Removal of phenol from wastewater using Luffa cylindrica fibers in a packed bed column: Optimization, isotherm and kinetic studies.

This research entails a comparison of the effectiveness of unmodified Luffa cylindrica fiber in a fully packed bed (RLCF) and NaOH-modified Luffa cylindrica fiber in another fully packed bed (MLCF) in the context of phenol removal from wastewater. Experimental data obtained through batch adsorption experiments were utilized to determine the most suitable model. It was observed that as the initial concentration of phenol increased from 100 to 500 mg/l, the maximum percentage removal increased from 63.5 to 83.1% for RLCF-PB and from 89.9 to 99.5% for MLCF-PB. The correlation coefficient (R2) was calculated for the Langmuir, Freundlich, Temkin, Harkin-Jura, Halsey, and Flory-Huggins models for both materials. The analysis revealed that the pseudo-second-order model was the most suitable, followed by the Elovich model, with the pseudo-first-order model being the least suitable. The Weber-Morris diffusion model suggested that pore diffusion was the rate-determining step, and diffusion at the border layer was determined to be endothermic, feasible, heterogeneous, and spontaneous. In summary, this study indicates that MLCF-PB is a promising material for the efficient removal of phenol from aqueous solutions.

A review of remediation technologies for uranium-contaminated water.

Uranium is a naturally existing radioactive element present in the Earth's crust. It exhibits lithophilic characteristics, indicating its tendency to be located near the surface of the Earth and tightly bound to oxygen. It is ecotoxic, hence the need for its removal from the aqueous environment. This paper focuses on the variety of water treatment processes for the removal of uranium from water and this includes physical (membrane separation, adsorption and electrocoagulation), chemical (ion exchange, photocatalysis and persulfate reduction), and biological (bio-reduction and biosorption) approaches. It was observed that membrane filtration and ion exchange are the most popular and promising processes for this application. Membrane processes have high throughput but with the challenge of high power requirements and fouling. Besides high pH sensitivity, ion exchange does not have any major challenges related to its application. Several other unique observations were derived from this review. Chitosan/Chlorella pyrenoidosa composite adsorbent bearing phosphate ligand, hydroxyapatite aerogel and MXene/graphene oxide composite has shown super-adsorbent performance (>1000 mg/g uptake capacity) for uranium. Ultrafiltration (UF) membranes, reverse osmosis (RO) membranes and electrocoagulation have been observed not to go below 97% uranium removal/conversion efficiency for most cases reported in the literature. Heat persulfate reduction has been explored quite recently and shown to achieve as high as 86% uranium reduction efficiency. We anticipate that future studies would explore hybrid processes (which are any combinations of multiple conventional techniques) to solve various aspects of the process design and performance challenges.

Management of sugar dust in the sugar industry.

Sugar dust poses significant risks in the sugar industry, threatening workers' safety and health as well as the potential for explosions and fires. The combustibility of sugar dust arises from its small, lightweight particles that disperse easily and ignite readily. Effective management strategies are essential to ensuring a safe work environment and preventing accidents. This perspective article provides an overview of sugar dust management in the global sugar industry. Various methods are employed to collect and manage sugar dust, including dust collectors, air handling systems, and proper housekeeping procedures. Advancements like electrostatic precipitators, high-efficiency particulate air filters, and self-cleaning dust collection systems show promise for future management. Utilizing both artificial intelligence and nanotechnology can also contribute to minimizing the concentrations of sugar dust in facilities. Stringent regulations and guidelines exist to control dust explosions in the industry. Implementation of robust safety measures and training programs significantly curbs the economic and environmental toll of sugar dust explosions. The paper concludes with recommendations to address sugar dust challenges, including enhanced regulation, investment in technology and research, and improved collaboration among industry stakeholders. These measures will mitigate hazards, ensure worker well-being, and safeguard the sugar industry's operations.

Ecotoxicological impact of dinotefuran insecticide and its metabolites on non-targets in agroecosystem: Harnessing nanotechnology- and bio-based management strategies to reduce its impact on non-target ecosystems.

