Impact of COVID-19 on Emerging Contaminants

In this chapter, we report on the state of PFAS in a major South Indian River Periyar, for the first time. These substances are classified as a pollutant in many countries. Ingestion of these substances is known to cause adverse effects on the humans. Periyar is the largest west-flowing river in southern India (5398 km² area covering 300 km in length). River water samples were collected from 16 stations (including the source, mouth, estuaries and main tributaries) in May 2013. HPLC MS/MS was used to measure the concentration of PFAS. The recovery of ¹³C labeled standards ranged between 60 and 100%. Perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) were found in all the 16 sampling stations. The PFBA concentration varied between 58 and 2174 ng/L. PFOA concentration varied between 22 and 1503 ng/L, and PFNA varied between 20 and 705 ng/L. Out of the six major PFAS analyzed, three perfluorosulfonates (PFSA) and three perfluoroalkyl carboxylic acids (PFCA) were detected. The highest concentration of PFAS was found near the Periyar estuary (12,958 ng/L).

Monitoring the concentration of pharmaceutical and personal care products (PPCPs) in the water system is essential, particularly in estimating the risk associated with their toxicity to the aquatic organism and humans. However, the significant challenge associated with using active sampling techniques (discrete and continuous) has been its complex procedure, high cost of operation, and lack of sensitivity and reliability, particularly in aquatic environments with a highly dynamic concentration of PPCPs. Passive sampling techniques have recently received increasing attention as an alternative tool in monitoring PPCPs as it offers significant advantages compared to the active sampling techniques. The present chapter summarizes the current literature on applying passive sampling techniques in monitoring PPCPs in an aqueous matrix from 2016 to 2020. More importantly, this review focuses on the most commonly applied passive sampling devices for monitoring of PPCPs in an aquatic environment, such as polar organic chemical integrative sampler (POCIS), a diffusive gradient in thin-film (DGT), and Chemcatcher^® with emphasis given to the theory, main components of passive sampling devices, methods of calibration, and their application. Finally, the analytical performance (i.e., deployment time, and the measured concentration of the analytes) of each passive sampling technique in monitoring PPCPs is examined and presented.

Pharmaceutical and personal care products (PPCPs) are ubiquitous with concentrations from ng/L to µg/L in the aquatic environment posing a potential threat to ecosystem and the human life across the globe. The discharge of untreated and semi-treated sewage from wastewater treatment plants (WWTPs) is the main point source of these compounds which continuously flow into the aquatic system. PPCPs are the prime group of emerging pollutants (ECs). The literature indicates increasing contaminant load by ECs which leads to an increasing number of antibiotic-resistant genes (ARGs) in microorganisms and humans due to horizontal gene transfer (HGT). Recent risk assessment studies have successfully overcome limitations such as including the chronic effect of a single compound, but have failed to include studies on the mixture of compounds. Biological remediation is a cost-effective approach with the effective degradation of PPCPs depending on their complexity. Furthermore, the influence of ARGs on the microbial cultures is lacking. The present study will give a comprehensive understanding of the source and fate of different groups of PPCPs in the aquatic environment. The details in the book chapter will help assess, compare, and identify gaps in risk assessment and treatment strategies for these emerging pollutants in the aquatic ecosystem.

The emerging contaminants (ECs) are of significant environmental concern globally in the twenty-first century. They are broadly dispersed far and wide into all the ecological matrices due to various anthropogenic inputs in the environment. The proper handling and management of these ECs are very crucial because their presence in even small concentrations has far-reaching consequences on the well-being of aquatic and terrestrial lives, including human health. The ECs comprise of pollutants mainly from industrial and agricultural sources, including micropollutants, synthetic dyes, compounds containing hazardous dyes, toxins, hormones, pharmaceuticals, endocrine disruptors, and pesticides. The persistent discharge of these ECs in regulated or unregulated manners has already damaged the environment irreversibly. The inefficiency of the conventional treatment approach in eliminating an array of ECs in different environmental and biological samples has compelled the engineers, scientific community, and policymakers alike to contemplate it. The recent developments in environmental engineering, biotechnology and, nanotechnology altogether establish novel and advanced methodologies for water remediation. In this chapter, we elaborately discuss various sources of the ECs in different water bodies, potential health risks associated with the widespread distribution of these ECs in water, and the novel water remediation approaches are facilitated by modern technological advancements.

