key: cord-0773294-xm0zmt39
authors: Majumder, Abhradeep; Gupta, Ashok Kumar; Ghosal, Partha Sarathi; Varma, Mahesh
title: A review on hospital wastewater treatment: A special emphasis on occurrence and removal of pharmaceutically active compounds, resistant microorganisms, and SARS-CoV-2
date: 2020-11-22
journal: J Environ Chem Eng
DOI: 10.1016/j.jece.2020.104812
sha: 94a62254d1701670fed07646704d04ec570330be
doc_id: 773294
cord_uid: xm0zmt39

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.

Hospitals play a pivotal role in the well-being of humanity and facilitate research in the field of medical advancement. They help in complementing various parts of the health system and provide continuous services to tackle the complex health conditions of human beings [1] . The healthcare sector is one of the largest employers in the United States (US), with more than six million people employed at US hospitals with around 36.3 million admissions in 2018 [2] . The worth of the Indian health sector has been projected to jump from 140 billion U.S. dollars in 2016 to 372 billion dollars by 2022 [3] . With the onset of the COVID-19 pandemic, hospitals and other health care facilities have been responsible for giving a chance for survival to more than 20 million people affected by the SARS-CoV-2 virus. Concerning the ever-growing expansion of medication and health care activities in the hospital, the generation of large quantities of wastewater and its management is an impounding challenge in environmental engineering J o u r n a l P r e -p r o o f mg/L, 37.5 mg/L, and 34.4 mg/L, respectively (Fig. 1 a) . Lan et al. (2018) reported high concentrations of nitrate (217 mg/L) in a hospital effluent of France [45] . The concentrations of TSS, nitrate, and TN in hospital effluents of Europe were found to be higher than that of Asia and South America (Fig. 1 b) .

HWW also hosts a range of PhACs, personal care products, bacteria, protozoa, viruses, etc. which have been addressed in the following sections.

Emerging contaminants, such as PhACs are prevalent in the hospital effluent because of their excessive use in medical facilities, and their component-specific and continent-wise occurrence in hospital effluent has been depicted in Fig. 1 c, and Fig. 1 d, respectively. Nevertheless, the concentration of analgesics, antibiotics, β-blockers, hormones, etc. in hospital effluent was found to be much higher as compared to their concentrations in domestic wastewater [19, [46] [47] [48] . Although there are hundreds of PhACs detected in HWW, in this review the PhACs, which are most commonly detected and whose concentrations are such that they may pose a threat to the environment, have been considered. Analgesics, such as acetaminophen, diclofenac, ketoprofen, ibuprofen, naproxen, etc. were frequently detected in various hospital effluents [19, 36, [46] [47] [48] . The average concentration of analgesics in hospital discharge was found to be more in North America, as compared to Asia and Europe ( Fig.1 d) . The concentration of acetaminophen was found to be 374 μg/L and accounted for 45 % of the total PhAC average concentration in a hospital effluent of the US [36] . Langford and Thomas (2009) reported 325 μg/L of acetaminophen in hospital effluents of Norway [49] . Ibuprofen was found in the range of 2.8 to 36.5 μg/L in various hospital effluents of the US, Italy, Spain, and Norway [23, 36, 42, 49] . Diclofenac was found in concentrations ranging from 0.5 μg/L to 3 μg/L in HWW of Norway which was higher than the DWEL (0.2 μg/L to 0.3 μg/L) [19, 49] . Prasertkulsak et al. (2016) reported around 3.8 μg/L of diclofenac in the hospital effluent of Thailand [50] . Ciprofloxacin, sulfamethoxazole, trimethoprim, norfloxacin, J o u r n a l P r e -p r o o f and ofloxacin were the most frequently reported antibiotics in hospital effluents [19] . The average concentration of antibiotics in the hospital effluents of Asia and Europe were found to be in the same range ( Fig. 1 d) . Researchers reported norfloxacin (29.6 μg/L), sulfamethoxazole (81 μg/L), and ciprofloxacin (237 μg/L) in various hospital effluents of India [48, 51] . Ciprofloxacin concentrations in some HWW samples of India (>200 μg/L) and Portugal (38.6 μg/L) were considerably higher than the acceptable DWEL values [19, 48, 51] . Traces of sulfamethoxazole were found in some hospital effluent of Portugal (8.7 μg/L) and the US (2.2 μg/L) [36, 52] . Ofloxacin, levofloxacin, erythromycin, azithromycin were among other antibiotics found in various hospital effluents [19, 36, [46] [47] [48] . Atenolol, metoprolol, and propranolol were the most common β-blockers found in the hospital effluents of North America and Europe (Table S2) . Propranolol was detected in the range of 10 μg/L to 25 μg/L in a hospital effluent of Oslo, Norway [49] . Stimulants, such as caffeine were found in the range of 53 μg/L to 325 μg/L in the hospital discharges of the USA [36] . Hormones, such as estriol, estradiol, and estrone Thailand [50] . PhACs, such as carbamazepine, metformin, theobromine, theophylline, and gabapentin, was also common in hospital effluents of the US [36] . HWW was found to host a wide variety of PhACs and their metabolites, with analgesics and antibiotics being the most prevalent. Although the concentration of these compounds is not very high, they are highly toxic to biotic components of the environment. Most of the PhACs found in hospital effluent were at concentrations higher than the predicted no effect concentration (PNEC) values, while few PhACs, such as diclofenac and ciprofloxacin were found at concentrations higher than the DWEL values indicating a detrimental effect on human beings upon exposure [19] .

J o u r n a l P r e -p r o o f hospital effluent have been depicted in Fig. 3 . In European countries, such as Ireland, France, Sweden, Spain, Netherlands, Poland, 3.8 % to 13.6 % of the E. coli present in hospital effluents were found to be ESBLE [59] . Chagas et al. (2011) reported that out of 7.4 × 10 3 CFU/mL of coliforms found in a HWWs of Brazil, 38.6 % were ESBL-producing coliforms [5] . The percentage of ESBLE present in HWW was much higher compared to that in urban wastewater and discharge of wastewater treatment plant (WWTP) [59] . This was because HWW contains large amounts of antibiotics, disinfectants, etc., making the ESBL producing microorganisms resistant to them. Unlike normal E. coli, these ESBLEs produce infections in human beings that can no longer be treated by ordinary antibiotics, making them a potential cause of concern [59] . Pseudomonas aeruginosa is another multidrug-resistant pathogen found in HWW.

They occur as a result of mutations or gene transfer. They can be found in the water medium, having sufficient dissolved oxygen (DO) [59] . They have the capacity to acquire resistance to multiple classes of antibiotics, thereby making infections caused by such microorganisms more complex. They have been found in HWW in the range of 4 × 10 3 CFU/mL, out of which 76 % of them were resistant to one or more classes of antibiotics [63] . Enterococci, a very common bacteria usually found in the gastrointestinal tracts of humans and animals, have also exhibited resistance to antibiotics, and their prevalence has increased in the last few decades. In a HWW of France 6.5 × 10 6 CFU/mL of enterococci were detected, out of which almost all were resistant to amoxicillin [59] . A high prevalence of vancomycin-resistant enterococci was observed in hospital effluents of the United Kingdom and Portugal [64] [65] [66] . Fluoroquinolone resistant E. coli in European countries was found to increase from 25 % to 50 % between 2002 and 2007. Among others, Acinetobacter baumanni and Staphylococcus aureus also have shown the capacity to develop resistance to antimicrobials, such as methicillin [67] . Different phylums in HWW, such as proteobacteria, planctomycetes, nitrospirae, caldithrix, chlorobi, and J o u r n a l P r e -p r o o f common [68] .

