Pollutant Discharge Research Articles

Implications of leaf burning for adverse respiratory conditions and release of fine particulates and air pollutants

The residential burning of leaves, brush, grass, and other forms of vegetation are major and underappreciated source of particulates smaller than 2.5 μm (PM2.5), carbon monoxide, and many other air pollutants including carcinogenic polycyclic hydrocarbons such as benzo(a)pyrene. Residential leaf burning has been linked to significantly poorer urban/suburban air quality, respiratory morbidity and mortality, serious burn injuries to people, and property damage. Other forms of biomass burning such as wildfires, wood burning, peatland wildfires, and the deliberate burning of woodlands and agricultural fields produce large amounts of air pollutants, which are somewhat similar in composition to those released from leaf burning. Leaf burning has been linked to significantly higher rates of asthma and other respiratory problems. Exposure to wildfire smoke has been linked to significantly higher rates of cancer, infections, and a wide range of health conditions including respiratory, cardiovascular, psychiatric, and reproductive problems. Leaf burning and other forms of biomass burning produce significant quantities of dark particulates that accelerate global warming. Leaf burning also presents serious risk of burn injuries to humans, wildlife, and buildings. A number of U.S. states and European Countries have imposed total state or national bans on leaf burning. In fact, many communities offer free or inexpensive community leaf pickup and composting services. Leaf composting offers many advantages over leaf burning; for instance, leaf compost is a valuable product useful for growing plants. In conclusion, homeowners, communities, and nations should compost leaves, brush, and grass clippings rather than burning them.

Synergistic degradation of refractory organic pollutant by underwater bubbling plasma combined with heterogeneous Fenton process

Excessive discharge of the refractory organic pollutants endangers the development of the society and economy, thus seeking an efficient wastewater abatement method is an urgent need. Herein, Iron (Ⅱ) sulfide (FeS) was employed as the heterogeneous catalyst and coupled with underwater bubbling plasma (UBP) for the elimination of the refractory organic pollutant, malachite green (MG). FeS catalyst was synthesized using the solvothermal method and subsequently characterized comprehensively, focusing on its microstructure, specific surface area, chemical bonds and elements valence states. The UBP system combined with FeS (UBP/FeS) exhibited the robust synergism with a maximum synergistic factor of 1.89. The MG degradation percentage and rate constant were up to 94.7% and 0.237 min−1 within 12 min. The parameter experiments revealed that FeS dosage, pulse frequency, initial MG concentration and solution conductivity of 150 mg/L, 56 Hz, 5 mg/L and 21.8 μS/cm, respective, were more conducive for MG elimination. The MG removal efficiency reached 86.2% after five consecutive applications of FeS. Reactive substances including ·OH, ·O2−, eaq, O3 and H2O2 were confirmed to contribute to MG elimination. Additionally, the conversion circle between ≡ Fe(Ⅱ) and ≡ Fe(Ⅲ) promoted the catalytic conversion of H2O2 and O3 into ∙OH. The comparison of UV–vis spectra and total organic carbon of MG solution before and after reaction revealed the superior degradation of MG in the UBP/FeS system. Hypotheses regarding to the decomposition pathways of MG were formulated based on the identified intermediates. The toxicity level of MG solution was lightened after reaction. The above results indicate that UBP/FeS has the advantages of quick degradation and high efficiency, representing a promising approach for refractory pollutants treatment.

Monitoring of insulator pollution discharge in overhead distribution network based on acoustic emission technology

Abstract During the continuous operation of the distribution network, dirt often accumulates on the surface of insulators. Once encountering a humid climate environment, it may cause accidental discharge, leading to the occurrence of flashover pollution accidents. In order to effectively monitor this issue, this study adopted a monitoring method based on acoustic emission technology. This article introduces the discharge process and acoustic emission phenomenon of insulators in overhead distribution networks under pollution conditions. By using emission signal detection devices, acoustic signals generated during insulator discharge are captured. And the wavelet denoising algorithm was used to process its signal, based on which the discharge characteristics of insulator pollution in the overhead distribution network were extracted. The emission amount of insulator pollution in the overhead distribution network was determined according to the set threshold, achieving monitoring of pollution emissions. The results indicate that the proposed method can accurately monitor the discharge of insulators in overhead distribution networks, provide scientific basis for timely maintenance measures, and improve the operational safety and reliability of distribution networks.

