Thermal stratification is considered to be the most important limnological feature of deep lake ecosystems affecting a water column’s chemical characteristics thereby directly connected with lake management. The lake is also attracting the attention of management authorities, being a growing tourist destination with sustainable environmental management plan. Lake Manasbal is only true warm monomictic urban lake in Kashmir and remains thermally stratified for 8–9 months, with separate layers of epilimnion, metalimnion and hypolimnion.We noticed that in the lower part of the hypolimnion, the process of stratification is characterized by an oxygen deficit (O₂ < 1 mg/L). The rate of oxygen depletion reported in the lake’s bottom layers is indicative of the water body’s more eutrophic nature. A clinograde type of pH curve with a wide range of fluctuation from top to bottom layers of water was observed. Thermal stratification of the lake allows ammonium and phosphates to pool in the hypolimnion for much of the stratification period, resulting in concentrations higher than in the epilimnion. Consequently, the lake was characterized by a nutrient-enriched hypolimnion and an epilimnion deprived of nutrients. With the advent of the lake stratification, the thermocline was formed on 15th March between 2 and 3 m and on 7th April between 4 and 6 m, which gradually moved down to 10 m on 4th July and remained at that depth until circulation. The concentration of phosphorus and nitrogen in Lake Manasbal showed an increase towards the bottom, thus revealing an inverse clinograde depth distribution. Due to stratification phenomena in this lake, the internal release and subsequent distribution of nutrients throughout water column especially phosphorus from sediment water interface after mixing is a cause of concern for management authorities as it has the potential to diminish the ecological and aesthetics of the lake.Therefore, we argue that this study will provide some valuable insights on how stratification is affecting the nutrient dynamics and will offer inputs for better management accordingly both from ecological and economic perspectives.

Complexities of biotic-abiotic interactions in soils result in the lack of integrated understanding of environmental variables that restrict the survival of shiga toxin-producing E. coli O157:H7. Herein, we reanalyzed previously published data and highlighted the influence of soil abiotic factors on E. coli O157:H7 survivability and elucidated how these factors took effect indirectly through affecting indigenous bacterial community. Interaction network analysis indicated salinity and pH decreased the relative abundances of some bacterial taxa (e.g., Acidobacteria_Gp4, Acidobacteria_Gp6, and Deltaproteobacteria) which were positively correlated with the survival of E. coli O157:H7 in soils, and vice versa (e.g., Gammaproteobacteria and Flavobacteria) (P < 0.05). An array of multivariate statistical approaches including partial Mantel test, variation partition analysis (VPA), and structural equation model (SEM) further confirmed that biotic and abiotic factors interactively shaped the survival profile of E. coli O157:H7. This study revealed that some bacterial taxa were correlated with survival of E. coli O157:H7 directly, and salinity and pH could affect E. coli O157:H7 survival through changing these bacterial taxa. These findings suggest that salinity in soil might benefit the control of fecal pathogenic E. coli invasion, while soil acidification caused by anthropogenic influences could potentially increase the persistence of E. coli O157:H7 in agro-ecosystem.

Interactions among multiple nutrients uptake certainly have a great effect on their retention in headwater streams, yet little research has been made to explore the quantitative characteristics of their interactions, especially in mesotrophic streams. In response, we conducted an identical series of instantaneous nutrient addition experiments, using ammonium nitrogen (NH₄-N) and phosphate phosphorus (PO₄-P) alone or together, in two mesotrophic agricultural headwater streams in Chaohu Lake Basin, China, to quantify the relationships between nutrient concentrations and uptake rates, and examine how NH₄-N and PO₄-P interact to affect their individual uptake. Both the Michaelis-Menten (M-M) equation and response surface model were utilized to analyze coupled NH₄-N and PO₄-P uptake patterns across a range of nutrient concentrations, by fitting the kinetic processes of NH₄-N and PO₄-P uptake in single- and dual-nutrient additions. The capacity of both NH₄-N and PO₄-P uptake was increased in different degrees in dual-nutrient additions. Response surface models could quantitatively characterize the three-dimensional dynamic evolution trend of NH₄-N or PO₄-P uptake rates at different concentrations. The influence of PO₄-P additions on NH₄-N uptake was generally greater than that of NH₄-N on PO₄-P uptake in the five tracer tests. In addition, results of correlation analysis indicated that water temperature might be the main factor affecting the coupling of N and P uptake in mesotrophic streams and followed by hydrological factors (e.g., discharge) and channel geomorphology.