The class of insecticides known as neonicotinoid insecticides has gained extensive application worldwide. Two characteristics of neonicotinoid pesticides are excellent insecticidal activity and a wide insecticidal spectrum for problematic insects. Neonicotinoid pesticides can also successfully manage pest insects that have developed resistance to other insecticide classes. Due to its powerful insecticidal properties and rapid plant absorption and translocation, dinotefuran, the most recent generation of neonicotinoid insecticides, has been widely used against biting and sucking insects. Dinotefuran has a wide range of potential applications and is often used globally. However, there is growing evidence that they negatively impact the biodiversity of organisms in agricultural settings as well as non-target organisms. The objective of this review is to present an updated summary of current understanding regarding the non-target effects of dinotefuran; we also enumerated nano- and bio-based mitigation and management strategies to reduce the impact of dinotefuran on non-target organisms and to pinpoint knowledge gaps. Finally, future study directions are suggested based on the limitations of the existing studies, with the goal of providing a scientific basis for risk assessment and the prudent use of these insecticides.

A review of the treatment technologies for hexavalent chromium contaminated water.

The toxicity of hexavalent chromium (Cr(VI)) present in the environment has exceeded the current limits or standards and thus may lead to biotic and abiotic catastrophes. Accordingly, several treatments, including chemical, biological, and physical approaches, are being used to reduce Cr(VI) waste in the surrounding environment. This study compares the Cr(VI) treatment approaches from several areas of science and their competence in Cr(VI) removal. As an effective combination of physical and chemical approaches, the coagulation-flocculation technique removes more than 98% of Cr(VI) in less than 30 min. Most membrane filtering approaches can remove up to 90% of Cr(VI). Biological approaches that involve the use of plants, fungi, and bacteria also successfully eliminate Cr(VI) but are difficult to scale up. Each of these approaches has its benefits and drawbacks, and their applicability is determined by the research aims. These approaches are also sustainable and environmentally benign, thus limiting their effects on the ecosystem.

Concentrations, bioaccumulation, and health risk assessments of heavy metals in fishes from Nigeria's freshwater: a general overview.

Heavy metals (HMs) have attracted global attention due to their toxicity, persistence, and accumulation in aquatic fish in the polluted water environment. The consumption of these fishes exposed humans to a higher risk of non-carcinogenic and carcinogenic risks. In this study, we provided a critical overview of the potential sources and concentration of HMs in Nigeria's freshwater. Furthermore, we reported their pollution level in widely eaten fish species in the country. Our findings show that effluent from anthropogenic and industrial activities is one of the major sources HMs in the country. The mean concentration of Zn (9.02 mg/L), As (7.25 mg/L), Cu (4.35 mg/L), Fe (1.77 mg/L), and Pb (1.46 mg/L) in Nigeria's freshwaters were found to be high than Nigerian Standard for Drinking Water Quality permissible limit. This study demonstrated considerable health risks associated HMs via dietary consumption of different fishes from polluted waters. Therefore, we recommended an urgent need for effective management HMs in water bodies in order to protect the lives of people living in the country.

Lycopene: a therapeutic strategy against coronavirus disease 19 (COVID- 19).

Lycopene is a group of phytochemicals found in nature, primarily in fruits and vegetables. Lycopene is thought to protect against a variety of diseases attributed to its antioxidant capabilities. Lycopene has anti-inflammatory, anti-cancer, and immunity-boosting qualities, among other biological and pharmacological benefits. COVID-19 (coronavirus disease 19) is an infectious disease caused by the SARS-CoV-2 virus, which has recently emerged as one of the world's leading causes of death. Patients may be asymptomatic or show signs of respiratory, cytokine release syndrome, gastrointestinal, or even multiple organ failure, all of which can lead to death. In COVID-19, inflammation, and cytokine storm are the key pathogenic mechanisms, according to SARS-CoV-2 infection symptoms. ARDS develops in some vulnerable hosts, which is accompanied by an inflammatory "cytokine syndrome" that causes lung damage. Immunological and inflammatory markers were linked to disease severity in mild and severe COVID-19 cases, implying that inflammatory markers, including IL-6, CRP, ESR, and PCT were significantly linked with COVID-19 severity. Patients with severe illness have reduced levels of several immune subsets, including CD4 + T, NK, and CD8 + cells. As a result, lycopene can be commended for bolstering physiological defenses against COVID-19 infections.