There are more than 120 identified human enteric viruses, among which the enteroviruses (polio-, echoand coxsackieviruses), adenoviruses, hepatitis A, rotaviruses, and human caliciviruses (noroviruses) are most prevalent in HWW [69] . The presence of viruses in HWW is a cause for major environmental and public health concerns. The outbreak of severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) in 2019-20, leading to the global pandemic, COVID-19 is the most recent example of the threat, which viruses possess. Viruses are known to be highly stable even under adverse conditions and pose a potential threat to human health. During wastewater treatment, they may settle on the suspended matter present in the wastewater and become highly stable. The pathway of viruses into the hospital effluent has been depicted in Fig. 3 The virus, SARS-CoV-2, responsible for the pandemic in 2019-20, has been extensively studied all over the world. Since fecal shedding of SARS-CoV-2 RNA is widely reported, researchers investigated the J o u r n a l P r e -p r o o f presence of such RNA is municipal WWTPs of Spain and detected them in the untreated water [74] . The SARS-CoV-2 RNA was present in 11 % of the secondary treated water samples. confirmed the presence of SARS-CoV-2 RNA in the sewage samples of the hospital of Zhejiang University, China [75] . In another study, SARS-CoV-2 RNA was found in high concentrations of 0.5-18.7 × 10 3 copies/L in the septic tanks of Wuchang Cabin Hospital, Wuhan, China [76] . This RNA persisted even after disinfection by sodium hypochlorite. The reason behind the high level of persistence may be because the virus was embedded in the stool particles. However, when the dose of sodium hypochlorite was increased, no RNA was found, but high levels of disinfection by-products were detected [76] . Ahmed et al. (2020) detected 1.9 to 12 copies/100 mL of SARS-CoV-2 RNA in wastewater samples in Australia [77] . In Ahmedabad, India, Kumar et al. (2020) tested water samples from a WWTP receiving effluent from a hospital treating COVID-19 patients [78] . Three genes of SARS-CoV-2, i.e., ORF1ab, N, and S genes, were detected in the influent of the WWTP. The number of copies of RNA detected increased by ten times over a period of 20 days, during which the number of COVID-19 patients also increased by two times in Ahmedabad. A similar correlation between the number of SARS-CoV-2 RNA and the number of COVID-19 patients was also observed in Australia, China, and France [76] [77] [78] [79] . reported 2 × 10 5 and 3 × 10 4 copies/L SARS-CoV-2 RNA copies/L in the wastewater of Massachusetts, United States of America, and Bozeman, Montana, respectively, while wastewater in France accounted for 10 5 to 10 6 SARS-CoV-2 RNA copies/L [80] .

Haramoto et al. (2020) reported 2.4 × 10 3 copies/L of SARS-CoV-2 RNA in the wastewater of Japan [82] . The frequency of detection of SARS-CoV-2 RNA in the wastewater and hospital effluent samples was correlated with the percentage of people (per country) affected by the virus (Fig. 2 b) . The person's correlation coefficient was calculated to be 0.79, which indicated a strong positive trend [83] . The results suggested that the occurrence of SARS-CoV-2 RNA in wastewater was directly related to the J o u r n a l P r e -p r o o f percentage of people infected. Furthermore, proper wastewater monitoring can help in identifying areas with COVID-19 infected people. Although most viruses are known to be highly stable even in adverse environmental conditions, SARS-CoV-2 was unstable in the presence of disinfectants and at a temperature higher than 20 °C [71, 84] . However, these viruses can survive when they get enveloped inside fecal particles or suspended solids. Furthermore, the entrapped virus in sewage can generate virus-laden aerosols during wastewater flushing and provide an air-borne route for the virus to transmit [85, 86] Tertiary treatment can also be provided directly after pre-treatment, however, the performance of these processes are usually hindered due to high organic and nutrient loading [87, 88] . The remediation of HWW using ASP has been widely practiced in countries all over the world ( Table   2 ). Kosma et al. (2010) implemented a full-scale HWW treatment system in Greece comprising of a grit chamber, mix tanks, aeration tank, and disinfection ( Table 2 ). The effluent from the aeration tank was treated with chlorine, and the average removal of PhAC obtained was 51.45 %. Amongst the PhACs, diclofenac was found to exhibit negative removal [89] . Mousaab et al. (2015) combined HDPE biofilms and ultrafiltration with ASP to treat wastewater having PhACs ( Table 2) . The system provided a removal percentage of around 100 %, 93 %, and 91 % for TSS, COD, and TN, respectively. The average PhAC removal was found to be 78 % [90] . However, diclofenac, trimethoprim, and hydrochlorothiazide showed low removal of 30 %, 21 %, and 11 %, respectively. Mousaab et al. (2015) also observed that there was a significant increase in the performance of the system when the HDPE biofilms were incorporated [90] . Yuan et al. (2013) studied the performance of two conventional full-scale ASPs in HWW treatment plants in China [91] . The average PhAC removal percentage obtained for the two ASPs were 84 % and 39 %, respectively. Although compounds, such as olanzapine (93-98 % andrisperidone (72-95 %) , showed high removal percentages, lorazepam, oxazepam, carbamazepine, clozapine, sulpiride, and quetiapine were found to be resistant to degradation due to their complex structures [91] .

Furthermore, negative removal of PhACs was also observed for compounds, such as lorazepam, oxazepam, zaleplon, sulfide, etc. in one of the ASPs. This may be the result of the conjugates of the parent compound present in the WWTP effluent return back to their parent form after undergoing enzymatic modifications in the treatment system [91] . Lien et al. (2016) studied the PhACs removal from HWW of Vietnam [11] . Two full-scale treatment units were considered for the study. Although more than 80 % removal was achieved, negative removal was observed for nitrite and nitrate in both the systems [93] . This may be due to the fact that there was no anaerobic unit to denitrify the produced nitrate and nitrite. The aeration unit converted the present ammonia to nitrate, thereby increasing the concentration of nitrate in the effluent [93, 94] .

It can be observed from Fig. 4 e, that the average PhACs removal resulting from ASP based technologies varied from 40 % to 99 %. Furthermore, there was a significant increase in PhAC removal when chlorination was combined with ASP. This may be because the presence of chlorine in water releases various radicals with high oxidizing potential, which helps in the degradation of the complex PhACs. The average TSS removal from all the ASP-based studies was found to be higher than 90 % ( Fig. 4 a) . The removal percentages of BOD, COD, and ammonia were also found to be around 80 % and higher (Fig. 4 b, c, and d), suggesting that the conventional ASP, if properly modified or provided with necessary pre-treatment can be an effective solution for remediating hospital effluent. 

CWs are rapidly gaining popularity in the field of wastewater treatment because of their versatility and robust nature [94, 95] . Although CWs require a large amount of land and regular maintenance of the macrophytes, various removal mechanisms, such as phytoremediation, filtration, microbial degradation, adsorption, etc. occur simultaneously in CWs, making them a suitable option for HWW management.

Along with the efficient removal of BOD, COD, etc., CWs have been known to degrade recalcitrant organic pollutants as well [94] . Auvinen et al. (2017) implemented a transportable pilot-scale subsurface flow CW (1 m 3 ) to treat HWW in Belgium [96] . The main features of this CW have been mentioned in Table 2 . This system achieved a COD and ammonia removal of 83 % and 95 %, respectively. However, negative removal for nitrate was observed, which was due to the conversion of ammonia to nitrate [96] . [99] .

