential of hospital effluents.

Hospital Wastewater as a Reservoir for Antibiotic Resistance Genes: A Meta-Analysis

Background: The emergence and dissemination of antibiotic resistance genes (ARGs) in the environment poses a huge global health hazard. Hospital wastewater (HWW), in which a high density of antibiotic residues and antibiotic-resistant bacteria are present, may be a reservoir of ARGs dissemination into the environment. Our meta-analysis comprehensively analyzes the prevalence of ARGs in HWW, as well as the influencing factors in ARGs distribution.

Methods: Online databases were used to search for literature using the subject terms: “Drug Resistance” AND “Genes” AND “Hospitals” AND “Wastewater.” Two reviewers independently applied predefined criteria to assess the literature and extract data including “relative abundance of ARGs,” “title,” “authors,” “country,” “location,” “sampling year,” and “sampling seasons.” The median values and 95% confidence intervals of ARGs abundance were calculated by Wilcox.test function in R. Temporal trends, spatial differences, seasonal variations and removal efficiency of ARGs were analyzed by Pearson correlation analysis and Kruskal-Wallis H test.

Results: Resistance genes to carbapenems, sulfonamides, tetracyclines and mobile genetic elements were found at high relative abundance (>10⁻⁴ gene copies/16S rRNA gene copies) in HWW. The abundance of resistance genes to extended-spectrum β-lactams, carbapenems, sulfonamides and glycopeptide significantly decreased, while tetracycline resistance genes abundance increased from 2014 to 2018. The abundance of ARGs was significantly different by country but not by season. ARGs could not be completely removed by on-site HWW treatments and the removal efficiency varies for different ARGs.

Conclusions: HWW presents more types of ARGs, and their abundance is higher than those in most wastewater systems. HWW may be a reservoir of ARGs and play an important role in the dissemination of ARGs.

Photo-inactivation of bacteria in hospital effluent via thiolated iron-doped nanoceria

Hospital wastewater is a major contributor of disease-causing microbes and the emergence of antibiotic resistant bacteria. In this study, thiolated iron-doped nanoceria was synthesised and tested for killing of microbes from hospital effluent. These particles were designed to inhibit the efflux pumps of the bacteria found in hospital effluent with further ability to activate in visible light via iron doping thus generating tunable amount of reactive oxygen species (ROS). The quantum yield of the ROS generated by the nanoceria was 0.67 while the ROS types produced were singlet oxygen (36%), hydroxyl radical (31%) and hydroxyl ions (32%), respectively. The particles were initially synthesised through green route using Foeniculum vulgare seeds extract and were annealed at 200°C and further coated with thiolated chitosan to enhance the solubility and efflux pump inhibition. X-ray diffraction confirmed the polycrystalline nature of nanoparticles and uniform spherical shape with 30 nm size, confirmed by scanning electron microscope. The nanoparticles exhibited 100% bactericidal activity at 100 µg/mL against all the isolated bacteria. The enhanced bactericidal effect of iron-doped nanoceria could be attributed to efflux inhibition via thiolated chitosan as well as the production of ROS upon illumination in visible light, causing oxidative stress against microbes found in hospital effluent.

Review on pulp and paper activated sludge pretreatment, inhibitory effects and detoxification strategies for biovalorization

Biovalorization of pulp and paper activated sludge to value-added products could be an effective alternative to traditional sludge management methods, which tend to pose serious environmental issues. Since pulp and paper activated sludge consists of microbial biomass, cellulose, hemicellulose and lignin and thus, could be subjected to different hydrolysis methods to solubilize sludge solids and release simple sugars to form value-added products by the microbial fermentation process. Hence, different sludge hydrolysis methods have been summarized in this review paper. However, hydrolysis of lignocellulosic materials generates variety of toxic compounds during hydrolysis and causes detrimental effects. Therefore, different toxic compounds and their impact on microorganisms, cellulolytic enzymes and fermentation process have been discussed in detail and recent strategies to counteract the problems of inhibitors have also been briefly explained.

Hospital wastewater treatment scenario around the globe

Wastewaters generated from hospitals contain pharmaceuticals residues, pathogens, chemical reagents, radionuclide, and other harmful matter. The wastewater characteristics, quantity, and handling methods have not only variations among countries but also within a country. Some hazardous substances of hospital wastewaters (HWWs) may have a regulatory status and should be treated accordingly while others have characteristics similar to that of domestic sewage. At a global level, guidelines do exist for treatment of these HWWs. But literatures have shown that legislation has various loopholes in implementation. This chapter outlines the current status of management and handling of HWWs around the major industrial hubs of worlds in two categories of developed (the United States, United Kingdom, and Europe) and developing (India, China, Iran, and Bangladesh) countries. Various literatures and guidelines of these countries have been referred which mainly highlight different treatment scenarios and status of coverage of HWW management guidelines.

Introduction to wastewater microbiology: special emphasis on hospital wastewater

The important role of proper sanitation in maintaining good public health has been confirmed in the past years. Wastewater treatment plants (WWTPs) serve as efficient processes in removing pathogens, organic pollutants, nutrients, and pharmaceuticals from wastewaters. However, the advance systems of treatment that we use today are the result of a series of inventions that have been performed since 19th century. This chapter explains the evolution of the wastewater origin and the treatment processes along with the developments in microbiology and pathology that led to the present-day scenario of research and advance facilities. Pharmaceuticals can easily enter the environment due to their incomplete degradation in the treatment processes and because of their adverse effects on organisms and environment they are becoming a matter of great concern. A brief discussion on the presence of pharmaceutical compounds in different environment sectors such as wastewater, WWTPs, and the natural aquatic environment has been provided.