Pesticide residues in honey can negatively affect bee health. Although recent studies have detected neonicotinoid residues in honeys from around the world, little is known about how residues relate to land use and vegetation composition. To investigate potential relationships, we sampled multi-floral honey from 30 Apis mellifera hives from urban, agricultural and semi-natural habitats (SNH), identified and quantified three neonicotinoids present (clothianidin, imidacloprid and thiacloprid) using UHPLC-MS, and classified surrounding land use up to 5 km around hive sites. Neonicotinoids were most frequently detected in honeys from hives in agricultural habitats, and 70% of all samples contained at least one of the three neonicotinoid compounds. Imidacloprid was the most frequently detected neonicotinoid (found in 43% of honey samples) followed by clothianidin (40%) and thiacloprid (37%). Almost half (48%) of samples contained at least two neonicotinoids, and two of the 30 samples contained all three. Clothianidin and thiacloprid were more frequently detected in honeys from urban habitats, highlighting that exposure to pesticides does not just occur in agricultural settings. This suggests that pesticide use in urban domestic, sport and amenity contexts, given potential exposure of bees and other pollinators, needs urgent consideration.

Air pollution is a problem faced by most countries across the globe. The modeling and evaluation of the probabilistic behavior of air pollution are crucial in providing useful information that can help in managing the environmental risk and planning for the adverse effects of air pollution. For modeling of air pollution, several statistical approaches have been considered; however, only a few approaches have been used for addressing the uncertainty in the analysis. This study proposes a new application of the Markov chain-based fuzzy states (MCFS) model using triangular fuzzy numbers for analysing the uncertainty in the occurrence of air pollution events and describing the transition behaviour of air pollution. In this study, the air pollution index (API) data collected from the city of Klang in Malaysia for a period between 2012 and 2014 is considered in the analysis. Based on the API data, a five-state Markov chain is considered for representing the five fuzzy states of air pollution. The fuzzy transition probabilities are estimated and used to determine the characteristics of air pollution such as the steady state probabilities and the mean first passage time for each state of air pollution. The findings show that, in general, the risk of occurrences for unhealthy events in Klang is small, nonetheless remains notably troubling. The results demonstrate that the MCFS can effectively model the air pollution index and it could be a better option in predicting air pollution. It may provide valuable information and more understanding about the dynamics of air pollution to the experts and policymakers. This will enable them to develop proper strategies to manage air quality.

Ambient air particulate matter (PM) and PM-associated environmentally persistent free radicals (EPFRs) have been documented to contribute to pollution-related health effects. Studies of ambient air PM potentially bear artifacts stemming from the collection methods. We have investigated the applicability of PM phytosampling (PHS) as a supplementary tool to a classic PM sampler in respect of achieving better PM chemical composition assessment (primarily organic fraction). Phytosampling is a static PM collection method relying on the particle entrapment by the plant’s leaf through electrostatic forces and surface trichomes. We have investigated the differences in the EPFR and polycyclic aromatic hydrocarbon (PAH) speciation and concentration on ambient air PM for PHS and high-volume PM sampler (HVS). The advantages of PHS are easy particle recovery from the matrix, collection under natural environmental conditions, and the ability to apply a dense collection network to accurately represent spatial pollutant distribution. The experimental results show that the PHS can provide valuable speciation information, sometimes different from that observed for HVS. For PM collected by PHS, we detected the larger contribution of oxygen-centered EPFRs, different decay behavior, and more consistent PAH distribution between different PM sizes compared to the PM from HVS. These results indicate that the isolation of samples from the ambient during HVS sampling and exposure to high-volume airflow may alter the chemical composition of the samples, while the PHS method could provide details on the original speciation and concentration and be more representative of the PM surface. However, PHS cannot evaluate an absolute air concentration of PM, so it serves as an excellent supplementary tool to work in conjunction with the standard PM collection method.