The performance of CWs in terms of COD, BOD, and TSS removal was comparable to other treatment methods (Fig. 4) . The removal of ammonia was a significant drawback, primarily in the case of horizontal subsurface flow CWs. This was primarily because there is insufficient dissolved oxygen present in such systems, thereby preventing complete nitrification of ammonia by aerobic microorganisms [94] . However, due to the prevailing anaerobic conditions, the horizontal subsurface and achieved more than 90 % removal of BOD and ammonia [102] . In another study, a pilot-scale submerged MBR with shallow ultrafiltration fiber membranes to treat HWW. This system provided J o u r n a l P r e -p r o o f more than 95 % removal of TSS, BOD, and ammonia after a HRT of 14 h [103] . Cartagena et al. (2013) used MBR based treatment to achieve more than 98 % COD removal, 99 % ammonia removal, and 82 % TN removal. Furthermore, the system could also remove around 78 to 82 % of the PhACs [100] . Kovalova et al. (2012) treated hospital effluent in Switzerland using a pilot-scale MBR set-up comprising of one oxic and one anoxic chamber [87] . The treatment unit handled a flow of 1.2 m 3 /day, and a primary clarifier was provided after the MBR unit. Although the average removal of PhACs was greater than 90 %, the average removal of iodinated X-ray contrast media was significantly low (2 %).

X-ray compounds, such as phenazonec and oseltamivirc showed high negative removal percentage of -158 % and -42 %, respectively [87] . In order to remove the X-ray contrast media, Kovalova et al. (2013) combined the MBR set-up separately with ozone treatment, UV treatment, and adsorption by powdered activated carbon (PAC) [88] . The removal percentage of PhACs and X-ray contrast media increased to 99 % and 51 %, respectively, when the effluent of the MBR was subjected to ozone treatment using 1.08 gO 3 /gDOC. The removal percentage of X-ray contrast media further increases to 62 %, when the effluent from MBR was subjected to adsorption by PAC (dose= 23 mg/L) instead of ozone treatment.

When the MBR effluent was subjected to UV treatment (2400 J/m 2 ), degradation of X-ray contrast media increased to 66 %, but the average removal of PhACs dropped to 93 % [88] .

In another study, a very low average PhAC removal of around 34 % using an MBR pilot unit. However, PhACs, such as oxcarbamazepine, paracetamol, sulfadiazine, and sulfamethoxazole, were almost completely removed [10] . In order to increase the performance of the system, the effluent of the MBR was further treated with PAC at a dose of 450 mg/L. The adsorption enhanced the PhAC removal percentage to around 80 to 90 % [10] . In another study, more than 95 % removal for COD and ammonia was observed using an MBR after 31.3 h retention time (Beier et al., 2012) [57] . Beier et al. (2010) observed the removal of PhACs from hospital effluent using another MBR based treatment system J o u r n a l P r e -p r o o f combined with reverse osmosis. The system was able to achieve greater than 99 % removal of PhACs [104] .

A combination of MBR and UV treatment to treat hospital effluent of Luxembourg. This pilot-scale treatment unit handled a flow of about 3.33 m 3 /day [105] . The wastewater was subjected to the radiation of a 10 kW UV medium-pressure lamp, and hydrogen peroxide was also added to enhance the performance of the system. A removal percentage of 90 % COD and 70 % TN was achieved from this system. Furthermore, an average removal percentage of 73 % of PhACs was observed. However, some PhACs like erythromycin and ifosfamide showed almost no removal [105] .

MBR based systems could effectively remove BOD, COD, ammonia, and TSS from HWW (Fig. 4) . It was also found that MBR systems can effectively remove PhACs. When they were used in the absence of any additional advanced treatment, an average removal of around 60 % was observed for PhACs (Fig.   S1 ). The performance of the MBRs further increased when the effluent from the MBR was subjected to UV treatment or adsorption. However, the maximum removal of PhACs was observed when the MBR was combined with ozone treatment or reverse osmosis (Fig. S1 ). MBR based technologies were found to be more effective as compared to other treatment methods demonstrating high removal of BOD, COD, TSS, ammonia, and PhAC (Fig. 4) . However, MBR based technologies are subjected to clogging and fouling of the membrane. As a result, they need regular cleaning with chemicals, and maintaining them is a costly affair. Fouling of membrane brings down the performance of the MBRs [106] [107] [108] [109] . This problem can be addressed by aeration, gas-scrubbing, or regular backwashing [110, 111] (Table 2 ). Aeration was provided at a rate of 0.50 L/h for proper mixing, and a retention time of 6 h was provided for the reactors [112] . Although Casas et al. (2015) attained more than 99 % removal for ammonium, there was negative nitrate removal [112] . This was due to the conversion of ammonium to nitrate, and the presence of excess aerobic conditions, denitrification of nitrate could not occur. The average removal percentage for PhACs was only 33 %, whereas sulfamethoxazole showed negative removal. However, ibuprofen and clindamycin showed more than 90 % removal [112] . Ooi et al. (2018) conducted another pilot study with six reactors with each reactor specially designed for particular purposes, such as denitrification and nitrification.

However, the average removal percentage of PhACs was around 50 % [113] . Shokoohi et al. (2017) implemented a pilot-scale treatment unit comprising of two cylindrical columns as MBBRs to treat hospital effluent in Iran. This treatment unit could effectively reduce COD and BOD of wastewater by more than 95 % [114] . It is evident from Fig. 4 that MBBR can perform effectively in terms of BOD, COD, and ammonia removal. However, denitrification is a major drawback for which additional denitrifying units have to be implemented to take into consideration the excess nitrate. Furthermore, the average PhAC removal of MBBR was also found to be less as compared to other treatment units (Fig.   4 ). This may be because the PhACs are toxic and kill the microorganisms, thereby limiting biological degradation [19] . Furthermore, loss of biofilms is a major problem associated with MBBR processes which can affect the performance of the systems [115, 116] of an up-flow anaerobic sludge blanket (UASB) followed by a filtration unit [6] . The HRT provided for the UASB digestion was 8 h, and the effluent coming out of it was passed through three anaerobic filters in series. This full-scale treatment unit was successful in achieving 82 % COD reduction, 90 % BOD reduction, and 74 % ammonia reduction [6] .

Hunachew and Getachew (2011) used waste stabilization ponds (WSP) as a full-scale treatment unit to treat hospital effluent in Ethiopia [117] . The system achieved a removal percentage of 87 %, 86 %, and 94 % for TSS, COD, and BOD, respectively, after an HRT of 29 days. However, there was a drastic increase in the concentration of total ammonia in the final effluent. This could be accounted for the rise in the pH of the effluent, which led to the conversion of ammonium ions to ammonia gas [117] . The reduction of TN by 54.5 % and nitrate by 68 % along with more than 80 % removal for TSS, BOD, and COD indicated that this system is robust, it can be used to treat large volumes of wastewater with high loading.

In Indonesia, an aerated fixed film bio-filter was followed by an ozone reactor (pilot-scale) for the treatment of PhACs [118] . Almost complete removal of PhACs was observed using this treatment, indicating ozone treatment is essential to enhance the degradation of PhACs. Similarly, Kovalova et al. % and 61 % of X-Ray contrast media, respectively [88] . It can be seen that UV treatment was not as efficient as ozone treatment and adsorption for degrading PhACs. Furthermore, ozone treatment, UV treatment, adsorption are not self-sufficient treatment technologies to completely remove recalcitrant organic pollutants. However, when they were combined with a MBR system, the removal percentages J o u r n a l P r e -p r o o f get significantly improved [88] . Sim et al. (2013) used chemical flocculation followed by adsorption using activated carbon in a full-scale HWW treatment unit in Korea [119] . It was observed that in spite of using adsorption using activated carbon, the average removal percentage of the PhACs was only 39 %. This may be due to the low log k ow values of the PhACs, making them hydrophilic in nature and preventing them from getting adsorbed [19] .

