Hazardous Pollutants Research Articles

Ambient Stable CsCu2I3 Flexible Gas Sensors for Reliable NO2 Detection at Room Temperature.

The advancement of the Internet of Things and artificial intelligence has increased the demand for air quality monitoring to protect human health. Nitrogen dioxide (NO2), a hazardous pollutant, causes inflammatory responses, even at low concentrations, necessitating sensitive gas sensors. Although metal oxide semiconductor sensors are commonly used, their high-operating temperature and reliance on additional heaters limit miniaturization and increase power consumption. Here, a lead-free, transparent, and flexible CsCu2I3 halide perovskite gas sensor was developed, demonstrating high sensitivity (1509% to 5 ppm) and selectivity for NO2 detection at room temperature with full recovery. The sensor exhibited high stability in ambient air and high-humidity environments, which is not achievable with traditional halide perovskite sensors. First-principles density functional theory calculations revealed the mechanisms underlying its stability and sensitivity. This study highlights the potential of halide perovskites for low-power gas sensing at room temperature, addressing critical challenges for commercially viable wearable applications.

Spatiotemporal distribution and ecological hazards of microplastic pollution in soil water resources around a wastewater treatment plant and municipal solid waste site

Spatiotemporal distribution and ecological hazards of microplastic pollution in soil water resources around a wastewater treatment plant and municipal solid waste site

The effects of polycyclic aromatic hydrocarbons on ecological assembly processes and co-occurrence patterns differ between soil bacterial and fungal communities

Polycyclic aromatic hydrocarbons (PAHs) are hazardous organic pollutants prevalent in soil ecosystems. Bacteria and fungi play important roles in the degradation of PAHs in the soils. However, little is known about the differences between the bacterial and fungal community assemblies in PAH-contaminated soils. In this study, soil bacterial and fungal community distributions were investigated in maize farmlands and roadside barelands around nine coking plants in Shanxi, China. Most of the soil samples were severely polluted with PAHs. A clear microbial biogeographic pattern was observed. Bacterial communities are primarily affected by environmental factors, whereas fungal communities are primarily affected by spatial factors. Null modeling showed that homogeneous selection (deterministic processes) and dispersal limitation (stochastic processes) dominated the bacterial and fungal community assemblages, respectively. PAH concentrations were closely linked to community assembly processes, and influenced microbial co-occurrence by mediating specific network modules. Overall, the effects of PAHs on bacterial community assembly and co-occurrence relationships were greater than those on fungal communities. Some microbial taxa associated with PAH degradation can be considered potential biomarkers that reflect the degree of PAH pollution. These results expand the understanding of the mechanisms underlying the assembly and maintenance of soil microbial communities in response to PAH contamination.

BIOREMEDIATION OF WATER POLLUTANTS FROM WASTEWATER

Environmental pollution caused by xenobiotics and other persistent compounds has been recognized as a significant threat to both human health and the natural environment. These pollutants, which include heavy metals, polychlorinated biphenyls, plastics, and various agrochemicals, are toxic and resistant to biodegradation. Bioremediation is an emerging and effective method for cleaning contaminated environments by removing toxic waste. This technique utilizes a range of microorganisms, both aerobic and anaerobic, to treat polluted sites. Microorganisms are crucial in bioremediation as they degrade, detoxify, and immobilize hazardous wastes and pollutants, transforming them into less toxic forms. Depending on factors like cost, pollutant type, and concentration, bioremediation can be conducted ex-situ or in situ. Consequently, the appropriate bioremediation method is selected based on these factors. This review addresses the major issue of contaminants in water, including its sources, effects on the ecosystem, remediation strategies using different biological processes that change the pollutants into less hazardous, source and types of pollutants, the principle of bioremediation, bioremediation strategies, and technologies, microorganisms in bioremediation, case study and application, monitoring, and assessment of bioremediation process, environmental impacts and sustainability, future perspectives, and challenges.

Dioxins and their impact: a review of toxicity, persistence, and novel remediation strategies.