Heavy metals, 1,4-dioxane, cyanotoxins, bacteria with antibiotic-resistant genes, pharmaceuticals, nanoparticles, and many more are listed as emerging contaminants due to their toxicity whether their origin is geogenic, microbial, or anthropogenic. These specific types of environmental impurities, at present, are excluded from regular scrutinizing programs but are potential nominees for future supervision and management subjected to their hazardous nature, community awareness, incidence, and depending on the amount present in distinct environments. A chemical or an organism does not need to be novel to be groped as an emerging contaminant. Primarily, these impurities had been in nature for decades, but their impact is being assessed only now. When these three types of pollutants coexist together the adverse impact they create on Mother Nature is enormous. With increasing population growth and with rapid urbanization, release of these contaminants gets accelerated and considered as a global issue. Due to their perseverance, in aquatic environments, they get accumulated in biota thereby contaminating the food web and humans and animals mostly get exposed through the food chain or by drinking the contaminated waters. This chapter focuses on emerging contaminants of geogenic, anthropogenic and microbial origin, their coexistence in the environment, ecotoxicity, and relative environmental risks.

Cities around the world and in India are water-stressed and are only able to make stop-gap arrangement to fight the crisis. The problems related to water shortage though they are relatively new but will stay for a considerable period. Community-based water management practices can be the answer to the water crisis problem and need to be revisited. These practices are decades-old and have survived many generations. The issue with such practices is that they are not efficient, are time-consuming and labour intensive contemporarily. Internet of Things (IoT) can be used to solve the problem associated with traditional community-based water management practices. The study discusses the problems associated with the six selected community-based water management practices and the importance of IoT as an assistive technology to solve the issues related to community-based water management practices. Finally, the study proposes strategies to integrate traditional community-based water management practices with modern technology which can be used during and post COVID-19 pandemic. The practical implication of the study can be that our policymakers may take up the study to manage water efficiently. Since the practices were selected based on geographic and hydrological characteristics, they can be introduced in other Indian states with similar characteristics.

With the outbreak of the COVID-19 pandemic, facemasks have become an integral part of our daily life irrespective of which nation we live in. The use of facemask is proportionally linked with a country’s population especially in highly populated countries like India. Without stringent guidelines and proper disposal schemes, dumping of facemasks in water bodies has further aggravated plastic-based water pollution hazards in Indian riverine and marine systems. The disposal of facemasks in water bodies also increases the chance of virus spread through water bodies, leading to biological and health disasters. The current review addresses the issues associated with the pollution caused by the facemask in Indian water systems and finds a set of solutions to mitigate its adverse effect. The chapter intends to review the guidelines recommended by different governmental and international agencies like the WHO, CDC, ICMR, and CPCB to mitigate the biohazard potential associated with facemasks. The chapter sheds light on the elemental composition of pristine facemasks and also discusses the health and environmental implications of those contaminants when released in an aquatic medium. The chapter also suggests ways to mitigate the aforementioned damage, caused by careless disposal of facemasks in the Indian riverine systems.

Enhancement of dissimilatory nitrate/nitrite reduction to ammonium (DNRA) in agricultural soils has recently gained attention as a means to decelerate nitrogen loss. Here, the potential effects of plant root exudates on the DNRA activity of a model organism Shewanella loihica and agricultural soil consortia were examined. The chemical composition of the root exudate collected from Arabidopsis thaliana (Col-0) plant was analyzed by gas chromatography time-of-flight mass spectrometry (GC TOF-MS) and applied to S. loihica cultures grown on lactate and \({\text{NO}}_{3}^{{^{ - } }}\) to examine the effects on the \({\text{NO}}_{3}^{{^{ - } }}\) fate. Additionally, artificial root exudate was synthesized consisting of the major root exudate constituents, and its impacts on denitrification vs. DNRA competition in agricultural soil extracts, as well as S. loihica cultures, were investigated. Incubation of S. loihica in media amended with A. thaliana root exudates or artificial root exudates both resulted in a significant enhancement of DNRA activity. The agricultural soil consortia amended with root exudates did not exhibit significant DNRA enhancement; however, artificial root exudates addition had significant DNRA enhancement effect, which was confirmed with \(^{{{15}}} {\text{NH}}_{4}^{ + }\) production from added \(^{{{15}}} {\text{NO}}_{3}^{{^{ - } }}\). The findings of this study suggest that plants’ root exudates may have stimulatory impact on the environmentally beneficial DNRA pathway.

