Heavy Pollution Research Articles

The adsorption and fixation of Cd and Pb by the microbial consortium weakened the toxic effect of heavy metal-contaminated soil on rice

With the rapid development of industry and agriculture, the toxicity and pollution of Cd and Pb in soil and plants are becoming increasingly severe. Microbial remediation is considered an economical and sustainable method for addressing heavy metal ion pollution. This experiment established a microbial consortium capable of efficiently adsorbing and fixing Cd and Pb. The consortium consisted of two isolated strains: the straw-degrading bacterium ZJW-6 (Cellulomonas iranensis) and the phosphate-solubilizing bacterium wj1 (Pseudomonas brassicacearum). The microbial consortium exhibited high resistance to Cd and Pb, resulting in a significant reduction in heavy metal toxicity. The minimum inhibitory concentrations of Cd and Pb for the mixed microbial consortium were 900 mg/L and 2500 mg/L, respectively. Results indicated that within seven days, the microbial consortium’s removal rates of Cd and Pb reached 94.25 % and 74 %, respectively, surpassing the removal abilities of the individual member bacteria. It also enriched the soil organic matter and produced larger aggregates to adsorb more heavy metals (Cd: 3.35 mg/kg, Pb: 86.57 mg/kg). By the 60th day, 91.2 % of Cd and 97.89 % of Pb in the soil rhizosphere had been removed, and the free Cd and Pb in plant tissues were significantly reduced. Soil aggregates, which are the basic units of soil and an important index for measuring soil structure, were improved. The microbial consortium also played a significant role in restoring the soil microbial community, mobilizing the combined action of microorganisms represented by Ramlibacter and Sphingomonas to repair heavy metal pollution and promote plant growth. This provides a new method to bioremediate metal-contaminated soil and enhance the plant growth environment.

Ship deployment problem with green technology adoption for an inland river carrier under non-identical streamflow and speed limits

The maritime industry is currently experiencing a shift towards green corridors. The inland waterway is the main transportation corridor with a relatively low adoption of green technologies, which produces heavy air pollution in inland cities. This paper investigates the ship deployment problem for an inland river carrier considering the adoption of green fuel and green technologies for a given ship fleet. A non-linear programming (NLP) model is proposed to jointly optimize green technology adoption, sailing speed, and routing problems while considering two unique characteristics of inland river shipping, including the non-identical streamflow and the speed limits on each shipping leg. The analytical propositions reveal the optimal operation strategy of the inland river ship fleet, and a column generation-based algorithm is further designed to solve the proposed model. By jointly investigating the ship operation strategy and sulphur emissions, we find the following management insights: Firstly, the ship would have a lower willingness to invest in shore power (scrubber) if it installed scrubber (shore power). The higher streamflow and looser speed limits would reduce the spillover effect of green technology adoption. Secondly, emissions will spillover from ports to river legs if only shore power is provided. Our findings provide valuable insights for policymakers to promote complete green technology adoption to achieve comprehensive abatement of the entire inland river.

Triboelectric Nanosensor Fabricated on Robotic Platform for Self-Powered Detection of Heavy Metal Ions in Aquatic Environments

The escalation of heavy metal ions pollution, caused by the natural processes as well as human activities has emerged as a significant global challenge. The accumulation of heavy metal ions in the human body primarily occurs through water and food consumption which poses a severe threat leading to irreversible health damage. To address this issue, the World Health Organization (WHO) has established permissible limits for various heavy metal ions in drinking water, ranging from 0.003 to 3 ppm. When these limits are exceeded, water is deemed contaminated which necessitates effective monitoring and detection strategies. Robotic chemical sensing platforms have become indispensable for tackling chemical threats by detecting harmful pollutants in toxic environments. However, chemical sensors integrated with robotic platforms encounter drawback such as reliance on external power sources. In response to this challenge, our approach integrates a highly sensitive, self-powered triboelectric nanosensor (TENS) into a robotic platform charged by a thermoelectric generator (TEG) and equipped with wireless transmission capabilities. This integration enables the rapid on-site detection of heavy metal ions. The system employs copper electrodes modified with ion-selective membranes (ISM) as sensing probes and solid triboelectric contact materials. Through periodic contact-separation cycles with ionic solutions, the system generates electrical output, facilitating the detection of various concentrations of Pb2+, As3+, and Cr6+ ions. The ionophores in the respective ISMs contribute to the selective binding capacity of the sensing probe to the particular ion. This self-powered robotic platform provides an innovative and cost-effective solution for automated chemical sensing in water environments. Its advantages include the avoidance of external power sources, low-cost operation, and the elimination of the need for frequent battery replacements. With its capability for remote monitoring and detection, this system emerges as an ideal tool for preventing and controlling heavy metal ions pollution, ultimately contributing to the intelligent monitoring of heavy metal ions in aquatic environments. Keywords: Heavy metal ions, Solid-liquid triboelectric nanosensor, Robotic platform, Self-powered detection, Copper electrodes.

