Water Quality and Water Pollution in Time of COVID-19: Positive and Negative Repercussions

Investigating chemical risk in green and loggerhead turtles foraging in Moreton Bay using species-specific cell-based bioassays

Differences in trophic level may result in differences in chemical exposure between species of sea turtles, as pollutants may bioaccumulate differentially in diet items. It is, therefore, crucial to understand species-specific differences in exposure and effect to accurately assess chemical risk to individual species. This study used blood collected from green and loggerhead turtles foraging in Moreton Bay, Queensland, Australia, to assess differences in chemical exposure and effect of two species foraging in the same area at different trophic levels. Organic contaminants were extracted from green and loggerhead turtle blood samples and assessed for cytotoxicity in species-specific cell cultures. The results indicated that chemical exposure to organic contaminants was similar between the two species, despite differences in trophic level. Overall, chemical risk was relatively low in both species, but temporal changes in toxicity observed in other similar studies illustrate the importance of ongoing toxicological assessments of sea turtle populations.

Water quality assessment of Upper Ganga and Yamuna river systems during COVID-19 pandemic-induced lockdown: imprints of river rejuvenation

Clean river water is an essential and life-sustaining asset for all living organisms. The upper Ganga and Yamuna river system has shown signs of rejuvenation and tremendous improvement in the water quality following the nationwide lockdown due to the coronavirus pandemic. All the industrial and commercial activity was shut down, and there was negligible wastewater discharge from the industries. This article addresses the water quality assessment from the study area, which is based on the original data of physical parameters, major and trace elements, and stable isotopes (hydrogen and oxygen) systematics during the nationwide lockdown. The impact of the lockdown could be seen in terms of an increase in dissolved oxygen (DO). Water samples were collected from the Upper Ganga and Yamuna river basins (Alaknanda, Bhagirathi, and Tons rivers) during an eight-week lockdown in Uttarakhand, India. We discussed the signs of rejuvenation of riverine based on physical parameters, major ions, trace elements, isotopic ratios, and water pollution index (WPI). Results reveal that the water quality of the entire upper basins of the Ganga has significantly improved by 93%, reflecting the signs of self-rejuvenation of the rivers. Multivariate analysis suggests a negative factor loading for an anthropogenic element (NO 3 - ), implying that they contribute little to the river water during the lockdown. Further, bicarbonate (HCO 3 - ) is a dominant element in both river basins. The geochemical facies are mainly characterized by the (Ca 2 + : Mg 2 + : H C O 3 - ) type of water, suggesting that silicate rock weathering dominates with little influence from carbonate weathering in the area. The positive factor loadings of some cations, likeHCO 3 - ,Ca 2 + , andMg 2 + reflect their strong association with the source of origin in the lockdown phases. Stable isotopic reveals that the glaciated region contributed the most to the river basin, as evidenced by the low d-excess in riverine water compared to anthropogenic contributions. Rivers can self-rejuvenate if issues of human influence and anthropogenic activities are adequately resolved and underline our responsibility for purifying the ecosystem. We observed that this improvement in the river water quality will take a shorter time, and quality will deteriorate again when commercial and industrial activity resumes.

Chemical elements in mussels: Insights into changes in coastal environments due to the COVID-19 pandemic

The concentrations of macro elements (Ca, K, Mg, and Na), essential trace elements (Cr, Cu, Fe, Li, Mn, Ni, and Zn), and nonessential trace elements (Al, As, Cd, Pb, and Ti) in the shell and soft tissues of Perna perna (L. 1758) mussels from Southeast Brazil are presented as a baseline reference for understanding the effects of the COVID-19 pandemic on the quality of coastal environments. For shells, the macro elements load was greater during the pandemic period at all sampling sites; however, for soft tissues, the opposite trend was recorded. On the contrary, the concentrations of trace elements in the shell were below the limit of quantification in most samples, and they tended to decrease in the soft tissues during the pandemic. Thus, the COVID-19 was a short-term conservation event that positively impacted the mussels. The results are relevant for monitoring the coastal environment in a post-COVID-19 scenario.