Dioxins rank among the most hazardous persistent organic pollutants, presenting a serious threat due to their long environmental lifespan and capacity for bioaccumulation. This comprehensive review delves into the historical, chemical, and toxicological aspects of dioxins, spotlighting significant incidents such as the Seveso disaster and the repercussions of Agent Orange. The review offers a thorough analysis of the sources of dioxin formation, encompassing natural occurrences like volcanic eruptions and wildfires, alongside man-made activities such as industrial combustion and waste incineration. It examines regional variations in dioxin contamination, revealing air concentrations that can range from less than 0.01 pg TEQ per m3 in remote regions to as high as 2 pg TEQ per m3 in urban environments. With global dioxin emissions estimated at around 97.0 kg TEQ per year, Asia and Africa emerge as the highest emitters among the continents, with the total global dioxin release approximately at 100.4 kg TEQ annually. Dioxin emissions per capita show stark contrasts across six continents, from 10.77 g TEQ per capita in Europe to a concerning 71.66 g TEQ per capita in Oceania. Furthermore, the concentration of dioxin compounds produced during combustion varies significantly, ranging from 15 to 555 ng m-2. While dioxin emission regulations are intricate and differ globally, most nations require that concentrations remain below one ng m-2. Globally, dioxin production is estimated at 17 226 kilograms annually, equating to about 287 kilograms in toxic equivalent (TEQ). This review critically examines the severe health implications of dioxins, which include carcinogenic effects, endocrine disruption, and immunotoxicity. Innovative remediation strategies, such as using nanomaterials for adsorption and advanced oxidation processes, are identified as promising pathways to tackle this pressing issue. Ultimately, this review underscores the necessity for enhanced monitoring systems and comprehensive policy frameworks to facilitate sustainable dioxin management and regulatory compliance. Taking decisive action is vital to protect public health and the environment from the ongoing threat posed by dioxins.

Unraveling the metabolic landscape of Exophiala spinifera strain FM: Model reconstruction, insights into biodesulfurization and beyond.

Exophiala spinifera strain FM, a black yeast and melanized ascomycete, shows potential for oil biodesulfurization by utilizing dibenzothiophene (DBT) as its sole sulfur source. However, the specific pathway and enzymes involved in this process remain unclear due to limited genome sequencing and metabolic understanding of E. spinifera. In this study, we sequenced the complete genome of E. spinifera FM to construct the first genome-scale metabolic model (GSMM) for this organism. Through bioinformatics analysis, we identified genes potentially involved in DBT desulfurization and degradation pathways for hazardous pollutants. We focused on understanding the cost associated with metabolites in sulfur assimilation pathway to assess economic feasibility, optimize resource allocation, and guide metabolic engineering and process design. To overcome knowledge gaps, we developed a genome-scale model for E. spinifera, iEsp1694, enabling a comprehensive investigation into its metabolism. The model was rigorously validated against growth phenotypes and gene essentiality data. Through shadow price analysis, we identified costly metabolites such as 3'-phospho-5'-adenylyl sulfate, 5'-adenylyl sulfate, and choline sulfate when DBT was used as the sulfur source. iEsp1694 encompasses the degradation of aromatic compounds, which serves as a crucial first step in comprehending the pan metabolic capabilities of this strain.

A New Model to Assess Compensation for Eco‐Environmental Damage

ABSTRACTTo improve procedures to initiate compensation for ecological damage, and to more quickly and efficiently quantify damage during the initial stages of damage, inspiration is drawn from the US Natural Resources Damage Assessment System to construct an ecological environment assessment model that includes indicators such as pollutant hazards, environmental functions, exceedance, pollution duration, pollutant quantity, and receptor sensitivity. According to rating values, a particular incident (a “case”) is apportioned to one of three levels: significantly minor, minor, and significant damage. These levels are used as a starting point for refining the case. We applied 126 cases from City A to this model. Results indicate that it is highly consistent with the actual situation. This model has good maneuverability. Based on existing standard specifications and practical cases, this model is validated. This model can be applied to provide technical guidance and a standardized response strategy to managers in instances of environmental impact.