Amongst other advanced oxidation processes, plasma discharge has gained substantial popularity in the past few years. Although such processes require high initial cost and skilled maintenance, they have been known to be highly effective in treating PhACs. However, the electrical energy required for these processes was found to be considerably low as compared to other advanced oxidation processes, such as photocatalysis, anodic oxidation, etc. [19] . Ajo More than 99 % removal of total coliforms was obtained using MBR, WSP, ASP and CWs J o u r n a l P r e -p r o o f [10, 12, 92, 98, 117] . Similar results were obtained in terms of removal of E. coli, fecal bacteria, and total enterococci using MBR based technologies, ASP and CWs [10, 12, 57, 92, 98, 102, 103] .

Although HWW treatment units have shown promise in terms of reduction of microbial load, the proportion of antibiotic-resistant microorganisms increase after the treatment [59] . Hocquet et al. (2016) reported that there was a significant increase in ESBL producing E. coli in the effluent of the WWTP effluent [59] . After conducting a thorough literature survey, Hocquet et al. (2016) concluded that the ratio of ESBL producing E. coli to normal E. coli in the wastewater increased after undergoing treatment [59] . On the other hand, the proportion of vancomycin producing enterococci was not altered after going through treatment units, and the proportion of multidrug-resistant P. aeruginosa was found to decrease in WWTP effluent. Although a portion of the antibiotic-resistant microorganisms has been removed in WWTPs, some strains of the resistant microorganisms are released to the environment, which may pose a serious threat to aquatic organisms [63] .

Various treatment strategies have also been implemented to remove ARB and ARG from water and wastewater [62] . Due to an insufficient number of studies related to the removal of ARG and ARB from HWW, studies pertaining to the removal of ARB and ARG from all kinds of water matrices have also been highlighted in this work. Disinfection was found to be very efficient in terms of drastically reducing the number of ARB and ARG in wastewater [120] [121] [122] [123] [124] [125] . In order to inactivate the ARG inside the bacteria cells, the disinfectant should be able to pass through the cell envelope without getting bound to other cellular constituents. A sufficient quantity of disinfectant should be present to react with the ARG containing DNA, thereby making disinfectant dose a vital factor in the efficient inactivation of ARG [126, 127] . During chlorination, various oxidizing radicals are generated, which help in the inactivation of the DNA [128, 129] . varied the dose of chlorine from 15 to 300 mg Cl 2 min/L to study its effect on the removal of ARB. A minimum dose of 60 mg Cl 2 min/L was required to J o u r n a l P r e -p r o o f inactivate sulfadiazine-and erythromycin-resistant bacteria. Furthermore, only 15 mg Cl 2 min/L was found to be sufficient for other types of bacteria present in the water [130] . However, a detailed quantitative real-time investigation by revealed that chlorination alone could not effectively remove ARG [130] . More than 40 % of erythromycin and tetracycline-resistant genes were persistent in wastewater even after chlorination. Auerbach et al. (2007) revealed that UV irradiation was also not effective in removing ARG [131] . studied the inactivation of ARG by only chlorine, only UV irradiation, and sequential UV/chlorination and found that the inactivation of ARG was directly proportional to chlorine dose and contact time [120] . The required chlorine dose for the inactivation of different microorganisms has been depicted in Fig. 6 . The maximum inactivation achieved was in the range of 1.30 to 1.49 log unit at 30 mg L −1 chlorine dose [120] . High intensity of UV irradiation (249.5 mJ/cm 2 ) was also required for the irradiation to be absorbed into the RNA and DNA, thereby inactivating the ARG. The synergistic effect of chlorination and UV irradiation was also prominent as it led to better inactivation of ARG. observed that at a dose of 80 mg Cl 2 min/L, the frequency of ARG transfer was greatly suppressed [132] . Fenton-based process, ozone treatment, and electron beam treatment have also been implemented to inactivate ARB and ARG [133] [134] [135] [136] ]. An absorbed dose of 0.5 kGy of the electron beam was required for 90 % removal of ARG and ARB [62, 134] . The performance of ozone treatment, electron beam treatment, and Fenton processes can be further increased by the addition of hydrogen peroxide [62] . Inactivation of ARG and ARB by photocatalysis have also been studied extensively [137] [138] [139] . The generation of hydroxyl radicals, superoxide radicals, and holes take part in oxidizing the ARG and ARB. An increase in the dose of photocatalysts led to decreased survival fractions of the bacteria [139] . Although advanced oxidation processes have shown considerable promise in terms of ARG and ARB inactivation, these processes have proved to be expensive and up-scaling them to pilot/full-scale treatment system is still a major J o u r n a l P r e -p r o o f challenge [19] . Alternatively, biological processes, such as CWs and MBR have been efficient in terms of ARG and ARB inactivation [10, 12, [140] [141] [142] [143] . Huang et al. (2015) used a vertical upflow CW to remove ARG. After a HRT of 5 days, around 99 % removal of ARGs was obtained [140] . Chen et al. (2015) studied the removal of ARGs using horizontal subsurface CWs and attained around 95 % to 99 % removal after a HRT of 1.5 days [141] . In another study, involving horizontal subsurface flow CW, 87 % to 97 % removal of ARG, such as tetA, tetB, and tetM was achieved. However, only 50 % removal of ARG, sul1 was achieved [142] . The high removal of ARGs in CWs may be due to exposure to sunlight, resulting in photolysis and aerobic degradation [62] . Dires et al. (2018) reported that 100 % of the Salmonella isolates found in hospital effluent of Ethiopia were resistant to ampicillin and 75 % of them were resistant to doxycycline, erythromycin, ceftazidime, cefoxitin, and chloramphenicol. 82 % of E. coli were found to be resistant to ampicillin, and around 73 % were found to be resistant to cotrimoxazole and amoxicillin-clavulanic acid [12] . After [143] . Although there was a decline in the number of ARB in the effluent of the ASP, complete removal was not achieved. However, no traces of ARB were found in the effluent of the MBR. On the other hand, the ARG present in MBR effluent was less than the detection limit of the instrument used to measure [143] .

Viruses have been found in varying quantities in treated HWW. Their numbers vary with other microbial cells in the ratio of 10:1, and the viral DNA represents 0.1 % of the total DNA in the J o u r n a l P r e -p r o o f microorganisms [68] . Viruses are small infectious agents having the size of 10 to 200 nm in crosssection and usually get adsorbed on to the surface of the suspended solids, thereby making them more stable [32, 69] . Furthermore, they are protected by layers of fat or protein [144] . Their persistence in the treating HWW of Tunisia using natural oxidizing lagoons and rotating bio disks [146] . However, around 90 % removal of sapovirus was achieved using the natural oxidizing lagoons and rotating bio disks [146, 147] .

Few biological treatment units have been efficient in removing viruses from wastewater. Lv et al. (2006) used submerged MBR and achieved almost complete removal of phage T4 (a model virus) [148] . Two different membrane modules were used for this study. In the case of the 0.22 μm module, the cake layer, the gel layer, and the membrane contributed to phage removal in 6.3, 3.1, and 1.7 log-scale, respectively.

On the other hand, for the 0.1 μm module, the membrane alone was responsible for the maximum removal of phage [148] . MBR based treatment technologies have been effective in terms of virus J o u r n a l P r e -p r o o f removal as the dynamic layer on the membrane surface helps in rejection of virus, and the activated sludge helps in the inactivation of the virus [32] . Virus exclusion by membrane-based technologies, such as reverse osmosis, microfiltration, and ultrafiltration, is achieved by size exclusion mechanism. The physicochemical properties of the membrane, surface properties of the virus, and their electrostatic or hydrophobic interaction with the aqueous solution also play a significant role in the removal of viruses by membrane processes [69] . Researchers have obtained significant amount of virus removal using reverse osmosis, ultrafiltration and microfiltration [149] [150] [151] [152] [153] [154] [155] [156] [157] . The 'capture cone' is referred to the passage of the virus through the holes in the membrane surface, and it was found to decrease with the increase in transmembrane pressure [152] . It was observed that the aged reverse osmosis membrane helped in the adsorption of a virus surrogate (MS2 phage), and the rejection of MS2 phage was found to be in the order of 4 log-scale, in spite of damage to the membrane [157] .