Occurrence of Micropollutants in Wastewater and Evaluation of Their Removal Efficiency in Treatment Trains: The Influence of the Adopted Sampling Mode

The monitoring of micropollutants in water compartments, in particular pharmaceuticals and personal care products, has become an issue of increasing concern over the last decade. Their occurrence in surface and groundwater, raw wastewater and treated effluents, along with the removal efficiency achieved by different technologies, have been the subjects of many studies published recently. The concentrations of these contaminants may vary widely over a given time period (day, week, month, or year). In this context, this paper investigates the average concentration and removal efficiency obtained by adopting four different sampling modes: grab sampling, 24-h time proportional, flow proportional and volume proportional composite sampling. This analysis is carried out by considering three ideal micropollutants presenting different concentration curves versus time (day). It compares the percentage deviations between the ideal concentration (and removal efficiencies) and the differently measured concentrations (removal efficiencies) and provides hints as to the best sampling mode to adopt when planning a monitoring campaign depending on the substances under study. It concludes that the flow proportional composite sampling mode is, in general, the approach which leads to the most reliable measurement of concentrations and removal efficiencies even though, in specific cases, the other modes can also be correctly adopted.

Alterations to embryonic development and teratogenic effects induced by a hospital effluent on Cyprinus carpio oocytes

Hospital functioning generates a great quantity of contaminants, among which organic materials, heavy metals, and diverse pharmaceuticals are noteworthy that can affect organisms if they are not properly removed from the effluents. The hospital effluent evaluated in the present study came from IMSS (Instituto Mexicano del Seguro Social) Clinic 221 in downtown Toluca, State of Mexico, a secondary care facility. The contaminants identified in hospitals have been associated with deleterious effects on aquatic organisms; however, it is necessary to continue with more studies in order to be able to regulate the production of said contaminants which are generally dumped into the city sewage system. The present study had the purpose of evaluating the alterations to embryonic development and teratogenic effects on oocytes Cyprinus carpio after exposure to different proportions of hospital effluent. For said purpose, the physicochemical properties of the effluent were determined. Concentrations of the main microcontaminants were also determined. An embryolethality study out and the determination of the main alterations to embryonic development and teratogenic effects produced, due to exposure of C. carpio at different proportions of the effluent, were carried out. The results showed that the physicochemical properties were within the values permitted by Mexican regulation; however, the presence of contaminants such as NaClO, metals, anti-biotics, anti-diabetics, non-steroidal anti-inflammatory drugs, hormones and beta-blockers, was detected. Lethal concentration 50 was 5.65% and the effective concentration for malformations was 3.85%, with a teratogenic index of 1.46. The main teratogenic alterations were yolk deformation, scoliosis, modified chorda structure, tail malformation, fin deformity and mouth hyperplasia. A high rate of hatching delay was observed. The results suggest that the hospital effluent under study is capable of inducing embryotoxicity and teratogenicity in oocytes of C. carpio.

Potential ecotoxicological effects of antimicrobial surface coatings: a literature survey backed up by analysis of market reports

This review was initiated by the COST action CA15114 AMICI "Anti-Microbial Coating Innovations to prevent infectious diseases," where one important aspect is to analyze ecotoxicological impacts of antimicrobial coatings (AMCs) to ensure their sustainable use. Scopus database was used to collect scientific literature on the types and uses of AMCs, while market reports were used to collect data on production volumes. Special attention was paid on data obtained for the release of the most prevalent ingredients of AMCs into the aqueous phase that was used as the proxy for their possible ecotoxicological effects. Based on the critical analysis of 2,720 papers, it can be concluded that silver-based AMCs are by far the most studied and used coatings followed by those based on titanium, copper, zinc, chitosan and quaternary ammonium compounds. The literature analysis pointed to biomedicine, followed by marine industry, construction industry (paints), food industry and textiles as the main fields of application of AMCs. The published data on ecotoxicological effects of AMCs was scarce, and also only a small number of the papers provided information on release of antimicrobial ingredients from AMCs. The available release data allowed to conclude that silver, copper and zinc are often released in substantial amounts (up to 100%) from the coatings to the aqueous environment. Chitosan and titanium were mostly not used as active released ingredients in AMCs, but rather as carriers for other release-based antimicrobial ingredients (e.g., conventional antibiotics). While minimizing the prevalence of healthcare-associated infections appeared to be the most prosperous field of AMCs application, the release of environmentally hazardous ingredients of AMCs into hospital wastewaters and thus, also the environmental risks associated with AMCs, comprise currently only a fraction of the release and risks of traditional disinfectants. However, being proactive, while the use of antimicrobial/antifouling coatings could currently pose ecotoxicological effects mainly in marine applications, the broad use of AMCs in other applications like medicine, food packaging and textiles should be postponed until reaching evidences on the (i) profound efficiency of these materials in controlling the spread of pathogenic microbes and (ii) safety of AMCs for the human and ecosystems.