Enhancing the efficiency of magnetically driven carbon nitride-based nanocomposites with magnetic nanoflowers for the removal of methylene blue dye at neutral pH

The present study focuses on the elaboration of magnetic nanocomposites by the in situ incorporation of magnetite (Fe3O4) nanoparticles (NPs) with spherical and nanoflower-like morphologies in graphitic carbon nitride (g-C3N4) sheets using two different synthetic routes. Nanomaterials are characterized by TEM, SEM, XRD, FTIR, BET, zetametry, vibrating sample magnetometry, and UV-vis absorption spectroscopy. The decoration of the carbon nitride matrix with the magnetic NPs enhanced optical and textural properties. The influence of the morphology of the magnetic NPs on the adsorptive and photocatalytic properties of the nanocomposites under different pH conditions (4.5, 6.9, and 10.6) was assessed from batch tests to remove methylene blue (MB) from aqueous solutions. In extreme pH conditions, the nanocomposites exhibited lower or equivalent MB removal capacity compared to the pure g-C3N4. However, at neutral medium, the nanocomposite with incorporated Fe3O4 nanoflowers showed a significantly higher removal efficiency (80.7%) due to the combination of a high adsorption capacity and a good photocatalytic activity in this pH region. The proposed nanocomposite is a promising alternative to remove cationic dyes from water by magnetic assistance, since no pH adjustment of the polluted effluent is required, reducing costs and environmental impact in the dyeing industry.

Trends in HIV incidence and mortality across Bharat (India) after the emergence of COVID-19

BACKGROUND

Human immunodeficiency virus (HIV) is a sexually transmitted infection impacting populations worldwide. While there have been major improvements in controlling HIV over recent years, the COVID-19 pandemic may have potentially resulted in major interruptions to this control of HIV. Bharat (India) is a country that has been greatly impacted by the COVID-19 pandemic, and we aimed to analyse the trends in HIV control since the start of the pandemic.

METHODS

In this study we evaluated changes in rates of HIV incidence and mortality across Bharat for the years both before, and after, the start of the COVID-19 pandemic. Percent and absolute changes were determined, and thereafter, both bivariate and multi linear regression was conducted to evaluate the relationship between COVID-19 burden and changes in HIV epidemiology across the nation.

RESULTS

It was shown that, despite the COVID-19 pandemic, annual incidence and deaths of HIV/AIDS have both decreased across Bharat. From 2019-2021, in Bharat, the total number of new HIV cases annually decreased by 9.03%, and the total number of HIV/AIDS deaths annually decreased by 28.82%. A similar trend was shown across most states/union territories; however, there were notable exceptions (such as Karnataka, Bihar, and Assam) where the rates have instead increased.

CONCLUSIONS

Our analysis has demonstrated that government efforts to control the HIV/AIDS epidemic have not been greatly impacted across the majority of Bharat since the emergence of COVID-19. The reduction in annual HIV/AIDS deaths in the country has been better than the world average, and the improvements from the period of 2019 to 2021 were greater than those from 2017 to 2019. Regardless, there are regions in the nation where the epidemic has instead worsened during this period.

Hazardous Elements in the Edible Portion of Perna perna Mussels: Relation with the COVID-19 Pandemic Period and Assessment of the Risk to Human Health

In this work, the concentrations of hazardous elements (As, Cd and Pb) in the edible portion of the Perna perna mussel from Southeast Brazil were analyzed to understand the effects of the COVID-19 pandemic on the coastal environment and to evaluate the quality of this fishery resource. Decreases in anthropogenic chemical outputs to the environment were expected to occur during the COVID-19 pandemic, with decreases in element concentrations in mussels. The ranges of median concentrations (µg g-1 dw) in the pre- and pandemic periods were 5.4-16.1 and 2.2-10.6 for As; 0.2-0.6 and 0.1-0.5 for Cd; and 1.2-3.2 and 0.7-1.8 for Pb, respectively. Temporal variations (prepandemic x pandemic) were more significant than spatial variations (five sampling sites). The relationships between the concentrations of hazardous elements and isotopic ratios (δ15N and δ13C) suggested that food sources were more diverse across the sampling sites during the pandemic period, when individuals exhibited less efficient trophic transfer. The concentrations of Cd and Pb were below the tolerable maximum limit, whereas for As, they were above the limit; however, these concentrations are not a risk to human health, as most As was present in the least toxic organic form. The intake estimates were below the tolerable intake limits, and only Pb concentrations are at risk of causing concern if the intake of mussels increases. This is the first study in Brazil that presents a spatial-temporal comparison of hazardous elements in marine fauna considering COVID-19 as a temporal landmark. The results are of interest for both public health and environmental health management in a post-COVID-19 scenario.