State Drainage Laws Muddy the Goals of the US Clean Water Act (1972)

The US Congress passed the Clean Water Act in 1972 to protect and restore America's waterbodies by regulating pollutant discharges from point sources such as industrial plants and sewer pipes. Over the years, Congress expanded the law to include non-point sources like polluted runoff from roads and agricultural areas. However, routine agriculture drainage maintenance activities, like continuously farmed wetlands and drainage ditch dredging, are exempted under the Clean Water Act. These exemptions allow sediment pollution to continue to be a major issue in agricultural streams and waterbodies managed by drainage districts. We examine the shortcomings of the Clean Water Act to address sediment pollution from the perspective of routine agricultural activities like drainage ditch maintenance and offer policy recommendations to mitigate its impacts. We discuss the exclusion of agricultural sediment originating from these activities as a major non-point pollution source under the Clean Water Act, the consequences of sediment pollution on aquatic ecosystems and stream water quality in agricultural streams, and the need for monitoring and regulation of sediment discharge from farming practices. In our analysis, we also consider the interaction between the state drainage laws and federal regulations. Finally, we seek to address gaps in the current regulatory structure and offer suggestions regarding better protection of water quality and ecosystem health in drainage districts.

Ethical and Legal Protection of Drinking Water Resources in Islamic Jurisprudence (with Emphasis on Drinking Water Resources in Kabul)

Water is a vital resource for all living beings. The increase in population and decrease in rainfall in many cities around the world have led to serious water scarcity and pollution of wells and water resources in countries. The expansion of industrial production has resulted in the release of pollutants into surface and groundwater in cities and farmlands of countries. Therefore, this research has been conducted in a library way to examine the views and solutions of Islamic jurisprudence on resolving the problems and preserving the health of drinking water resources and wells, especially in Kabul. The findings of this research are that to preserve the health of water resources, a legal or spatial boundary between neighboring wells or farmers is required to be 500 meters in soft land, but in hard land, at least 250 meters between them is necessary to prevent the resulting damages. However, the distance between a well and a septic tank is 2.5 meters in hard land, and at least 7 cubits or 3.5 meters in soft areas. This is to purify water pollutants and prevent the resulting damages to neighbors. The legal boundary approach has been stated to compensate for the damage caused by a well or a water canal. Moral boundary means the growth of human responsibility to prevent water and environmental pollution in Islamic jurisprudence. Natural pollutant filters for well and canal water are the elements of soil, sand, abundant or flowing water, and oxygen present in water in Islamic jurisprudence.

The Driving Factors and Path Selection for the Development Level of China’s Mariculture—A Dynamic Analysis Based on the TOE Framework

Mariculture is a key practice to promote the supply-side reform of fishery, and it is of strategic significance to explore the causes and paths of its high-level development. Based on the TOE (Technology-Organization-Environment) theoretical framework and the configuration methodology, this paper adopts the dynamic qualitative comparative analysis (QCA) method and panel data from 10 coastal provinces and cities in China from 2013 to 2021 to explore the configuration effects of six antecedents, namely, the intensity of technology promotion, investment in scientific research, personnel specialization, industry intensification, nearshore water quality, and offshore pollution discharge, along temporal and spatial dimensions, on the level of mariculture development. The results show that (1) individual driving factors do not constitute the necessary conditions for a high level of mariculture industry development, but the necessity of the three conditions—research funding, industry intensification and nearshore seawater quality—shows a general increasing trend; and (2) the results of the path analysis show that a total of seven configuration paths for a high level of development are generated, which can be further classified into “organization-led and technology synergistic”, “technology-organization-environment multiple-driven type”, and “technology-environment dual-driven type”. Based on the panel data, this study explores the impact of spatial and temporal changes in factor combinations on the development level of mariculture and provides a theoretical basis and practical insights for the development of locally adapted execution pathways.