Discharge of biocidal products from healthcare activities into a sewage system-a case study at a French university hospital

This study focused on the presence of three biocidal products specific to healthcare facilities, i.e. chlorhexidine digluconate (CHD), bis(aminopropyl)laurylamine (BAPLA), and didecyldimethylammonium chloride (DDAC), in a hospital sewage system. Five sampling campaigns were conducted in 2016 and 2017 throughout the entire Poitiers University Hospital sewage system. DDAC concentrations ranging from 933 ± 119 to 3250 ± 482 μg/L were detected in 24-h composite samples, while lower concentrations (both within the same range) were detected for the two other compounds (i.e. 25 ± 5 to 97 ± 39 μg/L for CHD and 18 ± 3 to 142 ± 16 μg/L for BAPLA). Based on these findings, a mass balance was determined for these discharged compounds to compare the quantities detected in discharges to the amounts used for healthcare in the hospital. Hence, 60-90% of the quantities of DDAC used were found to be present at the hospital sewage outfall. Higher percentages of CHD (100-242%) were noted because of the high presumably quantities used for antiseptic applications, which were not considered in mass balance calculation. Finally, only 10-30% of BAPLA quantities used were detected at the site outfall. Analysis of the results for the different sampling points revealed the nature of the emission sources. For surface applications of DDAC and BAPLA, management of hospital linen is thus a major source of discharged biocidal products, probably following the washing of biocide-soaked textiles used for hospital facility maintenance. Moreover, discharge of biocidal products from a healthcare establishment depends especially on biocide handling practices in the emitting establishment. For BAPLA, compliance with hospital recommended dosages and practices whereby operators are required to prepare tailored quantities of detergents and disinfectants for each specific task could largely explain the limited release of this compound.

Microalgal whole-cell biomarkers as sensitive tools for fast toxicity and pollution monitoring of urban wet weather discharges

Urban wet weather discharge (UWWD) management is an important issue. UWWD often represents a significant source of pollution in all aquatic bodies. The occurrence of this pollution is difficult to predict due to the variability of storm events and the unknown contents of urban watershed leached out by rain. Previous studies have tried to demonstrate the ecotoxic impact of UWWD. However, most of them merely highlight the limitations of classic monospecific bioassays, given the high dilution of micropollutants or the presence of nutrients masking toxic effects. Overcoming this problem is therefore of great interest. In this study, we demonstrated the utility of a battery of biomarkers (e.g. membrane permeability, chlorophyll fluorescence, esterase and alkaline phosphatase activities) on the microalgae Chlorella vulgaris to detect the toxic effects of 7 UWWD samples after short exposures (2 and 24 h). These biomarkers are linked to microalgal life traits. Complementarily, monospecific bioassays were carried on Pseudokirchneriella subcapitata, Chlorella vulgaris, Daphnia magna and Heterocypris incongruens to compare their sensitivity to the UWWD samples. No toxic effect was detected in any of the bioassays. Yet, algal biomarkers indicated a disturbance in microalgae physiology, and particularly a perturbation of chlorophyll fluorescence, which was observed in all of the samples tested. While algal membrane permeability was affected by only one UWWD, these two enzymatic activities were stimulated or inhibited depending on the sample. Finally, this study demonstrates the sensitivity of algal biomarkers and the need to develop new, fruitful approaches to characterizing UWWD toxicity.

Assessment of Pharmaceuticals, Personal Care Products, and Hormones in Wastewater Treatment Plants Receiving Inflows from Health Facilities in North West Province, South Africa

The presence of 17 pharmaceutical and personal care products (PPCPs) belonging to various therapeutic categories was investigated in two hospital wastewater treatment plants (WWTPs) in North West Province, South Africa. The compounds were extracted from wastewater samples by solid-phase extraction and analysed by liquid chromatography-tandem mass spectrometry. The results showed that ofloxacin, chloramphenicol, and bezafibrate were generally below the limit of quantification (LOQ) in the analysed samples. Acetaminophen and ibuprofen were the dominant pharmaceuticals in the influent streams with corresponding concentrations ranging from 21 to 119 μg/L and 0.3 to 63 μg/L, respectively. Both WWTPs were shown to have the capability to remove some of the target PPCPs, including acetaminophen (76-98%), tetracycline (15-93%), ibuprofen (44-99%), and triclocarban (13-98%). The monitoring of the target PPCPs in both influent and effluent samples of the investigated WWTPs revealed that the discharge of inadequately treated effluents could be contributing to the possible increase in the concentrations of these contaminants in the receiving environmental compartments. Further studies must be focused on the broader characterisation of these matrices in order to assess the potential ecological impacts of this waste disposal practice.

The fate and risk assessment of psychiatric pharmaceuticals from psychiatric hospital effluent

Psychiatric pharmaceuticals are gaining public attention because of increasing reports of their occurrence in environment and their potential impact on ecosystems and human health. This work studied the occurrence and fate of 15 selected psychiatric pharmaceuticals from 3 psychiatric hospitals effluent in Shanghai and investigated the effect of hospitals effluent on surface water, groundwater, soil and plant. Amitriptyline (83.57ng) and lorazepam (22.26ng) showed the highest concentration and were found frequently in hospital effluent. Lorazepam (8.27ng), carbamazepine (83.80ng) and diazepam (79.33ng) showed higher values in surface water. The concentration of lorazepam (46.83ng) in groundwater was higher than other reports. Only six target compounds were detected in all three soil points in accordance with very low concentration. Alkaline pharmaceuticals were more easily adsorbed by soil. Carbamazepine (1.29ng) and lorazepam (2.95ngg^-1) were frequently determined in plant tissues. The correlation analyses (Spearman correlations > 0.5) showed the main source of psychiatric pharmaceuticals pollutants might be hospital effluents (from effluent to surface water; from surface water to groundwater). However, hospital effluents were not the only pollution sources from the perspective of the dilution factor analysis. Although the risk assessment indicated that the risk was low to aquatic organism, the continuous discharge of pollution might cause potential environment problem.

