Environmental Science and Pollution Research最新文献

Biogenic coal bed methane has attracted great attention in recent years. During the process of biogas production, the interaction between microorganisms and coal is a crucial step. Sulfate-reducing bacteria (SRB) play an important role in biogas production. However, the interaction between SRB and coal has always remained an open problem. In the present work, the SRB strain Clostridium sp. and lignite were used to investigate the adsorption process with the extended DLVO (XDLVO) theory, calorimetry, and scanning electron microscopy (SEM). The results showed that the adsorption rate has a positive correlation with pH when it went from 3 to 8. XDLVO theoretical analysis was in good agreement with the adsorption experimental result. Acid-base potential energy is a more critical factor driving the adsorption comparing with electrostatic potential energy and Lifshitz-van Der Waals potential energy. The adsorption process of Clostridium sp. cells on lignite surface can be divided into three main stages: the direct adsorption, or reversible adsorption; desorption process; and irreversible adsorption. From the SEM results, the intercellular cohesion is also a very important adsorption form. The morphology and roughness of coal surface may also have a key effect on adsorption. Overall, our results provide some insights into the surface energy changes of Clostridium sp. adsorbed on coal and their interactions from the perspective of adsorption kinetics.

The study presents seasonal changes in nitrosamine concentrations in inhalable particulate matter (PM₁₀) collected from the atmosphere of Zonguldak, Turkey, during heating and non-heating periods, possible source apportionment, and risk assessment of human health. The daily collected PM_2.5 and PM_2.5-10 samples were analyzed for nitrosodimethylamine, nitrosomethylethylamine, nitrosodiethylamine, nitrosopyrrolidine, nitrosodipropylamine, nitrosomorpholine, nitrosoethylbutylamine, nitrosopiperidine, mono-nitrosopiperazine, di-nitrosopiperazine, nitrosodibutylamine, and nitrosodiphenylamine by gas chromatography-mass spectrometry (GC-MS). The mean concentrations of total nitrosamines in PM₁₀ were found to be 19.04 ng/m³ in summer, 113.67 ng/m³ in winter, and 98.88 ng/m³ annually, with a peak of 253.56 ng/m³ occurring in winter. The source apportionment of the analyzed data was conducted using principal component analysis, resulting in two primary factors: "Coal-Fuel Oil Combustion-Cooking" and "Traffic Emissions-Secondary Atmospheric Reaction-Landfill." These two factors collectively accounted for 82.944% of the total variance. In order to evaluate the health risks associated with the inhalation of mutagenic and carcinogenic nitrosamines present in airborne PM₁₀, cumulative lifetime cancer risks (LCR) were calculated for different age groups based on exposure time (ET) using annual mean concentrations. The average cumulative lifetime cancer risks, represented as the number of additional cancer cases per million exposed population, were in the range of 1.57-12.57 for the 0- < 1 age group, 4.18-33.52 for the 1- < 6 age group, 5.48-43.96 for the 6- < 21 age group, and 7.70-61.61 for the 21 < 70 age group. The estimated average cumulative lifetime cancer risks from inhalation exposure to nitrosamines in urban PM10 exceed the US Environmental Protection Agency's guideline for a negligible risk level of 1 excess cancer case per 1 million exposed individuals across all age groups. LCRs exceed the maximum acceptable value of 10 at different exposure times in all age groups but do not exceed the intolerable value of 100 in any age group.

The aim of this study was to estimate the effect of relatively large (1-5 mm) fragments of high-density polyethylene films on two widespread earthworm species belonging to different ecological groups-endogeic Aporrectodea caliginosa and epigeic Lumbricus rubellus. In a microcosm experiment lasting 8 weeks, we tested the food dilution hypothesis, which suggests that the adverse effect of microplastic on earthworms is caused by the dilution of food by plastic, which has zero energetic value. Both earthworm species ingested plastic particles, and both species were seemingly limited by the availability of food. In particular, the addition of food substrate (aspen litter) to the soil had a significant positive effect on the weight of A. caliginosa. In contrast to our expectations, microplastic at relatively high concentrations (0.3% and 2.3% w/w in the soil for A. caliginosa, and 33% and 48% w/w in the litter for L. rubellus) had no significant effect on earthworm biomass. This suggests that the food dilution effect is not likely to be the main mechanism of the adverse effect of microplastic on earthworms. Our work adds to the growing evidence that in many cases microplastic does not harm soil animals.