Emerging pollutants: Risks in salmon fish migration. A review

The release of pollutants into the environment is a serious ecological problem due to the significant risks they pose both to ecosystems and to human health. The review considers the issues of detection and distribution of new pollutants, as well as sources of their entry into the environment and potential impact on ecosystems. The problem of wastewater pollution is especially urgent in the context of conservation of salmonid fish species. Pharmaceutical and veterinary drugs, components of personal hygiene products, microplastics, per- and polyfluorinated substances, brominated flame retardants, oil and a number of other toxicants enter freshwater bodies, which are especially important for the early stages of the salmon development and its following migration. The presence of pollutants in the aquatic environment depends on a source, their ability to bioaccumulate, as well as to degrade in the processes of biological and abiotic purification. High-resolution mass spectrometry in combination with gas or liquid chromatography can be recommended for detection of new pollutants. Due to high mass measurement accuracy and high specificity, this method is able to effectively identify pollutants even in the complex fish matrix. When conducting non-targeted and targeted screening with highly sensitive full scanning, it is advisable to use high-resolution mass analyzers (TOF, Q-TOF, Q-Orbitrap), which allow determining a number of new compounds. A promising direction in the complex assessment of the impact of pollutants on salmon fish species and the identification of indicators characterizing this impact is metabolomics. It is based on the study of low-molecular organic compounds — metabolites, both intermediate and final metabolic products in body fluids and tissues. Metabolomic profiling allows identifying important markers of the state of a water body under the influence of pollutants, which is necessary for the development of comprehensive regulations and guidelines for the effective handling of these pollutants.

Simple fuzzy classification of metal qualities of Ona River, Ibadan, Nigeria, and its implication for fish production and other uses

Elevated concentrations of metals in rivers can pose significant risks to human health. Consequently, it is essential to monitor metal levels in river water to minimize human exposure, particularly through consumption of harvested fish and other uses. This study examined the water quality of the Ona River in Ibadan, Nigeria. Seven potentially toxic elements (PTEs), namely Fe, Cu, Mn, Zn, Pb, Cd, Cr and four macronutrients: Mg, Na, K, Ca were investigated. Surface and pore water samples were collected from six sampling points during the peak of the dry and the rainy seasons. These were analyzed according to standard procedures and processed using the Simple Fuzzy Classification (SFC) model with four classes. The results revealed that the PTEs: Fe, Pb, Cd, Cr, and Mn were detected above guideline limits in several sampling points, indicating possible contamination from anthropogenic sources. Simple fuzzy classification puts the quality of water in the investigated portion of the river in the range of 67.4–88.5% in the C1 (pristine) category during the dry season and 61.9–88.6% in C1 (pristine) during rainy season. However, there were membership functions of up to 58.7 and 63.2; 61.2 and 75.4 as well as 44.3 and 43.5% in C2, C3, and C4 categories (contaminated, polluted and extremely polluted, respectively) during the first and second sampling, respectively. Due to the high concentrations of toxic and bioaccumulative metals in the river, efforts should be made to control the discharge of pollutants into the river. These will prevent human health exposure risks tendencies for various uses, including fish production.

Cleaning Up Metal Contamination after Decades of Energy Production and Manufacturing: Reviewing the Value in Use of Biochars for a Sustainable Future

The lasting impact of ancestral energy production operations and global manufacturing has not only generated substantial CO2 emissions, but it has also led to the release of metal-based pollutants into Earth’s water bodies. As we continue to engineer, mine (coal and metals), and now bore into geothermal wells/fracking sites for alternative energy sources, we continue to contaminate drinking water supplies with heavy metals through infiltration and diffusion, limiting progress towards achieving Sustainable Development Goals 3 (Sustainable Development Goal 3: Good health and well-being), 6 (Sustainable Development Goal 6: Clean water and sanitation), 14 (Sustainable Development Goal 14: Life below water), and 15 (Sustainable Development Goal 15: Life on land). This review shows how the research community has designed and developed mesoporous biochars with customizable pore systems, as well as functionalized biochars, to extract various heavy metals from water sources. This article investigates how biochar materials (non-activated, activated, functionalized, or hybrid structures) can be adapted to suit their purpose, highlighting their recyclability/regeneration and performance when remediating metal-based pollution in place of conventional activated carbons. By utilizing the wider circular economy, “waste-derived” carbonaceous materials will play a pivotal role in water purification for both the developed/developing world, where mining and heavy manufacturing generate the most substantial contribution to water pollution. This review encompasses a wide range of global activities that generate increased heavy metal contamination to water supplies, as well as elucidates emerging technologies that can augment environmental remediation activities, improving the quality of life and standard of living for all.

