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Due to urbanization, there is an increasing need for infrastructure and services, leading to pressure on the sewage system. As a result, water contamination and sewage-related illnesses are emerging. On-site sanitary facilities are insufficient, and current sewage systems are outdated, causing freshwater contamination and diseases such as typhoid, malaria, etc. Untreated domestic sewage/wastewater, mining waste, industrial wastewater, agricultural waste, and other contaminants are polluting most aquatic ecosystems worldwide, leading to harm to surface water bodies, sewage drainage systems, surface water, and groundwater. Various sewage disposal methods are discussed, but they are not sustainable. The UN proposed Sustainable Development Goals (SDGs) in response to the need for sustainability and the effects of pollution and population growth. SDG 6 aims to ensure equitable access to safe and affordable drinking water, sanitation, and hygiene. It also includes goals to enhance water quality, increase water usage efficiency, develop integrated water resource management, and restore aquatic ecosystems. Efficient sewage disposal is crucial to reduce detrimental effects on the environment and public health. It is necessary to emphasize SDGs to protect the environment sustainably. It is crucial for the international community to work together to find effective and sustainable solutions to the problem of sewage management.

Antibiotic resistance surveillance is an objective of global action plan on antimicrobial resistance endorsed by the World Health Organization. The current study reports the identification of frequently occurring Gram-negative bacterial community (GNBC) previously isolated from municipal treated wastewater and their antibiotic resistance profiles. Further, the genes responsible for extended-spectrum beta lactamases (ESBL) activity were identified in ESBL-positive organisms. The isolates were characterized using biochemical assays and identification was confirmed by VITEK®2 automated system. Antibiotic susceptibility testing against seven different classes of antibiotics was also performed on the same system using AST-N280 cards. The most dominant isolates identified were Acinetobacter baumannii, Morganella morganii, Kluyvera intermedia, Stenotrophomonas maltophilia, Escherichia coli, Aeromonas hydrophila/caviae, Klebsiella pneumoniae, Enterobacter cloacae and Citrobacter freundii. The isolates were observed to be significantly resistant against the antibiotics amoxicillin-clavulanic acid, cefuroxime, cefuroxime axetil and colistin. Two of the isolates, E. cloacae sp. dissolvens and S. maltophilia, were found to be positive for ESBL activity encoded by blaCTX-M gene. The possible intrusion of hospital wastewater in domestic sewage is also discussed. This study may help assess the risk of wastewater reuse by detecting dominant bacteria as a step towards the development of new microbiological standards. HIGHLIGHTS Stenotrophomonas maltophilia found to be most resistant and E. coli least resistant among the isolates.; Five isolates found to be resistant to the last resort antibiotic Colistin.; Molecular determinant of two extended spectrum beta lactamase producing isolates found to be blaCTX-M gene.; This report might aid in devising a suitable strategy for reducing risk to human health upon treated wastewater reuse.

Biotechnological tools engaged in the bioremediation process are in reality, sophisticated and dynamic in character. For specialized reasons, a broad variety of such devices are employed to produce a safe and balanced environment free of all types of toxins and so make life simpler for humans on planet Earth. Actinomycetes is one of these extremely important and functionally helpful groups. They can be used for a variety of bioremediation objectives, including biotransformation, biodegradation, and many more. Actinomycetes are one of the most varied groups of filamentous bacteria, capable of prospering in a variety of ecological settings because to their bioactive capabilities. They’re famous for their metabolic diversity, which includes the synthesis of commercially useful primary and secondary metabolites. They produce a range of enzymes capable of totally destroying all of the constituents. They are well-known for their ability to produce bioactive secondary metabolites. Members of various genera of Actinomycetes show promise for application in the bioconversion of underutilized urban and agricultural waste into high-value chemical compounds. The most potential source is a wide range of important enzymes, some of which are synthesized on an industrial scale, but there are many more that have yet to be discovered. Bioremediation methods, which use naturally existing microbes to clear residues and contaminated regions of dangerous organic chemicals, are improving all the time. In the realm of biotechnological science, the potential of actinomycetes for bioremediation and the synthesis of secondary metabolites has opened up intriguing prospects for a sustainable environment.