Microbeads are small spherical plastic particles used as exfoliants in personal care products. Unfortunately, they have been found in the marine environment and are considered a significant contributor to global plastic pollution. In response, several countries have implemented microbead bans over the last few years. Here, we examined the exfoliant (scrubbing particles) composition of 28 facial scrubs from different regions in the presence and absence of microbead bans. We identified that over half of the exfoliant types identified in this study are microbeads, revealing the persistence of microbeads across various stages of microbead ban implementation. In regions with full bans, six out of eight products still contain microbeads, with some containing up to 6298 ± 1543 beads per gram of facial wash, suggesting the need for stronger legislation enforcement. We also identified challenges in distinguishing between microbeads composed of conventional plastics and synthetic waxes by Fourier-transform infrared spectroscopy. This study highlights the need to broaden the scope of microbead bans to include synthetic waxes, as they are not currently regulated. These findings underscore the importance of a broader and clearly articulated definition of microbeads in legislation to guide industry formulation and consumer choice of microbead-free products.

Utilization of perishable waste has emerged as the pivotal factor in enhancing the quality and efficiency of garbage classification in rural regions of China. Nevertheless, the operation of small-scale decentralized aerobic biological treatment facilities in rural areas will inevitably result in the emission of malodorous volatile organic compounds (VOCs). In this study, VOCs emission characteristics of three typical decentralized facilities for the treatment of perishable waste in rural areas were investigated using cold trap enrichment combined with gas chromatography and mass spectrometry to elucidate the characteristics and potential effects on environment and human health. The concentration range of different points in the mechanical composting (MC) treatment mode is from 43.555 to 4154.281 (mean value, 947.292) µg/m³, in the solar-assisted composting (SAC) it is from 99.050 to 2064.308 (636.170) µg/m³, and in the bioconversion by black soldier fly larvae (BBSF) it is 93.712 to 718.644 (283.444) µg/m³. Odor nuisance analysis showed that oxygenated compounds and aromatic compounds were the main odoriferous VOCs. Among all detected VOCs, o-xylene, toluene, and acrolein have the highest ozone formation potential (OFP). Toluene, ethyl benzene, and xylene are the VOCs with secondary organic aerosol generation potential (SOAP). Health risk analysis revealed that six VOCs collectively represent a potential carcinogenic risk, while acrolein exhibits a non-carcinogenic risk. In light of the odor nuisance, environmental impact, and potential health risk, the priority-controlled VOCs identified in decentralized aerobic treatment modes of rural perishable waste were acrolein, benzyl chloride, ethyl acetate, etc. The findings of this research can serve as a valuable reference for the selection of proper strategies in the precise control of VOCs.

This paper presents a comprehensive database on the morphological, mineralogical, chemical, and contaminant release characteristics of construction and demolition waste (CDW). Scanning Electron Microscopy (SEM) was employed to analyse the particle morphology, revealing their angular and porous nature. X-ray Diffraction (XRD) was used to identify key minerals, such as quartz, calcite, and gypsum, providing vital information on the mineralogical composition of CDW. X-ray Fluorescence (XRF) analysis allowed the characterisation of the elemental composition, highlighting predominant oxides, like SiO₂, Al₂O₃, and CaO, with a notable presence of Na₂O in glass waste. Critical oxides, such as Fe₂O₃ (8.78%) and MgO (14.19%), were also identified. Recycled aggregates exhibited higher porosity and water absorption compared to natural aggregates, with fines constituting less than 27%, which presents an opportunity for their reuse, particularly in the production of geopolymers. Organic matter content was low, reaching up to 4.6%. The main contaminants identified include arsenic, cadmium, lead, chromium, and sulphates, with sulphate concentrations reaching up to 6,000 mg/kg, while arsenic, chromium, and lead reach up to 28 mg/kg, 310 mg/kg, and 6,580 mg/kg, respectively. These findings support the adoption of circular economy principles and regulatory frameworks that promote recycling and the use of innovative materials, thereby reducing the environmental footprint of construction projects.

Two novel silica-based hybrid materials, M1 and M2, based on silica gel and MCM-41 with a ditopic triazole-pyrazole ligand grafted onto their surfaces, respectively, were successfully synthesized and fully characterized. The adsorption capacity of these organic-inorganic hybrid materials was evaluated for copper(II), cadmium(II), and lead(II) ions. Experimental parameters including solution pH, contact time, temperature, and adsorbate concentration were systematically investigated. The obtained experimental data were analyzed using diverse adsorption isotherms and models to assess and interpret the behavior of the adsorbents. Notably, the newly synthesized materials exhibited exceptional selectivity, ultra-rapid adsorption rates within the first few minutes, and high removal efficiencies of 81.40 and 121.26 mg/g for M1 and M2, respectively, towards Cd(II). Moreover, reusability assessments demonstrated excellent consistency, with only marginal decreases in adsorption capacities of less than 8% observed over five consecutive cycles. Interestingly, the application of M1 and M2 for the extraction of transition metals from real contaminated river water, from Nador city in Morocco, showcased their effectiveness in removing heavy metal ions even at low concentrations, with M2 achieving up to 67% cadmium removal. These findings highlight the potential of both materials as reliable systems for heavy metal removal in practical environmental remediation applications, with material M2 demonstrating superior performance over M1.

