Structural and genetic differences among various viruses play a significant factor in host infectivity and vulnerability to environmental stressors. Zoonoses of viruses require several recombinations and mutations in their genetic material and among several viruses allowing them to switch hosts and infect new species. Additionally, the host genetics play a significant role in successful viral transmission among various hosts. For example, human immunodeficiency virus (HIV), Ebola virus and influenza viruses. In efficient zoonotic events, selective stresses in the host milieu-interieur are critical during viral infection of the first human host. The genetic rearrangement of the virus and the selective environmental pressure of the host immune system dominate the emergence of new viral disease outbreaks.@en

The coronaviruses are the largest known RNA viruses of which SASR-CoV-2 has been spreading continuously due to its repeated mutation triggered by several environmental factors. Multiple human interventions and lessons learned from the SARS 2002 outbreak helped reduce its spread considerably, and thus, the virus was contained but the emerging mutations burdened the medical facility leading to many deaths in the world. As per the world health organization (WHO) droplet mode transmission is the most common mode of SASR-CoV-2 transmission to which environmental factors including temperature and humidity play a major role. This article highlights the responsibility of environmental causes that would affect the distribution and fate of the virus. Recent development in the risk assessment models is also covered in this article.@en

Industrial wastewater is a complex mixture of organic and inorganic substances, including nutrients, heavy metals, salts, and ionic components. Efficient removal of these compounds, along with achieving Zero Liquid Discharge is one of the biggest concerns faced by manufacturing industries. With the advancement in production and casting processes, followed by membrane modification, membrane-based hybrid technology has started gaining popularity since the early 2000s. Membrane-based treatment technology or membrane bioreactors (MBRs), coupled with other treatment processes, such as advanced oxidation processes (AOPs), and reverse and forward-reverse osmosis (RO/FO) is adopted in industries as an alternative to conventional wastewater treatment due to their ease of operation, and superior performance. This review chapter highlights the underlying mechanism and application of membrane-based hybrid processes, such as AOP-MBR and RO/FO-MBR, chemically aided-MBR to treat industrial wastewater. Other hybrid-MBRs integration of MBRs with nanomaterials, and the role of several factors that influence MBR operation are also covered in this review.@en

The contagious SARS-CoV-2 virus, responsible for COVID-19 disease, has infected over 27 million people across the globe within a few months. While literature on SARS-CoV-2 indicates that its transmission may occur predominantly via aerosolization of virus-laden droplets, the possibility of alternate routes of transmission and/or reinfection via the environment requires considerable scientific attention. This review aims to collate information on possible transmission routes of this virus, to ascertain its fate in the environment. Concomitant with the presence of SARS-CoV-2 viral RNA in faeces and saliva of infected patients, studies also indicated its occurrence in raw wastewater, primary sludge and river water. Therefore sewerage system could be a possible route of virus outbreak, a possible tool to assess viral community spread and future surveillance technique. Hence, this review looked into detection, occurrence and fate of SARS-CoV-2 during primary, secondary, and tertiary wastewater and water treatment processes based on published literature on SARS-CoV and other enveloped viruses. The review also highlights the need for focused research on occurrence and fate of SARS-CoV-2 in various environmental matrices. Utilization of this information in environmental transmission models developed for other enveloped and enteric viruses can facilitate risk assessment studies. Preliminary research efforts with SARS-CoV-2 and established scientific reports on other coronaviruses indicate that the threat of virus transmission from the aquatic environment may be currently non-existent. However, the presence of viral RNA in wastewater provides an early warning that highlights the need for effective sewage treatment to prevent a future outbreak of SARS-CoV-2.@en

Pharmaceutical compounds are nowadays ubiquitously detected in various environmental compartments around the world. As these compounds are present as complex mixtures and numerous other natural and anthropogenic chemicals, their transformation products (TPs), possible bio-conjugated counterparts, and their detection, quantification, and risk assessment prove extremely difficult. Recent advancements in mass spectrometry coupled with liquid chromatography (LC-MS) have enabled the detection of polar compounds with better reliability, precision, and accuracy. However, detecting trace levels of pharmaceuticals from complex matrices requires highly sensitive and selective techniques and sophisticated sample preparation steps to avoid analyte loss during sample preparation or in transit. Additionally, target analysis involves the use of expensive pharmaceutical standards and the corresponding isotope-labelled internal standards (ISs). Hence, before target analysis, it is much more viable to conduct suspect or nontarget analyses to obtain a more holistic understanding of the nature and composition of such contaminants present in environmental samples. This chapter aims to compare and compile the recent trends in suspect and nontarget screening of pharmaceuticals present in the water and wastewater matrices. Detailed information on the various mass banks, mass analyzers, and workflows for the screening of such contaminants are discussed here in detail.@en

Pharmaceutical compounds are categorized as contaminants of emerging concern owing to their widespread consumption, persistence in the aquatic environment, development of antibiotic resistance in microorganisms, and growing evidence of chronic and endocrine disruption effects. Therefore, pharmaceuticals have been reported to exist in numerous environmental compartments, including surface water, groundwater, and drinking water throughout the world. The principal pathway of entry of these compounds into water bodies is via treated and untreated sewage. In aquatic environments, natural attenuation of pharmaceuticals takes place through various physical, chemical, and biological processes, including dispersion and dilution, volatilization, sorption onto sediments, biotransformation, and phototransformation. Among the listed attenuation processes, both direct and indirect phototransformation play an important role in deciding the fate of pharmaceuticals. In addition to cations and anions present in the aquatic environment, dissolved organic matter (DOM) can have multiple impacts during photolytic degradation, such as photosensitization, light screening, scavenging, and oxidative inhibition. The absorption of UV rays by DOM results in the formation of a variety of photochemically produced reactive radicals, such as triplet excited states of DOM (3DOM), hydroxyl radical (HO•), and singlet oxygen (1O2). This work presents a thorough assessment of various attenuation processes, with specific attention to aqueous photochemistry of pharmaceuticals evaluated using laboratory-scale and on-site observations. This review will highlight the general extent of natural attenuation for specific classes of pharmaceuticals and focus on the governing mechanisms—underlying such attenuation processes based on studies conducted worldwide.@en

The manufacture and use of pharmaceuticals for human and veterinary use is on the rise in Southeast Asian countries. Thus, the discharge from wastewater treatment plants may contain pharmaceuticals across a wide range of drug classes. Various regions in Southeast Asia are characterized by species richness, presence of threatened species and diversity of endemic species. The rapidly growing economy, aquaculture and livestock industries, increased incidence of infectious diseases, and change in lifestyle may adversely affect these biodiversity hotspots due to increased release of pharmaceuticals. This review focuses on use and occurrence of five commonly used pharmaceutics, i.e., atenolol, carbamazepine, diclofenac, sulfamethoxazole, and 17 α-ethinylestradiol in the influent and effluent of wastewater treatment plants and in various aquatic environments, i.e., surface water, groundwater, marine environment and sediments. Threats posed by these pharmaceuticals are evident from a discussion on their adverse effects on various freshwater species. Species sensitivity distribution (SSD) constructed for each of the pharmaceuticals using reproductive toxicity data for universal biomarker species reported in the literature, reveal the community level toxic effects of these pharmaceuticals in the aquatic ecosystem. Based on SSD and occurrence data, 17 α-ethinylestradiol poses the highest risk, while atenolol and carbamazepine poses negligible risk on reproductive toxicity/reproductive failure at the concentrations currently prevailing in the aquatic environment. The high risk posed by 17 α-ethinylestradiol is due to its ability to cause reproductive failure and/or vitellogenin induction at concentrations of the order of ng/L.@en