Coral reef restoration can reduce coastal contamination and pollution hazards

Coral reef restoration can reduce the wave-driven flooding for coastal communities. However, this protection has yet to be assessed in terms of the reduced risk of flood-driven environmental contamination. Here we provide the first high-resolution valuation of the reduction of flood-related land-based environmental pollution provided by potential coral reef restoration. Along Florida’s 460 km-long coral reef-fringed coastline, coral reef restoration could reduce the risk of sewage and petrochemical contamination by preventing the flooding of petroleum storage tank systems (-9%), onsite sewage treatment and disposal systems (-4%), and wastewater treatment plants (-10%). The present value of critical infrastructure protection and contamination prevention benefits provided by coral reef restoration is $3,413,503, with some areas exceeding $1,500,000/km. Annually, 48,403 U.S. gal of petrochemicals, 10,404 GPD of wastewater treatment capacity, equivalent to $281,435, could be protected from flooding, demonstrating that coral reef restoration can provide environmental risk reduction and previously undocumented additional socioeconomic benefits.

Polycylic Aromatic Hydrocsbons as hazardous pollutant: Sources, impact on the environment and human health, monitoring and preventive strategies

Polycylic Aromatic Hydrocsbons as hazardous pollutant: Sources, impact on the environment and human health, monitoring and preventive strategies

Overexpression of E. coli formaldehyde metabolic genes pleiotropically promotes Arabidopsis thaliana growth by regulating redox homeostasis.

Formaldehyde (FA) is a hazardous pollutant causing acute and chronic poisoning in humans. While plants provide a natural method of removing FA pollution, their ability to absorb and degrade FA is limited. To improve the ability of plants to degrade FA, we introduced the E. coli FrmA gene into Arabidopsis thaliana alone (FrmAOE lines) or with FrmB (FrmA/BOE lines). The transgenic seedlings had approximately 30 % longer primary roots and a 20 % higher fresh weight than the control plants. The transgenic plants started flowering four days earlier and had about 30 % more kilo-seed weight than the wild type. FrmA/BOE and FrmAOE accumulated 40 % more reactive oxidative species (ROS) in mesophyll protoplasts and leaf tissue than wild-type plants under normal conditions. In the presence of FA, they produced 92 % and 26 % more glutathione (GSH) and 6 % and 4 % more ascorbate (AsA), respectively, compared to wild-type plants and thus scavenged FA-induced ROS more effectively. The degradation efficiency of the transgenic leaf extract for FA was 73 % and 44 % higher than that of the wild type, respectively, which was also emphasized by a 2 %-26 % increase in the activity of antioxidant enzymes such as SOD and APx. By revealing the functional divergence between microbial and plant FA metabolic pathways, our work has not only highlighted the promising pluripotency of microbial genes in promoting normal plant growth and detoxifying organic pollutants simultaneously, but also revealed another layer of complexity of plant defense mechanisms against organic toxins related to ROS scavenging.

Years of life lost attributable to air pollution, a health risk-based air quality index approach in Ningbo, China.

Air pollution remains a significant threat to human health and economic development. Most previous studies have examined the health effects of individual pollutants, which often overlook the combined impacts of multiple pollutants. The traditional composite indicator air quality index (AQI) only focuses on the major pollutants, whereas the health risk-based air quality index (HAQI) could offer a more comprehensive evaluation of the health effects of various pollutants on populations. Currently, research on HAQI to evaluate the influence of multiple air pollutants on life expectancy losses is limited. In this study, we employed HAQIto estimate years of life lost (YLL) caused by exposure to air pollution for total deaths and sub-groups by sex, age, and cause-specific disease in Ningbo from 2014 to 2018. Results reveal that significant improvement in air quality during the study period. Based on the AQI-classified air quality risk category, the HAQI estimated a more severe level, which suggests that the commonly used AQI significantly underestimates the hazards of multiple air pollutants. The YLL attributable to exposure above threshold concentrations of the Chinese Ambient Air Quality Standards (CAAQS) 24-hour Grade II standards was 1.375 years (95% CI, 1.044-1.707) per death based on the HAQI, while the YLL estimated using AQI was 1.047 years (95% CI, 0.809-1.286) per death. Females and elderly people over 65 years were vulnerable subgroups, with YLL of 1.232 and 1.480 years per death, respectively. Among deaths of cause-specific disease, the YLL attributed to polluted air was highest for patients with respiratory diseases (0.866 years, 95% CI: 0.668-1.064), followed by patients with circulatory diseases (0.490 years) and endocrine diseases (0.478 years), respectively. Improving the standards of air quality could promote the management of air quality and reduce the disease burden and economic losses caused by polluted air to populations, especially for vulnerable populations. Our study provides a basis for the formulation of policies and upgrade of air quality standards.