Characteristics and Source Analysis of VOCs Pollution During Emergency Response in Tianjin

To elucidate the characteristics of VOCs chemical components during heavy pollution episodes, hourly online VOCs data derived from 11 heavy pollution events in Tianjin from 2019 to 2020 were employed. The positive matrix factorization （PMF） and conditional bivariate probability function （CBPF） were employed to analyze the sources of VOCs during heavy pollution episodes. The results indicated that the average VOCs volume fraction during these episodes was recorded at 35.7×10-9. Furthermore, it was observed that during the winter emergency response period, there was a discernible increase in the volume fraction of VOCs when compared to that during the autumn season. Specifically, there was a notable upswing of 48% in the olefins category, whereas alkanes registered a 4% increase. Additionally, the VOCs component structure changed significantly during the heavy pollution episodes. During the orange warning period, the proportion of alkanes increased by 36%, and the proportion of acetylene decreased by 32%. During the yellow warning period, the proportion of alkanes increased by 14%, and the proportion of acetylene decreased by 5%. During the emergency response period, motor vehicle emission sources, natural gas evaporative sources, and solvent use sources were the main contributors of VOCs in environmental receptors, contributing 17.5%, 15.4%, and 15.2%, respectively. Compared with that during the period antecedent to the emergency response, the contribution of vehicle emission sources and diesel volatile sources to VOCs in environmental receptors decreased by 2.0% to 5.5% and 2.1% to 6.6%, respectively, and the contribution of solvent use sources decreased by 0.2% to 2.4% during the yellow warning period. During the orange warning period, the contribution of motor vehicle emission sources was reduced by 0.1% to 8.3%, and the contribution of solvent use sources was reduced by 0.5% to 6.2%.

Role of nanocomposites and nano adsorbents for heavy metals removal and dyes. An overview

Water scarcity and wastewater treatment are major concerns due to increased urbanization, industrialization, and anthropogenic practices. Various toxic heavy metals, dyes, pollutants, and chemicals are a matter of concern as they have severe environmental and ecological damage and health effects. Various advancements are being introduced in the field of adsorption using nano adsorbents and composites to deal with wastewater treatment problems. Nanocomposites are intelligent to eliminate bacteria, viruses, and inorganic and organic pollutants from wastewater due to precise binding action (chelation, absorption, ion exchange). Nanocomposite materials, such as metal nanocomposite, metal oxide nanocomposite, carbon nanocomposite, polymer nanocomposite, and membrane nanocomposite, are active in water purification. Nanoparticles (N.P.s) are important for remediation because of their large surface area, size, reactivity, and active sites. For high adsorption of pollutants, N.P.s were treated by increasing the electron density and surface area and adding functional groups. They are more capable of eliminating hazardous organic-inorganic pollutants, pathogens, and heavy metals from wastewater. This nanotechnology treatment technique has no hazardous by-products; these techniques have various regenerative efficiencies. Among various treatment methods, the adsorption process is considered one of the most highly effective treatments of heavy metals, and the functionalization of adsorbents can fully enhance the adsorption process. Therefore, four adsorbent sources are highlighted: polymeric, natural mineral, industrial by-product, and carbon nanomaterial adsorbent. The major purpose of this review is to gather up-to-date information on research and development on various adsorbents in the treatment of heavy metal and dyes from water by emphasizing the adsorption capability, the effect of pH, isotherm and kinetic model, removal efficiency, and the contact of time of every adsorbent.

Advances in Research on Bacterial Oxidation of Mn(II): A Visualized Bibliometric Analysis Based on CiteSpace.