Wastewater-based epidemiology (WBE) has been considered as a promising approach for population-wide surveillance of coronavirus disease 2019 (COVID-19). Many studies have successfully quantified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA concentration in wastewater (CRNA). However, the correlation between the CRNA and the COVID-19 clinically confirmed cases in the corresponding wastewater catchments varies and the impacts of environmental and other factors remain unclear. A systematic review and meta-analysis were conducted to identify the correlation between CRNA and various types of clinically confirmed case numbers, including prevalence and incidence rates. The impacts of environmental factors, WBE sampling design, and epidemiological conditions on the correlation were assessed for the same datasets. The systematic review identified 133 correlation coefficients, ranging from -0.38 to 0.99. The correlation between CRNA and new cases (either daily new, weekly new, or future cases) was stronger than that of active cases and cumulative cases. These correlation coefficients were potentially affected by environmental and epidemiological conditions and WBE sampling design. Larger variations of air temperature and clinical testing coverage, and the increase of catchment size showed strong negative impacts on the correlation between CRNA and COVID-19 case numbers. Interestingly, the sampling technique had negligible impact although increasing the sampling frequency improved the correlation. These findings highlight the importance of viral shedding dynamics, in-sewer decay, WBE sampling design and clinical testing on the accurate back-estimation of COVID-19 case numbers through the WBE approach.

The present study tracked the city-wide dynamics of severe acute respiratory syndrome-corona virus 2 ribonucleic acids (SARS-CoV-2 RNA) in the wastewater from nine different wastewater treatment plants (WWTPs) in Jaipur during the second wave of COVID-19 out-break in India. A total of 164 samples were collected weekly between February 19th and June 8th, 2021. SARS-CoV-2 was detected in 47.2% (52/110) influent samples and 37% (20/54) effluent samples. The increasing percentage of positive influent samples correlated with the city's increasing active clinical cases during the second wave of COVID-19 in Jaipur. Furthermore, wastewater-based epidemiology (WBE) evidence clearly showed early detection of about 20 days (9/9 samples reported positive on April 20th, 2021) before the maximum cases and maximum deaths reported in the city on May 8th, 2021. The present study further observed the presence of SARS-CoV-2 RNA in treated effluents at the time window of maximum active cases in the city even after tertiary disinfection treatments of ultraviolet (UV) and chlorine (Cl2) disinfection. The average genome concentration in the effluents and removal efficacy of six commonly used treatments, activated sludge process + chlorine disinfection (ASP + Cl2), moving bed biofilm reactor (MBBR) with ultraviolet radiations disinfection (MBBR + UV), MBBR + chlorine (Cl2), sequencing batch reactor (SBR), and SBR + Cl2, were compared with removal efficacy of SBR + Cl2 (81.2%) > MBBR + UV (68.8%) > SBR (57.1%) > ASP (50%) > MBBR + Cl2 (36.4%). The study observed the trends and prevalence of four genes (E, RdRp, N, and ORF1ab gene) based on two different kits and found that prevalence of N > ORF1ab > RdRp > E gene suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. Hence, it is imperative to say that using a combination of different detection genes (E, N, RdRp, & ORF1ab genes) increases the sensitivity in WBE.

Wastewater-based epidemiology (WBE) approach for COVID-19 surveillance is largely based on the assumption of SARS-CoV-2 RNA shedding into sewers by infected individuals. Recent studies found that SARS-CoV-2 RNA concentration in wastewater (CRNA) could not be accounted by the fecal shedding alone. This study aimed to determine potential major shedding sources based on literature data of CRNA, along with the COVID-19 prevalence in the catchment area through a systematic literature review. Theoretical CRNA under a certain prevalence was estimated using Monte Carlo simulations, with eight scenarios accommodating feces alone, and both feces and sputum as shedding sources. With feces alone, none of the WBE data was in the confidence interval of theoretical CRNA estimated with the mean feces shedding magnitude and probability, and 63% of CRNA in WBE reports were higher than the maximum theoretical concentration. With both sputum and feces, 91% of the WBE data were below the simulated maximum CRNA in wastewater. The inclusion of sputum as a major shedding source led to more comparable theoretical CRNA to the literature WBE data. Sputum discharging behavior of patients also resulted in great fluctuations of CRNA under a certain prevalence. Thus, sputum is a potential critical shedding source for COVID-19 WBE surveillance.