The toxicity of As(III) significantly disrupts the growth and development of plants. In this study, black gram plants were exposed to 75 μM NaAsO₂ and 10 mg/L SiO₂ NPs, and various physiological, biochemical, and molecular changes were observed. Arsenic toxicity led to a notable reduction in plant development, accompanied by an accumulation of ROS and disturbances in proline levels due to electrolyte production. Treating As(III) contaminated black gram with SiO₂ NPs resulted in increased root length and chlorophyll content, while decreasing ROS levels. The application of SiO₂ NPs effectively mitigated As(III) toxicity by enhancing the activity of antioxidant enzymes such as peroxidase, catalase, glutathione, and superoxide dismutase, consequently reducing lipid peroxidation attributed to lower ROS production. RNA-seq analysis revealed several differentially expressed genes. Additionally, Fourier Transform Infrared (FTIR) Spectroscopy was utilized to explore the plant's capability to remove arsenic, identifying ligands such as O-H, C-O, C-C, and C-H that aid in the accumulation of heavy metals in plant tissues. An investigation using HR-LC/MS unveiled about 199 potential phytochemical components. A SwissADME analysis of these compounds showed that 136 out of 199 compounds followed Lipinski's rule. The bioavailability radar determined that 71 of these phytoconstituents had good oral bioavailability. Overall, the study indicates that the phytoconstituents that were found to have a shedload of pharmacological potential. The overall study showed that identified potential phytochemical compounds with pharmaceutical values, showing promise for drug development.

In order to explore the impact of endogenous organic detritus on differentiation of nitrate reduction pathway and mechanism, our study hypothesizes that the source of organic matter leads to differences in its chemical structure, thus affecting the nitrate reduction pathway. An indoor incubation experiment was conducted by adding different organic detritus from nitrogen-fixing and non-nitrogen-fixing cyanobacteria, green algae, and submerged macrophyte (sediment mixed thoroughly with different algal detritus and topped with 60 cm of water). The chemical components of different organic detritus degradation were mainly composed of aliphatic and aromatic compounds from cyanobacterial detritus as well as from green algae and macrophyte detritus, respectively, but the proportion was entirely different. Although the abundance of functional genes involved in the nitrogen cycle is similar in all groups, the microbial community structures are vastly different. The dominant microbial community structure and nitrate reduction rate as well as their negative relationship all indicated the discrepancy between ecological function and dominant microbial community structure. This suggested that the minority microbial community plays a dominant role in the nitrate reduction process. However, there is a high consistency between nitrate reduction rates and nitrogen nutrient levels. In addition, the dissimilatory nitrate reduction to ammonium (DNRA) predominated (10 ~ 35 μmol/kg/h), followed by denitrification (0.2 ~ 1.4 μmol/kg/h) in the nitrate reduction process. Therefore, the degradation of endogenous organic detritus promoted the nitrogen retention process mainly carried out by a minority microbial community, contributing to maintain the original eutrophic state in water bodies.

The frequency of extreme weather events, such as flooding, wildfires and hurricanes, has increased due to global climate change. Recent reports and studies show potential for release and exposure risks associated with contaminants of emerging concern (CECs) during major extreme weather events. These events create conditions for releasing CECs into the environment, especially affecting surface and groundwater systems. Antibiotics are considered one of the largest categories of CECs, commonly used in livestock farms. Recent water quality measurements conducted in areas impacted by the November 2021 atmospheric river flooding in British Columbia revealed the release of this category of CECs into surface water bodies. This study employs the November 2021 Sumas Prairie Flooding as a case study and develops an agent-based modeling (ABM) tool for CECs release risk management using AnyLogic software. The model will aid in identifying mitigation, preparedness, response and recovery actions before, during and after flooding, ultimately minimizing the release and impacts of CECs. The findings indicate that implementing preventive measures, such as waterproof storage, elevated storage areas and sealed containers, can significantly decrease the amount of unprotected material likely to be released into the environment during a flood event by about 80%. This substantial reduction highlights the vital role of these measures in reducing environmental contamination following a flood.