Ecotoxicity and antibiotic resistance of a mixture of hospital and urban sewage in a wastewater treatment plant

Hospital and urban effluents are a source of diverse pollutants such as organic compounds, heavy metals, detergents, disinfectants, pharmaceuticals, and microorganisms resistant to antibiotics. Usually, these two types of effluent are mixed in the sewage network, but a pilot site in France now allows studying them separately or mixed to understand more about their characteristics and the phenomena that occur following their mixing. In this study, their ecotoxicity (Daphnia magna mobility, Pseudokirchneriella subcapitata growth, Brachionus calyciflorus reproduction, and SOS Chromotest) and antibiotic resistance (integron quantification) were assessed during mixing and treatment steps. The main results of this study are (i) the ecotoxicity and antibiotic resistance potentials of hospital wastewater are higher than in urban wastewater and (ii) mixing two different effluents does not lead to global synergistic or antagonistic effects on ecotoxicity and antibiotic resistance potential. The global additivity effect observed in this case must be confirmed by other studies on hospital and urban effluents on other sites to improve knowledge relating to this source of pollution and its management.

Toxicological assessment of hospital wastewater in different treatment processes

This study surveyed the hospital wastewater characters focusing on antibiotic contamination in seven hospitals in Bangkok. It detected 19 antibiotics of which the high-frequent detection were quinolones such as ofloxacin + levofloxacin, norfloxacin, ciprofloxacin including sulfamethoxazole. Norfloxacin and ciprofloxacin appeared the highest concentrations of 12.11 and 9.60 μg/L, respectively. Most antibiotic concentrations in the wastewaters of the studied hospitals gave a good correlation (r ²  = 0.77-0.99) to the amount of usage. In this study, batch acute toxicity tests were performed to assess the toxicity of hospital wastewater on mixed liquor, freshwater algae (Chlorella vulgaris and Scenedesmus quadricauda), and microcrustacean (Moina macrocopa). The hospital wastewaters could inhibit the mixed liquor growth and gave similar toxic levels among test species: algae and microcrustacean (9.81-13.63 and 2.62-3.09 TU, respectively). The conventional activated sludge (CAS) and rotating biological contactor (RBC) could remove fluoroquinolones and tetracycline via biomass adsorption. After treatment, most of treatment could reduce the toxicity. Nevertheless, the effluent gave slight toxicity on some test species which might be caused from chlorination and a common toxicant (NH₃-N).

Cytotoxic effects of seven Tunisian hospital wastewaters on the proliferation of human breast cancer cell line MDA-231: correlation with their chemical characterization

Hospital wastewaters contain large amounts of pharmaceutical residues, which may eventually be discharged into the aquatic environment through wastewater treatment plants, raising the question of their impact on human and environmental health. This has prompted the launch of several monitoring studies into the most commonly administered compounds in urban wastewater. The aim of this study was, therefore, to explore the cytotoxic potential of wastewaters samples collected from seven hospitals in Tunisia. The physicochemical analyses showed a large fluctuation of certain parameters in the collected samples, such as chemical oxygen demand (ranged from 860 to 1720 mg L^-1), biochemical oxygen demand (ranged from 385 to 747 mg L^-1), total organic carbon (ranged from 256 to 562 g L^-1), total suspended solids (ranged from 905 to 1450 mg L^-1), conductivity (ranged from 3.31 to 7.14 μsm/cm), and turbidity (ranged from 100 to 480 NTU). The analysis using inductively coupled plasma mass spectrometry (ICP-MS) also showed that hospital wastewater contains high concentrations of Hg (ranged from 0.0024 to 0.019 mg L^-1). This could be explained by the variation of the activity and the services in certain hospitals compared to others. All hospital wastewater samples induced the proliferation of human breast cancer cell line MDA-231, even at low concentrations (20 μL/assay). Moreover, the maximum induction reached at the concentration of 60 μL/assay in wastewater samples from hospitals located in Monastir, Sidi Bouzid, Mahdia, and Sfax with percentages of induction up to 42.33, 14, 7.61, and 5.42%, respectively. These observations could be due to the presence of endocrine disrupting compounds (EDCs) in these wastewaters. Given this, our results evidenced the potential risk of these hospital effluents to environmental and public health.

Combined use of VUV and UVC photoreactors for the treatment of hospital laundry wastewaters: Reduction of load parameters, detoxification and life cycle assessment of different configurations

The present research investigated the treatment of hospital laundry wastewaters by the combined use of photochemical VUV and UVC reactors. Seven different configurations were tested and the performances of each of them were evaluated based on the removal of the load parameters, detoxification and life cycle assessment (LCA). The characterization of studied wastewaters included analysis of the following parameters: COD, BOD₅, TKN, total P, pH, turbidity and conductivity. Acute ecotoxicity was evaluated using Daphnia magna. Ultraviolet-Visible (UV-Vis) spectroscopy was performed to determine the organic fraction and chromatography coupled to the mass spectrometer (GC-MS) was used for the qualitative characterization of priority pollutants. Characterization parameters showed the presence of drugs like lidocaine and dipyrone and a high organic load with a poor biodegradability. Wastewaters presented an extreme acute toxicity against D. magna (EC₅₀ 6.7%). The ozonation process (mainly generated by the VUV reactor) obtained the best results concerning the ratio between the consumed energy and the removed COD and the UVC process presented the lowest environmental impacts for the characterization and normalization parameters of the LCA. Normalization revealed that the highest environmental burdens were associated with human toxicity, ecotoxicity and eutrophication of surface waters as well as to the use of non-renewable resources. VUV/UVC/O₃ process presented the best results considering detoxification (EC₅₀ 100%).