A comprehensive review and perspective research in technology integration for the treatment of gaseous volatile organic compounds

Volatile organic compounds (VOCs) are harmful pollutants emitted from industrial processes. They pose a risk to human health and ecosystems, even at low concentrations. Controlling VOCs is crucial for good air quality. This review aims to provide a comprehensive understanding of the various methods used for controlling VOC abatement. The advancement of mono-functional treatment techniques, including recovery such as absorption, adsorption, condensation, and membrane separation, and destruction-based methods such as natural degradation methods, advanced oxidation processes, and reduction methods were discussed. Among these methods, advanced oxidation processes are considered the most effective for removing toxic VOCs, despite some drawbacks such as costly chemicals, rigorous reaction conditions, and the formation of secondary chemicals. Standalone technologies are generally not sufficient and do not perform satisfactorily for the removal of hazardous air pollutants due to the generation of innocuous end products. However, every integration technique complements superiority and overcomes the challenges of standalone technologies. For instance, by using catalytic oxidation, catalytic ozonation, non-thermal plasma, and photocatalysis pretreatments, the amount of bioaerosols released from the bioreactor can be significantly reduced, leading to effective conversion rates for non-polar compounds, and opening new perspectives towards promising techniques with countless benefits. Interestingly, the three-stage processes have shown efficient decomposition performance for polar VOCs, excellent recoverability for nonpolar VOCs, and promising potential applications in atmospheric purification. Furthermore, the review also reports on the evolution of mathematical and artificial neural network modeling for VOC removal performance. The article critically analyzes the synergistic effects and advantages of integration. The authors hope that this article will be helpful in deciding on the appropriate strategy for controlling interested VOCs.

Analysis of nutrient loads, heavy metals and physicochemical properties of wastewater, wetland grass, and papaya samples: Gondar Malt factory, Ethiopia with global implication

Robust attention was brought to researchers due to deterioration of wastewater quality of lakes and reservoirs as major global concerns by industrial release. The uncontrolled releases of effluents impose serious impacts for both aquatic and terrestrial environments. In the current study, many parameters like nutrient loads, heavy metals and physicochemical properties of wastewater, wetland grass, and papaya samples were analysed. The investigated nutrients, alkalinity, and total hardness in fresh water samples were within the allowable limits except for phosphate in fresh wastewater and alkalinity in wastewater. The detected levels of heavy metals (mg/L) in wastewater samples were:- Cd (0.386-0.905), Cr (ND-0.074), Cu (0.064-0.096), Mn (0.184-1.528), Fe (0.167-4.636), Zn (0.175-0.333), and Pb (0.044-0.892) (mg/L). The studied metals in the wastewater sample, except Cd, Fe, and Pb were lower than the allowable limit. The level of heavy metals in the grass and papaya samples ranged from Cd (37.14-147.62), Cr (ND-8.82), Cu (3.14-8.33), Mn (2.89-85.46), Fe(5.0-65.15), Zn (3.44-36.84), and Pb (ND-60.36) (mg/kg). The detected metals were below the permissible limits, except Cd, Cr, and Pb. The findings of the physicochemical characteristics in wastewater samples were computed: pH (6.61-8.54), temperatures (21.63-26.57 °C), TDS (205.9-1896 mg/L), EC (359.9-3226.67 μs/cm), BOD (12.0-732.67 mg/L), COD (3.67-1691.33 mg/L). Except for temperature and pH, all levels in the wastewater were above the recommended limit for wastewater discharge by USEPA.