The present study tracked the city-wide dynamics of severe acute respiratory syndrome-corona virus 2 (SARS-CoV-2) RNA in the wastewater from nine different wastewater treatment plants (WWTPs) in Jaipur during second wave of COVID-19 out-break in India. A total of 164 samples were collected weekly between February 19th and June 8th, 2021. SARS-CoV-2 was detected in 47.2% (52/110) influent samples and 37% (20/54) effluent samples. The increasing percentage of positive influent samples correlated with the city’s increasing active clinical cases during the second wave of COVID-19 in Jaipur. Furthermore, WBE based evidence clearly showed early detection of about 20 days (9/9 samples reported positive on April 20th, 2021) prior to the maximum cases & maximum deaths reported in the city on May 8th, 2021. The present study further observed the presence of SARS-CoV-2 RNA in treated effluents at the time window of maximum active cases in the city even after tertiary disinfection treatments of UV & Chlorine. The average genome concentration in the effluents and removal efficacy of six commonly used treatments; Activated Sludge Treatment + Chlorine disinfection (ASP + Cl2), Moving Bed Biofilm Reactor (MBBR) with Ultraviolet radiations disinfection (MBBR + UV), MBBR + Chlorine (Cl2), Sequencing Batch Reactor (SBR) and SBR + Cl2 were compared with removal efficacy of SBR + Cl2 (81.2%)> MBBR + UV (68.8%) > SBR (57.1%) > ASP (50%) > MBBR + Cl2(36.4%). The study observed the trends & prevalence of four genes (E, RdRp, N, and ORF1ab gene) based on two different kits and found that prevalence of N> ORF1ab >RdRp> E gene, suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. Hence, it is imperative to say that using a combination of different detection genes (E, N, RdRp & ORF1ab genes) reduce false positives in WBE.Graphical AbstractHighlightsSuccessful application of WBE with prediction of 14-20 days for COVID-19 in JaipurA comparison of SARS-CoV-2 RNA removal efficacy of 9 WWTPs was investigatedSBR showed better performance than MBBR with SARS-CoV-2 RNA removal from wastewaterPresence of SARS-CoV-2 in effluents even after UV and Chlorine disinfectionUsing a combination of different detection genes reduce false positives in WBE

As a cost-effective and objective population-wide surveillance tool, wastewater-based epidemiology (WBE) has been widely implemented worldwide to monitor the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA concentration in wastewater. However, viral concentrations or loads in wastewater often correlate poorly with clinical case numbers. To date, there is no reliable method to back-estimate the coronavirus disease 2019 (COVID-19) case numbers from SARS-CoV-2 concentrations in wastewater. This greatly limits WBE in achieving its full potential in monitoring the unfolding pandemic. The exponentially growing SARS-CoV-2 WBE dataset, on the other hand, offers an opportunity to develop data-driven models for the estimation of COVID-19 case numbers (both incidence and prevalence) and transmission dynamics (effective reproduction rate). This study developed artificial neural network (ANN) models by innovatively expanding a conventional WBE dataset to include catchment, weather, clinical testing coverage and vaccination rate. The ANN models were trained and evaluated with a comprehensive state-wide wastewater monitoring dataset from Utah, USA during May 2020 to December 2021. In diverse sewer catchments, ANN models were found to accurately estimate the COVID-19 prevalence and incidence rates, with excellent precision for prevalence rates. Also, an ANN model was developed to estimate the effective reproduction number from both wastewater data and other pertinent factors affecting viral transmission and pandemic dynamics. The established ANN model was successfully validated for its transferability to other states or countries using the WBE dataset from Wisconsin, USA.