Manganese (Mn) pollution poses a serious threat to the health of animals, plants, and humans. The microbial-mediated Mn(II) removal method has received widespread attention because of its rapid growth, high efficiency, and economy. Mn(II)-oxidizing bacteria can oxidize toxic soluble Mn(II) into non-toxic Mn(III/IV) oxides, which can further participate in the transformation of other heavy metals and organic pollutants, playing a crucial role in environmental remediation. This study aims to conduct a bibliometric analysis of research papers on bacterial Mn(II) oxidation using CiteSpace, and to explore the research hotspots and developmental trends within this field between 2008 and 2023. A series of visualized knowledge map analyses were conducted with 469 screened SCI research papers regarding annual publication quantity, author groups and their countries and regions, journal categories, publishing institutions, and keywords. China, the USA, and Japan published the most significant number of research papers on the research of bacterial Mn(II) oxidation. Research hotspots of bacterial Mn(II) oxidation mainly focused on the species and distributions of Mn(II)-oxidizing bacteria, the influencing factors of Mn(II) oxidation, the mechanisms of Mn(II) oxidation, and their applications in environment. This bibliometric analysis provides a comprehensive visualized knowledge map to quickly understand the current advancements, research hotspots, and academic frontiers in bacterial Mn(II) oxidation.

Impact of Combined Pollution of Ciprofloxacin and Copper on the Diversity of Archaeal Communities and Antibiotic-Resistance Genes.

This study aimed to explore the response of archaeal communities and antibiotic-resistance genes (ARGs) to ciprofloxacin (CIP, 0.05-40 mg/L) and copper (Cu, 3 mg/L) combined pollution during stress- and post-effect periods in an activated sludge system. With the increase in the CIP concentration, the diversity of archaea decreased, but the richness increased under the stress of 10 mg/L CIP. Under stress and post effects, the change in unknown archaeal community structure was more significant than that of the known archaea. The relative abundance of unknown archaea was significantly reduced with the increase in CIP concentration. Meanwhile, there were certain archaea that belonged to abundant and rare taxa with different resistance and recovery characteristics. Among them, Methanosaeta (49.15-83.66%), Methanoculleus (0.11-0.45%), and Nitrososphaera (0.03-0.36%) were the typical resistant archaea to combined pollution. And the resistance of the abundant taxa to combined pollution was significantly higher than that of the rare taxa. Symbiotic and competitive relationships were observed between the known and the unknown archaea. The interactions of abundant known taxa were mainly symbiotic relationships. While the rare unknown taxa were mainly competitive relationships in the post-effect period. Rare archaea showed an important ecological niche under the stress-effect. Some archaea displayed positive correlation with ARGs and played important roles as potential hosts of ARGs during stress- and post-periods. Methanospirillum, Methanosphaerula, Nitrososphaera and some rare unknown archaea also significantly co-occurred with a large number of ARGs. Overall, this study points out the importance of interactions among known and unknown archaeal communities and ARGs in a wastewater treatment system under the stress of antibiotics and heavy metal combined pollution.

Analysis of Influencing Factors of Green M&A on the Value of Heavy Polluting Enterprises

This paper explores the impact of green mergers and acquisitions on the value of heavily polluting enterprises, focusing on environmental disclosure and green innovation. Through literature review and empirical analysis, the study finds that green mergers and acquisitions not only significantly enhance companies' environmental governance but also effectively promote long-term value growth. Specifically, improvements in environmental disclosure enhance market recognition, while green innovation brings new profit opportunities and market competitiveness to enterprises. This research provides theoretical and empirical support for understanding the role of green mergers and acquisitions in corporate sustainable development.

Green economic efficiency and productivity for sustainable development in China: A ray epsilon-based measure model analysis

Improving green economic efficiency (GEE) and productivity are crucial for China to realize sustainable development goals. However, the economic growth of China has followed an extensive development model with high energy consumption and heavy pollution. This study conducts data envelopment analysis (DEA) to evaluate the GEE of China. First, we introduce the polar coordinates theory in the epsilon-based measure (EBM) model to construct a Ray epsilon-based measure (REBM) model. In addition to the merits of EBM model, the REBM model accounts for the weak disposable relationship between undesirable and desirable outputs. Second, based on REBM model, a REBM-Malmquist-Luenberger (REBM-ML) index is constructed to evaluate the green total factor productivity (GTFP). Finally, we conduct spatial econometric analysis to reveal the dynamic evolution of GTFP. According to the empirical results, the GEE of China is generally low, and the urban agglomerations located at coastal regions own higher GEE. However, the GTFP made progress overall, mainly benefited from the technical progress. Accordingly, in the process of sustainable development, China still faces the challenge of energy saving and emission reduction. The spatial econometric analysis reveals that the GTFP of China existed a significant divergence trend and there was spatial spillover effect between cities, as well as urban agglomerations. Furthermore, we provide policy implications and suggestions for Chinese sustainable development.