Emission Risk and Inhibition Technology of Asphalt Fume from Crumb Rubber Modified Asphalt

Crumb rubber-modified asphalt mixtures have been proven to have extensive utilization value in road engineering. However, the rubber releases more fumes during the construction period, which causes severe harm to human health and the environment. This research focused on the emission risk of asphalt fume from crumb rubber-modified asphalt, and then the inhibition technology was also optimized. Firstly, the emission behavior and the hazardous evaluation of the asphalt fume from crumb rubber-modified asphalt were investigated. Then, the characteristics of the inhibition materials were evaluated. Finally, the reduction in the emission of inhibited crumb rubber-modified asphalt fume was identified, and the optimized formula was determined based on the inhibition effect, rheological properties, and cost. The results indicate that crumb rubber-modified asphalts release more fume components with an increment in the temperature and crumb rubber content. Desulfurized rubber reduces the release of H2S and NO. Benzene compounds, including paraxylene, toluene, and benzene, are the most released pollutants that harm human health, especially DS CRA 20% and CRA 50%. Kaolin powder and expanded graphite have a sufficient pore structure and volume, the addition of which reduces the release of pollutants while possibly promoting the release of NO and H2S. Their addition also has a significant control effect on the release of particulate matter at 170 °C and 185 °C. With the consideration of emissions, rheological properties, and cost, CRA 40%-EG2%-KL2% was determined as the optimization formula. This research is helpful to the application of crumb rubber-modified asphalt in road construction and maintenance.

Spatial distribution and risk assessment of heavy metal pollution from enterprises in China

Heavy metal pollution (HMP) directly affects the safety of agricultural products, thereby impacting human health. Industrial emissions, as the main source of soil HMP in China, require in-depth research on their pollution risks. Based on national heavy metal (HM) enterprise data, this paper analyzes the spatial distribution characteristics of key enterprises involved in the HMP across the country. It constructs the risk assessment index system of enterprise HMP based on the “source-pathway-receptor” (SPR) process of the HMP, evaluates and partitions the risk of the HMP from enterprises nationwide. The results show that: (1) Enterprises and pollutant discharge outlets are mainly distributed in the eastern and southeastern coastal regions. Jiangxi, Yunnan, Guangdong, and Hunan Province are the main distribution regions of smelting enterprises, with the most types of HM pollutants. The hazard of pollution sources shows a spatial distribution pattern of higher risk in the southwest and north, and lower risk in the central region. Counties with high-risk pollution sources are mainly distributed in Yunnan, Hunan, Guangdong, Inner Mongolia, and Jiangxi Province. (2) The hazard of pollutant transmission pathways shows a spatial distribution pattern of higher risk in the southeast and lower risk in the central region. About 31.5 % of counties are at extremely high risk, mainly distributed in the southeastern coastal regions of Guangdong, Jiangsu, Zhejiang, Jiangxi, Shandong, and Fujian Province. (3) The vulnerability of the receptors shows significant clustering characteristics in the northeast and central regions. About 3.3 % of counties have a receptor vulnerability level of “extremely high,” mainly distributed in Inner Mongolia, Jilin, Heilongjiang, Liaoning Province in the northeast, as well as Hubei and Jiangsu Province. (4) About 1.55 % of counties nationwide have a comprehensive risk level of the HMP classified as “extremely high,” mainly distributed in Guangdong Province and Inner Mongolia. Additionally, some counties in Yunnan, Hunan, Jiangsu, Jiangxi, and Zhejiang Province have a risk of exceeding pollution standards, requiring further preventive measures to reduce pollution risks in the future. This paper can provide a scientific basis for the prevention and control (P&C) of the HMP in China.

