SARS-CoV-2 in environmental perspective: Occurrence, persistence, surveillance, inactivation and challenges.

The unprecedented global spread of the severe acute respiratory syndrome (SARS) caused by SARS-CoV-2 is depicting the distressing pandemic consequence on human health, economy as well as ecosystem services. So far novel coronavirus (CoV) outbreaks were associated with SARS-CoV-2 (2019), middle east respiratory syndrome coronavirus (MERS-CoV, 2012), and SARS-CoV-1 (2003) events. CoV relates to the enveloped family of Betacoronavirus (ßCoV) with positive-sense single-stranded RNA (+ssRNA). Knowing well the persistence, transmission, and spread of SARS-CoV-2 through proximity, the faecal-oral route is now emerging as a major environmental concern to community transmission. The replication and persistence of CoV in the gastrointestinal (GI) tract and shedding through stools is indicating a potential transmission route to the environment settings. Despite of the evidence, based on fewer reports on SARS-CoV-2 occurrence and persistence in wastewater/sewage/water, the transmission of the infective virus to the community is yet to be established. In this realm, this communication attempted to review the possible influx route of the enteric enveloped viral transmission in the environmental settings with reference to its occurrence, persistence, detection, and inactivation based on the published literature so far. The possibilities of airborne transmission through enteric virus-laden aerosols, environmental factors that may influence the viral transmission, and disinfection methods (conventional and emerging) as well as the inactivation mechanism with reference to the enveloped virus were reviewed. The need for wastewater epidemiology (WBE) studies for surveillance as well as for early warning signal was elaborated. This communication will provide a basis to understand the SARS-CoV-2 as well as other viruses in the context of the environmental engineering perspective to design effective strategies to counter the enteric virus transmission and also serves as a working paper for researchers, policy makers and regulators.

Endocrine disruptive estrogens role in electron transfer: bio-electrochemical remediation with microbial mediated electrogenesis.

Bioremediation of selected endocrine disrupting compounds (EDCs)/estrogens viz. estriol (E3) and ethynylestradiol (EE2) was evaluated in bio-electrochemical treatment (BET) system with simultaneous power generation. Estrogens supplementation along with wastewater documented enhanced electrogenic activity indicating their function in electron transfer between biocatalyst and anode as electron shuttler. EE2 addition showed more positive impact on the electrogenic activity compared to E3 supplementation. Higher estrogen concentration showed inhibitory effect on the BET performance. Poising potential during start up phase showed a marginal influence on the power output. The electrons generated during substrate degradation might have been utilized for the EDCs break down. Fuel cell behavior and anodic oxidation potential supported the observed electrogenic activity with the function of estrogens removal. Voltammetric profiles, dehydrogenase and phosphatase enzyme activities were also found to be in agreement with the power generation, electron discharge and estrogens removal.

Sorptive removal of endocrine-disruptive compound (estriol, E3) from aqueous phase by batch and column studies: kinetic and mechanistic evaluation.

Endocrine disruptive compounds (EDC) are a wide variety of chemicals which typically exert effects, either directly or indirectly, through receptor-mediated processes. They mimic endogenous hormones by influencing the activities of hormone activities even at nanogram concentrations and reported to disrupt the vital systems (e.g., the endocrine system) in aquatic organisms. The EDC are present in aquatic water bodies and sediments mainly due to the release of human and animal excreted waste. Estriol (E3) removal by adsorption process was investigated in this study to evaluate the potential of activated charcoal as adsorbent. Agitated non-flow batch sorption studies showed good E3 removal efficiency. Sorption kinetic data illustrated good fit with pseudo-first-order rate equation. Experimental data confirmed to linear Langmuir's isotherm model. Neutral pH condition showed comparatively good sorption of E3. Adsorption capacity showed a consistent increasing trend with increase in the operating temperature [DeltaH degrees , -9.189 kJ/mol); DeltaS degrees , 0.492 J/mol K) suggesting exothermic nature of E3 sorption process. Free energy (DeltaG degrees ) increased from 2.51 to 2.97 kJ/mol with increase in temperature from 0 to 50 degrees C. Further, E3 spiked distilled water, untreated domestic sewage and treated domestic sewage were studied in fixed bed column to assesses the potential of sorption process as tertiary unit operation in the ETP system. Total E3 concentration was determined quantitatively by employing direct competitive enzymatic-immuno assay (EIA) procedure.