A bibliometric analysis of pre- and post-Stockholm Convention research publications on the Dirty Dozen Chemicals (DDCs) in the African environment.

Persistent organic pollutants (POPs) are toxic chemicals that stay in the environment for a long time. To address the toxicity issues, global nations, including 53 African countries, ratified the Stockholm Convention to minimize or eliminate the production of 12 POPs known as the "Dirty Dozen". However, these Dirty Dozen Chemicals (DDCs) still exist in significant concentration in the African environment, prompting numerous research to investigate the level of their occurrences. Here, we conducted a bibliometric analysis to examine the publication trends in DDCs-related research in Africa using articles published between 1949 and 2021 from the Web of Science and Scopus databases. A total of 884 articles were published within the survey period, with a publication/author and author/publication ratio of 0.36 and 2.76, respectively. South Africa ranked first in terms of number of publications (n = 133, 15.05%), and total citations (n = 3115), followed by Egypt (n = 117), Nigeria (n = 77), USA (n = 40), and Ghana (n = 38). Research collaboration was relatively high (collaboration index = 2.88). The insignificant difference between the theoretical and observed Lotka's distribution indicates Lotka's law does not fit the DDC literature. An annual growth rate of 0.57% implies that a substantial increase of articles in years to come is not expected. More research programs should be established in other African countries to measure up to South Africa's supremacy. This is critical in order to provide a basis for effective compliance to the Stockholm Convention on POPs in Africa.

Considerations on environmental, economic, and energy impacts of wind energy generation: Projections towards sustainability initiatives.

The energy sector contributes significantly to the emission of greenhouse gases (GHGs) due to the use of fossil fuels which leads to climate change problems. Worldwide, there is a shift from fossil fuel-based energy to cleaner energy sources such as solar, wind, geothermal, and biomass. Wind energy is one of the promising cleaner energy sources as it is feasible and cost-effective. However, the development of wind farms causes impacts on sustainability aspects. This article aims to review the impacts of wind energy generation on environmental, economic, and social aspects of sustainability and their mitigation strategies. The aim was achieved by reviewing recent research papers on different aspects of wind energy sustainability. The environmental impacts reviewed include the effects on avian life, noise pollution, visual impacts, microclimate and vegetation. Apart from environmental impacts, wind energy generation faces issues in energy and financial sustainability, such as the wind power fluctuation, technology lagging and use of fixed feed-in tariff contracts that do not consider wind energy advancement and end-of-life management. We discussed that turbine deterrents, automatic curtailment, low gloss blades and sustainable siting of wind farms as some of the effective ways to combat wind energy environmental impacts. In addition, we discussed that energy storage systems, setting up microgrids, combination of solar, wind and energy storage, and renewable energies policies are some of the ways to combat wind energy's economic and energy impacts. Lastly, the recommendations, and future perspectives on wind energy generation sustainability are discussed.

Adsorption of persistent organic pollutants (POPs) from the aqueous environment by nano-adsorbents: A review.

The intensification of urbanisation and industrial activities significantly exacerbates the distribution of toxic contaminations into the aqueous environment. Persistent organic pollutants (POPs) have received considerable attention in the past few decades because of their persistence, long-distance migration, potential bioaccumulation, latent toxicity for humans and wildlife. There is no doubt that POPs cause serious effects on the global ecosystem. Therefore, it is necessary to develop a simple, safe and sustainable approach to remove POPs from water bodies. Among other conventional techniques, the adsorption process has proven to be a more effective method for eliminating POPs and to a larger extent meet discharge regulations. Nanomaterials can effectively adsorb POPs from aqueous solutions. For most POPs, a >70% adsorptive removal efficiency was achieved. The major mechanisms for POPS uptake by nano-adsorbents includes electrostatic interaction, hydrophobic (van der Waals, π-π and electron donor-acceptor) interaction and hydrogen bonding. Nano-adsorbent can sustain a >90% POPs adsorptive removal for about 3 cycles and reuseable for up to 10 cycles. Challenges around adsorbent ecotoxicity and safe disposal were also discussed. The present review evaluated recent research outcomes on nanomaterials that are employed to remove POPs in water systems.