The present study investigated the detection of severe acute respiratory syndrome– coronavirus 2 (SARS-CoV-2) genomes at each treatment stage of 14 aerobic wastewater treatment plants (WWTPs) serving the major municipalities in two states of Rajasthan and Uttarakhand in Northern India. The untreated, primary, secondary and tertiary treated wastewater samples were collected over a time frame ranging from under-lockdown to post-lockdown conditions. The results showed that SARS-CoV-2 RNA was detected in 13 out of 40 wastewater samples in Jaipur district, Rajasthan and in 5 out of 14 wastewater samples in the Haridwar District, Uttarakhand with the E gene predominantly observed as compared to the N and RdRp target genes in later time-points of sampling. The Ct values of genes present in wastewater samples were correlated with the incidence of patient and community cases of COVID-19. This study further indicates that the viral RNA could be detected after the primary treatment but was not present in secondary or tertiary treated samples. This study implies that aerobic biological wastewater treatment systems such as moving bed biofilm reactor (MBBR) technology and sequencing batch reactor (SBR) are effective in virus removal from the wastewater. This work might present a new indication that there is little to no risk in relation to SARS-CoV-2 while reusing the treated wastewater for non-potable applications. In contrast, untreated wastewater might present a potential route of viral transmission through WWTPs to sanitation workers and the public. However, there is a need to investigate the survival and infection rates of SARS-CoV-2 in wastewater. Published version This research was funded by research grants from the Department of Biotechnology-GoI [Grant No. BT/RLF/Re-entry/12/2016].

In the recent decades, the role of wastewater treatment plants has been entrenched for the dissemination of antibiotic resistant bacteria into the environment. The present study explores the dynamics of earthworms-microorganisms interactions involved in the high treatment efficacy of vermifiltration technology along with reduction of antibiotic resistant bacteria (ARB). This study is the first of its kind to investigate the performance efficacy of vermifilter (VF) for clinical laboratory wastewater treatment. The results of the study showed that earthworms and VF associated microbial community had a significant effect on Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) reduction (78–85%), coliforms and pathogen removal (>99.9%) and caused a significant shift in the prevalence pattern of ARB. Molecular profiling of resistance causing genes such as ESBL (blaSHV, blaTEM and blaCTX-M), MRSA (mec-A) and Colistin (mcr-1) confirmed the probable mechanisms behind the resistance pattern. The microbial community diversity in the influent, earthworm's coelomic fluid and gut and filter media layers associated with the VF assists in the formation of biofilm, which helps in the removal of pathogens from the wastewater. This biofilm formation further results in a paradigm shift in the resistance profile of ARB and ARG, specifically most effective against drugs, targeting cell wall and protein synthesis inhibition such as Ampicillin, Ticarcillin, Gentamicin and Chloramphenicol. These findings further validate vermifiltration technology as a sustainable and natural treatment technology for clinical laboratory wastewater, specifically for the removal of pathogens and antibiotic resistance.

We investigated the presence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) RNA at different treatment stages of 15 wastewater treatment plants (WWTPs) in two North Indian states of Rajasthan and Uttarakhand. Untreated (influent), biologically treated, and disinfected wastewater samples were collected from May to August 2020. The qualitative analysis of the wastewater for the presence of SARS-CoV-2 RNA was done using different pre-processing methods. SARS-CoV-2 RNA was detected in 11 out of 39 wastewater samples in Jaipur district and 5 out of 17 wastewater samples in Haridwar District using Reverse-Transcriptase Quantitative Polymerase Chain Reaction (RT-qPCR) for qualitative detection. None of the 56 samples tested for post-secondary or tertiary treatment were found positive for SARS-CoV-2 RNA. The findings indicate that there are no SARS-CoV-2 related risks involved with using the treated effluent for non-potable applications. In contrast, untreated wastewater may be a potential route of viral transmission to the WWTP and sanitation workers. Future studies are imperative to understand the survival rates of these viruses in wastewater.Graphical AbstractHighlightsMild to moderate genome load observed in the municipal wastewater samples.Increased patient numbers post-lockdown correspond to a decrease in the CTvalue of genes.Presence of SARS-CoV-2 genome load was observed in untreated wastewater.E gene was present in abundance in wastewaters as compared to the N gene and RdRp gene.SARS-CoV-2 genome load was absent in secondary and tertiary treated effluent.