A long-term Doppler wind LiDAR study of heavy pollution episodes in western Yangtze River Delta region, China

Previous studies are primarily based on surface air pollution for a single event, leaving research on the temporal characteristics of aerosols and wind fields in the atmospheric boundary layer (ABL) and their associations unclear due to a lack of long-term vertical profile data. This study was the first to conduct long-term Doppler wind LiDAR measurements from Sep. 2019 to Aug. 2022 in Hefei in western Yangtze River Delta (YRD) region, China. The spatiotemporal characteristics of retrieved aerosol backscatter coefficient (β) and wind profiles were analyzed from the perspective of long-term statistics and typical heavy pollution episodes (HPEs). The seasonal profile of β showed a peak in the near-surface layer meanwhile the overall β profile (<0.5 km) was the highest in winter but lowest in summer. Combined with ground-based meteorological and air quality observations, 12 HPEs were identified and classified into dust-related events and fog-haze episodes. The results showed a consistency between hourly variations in PM10 (particulate matter smaller than 10 μm) concentration and β retrieved at 300 m during a high PM10 concentration (>150 μg/m3) period. Different roles of horizontal wind at different altitudes and its associated time delay effect on surface PM10 pollution were evaluated based on correlation coefficients (Ф) and air pollution diffusion conditions. Significant positive Ф values were noticed below 0.5 km during the entire dust-related EP4 and EP6, indicating that the higher wind speeds could exacerbate PM10 pollution. In contrast, large negative Ф values meant the removal of PM10 pollutants by strong winds below 0.8 km during 24 h after peak in EP3. Combining with backward trajectory analysis and meteorological condition, notable transboundary pollution with positive contributions from upper winds (>1.5 km) was discovered in dust-related EP1, EP4, EP7, EP9, and EP10. Time delay effect (1-h/2-h lag) of upper winds (>0.8 km) on surface PM10 pollution was explored in EP5, EP6, EP7, EP8, and EP9. In spring dust-related HPEs, surface PM10 pollution was mostly contributed by long-range transport of aerosol particles at higher altitudes (>1.5 km) from the northwest direction, driven by the Mongolian cyclone and the cold front system. Transboundary aerosols originated from the northern part of Anhui province and the YRD region in the middle altitudes (∼0.5 km) was the main contributor to fog-haze HPEs. The findings demonstrated the ability of the real-time Doppler wind LiDAR system to monitor transboundary air pollution and provided a scientific reference for policy makers.

An organic visible-photocatalytic-adsorbence mechanism to high-efficient removal of heavy metal antimony ions

Purification of emerging heavy metal antimony contaminated water based on advanced ingenious strategies. An activated modified coconut shell charcoal (CSC) was synthesized and evaluated as a substrate-supported loaded organic photovoltaic material, PM6:PYIT:PM6-b-PYIT, to prepare a surprisingly highly efficient, stable, environmentally friendly, and recyclable organic photocatalyst (CSC–N–P.P.P), which showed excellent effects on the simultaneous removal of Sb(III) and Sb(V). The removal efficiency of CSC-N-P.P.P on Sb(Ⅲ) and Sb(V) reached an amazing 99.9% in quite a short duration of 15 min. At the same time, under ppb level and indoor visible light (∼1 W m−2), it can be treated to meet the drinking water standards set by the European Union and the U.S. National Environmental Protection Agency in 5 min, and even after 25 cycles of recycling, the efficiency is still maintained at about 80%, in addition to the removal of As (III), Cd (II), Cr (VI), and Pb (II) can also be realized. The catalyst not only solves the problems of low reuse rate, difficult structure adjustment and high energy consumption of traditional photocatalysts but also has strong applicability and practical significance. The pioneering approach provides a much-needed solution strategy for removing highly toxic heavy metal antimony pollution from the environment.

Examining temporal trends in heavy metal levels to analyze sediment pollution dynamics in the Saida urban watershed (N-W Algeria).