Viruses are also susceptible to chlorination, and UV treatment and a chlorine dose of 2 mg min/L to 30 mg min/L was found to be sufficient to obtain 4 log removal values [69] . High doses of UV (>186 mJ/cm 2 ) could also attain the 4 log removal values for adenovirus, which is known to be one of the most resistant viruses. Virus removal in the range of 8 log removal and 10 log removal was also achieved using such traditional disinfection methods in Australia and the US, respectively [69] . In order to attain 4 log removal of adenovirus, hepatitis A, and coxsackie B virus, 0.5 to 1.0 mg min/L, 1.0 to 8.0 mg min/L, and 11.0 to 30.0 mg min/L of free chlorine was required (pH = 6 to 9 and temperature = 5 to 20 °C), respectively [158] . On the other hand, while using monochloramine a dose of 1000 to 8000 mg min/L, 1000 to 2000 mg min/L, and 700 to 3000 mg min/L was required to attain 4 log removal of adenovirus, hepatitis A, and coxsackie B virus (pH = 7 to 8 and temperature = 5 to 15 °C) [158] . The required chlorine dose for the inactivation of different viruses has been depicted in Fig. 6 .

The presence of SARS-CoV-2 RNA in HWW and municipal wastewater has gained attention due to the recent outbreak of the COVID-19 pandemic. They have been reported in HWW, domestic sewage, effluents of WWTPs, raw municipal wastewater, pasteurized settled sewage, etc. [159] . The coronavirus is a virus that is enveloped in a protective layer of fat, thereby giving its stability. However, disinfectants tear apart the fat layer making them susceptible [144] . Over the years, many researchers have reported that the disinfection of the wastewater has proved to be efficient in terms of the removal of the SARS- 

ARG, ARB, viruses, recalcitrant organic compounds, such as PhACs, personal care products, X-ray contrast media form an integral part of the HWW. The presence of these components makes the HWW less biodegradable, toxic, and difficult to treat [163] . Over the past decade, research has been focused on the removal of PhACs, ARG, ARB, and other recalcitrant organic compounds by various emerging J o u r n a l P r e -p r o o f technologies, such as photocatalytic degradation, photolysis, anodic oxidation, Fenton's processes, treatment using nanoparticles, etc. [19, 24, 62, [163] [164] [165] [166] . These systems have been highly efficient in removing HWW specific contaminants and can be up-scaled for in-situ treatment of hospital effluents.

Photocatalytic treatment involves the use of materials (photocatalysts) having a low bandgap, which are excited by photons from a given light source. When the photons have an energy greater than the bandgap of the photocatalysts, electron-hole pairs are generated. The generated holes react with the water molecules to generate hydroxyl radicals, which in turn reacts with the organic contaminants to degrade them [19, [166] [167] [168] [169] . The other reactive species generated during photocatalysis, such as superoxide radicals, singlet oxygen, and holes also have a redox potential and can actively take part in photocatalytic degradation [19, 62] . Photocatalytic treatment can effectively bring down the concentration of PhACs by around 90 %. Furthermore, the reaction time in photocatalysis is also very less as compared to many biological processes [19, 166] . The performance of the photocatalytic process depends on several parameters, such as the type of catalyst used, the light source, the physicochemical properties of the PhACs, etc. [19] . Researchers have reported high removal of around 99 %, 100 %, 90 %, 88 %, 100 %, 95 %, 100 %, 95 %, 90 %, for various PhACs such as ciprofloxacin, erythromycin, trimethoprim, tetracycline, sulfamethoxazole, paracetamol, naproxen, atenolol, metoprolol, respectively [19, 167, [170] [171] [172] [173] [174] [175] . Photocatalytic processes have also been known to inactivate ARB as well. UV radiation is effective for the inactivation of viruses, ARB, and ARG [62] . Tsai et al. (2010) investigated the removal of methicillin-resistant S. aureus, multidrug-resistant Acinetabacter baumannii, vancomycin-resistant Enterococcus faecalis, S. aureus, A. baumannii, E. faecalis, and E. coli using titanium dioxide-based photocatalyst [139] . The photocatalytic degradation could oxidize the bacteria and the number of bacteria was reduced by 1 -3 log units [139] . Inactivation of different ARB and E. [176, 177] . The properties of photocatalysts to simultaneously degrade PhACs and oxidize microorganisms make the process a lucrative option that can be up-scaled for HWW management [164] .

Various studies have been carried out to degrade PhACs and microorganisms using Fenton-based processes [19, 62] . Hydroxyl radicals are the primary oxidizing radical in Fenton-based processes, which are generated resulting from the reaction between hydrogen peroxide and Fe +2 /Fe +3 [19, 62] . One significant advantage of Fenton processes over photocatalysis is that the consumed catalyst in Fenton processes can be regenerated using photo-radiation or electrolytic forces [19] . Mondal and H 2 O 2 to obtain almost complete removal of atenolol [180] . Alizadeh Fard and Barkdoll (2018) used iron electrodes and provided a current intensity of 300 mA to obtain 100 % removal of ketoprofen [181] . Karaolia et al. (2014) investigated the performance of solar-Fenton oxidation in terms of the inactivation of ARB and achieved a 5 log reduction of ARB [136] . In another study, 2.42 -3.48 log reduction of ARGs was observed using Fenton based processes. Fenton-based processes have been efficient in the removal of PhACs and microorganism in an average reaction time of 2 h [19, 62] . However, a significant drawback of this process is that the Fenton-based processes show better performance in acidic medium (pH of 3) [19, 62] .

J o u r n a l P r e -p r o o f

In anodic oxidation, water is oxidized to form hydroxyl radicals using high O 2 evolution overvoltage anodes (Pt, PbO2, SnO2, BDD) [19] . The hydroxide radicals along with other oxidizing agents, such as peroxydisulfate, hypochlorous acid, biphosphate, peroxydicarbonate, etc. which are generated due to the presence of sulfate ions, chlorine ions, phosphate ions, carbonate ions, etc., also take part in the degradation of the PhACs and microorganisms [19, 182] . Boron doped diamond anode is the most commonly used anode in anodic oxidation. The anodic oxidation processes involving boron-doped diamond as the anode could effectively degrade erythromycin, paracetamol, naproxen, and trimethoprim [187, 188] . Jeong et al. (2006) found out that the hydroxyl radicals generated during the anodic oxidation process are one of the major species responsible for the inactivation of E. coli in a chlorine-free environment. Furthermore, the inactivation of E. coli was promoted at lower temperatures [182] . In another study, a mixed metal oxide anode was used to effectively achieve log 2 reduction of Deinococcus geothermalis, Pseudoxanthomonas taiwanensis, and Meiothermus silvanus [189] . The electrical energy per order required to remove PhACs and inactivate ARB and other microorganisms was found to be less as compared to photocatalysis, ultrasound treatment, and other processes, which makes anodic oxidation a good alternative to address the HWW specific contaminants [19] .