Treatment technologies for bakers' yeast production wastewater.

Researchers in recent years have utilized a broad spectrum of treatment technologies in treating bakers' yeast production wastewater. This paper aims to review the treatment technologies for the wastewater, compare the process technologies, discuss recent innovations, and propose future perspectives in the research area. The review observed that nanofiltration was the most effective membrane process for the treatment of the effluent (at >95% pollutant rejection). Other separation processes like adsorption and distillation had technical challenges of desorption, a poor fit for high pollutant load and cost limitations. Chemical treatment processes have varying levels of success but they are expensive and produce toxic sludge. Sludge production would be a hurdle when product recovery and reuse are targeted. It is difficult to make an outright choice of the best process for treating the effluent because each has its merits and demerits and an appropriate choice can be made when all factors are duly considered. The process intensification of the industrial-scale production of the bakers' yeast process will be a very direct approach, where the process optimisation, zero effluent discharge, and enhanced recovery of value-added product from the waste streams are important approaches that need to be taken into account.

Effect of light on concomitant sequestration of Cu(II) and photodegradation of tetracycline by H-MOR/H-ß/H-ZSM5 zeolites.

It is important that a pollution remediation system be able to cater for a variety of pollutant species present in the water to be treated. The aim of this study was to utilise a series of commercial zeolites (H-MOR, H-ß, and H-ZSM5) for the concomitant adsorption and photodegradation of Cu2+ and tetracycline (TC) molecules. The adsorbent cum photocatalyst was characterised by SEM and FTIR. FTIR confirmed the key functional groups (Si-O-Si and Al-O-Si) in the series of zeolites, and H-ß zeolite was demonstrated to be the most effective adsorbent cum photocatalyst for both adsorption and photodegradation of Cu2+ and TC molecules. These results were further corroborated from the pseudo-first-order rate constant values. Among the investigated zeolites, H-ZSM5 displayed the least adsorption and photodegradation performance for Cu2+ and TC molecules. The photolysis reaction confirms the significant role of zeolites in the photodegradation test, as low performance was recorded in the absence of the zeolites.

Sewage sludge-derived biochar for the adsorptive removal of wastewater pollutants: A critical review.

The production of biochar from sewage sludge pyrolysis is a promising approach to transform the waste resultant from wastewater treatment plants (WWTPs) to a potential adsorbent. The current review provides an up-to-date review regarding important aspects of sewage sludge pyrolysis, highlighting the process that results major solid fraction (biochar), as high-value product. Further, the physio-chemical characteristics of sewage-sludge derived biochar such as the elemental composition, specific surface area, pore size and volume, the functional groups, surface morphology and heavy metal content are discussed. Recent progress on adsorption of metals, emerging pollutants, dyes, nutrients and oil are discussed and the results are examined. The sewage sludge-derived biochar is a promising material that can make significant contributions on pollutants removal from water by adsorption and additional benefit of the management of huge volume of sewage. Considering all these aspects, this field of research still needs more attention from the researchers in the direction of the technological features and sustainability aspects.

Photocatalytic remediation of methylene blue using hydrothermally synthesized H-Titania and Na-Titania nanotubes.

Although nanotube is among the most effective morphology of Titania due to its unilateral pathway for photo-generated charge transfer and mechanical stability, its performance is still hampered by high recombination. In the present study, to further improve the photocatalytic degradation performance of Titania, univalent elements of H and Na were respectively ion-exchanged into the Titania nanotubes (TNTs). The photocatalyst was characterized using XRD, TEM, ICP-AES, and FTIR. The modified samples displayed enhanced photocatalytic degradation performance over Degussa TiO2 under UV-A light illumination of MB. The rate constants of NaTNT and HTNT were 16 and 13 times that of Degussa TiO2. Specifically, the Na-TNTs showed better photocatalytic degradation activity than H-TNTs with a rate constant of 0.12 min-1 while the latter showed 0.09 min-1. The optimum adsorption and photocatalytic performance of NaTNT were determined at pH 6 achieving about 99% MB removal within 10 min of irradiation. The ion exchange NaTNT displayed excellent reusability after the fifth cycle of the photocatalytic tests and superoxide radicals were experimentally determined to be the main reactive oxygen species involved in the photocatalytic degradation of MB.