The study focuses on current pollution in the Saïda basin, a semi-arid region in north-western Algeria. By analyzing sediments, the study provides interesting results on urban pollution and its environmental impact. The research consists of two main phases, each addressing different aspects of pollution. In the first phase, different pollution indicators are used to analyze heavy metals and organic pollutants in urban drainage sediments. The results are compared with sediment quality guidelines, regulatory thresholds, and local and international references. Most of the metallic contaminants exceed the toxicity levels established by the continental crust and sediment quality guidelines, suggesting an anthropogenic origin. In addition, contamination indices show significant accumulation. In this context, the results highlight the importance of accumulation and transport processes in urban sediments. Hydrological parameters significantly influence heavy metal distribution mechanisms. Remarkable variations between copper (Cu) and lead (Pb) suggest a combined or singular source during transport. Conversely, chromium (Cr), nickel (Ni), and iron (Fe) are mainly derived from natural lithological sources. Cadmium (Cd) is associated with anthropogenic sources related to the agricultural use of phosphate fertilizers, whereas zinc (Zn) is mainly derived from physical corrosion processes. In the second phase, a combined descriptive and multivariate statistical analysis examines the mobility and distribution of heavy metals and their relationships with organic matter (OM) over time. Pronounced temporal variations in Cd, Zn, and Cu concentrations are attributed to human activities. Strong correlations exist between OM and cobalt (Co), Cu and Pb, confirming the ability of OM to adsorb these metals under specific geochemical conditions associated with waste disposal. Conversely, Zn, Cd, Cr, and Ni show weak or negative correlations with OM, suggesting diverse sources, including potential agricultural, industrial, and natural origins. The dendrogram confirms the existence of previously identified contaminant groups, suggesting common sources and potential co-occurrence patterns. This analysis highlights the role of the drainage network as a physico-chemical reactor in the mobilization of contaminants. It underlines the importance of sediment interactions in urban pollution processes. Finally, recommendations are proposed to ensure effective pollution control and remediation. PRACTITIONER POINTS: Useful information on pollution and its environmental impact is provided by the analysis of sediments in the urban basin of Saida (NW-Algeria). The results of this study indicate high levels of heavy metals in the sediments, in excess of toxicity limits, and evidence of anthropogenic sources. Temporal variations in metal concentrations indicate the influence of human activities. The study has made it possible to identify the sources, to understand the mobility and distribution, and to control the contamination by heavy metals in the urban sediments. Drainage system serves as a pathway for dispersing contaminants.

Effectiveness of inter-regional collaborative emission reduction for ozone mitigation under local-dominated and transport-affected synoptic patterns.

In recent years, the concentrations of ozone and the pollution days with ozone as the primary pollutant have been increasing year by year. The sources of regional ozone mainly depend on local photochemical formation and transboundary transport. The latter is influenced by different weather circulations. How to effectively reduce the inter-regional emission to control ozone pollution under different atmospheric circulation is rarely reported. In this study, we classify the atmospheric circulation of ozone pollution days from 2014 to 2019 over Central China based on the Lamb-Jenkinson method and the global analysis data of the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5) operation. The effectiveness of emission control to alleviate ozone pollution under different atmospheric circulation is simulated by the WRF-Chem model. Among the 26 types of circulation patterns, 9 types of pollution days account for 79.5% of the total pollution days and further classified into 5 types. The local types (A and C type) are characterized by low surface wind speed and stable weather conditions over Central China due to a high-pressure system or a southwest vortex low-pressure system, blocking the diffusion of pollutants. Sensitivity simulations of A-type show that this heavy pollution process is mainly contributed by local emission sources. Removing the anthropogenic emission of pollutants over Central China would reduce the ozone concentration by 39.1%. The other three circulation patterns show pollution of transport characteristics affected by easterly, northerly, or southerly winds (N-EC, EC, S-EC-type). Under the EC-type, removing anthropogenic pollutants of East China would reduce the ozone concentration by 22.7% in Central China.