The anti-microbial property of various nanoparticles, such as silver nanoparticles, copper oxide nanoparticles, zinc oxide nanoparticles, iron oxide nanoparticles, etc. have proved to be effective in J o u r n a l P r e -p r o o f inactivating ARB and ARG [62, [190] [191] [192] . Furthermore, nanoparticles are characterized by high surface area, which facilitates the adsorption of PhACs and other contaminants present in wastewater. The various functional groups present in synthesized adsorbents also enhance the adsorption of organic contaminants [19, [193] [194] [195] . Rajendran and Sen. (2018) achieved around 90 % removal of carbamazepine using biosynthesized hematite nanoparticles [195] . Ali et al. (2019) used composite iron nanoparticles to achieve 92 % removal of ibuprofen [196] . Metal-organic frameworks have also been efficient in terms of the removal of PhACs [193, 197] . Although nanoparticles are efficient in adsorption of PhACs, the PhACs are only transferred from the aqueous phase to a solid phase and they are not completely removed from the environment. Proper disposal of sludge is essential for the treatment of wastewater using adsorption [19, 194, 198] .

One of the major challenges in the field of HWW management is the monitoring and detection of the pollutants [199] . PhACs and other recalcitrant organic compounds are present in the HWW is the range of ng/L to μg/L, which require highly sensitive to quantify [19, 36, 169, 200, 201] . Proper detection of such contaminants in necessary to implement proper legislations for HWW management [199] . Only a few guidelines pertaining to hospital waste management, such as "Effluent Guidelines and Standards (CFR 40) (NPDES) (National Pollutant Discharge Elimination System)" by EPA, 2015, "Safe management of wastes from healthcare activities" by WHO, 2013, etc. exist [1, 199] . However, these guidelines do not provide any standards for specific pollutants, such as PhAC, personal care products, etc. Lack of such legislations has led to increased disparity in the characteristics of the effluent from one country to another. Hospital effluents are often discharged into the urban sewer system, where they mix with other effluents from different sectors, before undergoing treatment in a sewage treatment plant.

This practice is common in many developed and developing countries [21, 199] . However, in many other J o u r n a l P r e -p r o o f developing countries, hospital effluents are discharged into rivers, lakes, and drainage systems, without any prior treatment [21, 199] . In Pakistan, proper wastewater treatment facility lacked in many of the hospitals [202] . In Taiwan, few hospitals discharge their effluent in to the rivers with only scarce treatment [203] . In Indonesia, many of the hospitals discharge their effluent using infiltration wells or in to receiving water bodies [118] . The wastewater coming out of the hospitals without undergoing any specific or in-situ treatment comprises of PhACs and other recalcitrant components. These components, which are specific to hospital wastewater upon mixing with the municipal wastewater, make the municipal wastewater more complex and difficult to be treated. Many of the sewage treatment plants are not able to completely treat such complex wastewater because they are not designed to tackle the recalcitrant organic compounds [143, 200] . Hence, strict legislations should be implemented, which provides pollutant specific discharge standards and mandates the on-site treatment of HWW. General awareness among the public and participation of the community is integral for the proper management of HWW. However, only a small fraction of the general population understands the benefits of proper HWW management and shows interest in participating in activities related to HWW management, which causes a major hindrance to efficient HWW management. [204, 205] . The recalcitrant organic compounds are often completely not removed in biological treatment methods. Due to the inconsistent chemical, physical and biological properties of the PhACs and other recalcitrant organic compounds, different removal mechanisms have to occur, in order to enhance their removal. As a result, they were found to be removed effectively when tertiary treatment processes, such as a membrane process, adsorption process or oxidation process followed the biological systems [10, 88, 89, 103, 206, 207] . There are various emerging technologies, such as photocatalysis, anodic oxidation, adsorption, Fenton oxidation, etc. which can effectively remove PhACs, personal care products, ARGs, ARB, and other recalcitrant compounds. However, most of these studies are lab-scale and conducted on synthetic J o u r n a l P r e -p r o o f wastewater. As a result, more research is required on these technologies before they can be implemented in the field [166, 174, 208, 209] .

Hospitals are significant contributors to a large amount of complex wastewater to inland surface water and municipal sewer. Furthermore, it was found that hospitals in developed countries generated much higher quantities of wastewater than developing countries. HWW comprises a wide range of contaminants, such as recalcitrant PhACs, viruses, ARG, ARB, and high nutrient content. A low biodegradability index makes the treatment of HWW more challenging. PhACs, such as diclofenac and ciprofloxacin, were present in HWW at concentrations higher than the DWEL. Among the pilot/fullscale treatment units considered in this study, MBR and ASP were found to be the most efficient. The performance of these systems got further enhanced if an additional unit, such as ozone treatment, adsorption, chlorination, reverse osmosis, nanofiltration, etc. was incorporated into the system. It was also found that the advanced treatment systems, such as adsorption, UV, or ozone treatment, could only be used as a polishing unit, and these systems alone could not produce desirable outcomes if the wastewater is not pre-treated.

Apart from the PhACs, pathogenic entities were found to be present in large numbers. Although common microorganisms, such as E. coli, fecal bacteria, coliforms were efficiently removed by WWTPs, the ARG and ARB were more persistent and required high doses of chlorination ( J o u r n a l P r e -p r o o f Table 2 ).

J o u r n a l P r e -p r o o f 

Hospital wastewater treatment scenario around the globe

• Total hospitals number U.S. 1975-2018 | Statista

• India -healthcare sector size

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

Multiresistance, beta-lactamase-encoding genes and bacterial diversity in hospital wastewater in Rio de Janeiro, Brazil

Quantification and molecular characterization of enteric viruses detected in effluents from two

Surveillance of antimicrobial resistance among Escherichia coli in wastewater in Stockholm during 1 year: Does it reflect the resistance trends in the society?

Removal of APIs and bacteria from hospital wastewater by MBR plus O 3, O3 + H2O2, PAC or ClO2

Antibiotics in Wastewater of a Rural and an Urban Hospital before and after Wastewater Treatment, and the Relationship with Antibiotic Use-A One Year Study from Vietnam

Antibiotic resistant bacteria removal of subsurface flow constructed wetlands from hospital wastewater

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

Wastewater Engineering: Treatment and Reuse (Book), Fourth, McGraw-Hill Education

Water Analysis -Chemical Oxygen Demand, in: Encycl

Wastewater Engineering: Treatment and Reuse

Characteristics of water quality of municipal wastewater treatment plants in China: Implications for resources utilization and management

A novel approach for pathogen reduction in wastewater treatment

Pharmaceutically active compounds in aqueous environment: A status, toxicity and insights of remediation

Microbial and Viral Communities and Their Antibiotic Resistance Genes Throughout a Hospital Wastewater Treatment System

Hospital wastewater treatments adopted in Asia, Africa, and Australia

Drugs in the environment: Emission of drugs, diagnostic aids and disinfectants into wastewater by hospitals in relation to other sources -A review

Hospital effluent: Investigation of the concentrations and distribution of pharmaceuticals and environmental risk assessment

Occurrence, sources and conventional treatment techniques for various antibiotics present in hospital wastewaters: A critical review

Characterisation of the ecotoxicity of hospital effluents: A review

Hospital effluents as a source of emerging pollutants: An overview of micropollutants and sustainable treatment options

Liquid biomedical waste management: An emerging concern for physicians

Guide to infection control in the hospital

Groundwater contamination by microbiological and chemical substances released from hospital wastewater: Health risk assessment for drinking water J o u r n a l P r e -p r o o f consumers

Clinical Liquid Waste Management in Three Ghanaian Healthcare Facilities -a Case Study of Sunyani Municipality

Application of MBR for hospital wastewater treatment in China

Characterization of medical waste from hospitals in Tabriz

Hospital wastewater: Existing regulations and current trends in management

Faecal indicator bacteria and antibiotic-resistant β-lactamase producing Escherichia coli in blackwater: A pilot study