Recent Advancements in Biochar and its Composite for the Remediation of Hazardous Pollutants

: Biochar has garnered considerable attention in recent times due to its potential uses in the environmental field. In this study, we comprehensively examine and condense information on biochar production, characteristics, and adsorption mechanisms, with a focus on its economic applications for remediating hazardous contaminants. Our assessment is based on over 200 publications from the past decade. Biochar, a carbon-rich material, can be derived from various organic waste sources, such as food waste and urban sewage sludge. Researchers are particularly interested in biochar due to its high carbon content, cation exchange capacity, substantial specific surface area, and stable structure. We investigate how the physical and chemical properties of biochar may vary based on the feedstock used, providing a comprehensive overview of biochar and its composition for pollution remediation. The review also discusses common techniques such as gasification, hydrothermal carbonization, and pyrolysis used to produce biochar. We analyze current research on the mechanisms involved in pollutant treatment using biochar and its composites while also addressing future directions in biochar research.

Nanomaterials effectively alleviate cadmium hazards in soil-plant systems: A meta-analysis.

Soil cadmium (Cd) contamination is a non-negligible global environmental issue as it may threaten food security and human health through soil-plant interactions. Nanomaterials have a great potential to decrease Cd bioavailability and bioaccumulation, even though the effects have been inconsistent among various studies. Here we compiled data from 137 experiments on the remediation of Cd-contaminated soils by nanomaterials. The effects of experimental design, nanomaterial properties, soil characteristics, and plant attributes on Cd bioavailability and bioaccumulation under nanomaterials application were evaluated. Results showed that incorporating nanomaterials could reduce the bioavailability of Cd in soil by 45.3% and the bioaccumulation of Cd in plants by 37.6%. Composite and carbon-based nanomaterials showed the most notable Cd immobilization effects at low and medium application rates, respectively. Cd-contaminated soils with low sand content, neutral pH (6.5<pH≤7.5), high organic matter (>30gkg-1), and high cation exchange capacity (>20cmolkg-1) are more conducive to the efficacy of nanomaterials. Among the four plant tissues, the decrease in Cd accumulation in leaf (39.4%) and grain (37.7%) was significantly higher than that in root (31.8%) and stem (23.3%) after the application of nanomaterials. Compared to other plant families, nanomaterials significantly suppressed Cd uptake by 54.7% of Brassicaceae plants. Additionally, the Cd bioavailability showed a significantly positive correlation with Cd accumulation in the root (R2=0.46, p<0.001), leaf (R2=0.42, p<0.001), and grain (R2=0.13, p<0.01). Overall, our results highlighted that nanomaterials are an effective solution to mitigate the hazards of Cd pollution in soil-plant systems.

The impact of surfaces on indoor air chemistry following cooking and cleaning.

Cooking and cleaning are common sources of indoor air pollutants, including volatile organic compounds (VOCs). The chemical fate of VOCs indoors is determined by both gas-phase and multi-phase chemistry, and can result in the formation of potentially hazardous secondary pollutants. Chemical interactions at the gas-surface boundary play an important role in indoor environments due to the characteristically high surface area to volume ratios (SAVs). This study first characterises the VOC emissions from a typical cooking and cleaning activity in a semi-realistic domestic kitchen, using real-time measurements. While cooking emitted a larger amount of VOCs overall, both cooking and cleaning were sources of chemically reactive monoterpenes (peak mixing ratios 7 ppb and 2 ppb, respectively). Chemical processing of the VOC emissions from sequential cooking and cleaning activities was then simulated in a kitchen using a detailed chemical model. Results showed that ozone (O3) deposition was most effective onto plastic and soft furnishings, while wooden surfaces were the most effective at producing formaldehyde following multi-phase chemistry. Subsequent modelling of cooking and cleaning emissions using a range of measured kitchen SAVs revealed that indoor oxidant levels and the subsequent chemistry, are strongly influenced by the total and material-specific SAV of the room. O3 mixing ratios ranged from 1.3-7.8 ppb across 9 simulated kitchens, with higher concentrations of secondary pollutants observed at higher O3 concentration. Increased room volume, decreased total SAV, decreased SAVs of plastic and soft furnishings, and increased wood SAV contributed to elevated formaldehyde and total peroxyacetyl nitrates (PANs) mixing ratios, of up to 1548 ppt and 643 ppt, respectively, following cooking and cleaning. Therefore, the size and material composition of indoor environments has the potential to impact the chemical processing of VOC emissions from common occupant activities.