The present study points to the relevance of the earthworms-microorganism’s symbiotic and synergistic interactions that drive the wastewater treatment by identifying the most essential mechanisms underlying the removal of contaminants during vermifiltration technology. Previous studies have showed the presence of earthworms improves treatment performance of vermifilter (VF), but earthworm microbial community dynamics, their structure and functional characteristics in VF were not fully investigated. To investigate the effects of earthworms on the inherent microbial community of the VF, the present study envisages the dynamics of the complex symbiosis of earthworms & microorganisms associated to the treatment mechanisms. In this study, the design, operations and performance evaluation and influent, effluent and filter media layer were investigated for microbial diversity inside the earthworm population, along with the antimicrobial activity, enzymatic activity, and protein profiling assays. The results showed that earthworm gut microbial communities were dominated by Gammaproteobacteria, and the percentages arrived to 59–60% of the microbial species detected, while filter media layer showed presence of Firmicutes and Actinobacteria. The protein profiling of the microbiota associated with the VF showed that earthworms feeding and earthworm–microorganism interaction were responsible for enhanced treatment performance. The finding provides an insight into the complex earthworm microbial dynamics and mechanisms for wastewater treatment in VF. Furthermore, earthworm predation strongly regulated microbial biomass while improving microbial activity, and is deciphered as the possible mechanisms behind the vermifiltration technology.

The infection with SARS-CoV-2 is reported to be accompanied by the shedding of the virus in stool samples of infected patients. Earlier reports have suggested that COVID-19 agents can be present in the fecal and sewage samples and thus it can be a good indication of the pandemic extent in a community. However, no such studies have been reported in the Indian context so far. Since, several factors like local population physiology, the climatic conditions, sewage composition, and processing of samples could possibly affect the detection of the viral genome, it becomes absolutely necessary to check for the presence of the SARS-CoV-2 in the wastewater samples from wastewater treatment plants (WWTPs) serving different localities of Jaipur city, which has been under red zone (pandemic hotspots) since early April 2020. Samples from different local municipal WWTPs and hospital wastewater samples were collected and wastewater based epidemiology (WBE) studies for the presence of SARS-CoV-2 were carried out using the RT-PCR technique to confirm the presence of different COVID-19 target genes namely S gene, E gene, ORF1ab gene, RdRp gene and N gene in the viral load of wastewater samples. In the present study, the untreated wastewater samples from the municipal WWTPs and hospital wastewater samples showed the presence of SARS-CoV-2 viral genome, which was correlated with the increased number of COVID-19 positive patients from the concerned areas, as per reported in the publically available health data. This is the first study that investigated the presence of SARS-CoV-2 viral genome in wastewater, at higher ambient temperature (above 40°C), further validating WBE as a potential tool in predicting and mitigating outbreaks.HighlightsThe study reports detection of SARS-CoV-2 in sewage in India.The presence of SARS-CoV-2 was confirmed by RT-PCR.The presence of viral genome was detected at high ambient temperatures of 40-45° C.Corroborates trends in the WWTPs showing viral genome with public health data.Treated effluent from WWTPs appears safe for reuse with low public health concern.Graphical Abstract