Contaminants in municipal sewage are generally organic and inorganic, originating from households and industrial activities. Some are categorized as heavy metals, nutrients (nitrates, phosphates), and emerging contaminants (ECs) such as pharmaceuticals and personal care products (PPCPs) associated with lifestyle in a known area. Because of their physicochemical properties, they tend to accumulate in sewage sludge during wastewater treatment. Treatment processes can still be expensive and partially effective. Rather, high concentration of ECs in municipal sewage might have a significant influence on treatment costs. Thus, there is a need for new approaches that are effective to remove these contaminants. Algae bioremediation through metabolic and cometabolic pathways could be a promising approach if combined with microbial consortia or other advanced biotechnological technologies to degrade ECs. The algal removal mechanisms involve bio-absorption, bioadsorption followed by biotransformation, which can be achieved intra- and extra-cellularly. In the process, microalgae supply oxygen to microorganisms, and CO₂ generated during wastewater treatment is utilized by the microalgae. Acclimatized culture could be effective for ECs present in sewage at a concentration ranging from ng/L to µg/L.

A vast number of emerging pollutants accumulate in aquatic environment due to release of domestic, agricultural, hospital and industrial wastes. The conventional treatment strategies are not always effective for removal of emerging contaminants and are often associated with inadequate removal, toxic by-products and sludge generation. Further, concentration of these contaminants has not been measured frequently due to the absence of specific discharge norms. Thus, advanced water treatments are necessary. The chapter discussed the details of potential technologies available for various emerging contaminants like pharmaceuticals and personal care products (PPCPs), pesticides and herbicides removal in the surface water bodies, ground water reserves, as well as, wastewater streams, innovations in remediation strategies and future challenges. The focused processes are membrane technology involving ultrafiltration, nanofiltration and reverse osmosis, adsorption using carbonaceous adsorbent, metal laden spent biosorbent, industrial sludge, carbon nanotubes and metallic-nanoparticles, etc., ceramic membrane-based hybrid technology, membrane bioreactors and advanced oxidation techniques.

Pharmaceuticals and personal care products (PPCPs) have been drawing increasing attention as emerging contaminants due to their ubiquitous existence leading to the potential risk to the human and aquatic ecosystem. The complex chemical structures and lower concentrations make them resistant to remove from the aquatic environment. Amid various processes, adsorption coupled with photocatalysis is considered as a promising dual-modality approach for the removal of PPCPs. Adsorbents are often combined with appropriate photocatalyst to enhance the removal efficiency during remediation. This approach also ensures complete or partial mineralization of adsorbed organic matters and thereby facilitates self-rejuvenation of the adsorbent. Semiconductors are generally used in the process of photocatalysis. A good photocatalyst should have excellent photocatalytic property over visible region, low toxicity and high biological and chemical stability. This chapter discusses the progress made in the field of adsorptive–photocatalytic approach for remediation of PPCPs. Various adsorbent–photocatalysts combination used for the removal of contaminants from the aquatic environment as well as design approaches used to increase the effectiveness of this dual-modality actions are also discussed.

Food industry is one of the major sources of pollutants and waste. Aquaculture is one of the fastest-growing food industries. Culturing of fish and its associated food processing creates significant amount of pollutants and waste. Fish feed, disinfectants, antibiotics, hormones, and plastics used in aquaculture are the main sources of organic and inorganic pollutants. In addition to the pollutants created during the culture period, tremendous amount of waste is created in fish meat processing units. Common aquaculture species like shrimps produce waste equal to 50% of their body weight, and on the other hand, certain special processing like surimi results in 70% wastage by body weight. If these pollutants and wastes are not recycled properly, it may harm the environment. Different remediation concepts including biofloc technology, agriculture, and recycling techniques are discussed in detail.