Nanocarbon eco-hydrogel kit: on-site visual metal ion sensing and dye cleanup, advancing the circular economy in environmental remediation.

The naked-eye detection of hazardous pollutants through simple and cost-effective techniques is of great interest to the scientific community and related stakeholders in analytical science. The present study emphases the development of a stimuli-responsive probe by encountering sophisticated techniques for the detection of environmental pollutants. Herein, highly swellable and fluorescent-WTR-CDs-loaded HB-Alg/Gel@WTR-CDs was fabricated through a simple extrusion dripping method. The fluorescent WTR-CDs-loaded composite hydrogel showed rapid (within 10-15 min) naked-eye detection with high selectivity and sensitivity towards Cr6+ and Mn7+ ions over other metal ions. The developed probe had a linear detection range of 0-10 μg mL-1 with a detection limit of 0.28 μg mL-1 and 0.30 μg mL-1 for Cr6+ and Mn7+ ions, respectively. Interestingly, the hydrogel-based fluorescent sensor enabled on-site naked-eye detection of real water samples with good recovery. Additionally, the recyclability and reusability approach were employed for the removal of model pollutant dyes with Alg/Gel-carbon, which was synthesized using spent hydrogel beads after sensing. The present study demonstrates the tremendous potential applications of HB-Alg/Gel@WTR-CDs for simple, low-cost and fast visual detection of environmental pollutants. According to the analytical greenness evaluation (AGREE), the developed analytical method is green with an AGREE score of 0.81 and an ecofriendly circular-economy approach.

Rational decoration of porous organic polymers with silver nanoparticles for strategic reduction of hazardous nitroaryl compounds

We offer a rational study of simple synthesis of porous organic polymers which impregnate their own reducing sites of Ag+ into Ag nanoparticles at the meantime we utilized these nanocomposites for reducing hazardous pollutants.

Whole genome analysis of 26 bacterial strains reveals aromatic and hydrocarbon degrading enzymes from diverse environmental soil samples

Polycyclic aromatic compounds and petroleum hydrocarbons (PHs) are hazardous pollutants and seriously threaten the environment and human health. However, native microbial communities can adapt to these toxic pollutants, utilize these compounds as a carbon source, and eventually evolve to degrade these toxic contaminants. With this in mind, we isolated 26 bacterial strains from various environmental soil samples. Utilizing whole genome shotgun sequencing and analyses of these genomes revealed that they all belong to a single phylum with seven genera and sixteen species, and displayed variable genome sizes with CDS features, % GC contents, and GC skews. The analysis of genome annotation predicted genes/enzymes related to aromatic compound degradation, including the metabolism of homogentisate, salicylate and gentisate catabolism, benzoate, biphenyl, and phenylpropanoid compound degradation, and protocatechuate branch of beta-ketoadipate pathways. The majority of enzymes were found to belong to species Achromobacter pulmonis A (16%) & Achromobacter mucicolens (15%), Pseudomonas citronellolis (10%), and Comamonas thiooxydans (8%). Conversely, the highest number of hydrocarbon-degrading enzymes were found to be annotated in the species Pseudomonas citronellolis (13%), Comamonas thiooxydans (9%), Acinetobacter variabilis (7%), Pseudomonas aeruginosa, and Pseudomonas E sp002113165 (6%). These enzymes were categorized as dioxygenase, monooxygenase, hydroxylase, dehydrogenase, hydrolase, decarboxylase, aldolase, etc., and were predicted to function for benzoate, benzene, toluene, naphthalene, xylene, phthalate & terephthalate, anthranilate, protocatechuate & homoprotocatechuate, salicylate, aerobic & anaerobic gallate, and lignin subunit degradation, and catechol meta & ortho-cleavage pathways. In the future, molecular and biochemical characterization of these enzymes, together with strain assays for their capacity to degrade various pollutants, will help to improve the bioremediation process for environmental contaminations.