Wastewater-based surveillance has been emerging as an efficient and advantageous tool to predict COVID-19 prevalence in the population, much earlier (7–28 days) than reported clinical cases, thus providing sufficient time to organize resources and optimize their use in managing COVID-19. Since the commencement of the COVID-19 pandemic, SARS-CoV-2 genetic lineages have emerged and are circulating all over the world. The assessment of SARS-CoV-2 variants of concern (VOCs) in wastewater has recently been proven to be successful. The present research demonstrates a case study utilizing an established approach to perform monitoring of SARS-CoV-2 variants from 11 distinct wastewater treatment plants across Jaipur (India) during the second peak period of COVID-19 (from 19 February 2021 to 8 June 2021). The sequences obtained were analyzed to detect lineage using the Pangolin tool and SNPs using the mpileup utility of Samtools, which reported high genome coverage. The mutation analyses successfully identified the penetration of the B.1. in the first two weeks of sampling (19–26 February), followed by the B.1.617.2 variant into Jaipur in the first week of March 2021. B.1.617.2 was initially discovered in India in October 2020; however, it was not reported until early April 2021.The present study identified the presence of B.1.617.2 in early March, which correlates well with the clinical patient’s data (290 cases were reported much later by the government on 10 May 2021). The average total genome coverage of the samples is 94.39% when mapped onto the severe acute respiratory syndrome coronavirus 2 isolate Wuhan-Hu-1; a complete genome (NC_045512.2) sequence and SNP analysis showed that 37–51 SNPs were identified in each sample. The current study demonstrates that sewage surveillance for variant characterization is a reliable and practical method for tracking the diversity of SARS-CoV-2 strains in the community that is considerably faster than clinical genomic surveillance. As a result, this method can predict the advent of epidemiologically or clinically important mutations/variants, which can help with public health decision making.

The study brings insight to earthworms-microorganism's symbiotic interactions for wastewater treatment for the most essential mechanisms (antimicrobial and enzymatic activity) during vermifiltration. The results showed that vermifilter (VF) resulted in effluent with biochemical oxygen demand (BOD)

A comparative study was performed to treat the domestic wastewater through two different epigeic earthworms (Eisenia fetida and Eudrilus eugeniae) based vermifiltration unit (VF1 and VF2). Results revealed a significant removal of biochemical oxygen demand (88%), total suspended solids (78%), and total dissolved solids (75%) in the treated wastewater from VF1; while in VF2, it was observed to be 70, 67, and 66%, respectively, at hydraulic loading rate (HLR) of 2.5 m3 m−2 d−1. Beside this, a significant reduction of total coliform (3.1 log) was observed in VF1 as compared with 0.98 log reduction in VF2. In addition to this, an increase in earthworm biomass in reactor VF1 was found to be 11.4%; while in VF2, mortality was observed, since the earthworm species E. eugeniae could not survive during the process. Overall, in VF1, the effluent was rich in nitrate, phosphate, and showed the potential of E. fetida for wastewater treatment during vermifiltration process.

Performance evaluation of vermireactors (Trials T1, T2, T3) for co-treatment of organic fractions of municipal solid waste (OFMSW) and sewage was conducted on three different earthworm species such as Eisenia fetida, Perionyx excavatus, and Perionyx sansibaricus. The results were compared with control reactor (T4) (without earthworms) for 120 days. Sewage was applied at hydraulic loading rate of 1 m3/m2/day, and earthworm biomass of 500 mg per 2 kg of organic waste was used for the treatment purpose. A significant gain in earthworm biomass was noted, and maximum growth was observed in T1 followed by T2 than T3. The treatment process due to earthworms causes removal of total organic carbon (65–75%), CODtot (85–86%), BOD5 (84–87%), ammonia nitrogen (45–59%), and coliforms (99.9%), but increase in nitrate nitrogen (172.5–186.7%) and total phosphorous (161–201%) subsequently in treated effluent and nutrient enhancement in solid waste samples was observed. Scanning electron micrographs revealed the final products (vermicompost) exhibited a distinct physical appearance than initial solid waste samples characterized by predominantly spherical cell-like structure and significantly lower number of filamentous bacteria. Moreover, it can be concluded that these three earthworm species are suitable for onsite co-treatment of OFMSW and municipal sewage.