Study of the Dynamic Adaptive Calculation Method for River Water Environmental Capacity

Controlling the total amount of river pollutant discharge is an important means of water resource protection and management, and it is also a necessary condition for ensuring the normal functioning of water areas. The total amount of pollutant discharge is closely related to the water environmental capacity (WEC). Shifting from the traditional method of calculating WEC to dynamic analyses and calculations, concerning practical applications, in this paper, a dynamic adaptive calculation method is proposed for the river WEC that considers the changes in adaptive demand and hydrological conditions. In this method, the dynamic WEC is represented by intervals based on dynamic changes in different spatial and temporal scales, various calculation methods, hydrological conditions, and parameters. According to the calculation results for the WEC, a variable interval was formed. Taking the Shaanxi section of the main stream of the Wei River as the research object, with the support of an integrated platform, the dynamic adaptive calculation of the WEC in the Shaanxi section of the Wei River was realized, and a corresponding simulation system was constructed. The verification results show that (1) the dynamic calculation of WEC can be realized by freely combining different model methods and calculation conditions; (2) the WEC is described using a variable interval, which has strong applicability and operability; and (3) the simulation system can quickly adapt to the changing needs of practical applications and provide managers with visual and credible decision support. The research results provide a theoretical basis for river water environment pollution prevention and environmental management decision-making and help in the high-quality development of the river basin.

Analysis on the relationship between coastal tourism and marine pollution: an empirical analysis of China’s 11 coastal regions

IntroductionCoastal tourism has become an important pillar of economic growth in China's coastal regions, yet no quantitative research has analyzed the relationship between coastal tourism and marine pollution.MethodsThis study, within a multivariate framework, comprehensively examines the impact of coastal tourism on marine pollution by employing various econometric techniques and focusing on four different types of marine pollutant discharges: chemical oxygen demand (COD), petroleum (PET), ammonia nitrogen (NHN), and total phosphorus (TP).Results and discussionPanel cointegration tests confirm a long-term relationship between coastal tourism and these four types of marine pollutant discharges. In the long run, coastal tourism has a significantly negative impact on COD, NHN, and TP. The results of Pooled Mean Group (PMG), Fully Modified Ordinary Least Squares (FMOLS), and Dynamic Ordinary Least Squares (DOLS) estimators show that for every 1% increase in coastal tourism revenue (TOUR), COD decreases by 0.734%, 0.536%, and 0.952% respectively; NHN decreases by 0.746%, 0.340%, and 1.633%; and TP decreases by 5.169%, 0.899%, and 0.334% respectively. However, the impact of coastal tourism on PET is not significant. The Dumitrescu-Hurlin (D-H) panel causality test results indicate different causality patterns between coastal tourism and various marine pollutant discharges. Specifically, there is a bidirectional causality between coastal tourism and COD, NHN, and a unidirectional causality between coastal tourism and PET, TP. Moreover, heterogeneity analysis reveals that coastal tourism does not significantly reduce all marine pollutant discharges in low-and middle-income coastal regions. Furthermore, compared to the central and southern coastal regions, the coastal tourism of northern regions has not significantly reduced marine pollution. This study can provide policymakers with references for developing coastal tourism and reducing marine pollutant discharges.

A probabilistic neural network assessment method for insulator pollution level based on discharge noise

The insulators of a transmission line are exposed to air for a long time, a mount of dust particles will be deposited on the surface. When there rain, fog or high humidity, the surface of the insulator will discharge or even flashover to breakdown. For this, in this paper, the characteristic parameters of insulator discharge noise under different pollution levels, ambient temperature and relative humidity are extracted, and the influence of insulator discharge noise are analyzed respectively. Probabilistic neural network (PNN) model training samples are used to propose an insulator pollution level assessment method based on discharge noise and verify it. The results show that the pollution level has obvious influence on the characteristic parameters of insulator discharge noise. The higher the pollution level, the more obvious the discharge phenomenon and the greater the discharge intensity. When the relative humidity ranges from 70 % to 90 %, the greater the relative humidity, the greater the pollution discharge intensity of the insulator. The energy of the noise signal gradually concentrated in the 5.5 kHz to 8.3 kHz frequency band, and the pollution discharge in the 5.5 kHz to 16.5 kHz frequency band reflected in the low-frequency part of the information increased. Ambient temperature has no obvious effect on insulator discharge noise. The precision rate of the assessment method for pollution levels Ⅰ, Ⅱ, Ⅲ and Ⅳ are 91.5 %, 88.2 %, 86.5 % and 94.0 %, respectively.