The incessant use of pharmaceuticals and personal care products (PPCPs) has led to their increased concentrations in environmental water matrices. The ongoing COVID-19 pandemic has further increased the consumption and release of these pharmaceuticals and antimicrobial compounds in the wastewater streams. Of these, some are highly recalcitrant and thus escape removal during conventional treatment. This is attributed to their lipophilicity; leading to bioaccumulation, transformation into another product and non-biodegradability. Though advanced treatment by advanced oxidation processes, ozonation, etc., offer better PPCP removal efficiencies, their use is limited by economic constraints. Constructed wetlands provide techno-economically feasible solution for sewage treatment; nonetheless, they too cause incomplete removal of PPCPs. Consequently, it is indispensable to adopt promising cost-effective tertiary treatment along with wetlands. In this regard, this chapter focusses on recent developments in PPCPs removal using constructed wetlands highlighting its performance separately and in combination with other tertiary treatment processes viz., adsorption, membrane processes, etc., and fate of PPCPs in sewage treatment plants. It is observed that the hybrid wetland and the integrated wetland-tertiary treatment-based technologies exhibit better PPCPs removal efficiencies than wetlands alone. Hence, constructed wetlands-based integrated treatment systems are the most sustainable and cost-effective solution of PPCPs removal from wastewater.

Cyanide is a major concern in industrial wastewaters and gold mine effluents. Considering the adverse effects to human health and safeguard of environment, stringent regulatory norms have been laid by various authorities. Therefore, it is imperative to develop a feasible technology for the cyanide removal up to a safe level before discharging to water bodies or lands. Activated carbon is well known for adsorption along with oxidation properties, which can be explored for the treatment free cyanide. One major advantage of treatment of free cyanide by activated carbon is the possibility of mineralization of free cyanide to safe out products like cyanate. In this article, we have incorporated relevant literatures on application of carbons and modified carbon for cyanide removal in aqueous matrices and the current state of knowledge. Further, we have thoroughly discussed the mechanism of adsorption and catalytic removal of carbon, especially emphasizing the role of oxygen-containing surface groups. This chapter also thoroughly discussed the effect of various operational parameters on cyanide adsorption and methods for regeneration of activated carbon surface for reuse of the material. Finally, we have concluded with a note on treatment strategies and cost evaluation for the treatment of cyanide bearing wastewater using activated carbon.

Though the industrial revolution has made our life easy, it affected the natural water resources with tremendous discharge of waste products. To tackle these problems, several research groups have discovered advanced oxidation processes with a variety of materials (Pt, Au, TiO₂, ZnO, etc.) as a catalyst to decompose the toxic pollutants to get potable water. However, the rapid industrialization, generating varieties of pollutants, has forced the scientific community to search for robust, efficient, and stable catalysts. Transition metal carbides (TMCs) have been explored to understand their fundamental characteristics for photocatalytic removal of organic pollutants. But the preparation of TMCs requires very high temperature. Therefore, the present chapter presents a novel single-step solid-state reaction route to synthesize TMCs at relatively low temperature using a specially designed autoclave. It induces the oxygen centers near the surface of TMC particles which is responsible for the photon absorption ability resulting to the charge-carrier availability for photochemical reactions. This chapter describes a detailed review of the structural–optical co-relationship of different TMCs as a potential candidate for the photochemical treatment of organic pollutants under different illumination sources with excellent photostability.

The new coronavirus (COVID-19) has become a global pandemic within a short period. Current attention is to restrict its direct transmission. However, the focus on secondary transmission via wastewater is lacking. The virus has been identified in fecal matter, raw wastewater, sewage samples, urine, secondary treated effluent, etc., in different countries. Specifically, Australia, Bangladesh, China, Germany, Turkey, India, UAE report evidence that SARS-CoV-2 RNA has been detected in different rates as 22%, 75%, 36%-100%, 89%, 71%, 75%-100%, 78%, respectively. Therefore, wastewater surveillance has received exciting attention. In developing nations, wastewater from households and quarantine centers is discharged directly into the environment without treatment. Hospital wastewater treatment is also limited, which possesses a risk of secondary transmission. Hence, the treatment of wastewater is necessary for limiting the resurgence of COVID-19. In particular, paste knowledge on the SARS-CoV-1 provides some conclusions to combat novel SARS-CoV-2 since both RNAs show similar characteristics in their occurrence and persistence. Scholars investigate the methodologies to tackle the virus by enhancing conventional primary, secondary, tertiary treatments in WWTPs. Hence, this chapter summarizes the wastewater treatment technologies for low-income countries in tackling COVID-19 to mitigate the possibility of secondary transmission via wastewater.