Toxicity of individual and mixture of organic compounds to P. Phosphoreum and S. Capricornutum using interpretable simple structural parameters

Human and environmental ecosystem beings are exposed to multicomponent compound mixtures but the toxicity nature of compound mixtures is not alike to the individual chemicals. This work introduces four models for the prediction of the negative logarithm of median effective concentration (pEC50) of individual chemicals to marine bacteria Photobacterium Phosphoreum (P. Phosphoreum) and algal test species Selenastrum Capricornutum (S. Capricornutum) as well as their mixtures to P. Phosphoreum, and S. Capricornutum. These models provide the simplest approaches for the forecast of pEC50 of some classes of organic compounds from their interpretable structural parameters. Due to the lack of adequate toxicity data for chemical mixtures, the largest available experimental data of individual chemicals (55 data) and their mixtures (99 data) are used to derive the new correlations. The models of individual chemicals are based on two simple structural parameters but chemical mixture models require further interaction terms. The new model's results are compared with the outputs of the best accessible quantitative structure-activity relationships (QSARs) models. Various statistical parameters are done on the new and comparative complex QSAR models, which confirm the higher reliability and simplicity of the new correlations.

Spatio-Temporal Variation in the Exceedance of Enterococci in Lake Burley Griffin: An Analysis of 16 Years' Recreational Water Quality Monitoring Data

Recreational waterbodies with high levels of faecal indicator bacteria (FIB) pose health risks and are an ongoing challenge for urban-lake managers. Lake Burley Griffin (LBG) in the Australian Capital city of Canberra is a popular site for water-based recreation, but analyses of seasonal and long-term patterns in enterococci that exceed alert levels (>200 CFU per 100 mL, leading to site closures) are lacking. This study analysed enterococci concentrations from seven recreational sites from 2001-2021 to examine spatial and temporal patterns in exceedances during the swimming season (October-April), when exposure is highest. The enterococci concentrations varied significantly across sites and in the summer months. The frequency of the exceedances was higher in the 2009-2015 period than in the 2001-2005 and 2015-2021 periods. The odds of alert-level concentrations were greater in November, December, and February compared to October. The odds of exceedance were higher at the Weston Park East site (swimming beach) and lower at the Ferry Terminal and Weston Park West site compared to the East Basin site. This preliminary examination highlights the need for site-specific assessments of environmental and management-related factors that may impact the public health risks of using the lake, such as inflows, turbidity, and climatic conditions. The insights from this study confirm the need for targeted monitoring efforts during high-risk months and at specific sites. The study also advocates for implementing measures to minimise faecal pollution at its sources.

The effects of COVID-19 on agriculture supply chain, food security, and environment: a review

COVID-19 has a deep impact on the economic, environmental, and social life of the global population. Particularly, it disturbed the entire agriculture supply chain due to a shortage of labor, travel restrictions, and changes in demand during lockdowns. Consequently, the world population faced food insecurity due to a reduction in food production and booming food prices. Low-income households face food security challenges because of limited income generation during the pandemic. Thus, there is a need to understand comprehensive strategies to meet the complex challenges faced by the food industry and marginalized people in developing countries. This research is intended to review the agricultural supply chain, global food security, and environmental dynamics of COVID-19 by exploring the most significant literature in this domain. Due to lockdowns and reduced industrial production, positive environmental effects are achieved through improved air and water quality and reduced noise pollution globally. However, negative environmental effects emerged due to increasing medical waste, packaging waste, and plastic pollution due to disruptions in recycling operations. There is extensive literature on the effects of COVID-19 on the environment and food security. This study is an effort to review the existing literature to understand the net effects of the pandemic on the environment and food security. The literature suggested adopting innovative policies and strategies to protect the global food supply chain and achieve economic recovery with environmental sustainability. For instance, food productivity should be increased by using modern agriculture technologies to ensure food security. The government should provide food to vulnerable populations during the pandemic. Trade restrictions should be removed for food trade to improve international collaboration for food security. On the environmental side, the government should increase recycling plants during the pandemic to control waste and plastic pollution.