Inhibit or stimulate? Green credit guidelines and corporate financialization

Although the green credit guidelines (GCGs) can force firms to engage in green transformation, it is still unknown whether the GCGs inhibit or stimulate corporate financialization. This research explores the effects and mechanisms of GCGs on financialization of heavy polluters using difference-in-differences estimators. The results indicate that the GCGs tend to strengthen heavy polluters’ motivations for precautionary saving and stimulate them to allocate liquid financial assets, while weakening their motivations for investment substitution and inhibiting their speculative allocation of financial assets. After several robustness tests, these conclusions remain valid. The mechanism tests suggest that the guidelines affect corporate financialization through increased financing constraints and reduced agency costs. Further analysis reveals that both types of financial asset allocation used by heavy polluters increase their levels of total factor productivity and green innovation. Heterogeneity analysis demonstrates that the impact of GCGs is more pronounced in nonstate-owned enterprises and firms which are located in regions with underdeveloped financial development and weak environmental law enforcement. In summary, this research explores the differentiated impacts and economic outcomes of GCGs, which not only provides insights into how financial institutions prevent corporate credit risk and achieve the targeted implementation of GCGs but also has certain reference value for the rationalization of asset allocation and green transformation for heavy polluters.

Biophysics indicators as the sustainable strategy for river pollution control (case study in Jangkok River, Mataram City, West Nusa Tenggara)

Background: Sungai Jangkok is one of those considered heavily polluted in NTB. The Biochemical Oxygen Demand (BOD) value has exceeded the standard for Class II water quality, and according to the Family Biotic Index (FBI) value, the river falls under the category of heavy organic pollution. The research objective is to realize sustainable management of the Jangkok Watershed in accordance with its river functions by implementing pollution control strategies. Methods: Data collection was conducted using questionnaires and interviews with the public and stakeholders (government and NGOs). Water quality data was obtained from DLHK NTB and DLH Mataram City, and sampling was carried out using the composite sample technique. The methods employed were STORET, QUAL2Kw, logistic regression, and SWOT. Findings: The research findings indicate that, in general, the Jangkok River in Mataram City falls into the heavily polluted category from 2015 to 2022, with an average STORET score of -79.25. Moreover, the pollution loads of BOD, COD, and TSS entering the river have exceeded the pollution carrying capacity. The condition is influenced by several factors, including the less favorable perception of pollution status (67%) and the usefulness of the river (59%) by the community. Additionally, the persistent behavior of littering and/or defecating in the river (23%), inadequate preventive practices (59%), insufficient wastewater disposal facilities (40%), and improper waste management (58%) are contributing factors. Moreover, the existence of houses backing up to the river (59%) also plays a role in the current condition. Some of the causes are the lack of synergy across administrative regions between stakeholders, the absence of law enforcement for the community, dependency on government budget for work programs, and the lack of incentives. Conclusion: The conclusion of this research suggests that the most effective strategy for taking is to develop a program for reducing pollutant loads that is integrated across districts and cities, integrated across agencies with various levels of authority, integrated with the community, and in accordance with the river's actual conditions and the socioeconomic community. Novelty/Originality of this Study: This study provides a novel approach by integrating quantitative water quality modeling (QUAL2Kw) with community behavior analysis to develop a sustainable and comprehensive strategy for controlling river pollution in the Jangkok watershed, Mataram City.

Exploring bioremediation strategies for heavy metals and POPs pollution: the role of microbes, plants, and nanotechnology

Heavy metal and Persistent Organic Pollutants (POPs) pollution stemming from industrialization, intensive agriculture, and other human activities pose significant environmental and health threats. These contaminants persist in the air, soil, and water, particularly in industrialized nations, adversely affecting human health and ecosystems. While physical and chemical methods exist for detoxifying contaminated soil, they often have drawbacks such as high cost and technical complexity. Bioremediation, utilizing plants and microbes, offers a promising solution. Certain microorganisms like Streptomyces, Aspergillus and plant species such as Hibiscus and Helianthus show high metal adsorption capacities, making them suitable for bioremediation. However, plants’ slow growth and limited remediation efficiency have been challenges. Recent advancements involve leveraging plant-associated microbes to enhance heavy metal removal. Additionally, nanotechnology, particularly nano-bioremediation, shows promise in efficiently removing contaminants from polluted environments by combining nanoparticles with bioremediation techniques. This review underscores bioremediation methods for heavy metals using plants and microbes, focusing on the role of Plant Growth Promoting Rhizobacteria (PGPR) in promoting phytoremediation. It also explores the implementation of nanotechnologies for eliminating metals from polluted soil, emphasizing the significance of soil microbiomes, nanoparticles, and contaminant interactions in developing effective nano-remediation strategies for optimizing agriculture in contaminated fields.