Light-Assisted Advanced Oxidation Processes for the Elimination of Chemical and Microbiological Pollution of Wastewaters in Developed and Developing Countries

In this work, the issue of hospital and urban wastewater treatment is studied in two different contexts, in Switzerland and in developing countries (Ivory Coast and Colombia). For this purpose, the treatment of municipal wastewater effluents is studied, simulating the developed countries’ context, while cheap and sustainable solutions are proposed for the developing countries, to form a barrier between effluents and receiving water bodies. In order to propose proper methods for each case, the characteristics of the matrices and the targets are described here in detail. In both contexts, the use of Advanced Oxidation Processes (AOPs) is implemented, focusing on UV-based and solar-supported ones, in the respective target areas. A list of emerging contaminants and bacteria are firstly studied to provide operational and engineering details on their removal by AOPs. Fundamental mechanistic insights are also provided on the degradation of the effluent wastewater organic matter. The use of viruses and yeasts as potential model pathogens is also accounted for, treated by the photo-Fenton process. In addition, two pharmaceutically active compound (PhAC) models of hospital and/or industrial origin are studied in wastewater and urine, treated by all accounted AOPs, as a proposed method to effectively control concentrated point-source pollution from hospital wastewaters. Their elimination was modeled and the degradation pathway was elucidated by the use of state-of-the-art analytical techniques. In conclusion, the use of light-supported AOPs was proven to be effective in degrading the respective target and further insights were provided by each application, which could facilitate their divulgation and potential application in the field.

Treatment of hospital laundry wastewater by UV/H2O2 process

Hospitals consume a large volume of water to carry out their activities and, hence, generate a large volume of effluent that is commonly discharged into the local sewage system without any treatment. Among the various sectors of healthcare facilities, the laundry is responsible for the majority of water consumption and generates a highly complex effluent. Although several advanced oxidation processes (AOPs) are currently under investigation on the degradation of a variety of contaminants, few of them are based on real wastewater samples. In this paper, the UV/H₂O₂ AOP was evaluated on the treatment of a hospital laundry wastewater, after the application of a physicochemical pretreatment composed of coagulation-flocculation and anthracite filtration. For the UV/H₂O₂ process, a photoreactor equipped with a low-pressure UV-C lamp was used and the effects of initial pH and [H₂O₂]/chemical oxygen demand (COD) ratio on COD removal were investigated through a randomized factorial block design that considered the batches of effluent as blocks. The results indicated that the initial pH had no significant effect on the COD removal, and the process was favored by the increase in [H₂O₂]/COD ratio. Color and turbidity were satisfactorily reduced after the application of the physicochemical pretreatment, and COD was completely removed by the UV/H₂O₂ process under suitable conditions. The results of this study show that the UV/H₂O₂ AOP is a promising candidate for hospital laundry wastewater treatment and should be explored to enable wastewater reuse in the washing process.

Removal of pharmaceuticals from wastewater by fungal treatment and reduction of hazard quotients

The elimination of 81 pharmaceuticals (PhACs) by means of a biological treatment based on the fungus Trametes versicolor was evaluated in this work. PhAC removal studied in different types of wastewaters (urban, reverse osmosis concentrate, hospital, and veterinary hospital wastewaters) were reviewed and compared with conventional activated sludge (CAS) treatment. In addition, hazard indexes were calculated based on the exposure levels and ecotoxicity for each compound and used for the evaluation of the contaminants removal. PhAC elimination achieved with the fungal treatment (mean value 76%) was similar or slightly worse than the elimination achieved in the CAS treatment (85%). However, the fungal reactor was superior in removing more hazardous compounds (antibiotics and psychiatric drugs) than the conventional activated sludge in terms of environmental risk reduction (93% and 53% of reduction respectively). Fungal treatment can thus be considered as a good alternative to conventional treatment technologies for the elimination of PhACs from wastewaters.

Predicted and measured concentrations of pharmaceuticals in hospital effluents. Examination of the strengths and weaknesses of the two approaches through the analysis of a case study

This study deals with the chemical characterization of hospital effluents in terms of the predicted and measured concentrations of 38 pharmaceuticals belonging to 11 different therapeutic classes. The paper outlines the strengths and weaknesses of the two approaches through an analysis of a case study referring to a large hospital. It highlights the observed (and expected) ranges of variability for the parameters of the adopted model, presents the results of an uncertainty analysis of direct measurements (due to sampling mode and frequency and chemical analysis) and a sensitivity analysis of predicted concentrations (based on the annual consumption of pharmaceuticals, their excretion rate and annual wastewater volume generated by the hospital). Measured concentrations refer to two sampling campaigns carried out in summer and winter in order to investigate seasonal variability of the selected compounds. Predicted concentrations are compared to measured ones in the three scenarios: summer, winter and the whole year. It was found that predicted and measured concentrations are in agreement for a limited number of compounds (namely atenolol, atorvastatin and hydrochlorothiazide), and for most compounds the adoption of the model leads to a large overestimation in all three periods. Uncertainties in predictions are mainly due to the wastewater volume and excretion factor, whereas for measured concentrations, uncertainties are mainly due to sampling mode.