Rapid assays of SARS-CoV-2 virus and noble biosensors by nanomaterials

The COVID-19 outbreak caused by SARS-CoV-2 in late 2019 has spread rapidly across the world to form a global epidemic of respiratory infectious diseases. Increased investigations on diagnostic tools are currently implemented to assist rapid identification of the virus because mass and rapid diagnosis might be the best way to prevent the outbreak of the virus. This critical review discusses the detection principles, fabrication techniques, and applications on the rapid detection of SARS-CoV-2 with three categories: rapid nuclear acid augmentation test, rapid immunoassay test and biosensors. Special efforts were put on enhancement of nanomaterials on biosensors for rapid, sensitive, and low-cost diagnostics of SARS-CoV-2 virus. Future developments are suggested regarding potential candidates in hospitals, clinics and laboratories for control and prevention of large-scale epidemic.

Fabrication of gelatin-incorporated nanoporous chitosan-based membranes for potential water desalination applications

Membrane technology has extensively been used in diverse phenomena such as separation, purification and controlled transportation. Herein, gelatin-incorporated porous chitosan membranes have been prepared using the sol-gel approach for potential water desalination applications. The porogens of poly(ethylene glycol) and Triton X-100 were employed for the mentioned purpose. The prepared porous membranes have been characterized for surface chemical, structural, thermal, mechanical and functional attributes using appropriate analytical approaches. Electron microscopy expressed porous surface morphologies of the resultant films with an average pore size of 14.5 nm. The infrared analysis demonstrated a successful crosslinking of the precursors in the resulting membranes via maleic anhydride. Differential scanning calorimetry analysis disclosed acceptable thermal stability of the test membranes, workable above ambient temperatures. The membrane expressed a water contact of 68.59°, which indicated moderate hydrophilicity, thus allowing controlled transport of the aqueous media. The resultant gelatin/chitosan porous membrane exhibited a porosity of 98 % against kerosene oil. In contrast, the flowability of 7.14 (ethanol), 5.00 (distilled water) and 0.53 (ethylene glycol) mL/min has been recorded against the mentioned liquids. The membrane efficiently purified the local canal water to permissible limits. Such membranes have been qualified for potential applications in water purification systems.

Assessing the impact of COVID-19 lockdown on surface water quality in Ireland using advanced Irish water quality index (IEWQI) model

The COVID-19 pandemic has significantly impacted various aspects of life, including environmental conditions. Surface water quality (WQ) is one area affected by lockdowns imposed to control the virus's spread. Numerous recent studies have revealed the considerable impact of COVID-19 lockdowns on surface WQ. In response, this research aimed to assess the impact of COVID-19 lockdowns on surface water quality in Ireland using an advanced WQ model. To achieve this goal, six years of water quality monitoring data from 2017 to 2022 were collected for nine water quality indicators in Cork Harbour, Ireland, before, during, and after the lockdowns. These indicators include pH, water temperature (TEMP), salinity (SAL), biological oxygen demand (BOD5), dissolved oxygen (DOX), transparency (TRAN), and three nutrient enrichment indicators-dissolved inorganic nitrogen (DIN), molybdate reactive phosphorus (MRP), and total oxidized nitrogen (TON). The results showed that the lockdown had a significant impact on various WQ indicators, particularly pH, TEMP, TON, and BOD5. Over the study period, most indicators were within the permissible limit except for MRP, with the exception of during COVID-19. During the pandemic, TON and DIN decreased, while water transparency significantly improved. In contrast, after COVID-19, WQ at 7% of monitoring sites significantly deteriorated. Overall, WQ in Cork Harbour was categorized as "good," "fair," and "marginal" classes over the study period. Compared to temporal variation, WQ improved at 17% of monitoring sites during the lockdown period in Cork Harbour. However, no significant trend in WQ was observed. Furthermore, the study analyzed the advanced model's performance in assessing the impact of COVID-19 on WQ. The results indicate that the advanced WQ model could be an effective tool for monitoring and evaluating lockdowns' impact on surface water quality. The model can provide valuable information for decision-making and planning to protect aquatic ecosystems.