New media surveillance, environmental information uncertainty and corporate environmental information disclosure

This paper selects A-share heavy polluting enterprises in China's Shanghai and Shenzhen cities from 2009 to 2022. The following conclusions are obtained from the empirical evidence: new media monitoring can encourage enterprises to disclose information. Environmental information uncertainty can encourage enterprises to disclose information. The positive effect of environmental information uncertainty on environmental information disclosure is more significant for firms with poorer environmental performance than those with better environmental performance. The effect of the new media monitoring on environmental information disclosure of non-state-owned enterprises is more significant when other information is held constant.

Research on the path of green technology innovation driven by the Environmental Protection Tax Law: Based on data of heavy polluting enterprises.

Environmental Protection Tax Law (EPTL) is a compulsory environmental regulation measure adopted by China to deal with environmental problems. However, with the advancement of implementation, the EPTL produces a dissimilation effect and damages the realization of the Porter hypothesis effect. The study examines the dissimilation effect of green technology innovation regulated by the EPTL using sample data from heavy pollution firms in China. According to the empirical test results: (1) the coordination between levies and administrations, differential tax rate setting, tax information sharing, definition of the scope of levy and administration, tax declaration counseling, and tax rate level verification produce the dissimilation effect; (2) the Porter hypothesis effect of the EPTL is the most significant in medium-sized enterprises and foreign-funded enterprises. By constructing the research model group of dissimilation effect, this study analyzes the application of environmental regulation in China's social and economic background, thus providing a reference for developing of the green economy.

Ecofriendly synthesized Zeolite 4A for the treatment of a multi-cationic contaminant-based effluent: Central composite design (CCD) statistical approach

One of the key aspects of futureproofing the sustainability of life on earth lies in the protection of the hydrosphere, particularly from soluble heavy metal ion pollutants. In the current study, the central composite design and optimization of the ion-exchange process have been carried out for the simultaneous removal of selected cations; Cd2+, Cu2+, and Zn2+ cations using synthesized zeolite 4A. X-ray diffraction analysis confirmed the formation of zeolite 4A. The Brunauer-Emmett-Teller (BET) surface area of the synthesized zeolite was 32 m2/g. Results mainly indicate that there is a strong relationship between the experimental data and central composite design-based models of ion removal efficiency with R2 > 0.9 and the lack of fit less than 0.1 %. All the selected ion exchange parameters (time, dosage, pH, and temperature) were found to be statistically significant, with a p-value less than 0.05.For the complete simultaneous removal of selected cations, the optimal zeolite dosage, pH, and contact time are 1.2 g/100 cm3, 6, and 3 h. The optimal temperature ranges from 25 to 27 °C. The initial concentration of each selected cation is 450 mg/L. The ion exchange is in good agreement with the Freundlich and Langmuir isotherm models. Based on the Langmuir isotherm model, the maximum Cd2+, Cu2+, and Zn2+ uptake capacity values of zeolite are 103, 99.89, and 82.08 mg/g, respectively. In this study, it has been mainly inferred that CCD can be considered a useful tool for the modeling and optimization of zeolite ion exchange applications.

Evaluation of soil pollution effects on maize (Zea mays) at selected Pb-Zn and limestone mine sites in Ebonyi State, Southeastern Nigeria.

This research examined soil contamination and the uptake of potentially toxic elements (PTEs) by maize plants in mining communities. We collected 192 soil samples and 40 maize plant samples from two mining areas and a pristine site. We analyzed the physical properties and element content of the soil, including phosphorus, nitrogen, potassium, Fe, Zn, Co, Pb, Cd, Cr, and Ni. We also measured the elemental concentrations in the maize plants. The study found higher levels of Zn, Cu, and Pb at the mining sites compared to the control areas. The pollution factor (CF) indicated pollution with Cu > Pb > and > Zn at both mine sites. The pollution index (PLI) showed no pollution in the Nkalagu mine and control sites, but heavy and moderate pollution at the Ameka mine and control sites, respectively. The Ameka mine site was enriched with Zn. The bioaccumulation coefficient (BAC) was < 1 except for Zn at the Nkalagu mine and control site. The transfer factor for Fe and Zn from root to shoot was > 1. Pb was > 1 in all study areas except the Ameka mining areas. The results suggest remediation is needed for the two mine sites, especially at Ameka.