Hospital Effluents Are One of Several Sources of Metal, Antibiotic Resistance Genes, and Bacterial Markers Disseminated in Sub-Saharan Urban Rivers

Data concerning the occurrence of emerging biological contaminants such as antibiotic resistance genes (ARGs) and fecal indicator bacteria (FIB) in aquatic environments in Sub-Saharan African countries is limited. On the other hand, antibiotic resistance remains a worldwide problem which may pose serious potential risks to human and animal health. Consequently, there is a growing number of reports concerning the prevalence and dissemination of these contaminants into various environmental compartments. Sediments provide the opportunity to reconstruct the pollution history and evaluate impacts so this study investigates the abundance and distribution of toxic metals, FIB, and ARGs released from hospital effluent wastewaters and their presence in river sediments receiving systems. ARGs (bla TEM, bla CTX-M, bla SHV, and aadA), total bacterial load, and selected bacterial species FIB [Escherichia coli, Enterococcus (ENT)] and species (Psd) were quantified by targeting species specific genes using quantitative PCR (qPCR) in total DNA extracted from the sediments recovered from 4 hospital outlet pipes (HOP) and their river receiving systems in the City of Kinshasa in the Democratic Republic of the Congo. The results highlight the great concentration of toxic metals in HOP, reaching the values (in mg kg(-1)) of 47.9 (Cr), 213.6 (Cu), 1434.4 (Zn), 2.6 (Cd), 281.5 (Pb), and 13.6 (Hg). The results also highlight the highest (P < 0.05) values of 16S rRNA, FIB, and ARGs copy numbers in all sampling sites including upstream (control site), discharge point, and downstream of receiving rivers, indicating that the hospital effluent water is not an exclusive source of the biological contaminants entering the urban rivers. Significant correlation were observed between (i) all analyzed ARGs and total bacterial load (16S rRNA) 0.51 to 0.72 (p < 0.001, n = 65); (ii) ARGs (except bla TEM) and FIB and Psd 0.57 < r < 0.82 (p < 0.001, n = 65); and (iii) ARGs (except bla TEM) and toxic metals (Cd, Cr, Cu, and Zn) 0.44 to 0.72, (p < 0.001, n = 65). These findings demonstrate that several sources including hospital and urban wastewaters contribute to the spread of toxic metals and biological emerging contaminants in aquatic ecosystems.

Ciprofloxacin residue and antibiotic-resistant biofilm bacteria in hospital effluent

Discharge of antimicrobial residues and resistant bacteria in hospital effluents is supposed to have strong impacts on the spread of antibiotic resistant bacteria in the environment. This study aimed to characterize the effluents of the Gabriel Montpied teaching hospital, Clermont-Ferrand, France, by simultaneously measuring the concentration of ciprofloxacin and of biological indicators resistant to this molecule in biofilms formed in the hospital effluent and by comparing these data to ciprofloxacin consumption and resistant bacterial isolates of the hospital. Determination of the measured environmental concentration of ciprofloxacin by spot sampling and polar organic chemical integrative (POCIS) sampling over 2 weeks, and comparison with predicted environmental concentrations produced a hazard quotient >1, indicating a potential ecotoxicological risk. A negative impact was also observed with whole hospital effluent samples using the Tetrahymena pyriformis biological model. During the same period, biofilms were formed within the hospital effluent, and analysis of ciprofloxacin-resistant isolates indicated that Gamma-Proteobacteria were numerous, predominantly Aeromonadaceae (69.56%) and Enterobacteriaceae (22.61%). Among the 115 isolates collected, plasmid-mediated fluoroquinolone-resistant genes were detected, with mostly aac(6')-lb-cr and qnrS. In addition, 60% of the isolates were resistant to up to six antibiotics, including molecules mostly used in the hospital (aminosides and third-generation cephalosporins). In parallel, 1247 bacteria isolated from hospitalized patients and resistant to at least one of the fluoroquinolones were collected. Only 5 of the 14 species identified in the effluent biofilm were also found in the clinical isolates, but PFGE typing of the Gram-negative isolates found in both compartments showed there was no clonality among the strains. Altogether, these data confirm the role of hospital loads as sources of pollution for wastewater and question the role of environmental biofilms communities as efficient shelters for hospital-released resistance genes.

The contribution of pharmaceutically active compounds from healthcare facilities to a receiving sewage treatment plant in Canada

Concentrations and percent loadings of pharmaceutically active compounds (PhACs) and other emerging contaminants released from healthcare facilities (2 hospitals and a long-term care facility) to a sewage treatment plant (STP) in a large urban sewershed were evaluated. An additional hospital outside the sewershed was also monitored. Fourteen of the 24 steroids/hormones and 88 of the 117 PhACs and emerging contaminants were detected at least once. Commonly used substances, including cotinine, caffeine and its metabolite 1,7-dimethylxanthine, ibuprofen and naproxen (analgesics), venlafaxine (antidepressant), and N,N-diethyl-meta-toluamide (insect repellant), were detected in all samples at all sites. Concentrations detected in the large specialty hospital outside the sewershed were similar to those within the sewershed. Cytotoxic drugs (tamoxifen and cyclophosphamide) and x-ray contrast media (iopamidol and diatrizoic acid) were infrequently detected in hospital effluents. Analysis for antibiotics indicated that azithromycin, clarithromycin, ciprofloxacin, erythromycin, ofloxacin, and sulfamethoxazole were consistently detected in hospital wastewaters, as was triclosan (antibacterial agent). Fifteen compounds individually contributed greater than 1% to the total PhAC and emerging contaminant load to the STP from the 2 hospitals in the sewershed, and 9 compounds in the STP effluent exceeded ecotoxicological criteria. The present survey demonstrates that point source discharges from healthcare facilities in this sewershed make a small contribution to the overall PhAC and emerging contaminant loading compared with the total concentrations entering the receiving STP.