COVID-19 pandemic in Uttarakhand, India: Environmental recovery or degradation?

The human coronavirus disease-2019 (COVID-19) caused by SARS-CoV-2 is now a global pandemic. Personal hygiene such as hand-washing, the use of personal protective equipment, and social distancing via local and national lockdowns are used to reduce the risk of transmission of SARS-CoV-2. COVID-19 and the associated lockdowns may have significant impacts on environmental quality and ergonomics. However, limited studies exists on the impacts of COVID-19 and the associated lockdowns on environmental quality and ergonomics in low-income settings. Therefore, the present study investigated the impacts of the COVID-19 outbreak on socioeconomics, ergonomics and environment (water quality, air quality and noise) in Uttarakhand, India. Approximately 55% of respondents experienced headaches, and the other common health-related issue was back pain, with 45% of respondents having problems with their backs. Water and air quality significantly improved during the lockdown relative to the pre-lockdown period, but was observed to return to their previous characteristics afterwards. Lockdowns significant increased the concentration of indoor air pollutants while noise pollution levels significantly declined. In summary, lockdowns have adverse impacts on ergonomics, resulting in work-related human health risks. The impacts of lockdowns on environmental quality are mixed: temporary improvements on water and air quality, and noise reduction were observed, but indoor air quality deteriorated. Therefore, during lockdowns there is a need to minimize the adverse environmental and ergonomic impacts of lockdowns while simultaneously enhancing the beneficial impacts.

Removal of ibuprofen from aqueous media by adsorption: A comprehensive review.

Ibuprofen (IBP) is a non-steroidal anti-inflammatory drug released into the environment through hospital and medical effluents, pharmaceutical wastewater and veterinary use. The aim of this paper is to review the empirical findings on the adsorption of IBP from aqueous media. A preliminary ecotoxicological assessment confirmed the environmental risk of IBP in the aqueous environment. Open literature works considered in this review were for the past decade (2010-2020). Carbon-based adsorbents are the best class of adsorbent for the uptake of IBP and the highest reported maximum adsorption capacity (qmax) for IBP is 496.1 mg/g by SWCNTs. The range of adsorption capacities for IBP uptake in this review is between 0.0496 and 496.1 mg/g. The mechanism of uptake is majorly by hydrophobic interactions, π - π stacking, hydrogen bonds, electrostatic interactions and dipole-dipole interaction. IBP uptake was best fit to a wide variety of isotherm models but was well suited to the pseudo-second order kinetics model. The thermodynamics of IBP uptake depends majorly on the nature of the adsorbent and desorption from the solid phase is based on an appropriate choice of the eluent. Knowledge gaps were observed in used adsorbent disposal and process improvement. In the future, interest would increase in scale-up, industrial applications and practical utilisation of the research findings which would help in sustainable water resource management.

3D reconstruction and morphological analysis of electrostimulated hyperthermophile biofilms of Thermotoga neapolitana.

In this study, the morphological characteristics of the T. neapolitana biofilms on a ceramic carrier, stainless steel, graphite foil, carbon paper, carbon felt and carbon cloth using 3D reconstruction technology was investigated. This was based on the micrographs available in Squadrito et al. (Data Brief 33: 106-403, 2020). Besides the ceramic carrier, the other surfaces were conductive and slightly positively polarised (0.8 and 1.2 V). A simple drying technique was used to show the biofilm and avoid its detachment while chemical fixing with glutaraldehyde was used to better highlight the bacterial morphology within the biofilm. The latter was more suitable for investigating biofilm morphology while the former for bacteria morphology. For the ceramic carrier and stainless steel electrode surfaces, a regular undulating pattern of the biofilm was highlighted by the 3D rendering whilst the glutaraldehyde fixed sample showed a rod-like bacteria morphology. For the other surfaces, a regular undulating pattern of the biofilm and a mixture of a rod-like and a coccoid form of settled bacteria were evidenced also. Carbon cloth was the more suitable electrode for the current application due to its richer filamentous network of bacteria biofilm suggesting a better prevention of bacteria detachment from the electrode surface. Indeed, a preserved biofilm was highlighted on the surfaces of the polarised carbon cloth.