Characterization of Pharmaceuticals and Personal Care products in hospital effluent and waste water influent/effluent by direct-injection LC-MS-MS

Effective adsorption of non-biodegradable pharmaceuticals from hospital wastewater with different carbon materials

The status of industrial and municipal effluent treatment with membrane bioreactor technology

Degradation of β-blockers in hospital wastewater by means of ozonation and Fe2+/ozonation

Application of advanced oxidation processes followed by different treatment technologies for hospital wastewater treatment

Horizontal sub surface flow Constructed Wetlands coupled with tubesettler for hospital wastewater treatment

Pre-treatment of hospital wastewater by coagulation-flocculation and flotation

Physico-chemical, microbiological and ecotoxicological evaluation of a septic tank/Fenton reaction combination for the treatment of hospital wastewaters

Evaluation of biodegradability and oxidation degree of hospital wastewater using photo-Fenton process as the pretreatment method

Nanofiltration performances after membrane bioreactor for hospital wastewater treatment: Fouling mechanisms and the quantitative link between stable fluxes and the water matrix

The occurrence of pharmaceuticals, personal care products, endocrine disruptors and illicit drugs in surface water in South Wales

Occurrence patterns of pharmaceutical residues in wastewater, surface water and groundwater of Nairobi and Kisumu city

A review of the occurrence of pharmaceuticals and personal care products in Indian water bodies

Determination of pharmaceutical compounds in hospital effluents and their contribution to wastewater treatment works

Removals of treatment plant

MBR technology: A promising approach for the (pre-)treatment of hospital wastewater

Wastewater Treatment Plants Release Large Amounts of Extended-Spectrum

Lactamase-Producing Escherichia coli Into the Environment Wastewater Treatment Plants Release Large Amounts of Extended-Spectrum β-Lactamase-Producing Escherichia coli Into the Environment

What happens in hospitals does not stay in hospitals: antibiotic-resistant bacteria in hospital wastewater systems

Enumeration and characterization of antimicrobial-resistant escherichia coli bacteria in effluent from municipal, hospital, and secondary treatment facility sources

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

A review of the influence of treatment strategies on antibiotic resistant bacteria and antibiotic resistance genes

Tracking Down Antibiotic-Resistant Pseudomonas aeruginosa Isolates in a Wastewater Network

Presence of vancomycin and ampicillin-resistant Enterococcus faecium of epidemic clonal complex-17 in wastewaters from the south coast of

Vancomycin resistant enterococci: From the hospital effluent to the urban wastewater treatment plant

BlaTEM and vanA as indicator genes of antibiotic resistance contamination in a hospital-urban wastewater treatment plant system

Antimicrobial Residues and Antimicrobial-Resistant Bacteria: Impact on the Microbial Environment and Risk to Human Health-A Review

Fate of pathogens and viruses in hospital wastewater and their treatment methods

Reverse osmosis integrity monitoring in water reuse: The challenge to verify virus removal -A review

Molecular detection and genoty

Study on the resistance of severe acute respiratory syndrome-associated coronavirus

Survival of Coronaviruses in Water and Wastewater

Concentration and detection of SARS coronavirus in sewage from Xiao Tang Shan Hospital and the 309th Hospital

SARS-CoV-2 RNA in wastewater anticipated COVID-19 occurrence in a low prevalence area

SARS-CoV-2 RNA detection of hospital isolation wards hygiene monitoring during the Coronavirus Disease 2019 outbreak in a Chinese hospital

Potential spreading risks and disinfection challenges of medical wastewater by the presence of Severe Acute Respiratory Syndrome Coronavirus

RNA in septic tanks of Fangcang Hospital

First confirmed detection of SARS-CoV-2 in untreated wastewater in Australia: A proof of concept for the wastewater surveillance of COVID-19 in the community

The first proof of the capability of wastewater surveillance for COVID-19 in India through the detection of the genetic material of SARS-CoV-2

Quantification and Genetic Analysis of Salivirus/Klassevirus in Wastewater in Arizona, USA

SARS-CoV-2 in wastewater: State of the knowledge and research needs

First environmental surveillance for the presence of SARS-CoV-2 RNA in wastewater and river water in Japan

First environmental surveillance for the presence of SARS-CoV-2 RNA in wastewater and river water in Japan

The correlation between effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) with renal scintigraphy 99mTc-DTPA study

Current emerging SARS-CoV-2 pandemic: Potential direct/indirect negative impacts of virus persistence and related therapeutic drugs on the aquatic compartments

An Imperative Need for Research on the Role of Environmental Factors in Transmission of Novel Coronavirus (COVID-19)

Gamal El-Din, Transmission of SARS-CoV-2 via fecal-oral and aerosolsborne routes: Environmental dynamics and implications for wastewater management in underprivileged societies

Hospital wastewater treatment by membrane bioreactor: Performance and efficiency for organic micropollutant elimination

Elimination of micropollutants during post-treatment of hospital wastewater with powdered activated carbon, ozone, and UV

Occurrence and removal of PPCPs in municipal and hospital wastewaters in Greece

Upgrading the performances of ultrafiltration membrane system coupled with activated sludge reactor by addition of biofilm supports for the treatment of hospital effluents

Detection, occurrence and fate of 22 psychiatric pharmaceuticals in psychiatric hospital and municipal wastewater treatment plants in Beijing, China

Investigation of optimal method for hospital wastewater treatment

Investigating the removal of some pharmaceutical compounds in hospital wastewater treatment plants operating in Saudi Arabia

A review on treatment of petroleum refinery and petrochemical plant wastewater: A special emphasis on constructed wetlands

A review on performance of constructed wetlands in tropical and cold climate: Insights of mechanism, role of influencing factors, and system modification in low temperature

Removal of pharmaceuticals by a pilot aerated sub-surface flow constructed wetland treating municipal and hospital wastewater

Use of broken brick to enhance the removal of nutrients in subsurface flow constructed wetlands receiving hospital wastewater

Constructed Wetland technology transfer to Nepal

Removal and monitoring acetaminophen-contaminated hospital wastewater by vertical flow constructed wetland and peroxidase enzymes

Reduction of emerging micropollutants, organic matter, nutrients and salinity from real wastewater by combined MBR-NF/RO treatment

Bacterial population changes in hospital effluent treatment plant in central India

Treatment of hospital wastewater using a submerged membrane bioreactor

Management of hospital wastewaters: The case of the effluent of a large hospital situated in a small town

Treatment of hospital wastewater effluent by nanofiltration and reverse osmosis

Elimination of pharmaceutical residues in biologically pre-treated hospital wastewater using advanced UV J o u r n a l P r e -p r o o f irradiation technology: A comparative assessment

Application of membrane bioreactor technology in treating high strength industrial wastewater: A performance review

Efficacy of relaxation, backflushing, chemical cleaning and clogging removal for an immersed hollow fibre membrane bioreactor

Biofouling Mitigation in Forward Osmosis Using Graphene Oxide Functionalized Thin-Film Composite Membranes

Fouling characterisation in membrane bioreactors

Membranes and wastewater: Modular treatment systems offer solutions, Filtr

Effective biodegradation of organic matter and biogas reuse in a novel integrated modular anaerobic system for rural wastewater treatment: A pilot case study

Biodegradation of pharmaceuticals in hospital wastewater by staged Moving

Biological removal of pharmaceuticals from hospital wastewater in a pilot-scale staged moving bed biofilm reactor (MBBR) utilising nitrifying and denitrifying processes

Modelling of moving bed biofilm reactor (MBBR) efficiency on hospital wastewater (HW) treatment: a comprehensive analysis on BOD and COD removal

Nitrifying moving bed biofilm reactor (MBBR) biofilm and biomass response to long term exposure to 1°C

To study the performance of biocarriers in moving bed biofilm reactor (MBBR) technology and kinetics of biofilm for retrofitting the existing aerobic treatment systems: A review

Assessment of Waste Stabilization Ponds for the Treatment of Hospital Wastewater: The Case of Hawassa University Referral Hospital

Hospital wastewater treatment using aerated fixed film Biofilter--ozonation (Af2b/O3)

Hospital wastewater treatment with pilot-scale pulsed corona discharge for removal of pharmaceutical residues

Inactivation of antibiotic resistance genes in municipal wastewater by chlorination, ultraviolet, and ozonation disinfection

Removal of bacterial contaminants and antibiotic resistance genes by conventional wastewater treatment processes in Saudi Arabia: Is the treated wastewater safe to reuse for agricultural irrigation?