Dynamics of active pharmaceutical ingredients loads in a Swiss university hospital wastewaters and prediction of the related environmental risk for the aquatic ecosystems

The wastewater contamination of a Swiss university hospital by active pharmaceutical ingredient (API) residues was evaluated with a three months monitoring campaign at the outlet of the main building. Flow-proportional samples were collected with an automatic refrigerated sampler and analyzed for 15 API, including antibiotics, analgesics, antiepileptic and anti-inflammatory drugs, by using a validated LC-MS/MS method. The metals Gd and Pt were also analyzed using ICP-MS. Measured concentrations were compared to the predicted ones calculated after the drug average consumption data obtained from the hospital pharmacy. The hospital contribution to the total urban load was calculated according to the consumption data obtained from city pharmacies. Lastly, the environmental hazard and risk quotients (RQ) related to the hospital fraction and the total urban consumption were calculated. Median concentrations of the 15 selected compounds were ranging from 0.04 to 675 μg/L, with a mean detection frequency of 84%. The ratio between predicted and measured environmental concentrations (PEC/MEC) has shown a good accuracy for 5 out of 15 compounds, revealing over- and under-estimations of the PEC model. Mean daily loads were ranging between 0.01 and 14.2g/d, with the exception of paracetamol (109.7 g/d). The hospital contribution to the total urban loads varied from 2.1 to 100% according to the compound. While taking into account dilution and removal efficiencies in wastewater treatment plant, only the hospital fraction of the antibiotics ciprofloxacin and sulfamethoxazole showed, respectively, a high (RQ>1) and moderate (RQ>0.1) risk for the aquatic ecosystems. Nevertheless, when considering the total urban consumption, 7 compounds showed potential deleterious effects on aquatic organisms (RQ>1): gabapentin, sulfamethoxazole, ciprofloxacin, piperacillin, ibuprofen, diclofenac and mefenamic acid. In order to reduce inputs of API residues originating from hospitals various solutions can be envisioned. With results of the present study, hospital managers can start handling this important issue.

Hospital effluents management: Chemical, physical, microbiological risks and legislation in different countries

Hospital wastewater (HWW) can contain hazardous substances, such as pharmaceutical residues, chemical hazardous substances, pathogens and radioisotopes. Due to these substances, hospital wastewater can represent a chemical, biological and physical risk for public and environmental health. In particular, several studies demonstrate that the main effects of these substances can't be neutralised by wastewater treatment plants (WWTPs). These substances can be found in a wide range of concentrations due to the size of a hospital, the bed density, number of inpatients and outpatients, the number and the type of wards, the number and types of services, the country and the season. Some hazardous substances produced in hospital facilities have a regulatory status and are treated like waste and are disposed of accordingly (i.e., dental amalgam and medications). Legislation is quite homogeneous for these substances in all industrial countries. Problems that have emerged in the last decade concern substances and microorganisms that don't have a regulatory status, such as antibiotic residues, drugs and specific pathogens. At a global level, guidelines exist for treatment methods for these effluents, but legislation in all major industrial countries don't contain limitations on these parameters. Therefore, a monitoring system is necessary for these effluents as well as for substances and pathogens, as these elements can represent a risk to the environment and public health.

Biomarkers of Cytotoxic, Genotoxic and Apoptotic Effects in Cyprinus carpio Exposed to Complex Mixture of Contaminants from Hospital Effluents

Hospital wastewater is an important source of emerging contaminants. Recent studies emphasize the importance of assessing the effects of mixtures of contaminants rather than environmental risk of their individual components, as well as the determination of intrinsic toxicity of wastewater. Mixtures of pollutants has possible interactions that have notable environmental side effects. The aim of this study is an attempt to characterize biomarkers in Cyprinus carpio related to the exposure to a complex mixture of contaminants found in hospital wastewater. Results of a particular hospital effluent show the presence of traces of heavy metals, high chlorine concentration and emerging contaminants such as non-steroidal anti-inflammatory drugs. The LC50 was of 5.49 % at 96 h. The cytotoxic, genotoxic and apoptotic biomarkers increase when fishes were exposed to wastewater (1/10 CL50) from hospital wastewater. This study emphasizes the importance of identifying and quantifying the effects of contaminants as pharmaceuticals, disinfectants and surfactants in order to design and implement an ecotoxicological plan.

A posteriori assessment of ecotoxicological risks linked to building a hospital

Hospital wastewater (HWW) contain a large number of chemical pollutants such as disinfectants, surfactants, and pharmaceutical residues. A part of these pollutants is not eliminated by traditional urban wastewater treatment plants (WWTP), leading to a risk for the aquatic ecosystems receiving these effluents. In order to assess this risk, we formulated a specific methodology based on the ecotoxicological characterisation of the hospital wastewater using a battery of three chronic bioassays (Pseudokirchneriella subcapitata, Heterocypris incongruens and Brachionus calyciflorus). We used it for the posteriori risk assessment of a hospital recently built in south-east France, and we studied the evolution of this risk during two years. We also used it to assess the decrease of the ecotoxicological risk after treatment of the effluent in a specific line of the local WWTP. Lastly, we compared these results with the risk assessment made before the building of the hospital in the context of a priori risk assessment. The results obtained showed an important evolution of the risk overtime, according to the hospital activities and the river flows, and a real decrease of the risk after treatment in the dedicated line. They also showed that the a priori assessment of ecotoxicological risks, made previously, was overstated, mainly because of the application of the precautionary principle.