Influence of COVID-19 lockdown on river water quality and assessment of environmental health in an industrialized belt of southern Western Ghats, India

The COVID-19 pandemic and sudden lockdown have severely hampered the country's economic growth and socio-cultural activities while imparting a positive effect on the overall fitness of the environment especially air and water resources. Increased urbanization and rapid industrialization have led to rising pollution and deterioration of rivers and associated sectors such as agriculture, domestic and commercial needs. However, various available studies in different parts of the country indicate that the COVID-19 pandemic has changed the entire ecosystem. But it is noted that studies are lacking in the southern Western Ghats region of India. Therefore, the present study attempts to investigate how the continuous lockdowns affect the River Water Quality (RWQ) during lockdown (October 2020) and post-lockdown (January 2021) periods in the lower catchments (Eloor-Edayar industrialized belt) of Periyar river, Kerala state, South India. A total of thirty samples (15 samples each) were analyzed based on drinking water quality, irrigational suitability, and multivariate statistical methods to evaluate the physical and chemical status of RWQ. The results of the Water Quality Index (WQI) for assessing the drinking water suitability showed a total of 93% of samples in the excellent and good category during the lockdown, while only 47% of samples were found fit for drinking during the post-lockdown period. Irrigational suitability indices like Mg hazard, KR, PI, SAR, and Wilcox diagram revealed lockdown period samples as more suitable for irrigational activities compared to post-lockdown samples with site-specific changes. Spearman rank correlation analysis indicated EC and TDS with a strong positive correlation to Ca2+, Mg2+, Na+, K+, TH, SO42-, and Cl- during both periods as well as strong positive correlations within the alkaline earth elements (Ca2+ and Mg 2+) and alkalis (Na+ and K+). Three significant components were extracted from principal component analysis (PCA), explaining 88.89% and 96.03% of the total variance for lockdown and post-lockdown periods, respectively. Variables like DO, BOD, Ca2+, NO3-, and Cl- remained in the same component loading during both periods elucidating their natural origin in the basin. The results of health risk assessment based on US EPA represented hazard quotient and hazard index values below the acceptable limit signifying no potential noncarcinogenic risk via oral exposure except As, suggesting children as more vulnerable to the negative effects than adults. Furthermore, this study also shows rejuvenation of river health during lockdown offers ample scope to policymakers, administrators and environmentalists for deriving appropriate plans for the restoration of river health from anthropogenic stress.

Did the COVID-19 pandemic play a role in the spatial and temporal variations of microplastics? Evidence from a tropical river in southern India

Personal protective equipment (PPE) use has increased because of COVID-19, producing more microplastics (MPs). The pandemic's impact on MP pollution in Indian rivers is little understood. In this study, the Netravathi River in Karnataka was investigated for the spatiotemporal distribution of MPs. The MPs abundance, size, and categories varied seasonally, with a higher concentration during the monsoon seasons. The reduction in rainfall during MON20 and the COVID-19 lockdown can be the reasons for the significant decrease in the MP concentration when compared to MON19. Polyethylene and polyethylene terephthalate were the most abundant polymers, with a shift from polyethylene to the latter (74 %) during post-monsoon season post-lockdown. The situation of MP pollution in Western Ghats can be mitigated with the aid of appropriate waste management of plastic trash and greater public awareness about the disposal of single-use plastics, which has risen significantly during the COVID-19 pandemic.

Environmental and human health impacts of volatile organic compounds: A perspective review

Volatile organic compounds (VOCs) are synthetic chemicals that are broadly used in the production of numerous day-to-day products for residential and commercial-based applications. VOCs are naturally occurring in the environment; however, average annual emissions of man-made volatile organic compounds may have increased dramatically in recent decades. Although many factors were attributed to influencing volatile compounds' emission, only mankind's activities are mainly proclaimed. Since vehicle and industrial pollution are mounting for years and years, urban areas are highly prone to the impacts of VOCs. Generally, volatile compounds are highly spontaneous and readily react with the particles of ambiance and produce a polluted atmosphere through several physical and chemical reactions. Though the volatile compounds play an indispensable role in the manufacture and maintaining the stability of many products, the health impacts associated with their prolonged exposure are gaining attention as recent research reports underline the influence of a wide range of diseases and disorders. Likewise, since the modern way of life applies a lot of day-to-day chemicals, it is imperative to spread a wide knowledge and safety aspects about these chemicals so that people of a wide category can implement preventive measures according to their exposure and living style. In this context, the review article attempts to shed light on past and current updates concerning the relationship between VOCs exposure and environmental and human health impacts.