Insights into hazardous solid waste generation during COVID-19 pandemic and sustainable management approaches for developing countries.

The recent emergence of the COVID-19 pandemic has contributed to the drastic production and use of healthcare and personal protective equipment, leading to the release of a huge quantity of hazardous medical and solid wastes in the environment. Meanwhile, these solid wastes may contribute to the spread of the SARS-CoV-2 viral particles when disposed of without proper treatment and care. Since SARS-CoV-2 could persist on different material surfaces including plastic, steel, paper, cardboard, cloth, and wood, proper management of these hazardous solid wastes has become a challenging task during the COVID-19 pandemic. In this paper, an overview of the consumption of COVID-19-related healthcare and personal protective equipment along with the production of hazardous solid waste is presented. The efficient management of these wastes is necessary to prevent the entering of SARS-CoV-2 in various environmental compartments. Therefore, some preventive measures including the use of biodegradable materials for manufacturing personal protective equipment, minimizing the use of non-biodegradable materials, efficient pre- and-post planning, careful segregation, and disposal are, therefore, proposed for their sustainable management. The findings reported in this paper contribute to tackling the problems associated with hazardous solid waste management, particularly for low- and middle-income countries.

Assessment of socioeconomic inequality based on virus-contaminated water usage in developing countries: A review.

Water is an essential resource required for various human activities such as drinking, cooking, and other recreational activities. While developed nations have made significant improvement in providing adequate quality water and sanitation devoid of virus contaminations to a significant percentage of the residences, many of the developing countries are still lacking in these regards, leading to many death cases among the vulnerable due to ingestion of virus-contaminated water and other waterborne pathogens. However, the recent global pandemic of COVID-19 seems to have changed the paradigm by reawakening the importance of water quality and sanitation, and focusing more attention on the pervasive effect of the use of virus-contaminated water as it can be a potential driver for the spread of the virus and other waterborne diseases, especially in developing nations that are characterized by low socioeconomic development. Therefore, this review assessed the socioeconomic inequalities related to the usage of virus-contaminated water and other waterborne pathogens in developing countries. The socioeconomic factors attributed to the various waterborne diseases due to the use of virus-contaminated water in many developing countries are poverty, the standard of living, access to health care facilities, age, gender, and level of education. Some mitigation strategies to address the viral contamination of water sources are therefore proposed, while future scope and recommendations on tackling the essential issues related to socioeconomic inequality in developing nations are highlighted.

Ecotoxicology of glyphosate and recent advances in its mitigation by adsorption.

Glyphosate (N-[phosphonomethyl]glycine) is one of the most popular herbicides now used in agricultural practice. The aim of this paper was to discuss the research progress and innovations in recent years on the mitigation of glyphosate (GLY) from aqueous media by adsorption. The ecotoxicology of GLY was discussed in the domain of its chronic and sub-chronic toxicity, genotoxicity, reproductive toxicity, and carcinogenicity, and potential risks of food contamination were discussed. It was observed that polymers and resins are the best class of adsorbents for GLY adsorption from aqueous media. GLY adsorption was best fit to either Freundlich or Langmuir isotherm depending on the nature of the adsorbent. The pseudo-second-order kinetics was also the best fit for modelling the kinetics of GLY adsorption. A review of the thermodynamics revealed that GLY adsorption was usually spontaneous and exothermic. Research trends and knowledge gaps are in the area of chemical mobility in environmental systems (especially in the presence of other chemical species), the use of heavy metal-laden adsorbent and molecular modelling. Furthermore, it was observed that the ecotoxicology of GLY still has some contentious areas where there is no conclusive stance.