The Study Of The Knowledge, Attitude, And Practice About The Air Pollution Among The Residents Of Kolar Town Of South India

Introduction: Air pollution is a major environmental health problem affecting everyone.Few studies have revealed the specific needs of the residents; hence the thought demand for residents to the knowledge of air pollution information was explored using a questionnaire. Aims and objective: To develop awareness and understanding of pollution hazards and their prevention among the Kolar population on air pollution by using a questionnaire. Materials and methods:A cross-sectional study was conducted among 120 subjects in Kolar town by Purposive sampling technique with a validated, standard questionnaire by interview method and collectedwasanalysedby SPSS version 20. Results:Majoritygainedknowledge on air pollution from mobile phones and television, Whilea few said from the public and newspapers. Regarding attitude, 91% agreed that air pollution affected their health and the environment, with 116 (96.7%) 106 (88.3%) saying it from outdoor and indoor activities respectively.Statistically significant association was established between knowledge gained among educators with (P=0.004) and attitude toward outdoor air pollution with (P=0.001) and changes in behavioural patterns with (P=0.042). Conclusion: This work served as a starting point for a more timely and complete survey on air pollution and its relation to health and economic growth.

Bioremediation of Soil Contamination with Polycyclic Aromatic Hydrocarbons—A Review

Polycyclic aromatic hydrocarbons (PAHs) are considered hazardous pollutants due to their negative impact on the environment and human health. PAHs can accumulate and be retained in the soil, so PAH pollution is a worldwide problem. This review paper highlights the sources of PAH soil pollution, factors affecting the bioavailability of PAHs in soil, and soil bioremediation methods, as well as the advantages and limitations of the application of these methods. Aspects regarding the impact of the application of surfactants are presented in order to obtain good bioavailability during PAH bioremediation. Bioremediation techniques of soil polluted by these hydrocarbons are addressed: phytoremediation, rhizoremediation, composting, vermiremediation, micoremediation, and electrokinetic bioremediation of PAH-polluted soils. A comprehensive overview of bioremediation technologies for PAH-polluted soils is needed so that the right soil remediation technology is chosen. It has been observed the bioremediation of contaminated soils through rhizoremediation proved to be an effective process, the future of organic pollutants in interaction with plants and microbes must be researched. Vermiremediation, electrokinetic bioremediation, and microcomposting are effective processes for treating soils in situ. Phytoremediation is a sustainable and ecological method of PAH depollution. It improves soil fertility by releasing different organic matter in the soil, and it can be applied on a large scale.

PLASTIC AND IRON WASTE RECYCLING POLLUTION IN LAGOS STATE, NIGERIA

Lagos State has experienced adverse pollution as a result of lack of proper waste management and diverse industrial activities within its environs. The repercussion of this has consequently led to the deplorable state of the environment as well as the low quality of health amongst residents. Waste management has become a huge and intricate problem due to geometric population growth, urbanisation, industrialisation and the rising standard of living. This study investigated Plastic and Iron Waste Recycling Pollution in Lagos State, Nigeria. This study concluded that hazards of Plastic and Iron Waste Recycling Pollution in Lagos State; the drainage systems habitually blocked causing yearly flooding which usually lasted throughout the rainy seasons from April to October and displaced millions of residents. The clogged sewage systems became the perfect breeding environment for mosquitoes and flooding washed away footpaths caused people to move around in dirty water from overflowed gutters and polluted major sources of drinking water which led to the spread of cholera and typhoid fever. Also, higher levels of toxic heavy metals were observed among residents at close proximity to recycling iron factories. For environmental sustainability in Lagos State plastic and iron waste recycling pollution must be seriously cautioned in following; environmental impact assessment is necessary for any development in Lagos State, recycling programmes and waste to energy facilities can be reawaken with modernised and ecological friendly technologies. Keywords: Iron waste, Plastic waste, Pollution, Waste recycling, Waste management.