Assessing the impact of COVID-19 restrictions on the microbial quality of an urban water catchment and the associated probability of waterborne infections

The World Health Organization reported that COVID-19 cases reached 611,421,786 globally by September 23, 2022. Six months after the first reported case, the disease had spread rapidly, reaching pandemic status, leading to numerous preventive measures to curb the spread, including a complete shutdown of many activities worldwide. Such restrictions affected services like waste management, resulting in waste accumulation in many communities and increased water pollution. Therefore, the current study investigated if lockdown impacted surface water microbial quality within an urban water catchment in South Africa. Using quantitative microbial risk assessment, the study further assessed changes in the probability of infection (Pi) with gastrointestinal illnesses from exposure to polluted water in the catchment. Escherichia coli data for 2019, 2020 and 2021 - pre-COVID, lockdown, and post-lockdown periods, respectively - were collected from the area's wastewater treatment management authorities. The Pi was determined using a beta-Poisson model. Mean overall E. coli counts ranged from 2.93 ± 0.16 to 5.30 ± 1.07 Log₁₀ MPN/100 mL. There was an overall statistically significant increase in microbial counts from 2019 to 2021. However, this difference was only accounted for between 2019 and 2021 (p = 0.008); the increase was insignificant between 2019 and 2020, and 2020 and 2021. The Pi revealed a similar trend for incidental ingestion of 100 mL and 1 mL of polluted water. No statistically significant difference was observed between the years based on multiple exposures. Although the overall microbial load and Pi estimated within the catchment exceeded the local and international limits recommended for safe use by humans, especially for drinking and recreation, these were not significantly affected by the COVID-19 restrictions. Nevertheless, these could still represent a health hazard to immunocompromised individuals using such water for personal and household hygiene, especially in informal settlements without access to water and sanitation services.

Linear and Nonlinear Regression Analysis for the Adsorption of Remazol Dye by Romanian Brewery Waste By-Product, Saccharomyces cerevisiae

Earth’s water balance and economy are becoming increasingly fragile due to overpopulation, global warming, severe environmental pollution and both surface and groundwater pollution. Therefore, it is essential to find solutions to the problems of water scarcity and water pollution. In this research, an experiment was designed to optimize the technique for the adsorption of Remazol Red F3B (RR) dye by lyophilized brewery yeast waste from the fermentation process. Moreover, we proved that brewery yeast is a great adsorbent. Batch adsorption experiments were carried out for optimization of different initial parameters, such as initial dye concentration (5–1000 mg/L), amount of yeast (0.5–2.5 g), pH (3–11) and temperature (20 to 40 °C). Furthermore, the structure and elemental composition of the adsorbent were analyzed with SEM, EDS and FTIR before and after biosorption. The best fits for the mathematical isotherm models in the case of the linear form were the Langmuir I and Freundlich models (R² = 0.923 and R² = 0.921) and, for the nonlinear form, the Khan model (R² = 0.9996) was the best fit. The pseudo-second-order kinetic model showed the best fit for both linear (plotting t/q_t vs. t) and nonlinear forms, are the calculated q_e values were similar to the experimental data.

Lake ecosystems as proxies of change in a post-pandemic era

A wide spectrum of algal-bacterial-viral relationships in aquatic ecosystems provide a complex matrix of interactions with abiotic factors such as temperature, pH and total solids concentrations in water. These relationships are quite reflective of the summative status of changes undergone by the lacustrine environments. However, the environmental risks and vulnerability of aquatic ecosystems in the regions of Global South including India, owing to the increase in sewage and domestic discharges with high loads of viral particles in the post-COVID-19 times have only been sparsely reported. Collective scenarios emerging from the influential factors such as the increase in salinity and total solids need to be explored for scientific significance and understanding. The present article opines that while the changes in the biotic and abiotic factors can enhance or alleviate these risks, identification of the stable and alternate states of the ecosystems make excellent ecosystem level proxies for pandemic-related disturbances at a macro-scale. Further, the need to plan Nature based Solutions to counter these risks under pandemic-like scenarios is discussed.