Influence of earthworms on the mobility and bioavailability of metals, metalloids and radionuclides in historically contaminated soil

While soil characteristics such as pH, cation exchange capacity and organic matter are known to influence the mobility of pollutants in soil and the transfer to vegetation, far less attention has been paid to the possible non-trophic influence of organisms on pollutant transfer to other species. When pollutants are present in a bound unavailable form in the mineral or organic fraction, they can be made available through bio-weathering and decomposition of organic material. Within this study, the impact of earthworms on the mobility of metal(loid)s and radionuclides in soil and their transfer to vegetation was evaluated and the pathways through which earthworms work were studied. Soil from a Belgian field, historically contaminated with metal(loid)s and radionuclides, was used and microcosm systems were applied to mimic the natural interactions between soil, earthworms (Lumbricus terrestris) and vegetation (Lolium perenne). Metal and radionuclide concentrations were determined in soil, pore water and grass. In addition, soil pH, (chromophoric) dissolved organic matter, the ionic composition of pore water and the soil microbial activity were analysed. In general, earthworm presence significantly increased the concentration of most pollutants in soil pore water. This could be a direct consequence of decreased soil pH and increased humification. The latter also lead to higher nutrient concentrations in pore water that were depleted in the root zone due to high accumulation by plants. Indications were found for earthworm-induced effects on the soil microbial activity. The results show that earthworm activity can increase leaching of metal(loid)s and radionuclides and enhance dispersion into the environment and transfer to other biota and the food chain. Biologically induced release or remobilization of pollutants in the soil should therefore be considered in the context of risk assessment and site management strategies.

Thermodynamics of Combustion and Environmental Impacts of Industrial Fuels: A Comparative Study

This study examines the combustion processes of different fuel types such as benzene, butane, ethane, hydrogen, methane, and propane, and evaluates the thermodynamic effects of these processes, as well as their impact on the quantity of gases emitted into the atmosphere. The findings reveal that each fuel type differs in terms of combustion efficiency, heat release, and emissions of pollutants into the atmosphere. These analyses yield important implications for energy production, industrial applications, and environmental policies. Future studies could focus on more in-depth comparative analyses of fuels, assessment of advanced combustion technologies, and dynamic modeling of combustion processes, thereby facilitating the development of strategies for more sustainable fuel usage and reduction of environmental impacts.

Development of a green microextraction procedure for determining polyaromatic hydrocarbons in electronic equipment plastics

The global proliferation of electronic devices, driven by technological advancements, has led to the release of organic pollutants from the plastic components of these devices, particularly in indoor environments. Among these pollutants, polycyclic aromatic hydrocarbons (PAHs), which are emitted into the air from plastic components, play a critical role in the field of indoor environment pollution. Consequently, effectively monitoring the PAH content in plastics used in electronic equipment is crucial for preventing indoor contamination.In this study we aimed to develop a fast, inexpensive, easy, and environmentally friendly analysis method for determining PAH content in plastic equipment. A dispersive liquid liquid microextraction (DLLME) combined with solidified organic drop (SFO) microextraction technique was developed.Considering the eleven number of parameters that can affect the signal in the DLLME-SFO method, Plackett Burmann's design was applied to select the most three impactful parameters for 18 PAH species. A Box-Behnken experimental design was also applied to optimize the identified parameters. The optimal conditions for the most influential parameters such as solvent type, pH, and the sample weight were identified as 1-dodecanol, 12 and 0.24 g, respectively.The proposed method was validated under these optimized conditions, yielding low detection limits ranging from 0.004 to 0.11 ng mL−1. The calibration curves were linear with correlation coefficients above 0.98 and relative standard deviation (RSD) values ranging from 2.4% to 20%. This method was successfully applied to analyze PAH content in the plastic components of electronic devices. The extraction technique developed in this study is a newly developed technique and has not been previously used to analyze organic pollutants that may be present in electronic equipment plastic.