Separate treatment of hospital and urban wastewaters: A real scale comparison of effluents and their effect on microbial communities

Hospital wastewaters (HWW) contain wider spectrum and higher quantity of pharmaceuticals than urban wastewaters (UWW), but they are generally discharged in sewers without pretreatment. Since traditional urban wastewater treatment plants (WWTP) are not designed to treat HWWs, treated effluents may still contain pollutants that could impair receiving aquatic environments. Hence, a better understanding of the effect of pharmaceuticals in the environment is required. Biofilms are effective "biological sensors" for assessing the environmental effects of pharmaceuticals due to their ability to respond rapidly to physical, chemical and biological fluctuations by changes in their structure and composition. This study evaluated the efficiency of biological treatment with conventional activated sludge system performed parallel on HWW and UWW. Furthermore, six successive monthly colonizations of biofilms were done on autoclaved stones, placed in grid-baskets in the hospital treated effluents (HTE) and urban treated effluents (UTE). The biomass of these biofilms as well as the structure and diversity of their bacterial communities were investigated. Results showed better treatment efficiency for phosphate and nitrite/nitrate during the treatment of UWW. Pharmaceuticals from all investigated therapeutic classes (beta-blockers, nonsteroidal anti-inflammatory drugs, antibiotics, analgesics and anticonvulsants) were efficiently removed, except for carbamazepine. The removal efficiency of the antibiotics, NSAIDs and beta-blockers was higher during the treatment of HWW. HTE and UTE shaped the bacterial communities in different ways. Higher concentrations of pharmaceuticals in the HTE caused adapted development of the microbial community, leading to less developed biomass and lower bacterial diversity. Seasonal changes in solar irradiance and temperature, caused changes in the community composition of biofilms in both effluents. According to the removal efficiency of pharmaceuticals, the separate treatment was beneficial. However, their high concentrations in the HTE and the following adaptations of biofilm communities identify the importance of adapting wastewater treatment to specific hospital pollutants.

Dynamics of toxicity within different compartments of a peri-urban river subject to combined sewer overflow discharges

Combined Sewer Overflows (CSO) in small peri-urban streams and rivers are potentially toxic for their biocenosis. Improving the management of CSO discharges requires better knowledge of their dynamics and toxicity. In view to characterizing this toxicity, we sampled the different compartments (benthic and hyporheic zone) of a peri-urban stream located near the city of Lyon in France. The samples were taken at different distances from a CSO and at three period characteristic of different hydrological conditions. Their toxic effects were assessed by bioassays on the dissolved fraction (D. magna, V. fisheri and B. calyciflorus bioassays) and on the particle fraction (V. fisheri and H. incongruens bioassays). The results highlighted significant toxicity of the particulate fraction for the benthic and hyporheic samples, in particular downstream of the CSO, but with high spatio-temporal variability. This variability can first be attributed to the variability of CSO discharge sampling as a function of season and rainfall, and the dynamics of polluted particles (trapping of transported particles in infiltration zones, mobilization during floods). These parameters play a fundamental role in the distribution of pollutants according to the geomorphology of stream facies. Regarding dissolved pollutants, the chemical exchanges taking place at the "water-sediment" interface trigger the transfer of pollutants from one phase to another, after which the dispersion of these pollutants is governed by hydraulic flows. Finally, critical zones and periods are identified for the peri-urban river toxicity studied: benthic sediments under mean flow downstream; hyporheic sediments after a storm event downstream, close to the CSO. Recommendations are made on the basis of the knowledge obtained to optimize the management of these discharges.

What have we learned from worldwide experiences on the management and treatment of hospital effluent? - an overview and a discussion on perspectives

This study overviews lessons learned from experimental investigations on dedicated treatment systems of hospital effluent carried out worldwide in the last twenty years. It includes 48 peer reviewed papers from 1995 to 2015 assessing the efficacy of different treatment levels (preliminary, primary, secondary and polishing) of hospital wastewater in removing a wide spectrum of pharmaceutical compounds as well as conventional contaminants. Moreover, it highlights the rationale and the reasons for each study: reducing the discharge of micropollutants in surface water, improving existing wastewater treatment technologies and reducing the risk of spread of pathogens causing endemic diseases and finally, it offers a critical analysis of the conclusions and suggestions of each study. The most investigated technologies are membrane bioreactors equipped with ultrafiltration membranes in the secondary step, ozonation followed by activated carbon filtration (in powder and in granules) in the polishing step. Interesting research projects deal with photo-Fenton processes acting as primary treatments to enhance biodegradation before biological treatment, and as a polishing step, thus further reducing micro-contaminant occurrence. Investment and operational costs are also presented and discussed for the different treatment technologies tested worldwide, in particular membrane bioreactors and various advanced oxidation processes. This study also discusses the need for further research to evaluate toxicity resulting from advanced oxidation processes as well as the need to develop an accurate feasibility study that encompasses technical, ecotoxicological and economic aspects to identify the best available treatment in the different situations from a global view point.