Inactivation and regrowth of multidrug resistant bacteria in urban wastewater after disinfection by solar-driven and chlorination processes

Effects of ultraviolet light disinfection on tetracycline-resistant bacteria in wastewater effluents

Effect of ultraviolet irradiation and chlorination on ampicillin-resistant Escherichia coli and its ampicillin resistance gene

Bacterial Community Shift Drives Antibiotic Resistance Promotion during Drinking Water Chlorination

Potential impacts of disinfection processes on elimination and deactivation of antibiotic resistance genes during water and wastewater treatment

Mechanisms of Escherichia coli inactivation by several disinfectants

The acid ionization constant of HOCl from 5 to 35°

Reactions of chlorine with inorganic and organic compounds during water treatment-Kinetics and mechanisms: A critical review

Fate of antibiotic resistant bacteria and genes during wastewater chlorination: Implication for antibiotic resistance control

Tetracycline resistance genes in activated sludge wastewater treatment plants

Distinguishing effects of ultraviolet exposure and chlorination on the horizontal transfer of antibiotic resistance genes in municipal wastewater

Treatment of E. coli HB101 and the tetM gene by Fenton's reagent and ozone in cow manure

The effect of tetracycline in the antibiotic resistance gene transfer before and after ozone disinfection

Trends in the Intensification of the Fenton Process for Wastewater Treatment: An Overview

Reduction of clarithromycin and sulfamethoxazole-resistant Enterococcus by pilot-scale solar-driven Fenton oxidation

Visible-light activation of TiO2 photocatalysts: Advances in theory and experiments

Effect of photocatalysis on the transfer of antibiotic resistance genes in urban wastewater

A comparative study of the bactericidal effect of photocatalytic oxidation by TiO2 on antibiotic-resistant and antibioticsensitive bacteria

Performance of vertical up-flow constructed wetlands on swine wastewater containing tetracyclines and tet genes

Removal of antibiotics and antibiotic resistance genes in rural wastewater by an integrated constructed wetland

Dynamics of antibiotic resistance genes and their relationships with system treatment efficiency in a horizontal subsurface flow constructed wetland

Removal of antibiotic residues, antibiotic resistant bacteria and antibiotic resistance genes in municipal wastewater by membrane bioreactor systems

Does disinfecting surfaces really prevent the spread of coronavirus?, Science (80-. ). f (2020)

A review of virus removal in wastewater treatment pond systems

Removal of human astroviruses from hospital wastewater by two biological treatment methods: natural oxidizing lagoons and rotating biodisks

Detection of Sapoviruses in two biological lines of Tunisian hospital wastewater treatment

Virus removal performance and mechanism of a submerged membrane bioreactor

Micro-organism rejection by membrane systems

Removal of coliphages in secondary effluent by microfiltration -Mechanisms of removal and impact of operating parameters

Understanding virus filtration membrane performance

Virus passage through compromised low-pressure membranes: A particle tracking model

Effect of transmembrane pressure on rejection of viruses by ultrafiltration membranes

Role of hydrophobic and electrostatic interactions for initial enteric virus retention by MF membranes

Monitoring the integrity of reverse osmosis membranes

Removal of biological and non-biological viral surrogates by spiral-wound reverse osmosis membrane elements with intact and compromised integrity

Virus removal and integrity in aged RO membranes

Required Chlorination Doses to Fulfill the Credit Value for Disinfection of Enteric Viruses in Water: A Critical Review

A review on presence, survival, disinfection/removal methods of coronavirus in wastewater and progress of wastewater-based epidemiology

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Disinfecting Water: Plasma Discharge for Removing Coronaviruses

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A comprehensive review on the use of second generation TiO2 photocatalysts: Microorganism inactivation

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Advanced oxidation process-mediated removal of pharmaceuticals from water: A review

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Enhanced photocatalytic degradation of 17β-estradiol by polythiophene modified Al-doped ZnO: Optimization of synthesis parameters using multivariate optimization techniques

Kinetics and mechanism of advanced oxidation processes (AOPs) in degradation of ciprofloxacin in water

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Emerging pollutant mixture mineralization by TiO 2 photocatalysts. The role of the water medium

Inactivation/reactivation of antibiotic-resistant bacteria by a novel UVA/LED/TiO2 system

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Kinetics of the Chemical Oxidation of the Pharmaceuticals Primidone, Ketoprofen, and Diatrizoate in Ultrapure and Natural Waters

Photo-Fenton decomposition of beta-blockers atenolol and metoprolol; study and optimization of system parameters and identification of intermediates

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Development and optimization of the BDD-electrochemical oxidation of the antibiotic trimethoprim in aqueous solution

Mineralization of paracetamol in aqueous medium by anodic oxidation with a boron-doped

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The electrochemical degradation of ciprofloxacin using a SnO 2 -Sb / Ti anode : Influencing factors , reaction pathways and energy demand

Experimental design methodology applied to electrochemical oxidation of carbamazepine using Ti/PbO2 and Ti/BDD electrodes

Electrochemical inactivation of paper mill bacteria with mixed metal oxide electrode

Silver polymeric nanocomposites as advanced antimicrobial agents: Classification, synthetic paths, applications, and perspectives

Organic-coated silver nanoparticles in biological and environmental conditions: Fate, stability and toxicity

Characterisation of copper oxide nanoparticles for antimicrobial applications

Adsorptive Removal of Pharmaceuticals and Personal Care Products from Water with Functionalized Metal-organic Frameworks: Remarkable Adsorbents with Hydrogen-bonding Abilities

Green synthesis of iron oxide nanoparticles for arsenic remediation in water and sludge utilization

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Synthesis of composite iron nano adsorbent and removal of ibuprofen drug residue from water

Adsorptive removal of pharmaceuticals from water using metalorganic frameworks: A review

Industrial waste derived biosorbent for toxic metal remediation: Mechanism studies and spent biosorbent J o u r n a l P r e -p r o o f management

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Yew-Hoong Gin, Occurrence and fate of emerging contaminants in municipal wastewater treatment plants from different geographical regions-a review

Photo-induced degradation of bio-toxic Ciprofloxacin using the porous 3D hybrid architecture of an atomically thin sulfur-doped g-C3N4/ZnO nanosheet

Occurrence and ecological risk assessment of fluoroquinolone antibiotics in hospital waste of

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Public Opinion on Environmental Policy in the United States

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Evaluation of pharmaceuticals and personal care products with emphasis on anthelmintics in human sanitary waste, sewage, hospital wastewater, livestock wastewater and receiving water

Advanced oxidation processes in water/wastewater treatment: Principles and applications. A review

Facile synthesis of Fe/Bi2SiO5 nanocomposite with enhanced photocatalytic activity for degradation of 17β-Estradiol(E2)

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Monitoring hospital wastewaters for their probable genotoxicity and mutagenicity

Preliminary study of physico-chemical treatment options for hospital wastewater

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The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.