2D-nanostructures as flame retardant additives: Recent progress in hybrid polymeric coatings

The use of polymers in day-to-day life is undeniable; nevertheless, applicability of these polymers in the fire risk sector poses serious limitations as most of the polymeric materials/coatings employed are prone to fire. Hence to improve the fire retardant (FR) properties of polymers, researchers recommend the use of FR materials/additives, either physically blended or incorporated chemically via suitable modifications. However, to achieve sufficient FR property, usually higher amounts of traditional FRs are required which understandably deteriorates the mechanical and other important properties of the polymers. Moreover, use of halogenated FRs are under immense scrutiny due to the possible release of carcinogenic and organic pollutants. As a result development of halogen-free FRs is an emerging field of research. In this context, incorporation of nanostructured two-dimensional (2-D) materials to form polymer composites that can not only reinforce the mechanical, thermal and other important properties but also improve flame retardancy has opened up new prospects. The 2-D nanostructured materials, particularly, layered double hydroxide (LDH), MXenes, Graphene and its derivatives, Boron Nitride (BN) and molybdenum disulphide (MoS2) have demonstrated capabilities to enhance the FR properties as a green and environmentally benign material. Incorporation of these 2-D materials into polymers to form nanohybrids can be achieved either as conventional filler or as surface modified systems chemically bonded to the parent matrix. In the present review, the recent development strategies of surface modifications employed on 2-D nanostructured materials (LDH, MXenes, GO, BN and/or MoS2) to form polymeric nanocomposites and the FR properties achieved are discussed. The significant outcomes reported by various research groups, the key insights gained and viewpoints are deliberated. A plausible underlying mechanism for flame retardancy offered by 2-D nanostructured materials (LDH, MXenes, GO, BN and/or MoS2) based polymer nanocomposites as extended by several research groups is discussed.

Catalytic engineering of transition metal (TM: Ni, Pd, Pt)-coordinated Ge-doped graphitic carbon nitride (Ge@g-c3n4) nanostructures for petroleum hydrocarbon separation: An outlook from theoretical calculations

The extraction, processing, and utilization of petroleum often results in the release of diverse hydrocarbon pollutants into the environment, leading to severe ecological and health implications. Herein, the adsorption and separation of ethane (EAN), ethene (EEN), ethyne (EYN), and benzene (BZN) fractions of paraffin, olefin, acetylene, and aromatic petroleum hydrocarbons were investigated via the catalytically engineered nickel group transition metals; nickel (Ni), palladium (Pd), and platinum (Pt). These transition metals were coordinated on Germanium-doped graphitic carbon nitride (Ge@g-C3N4) nanostructures, and the behavior of the systems was studied through Kohn–Sham density functional theory (KS-DFT) with the B3LYP–D3(BJ)/Def2-SVP computational method. The adsorption of petroleum hydrocarbons decreased in the order Ge_Ni@C3N4 > Ge_Pd@C3N4 > Ge_Pt@C3N4>Ge_Pt@C3N4. These results showed that the coordination of Ni, Pd, and Pt within Ge@C3N4 improved the separation of petroleum hydrocarbons.

Calcium self-release bioremediation system combined with microbially induced calcium precipitation for the removal of ammonium nitrogen, phosphorus and heavy metals

Natural landscape water and substrate were taken to simulate the release of substrate pollutants in micropolluted water bodies, and a calcium silicate- sodium alginate (CS-SA) bioremediation system was constructed. The removal of ammonium nitrogen (NH4+-N), total nitrogen (TN) and Phosphate (PO43--P) were 99.14 %, 98.90 % and 84.44 %, respectively. The Ca2+ continuously released by CS-SA provided good microbial-induced calcium precipitation (MICP) conditions for Acinetobacter calcoaceticus strain HM12, and the removal efficiency of both Zn2+ and Cd2+ was 100 %, and the pH after remediation was consistent with that of natural water bodies. NH4+-N was removed by heterotrophic nitrification- aerobic denitrification (HN-AD) of strain HM12, and heavy metals and phosphorus were removed by co-precipitation and adsorption by MICP. High-throughput sequencing results showed that strain HM12 was effective as a bioinoculant for the remediation of the aquatic environment. The construction and operation of this bioremediation system provided a method for micropolluted water treatment and recovery of phosphorus and heavy metals.