The spent ternary lithium-ion batteries were utilized as the precursors to prepare Sm–Mn and Sm–Co perovskite oxides (SmMnO₃-spent ternary lithium-ion battery [STLIB] and SmCoO₃-STLIB) for the first time. Their catalytic activities were evaluated by catalytic oxidation of propylene glycol methyl ether. Compared with that of the catalysts synthesized by analytical reagents, the catalytic activities of SmMnO₃-STLIB and SmCoO₃-STLIB had been significantly enhanced. The analysis of X-ray photoelectron spectroscopy (XPS) showed that the molar ratios of Mn⁴⁺/Mn³⁺ and Oₐdₛ/Oₗₐₜₜ of SmMnO₃-STLIB were higher than that of pure SmMnO₃ and the Co³⁺/Co²⁺ ratios of SmCoO₃-STLIB was much larger than that of pure SmCoO₃. The hydrogen temperature-programmed reduction (H₂-TPR) and N₂ adsorption-desorption tests determined that the reducibilities and specific surface areas of SmMnO₃-STLIB and SmCoO₃-STLIB were also superior to pure catalysts. Ultimately, the by-products of the catalytic oxidation of propylene glycol methyl ether over SmMnO₃-STLIB were also detected by gas chromatography–mass spectrometry (GC-MS). This work will provide a demonstration for the resource utilization of spent lithium ions batteries and the analysis of the increased activity obtained by using spent lithium ions batteries as the precursors to prepare catalysts.

Biological nitrogen and phosphorus removal often requires an external carbon source to be effective during wastewater treatments. The purpose of this work was to evaluate a sequencing batch reactor (SBR) operated in a non-conventional anoxic/aerated (An/O) regime (alternated condition) treating synthetic wastewater simulating secondary anaerobic effluent mainly composed by P-phosphate and N-nitrate. The focus was to report the achieved biological efficiency removal of phosphorus and nitrate from the synthetic inlet when adding pre-fermented glycerol as the sole external carbon source. Experimental phase I aimed at the glycerol fermentation in batch reactors, leading to the formation of ethanol and volatile fatty acids. During experimental phase II, a non-acclimated (C1) and an acclimated biomass (C2) were used as inoculum of the SBR operated in the (An/O) regime. The anoxic phase was set to couple denitrification and P-release/uptake. The aerated phase was set to remove any remaining phosphorus. The fermented glycerol was applied in 15 gCOD g⁻¹ N-NO₃⁻ and 29 gCOD g⁻¹P-PO₄⁻³ ratios in a sequential batch reactor during a non-aerated phase. This operation favored the development and maintenance of phosphorus-accumulating organisms (PAO), as well as denitrifying organisms, resulting in approximately 90 ± 11% and 98 ± 3% for phosphorus and nitrogen removal, respectively. The study showed that the fermented glycerol can be successfully applied as an electron donor for biological nitrogen and phosphorus removal during wastewater treatments.

Exposure to PM₂.₅ can cause adverse health outcomes. In this study, we analyzed PM₂.₅ samples collected from suburban and urban sites, including a traffic tunnel in Suzhou, China, for their physicochemical properties, endotoxin contents, and effects on HepG2 and A549 cells in vitro. The greatest cellular responses, including oxidative stress, cytotoxicity, genotoxicity, inflammatory, and transcriptional activation of stress-responsive genes (i.e., HSPA1A, GADD45α), were observed in cells treated with traffic tunnel PM₂.₅. Cytokine expression was also measured and closely correlated with endotoxin content, while other toxic effects were largely related to PM₂.₅-bound metals and polycyclic aromatic hydrocarbons (PAHs). These findings suggested that chemical and biological composition of PM₂.₅, including adsorbed trace metals, PAHs, and endotoxin, may contribute significantly to their toxicity. In addition to commonly used in vitro toxicity tests, HSPA1A and GADD45α promoter-driven luciferase reporter cells may provide a potential new tool for rapid screening and quantification of PM₂.₅ toxicity.

This paper examines the impact of environmental treaties on the environment across 74 countries: 50 resource-rich and 24 non-resource-rich countries. Using data spanning over 35 years, we find a negative and significant association between environmental treaties and environmental quality in resource-rich countries. On the contrary, we find environmental treaties positively and significantly affect the environment in non-resource-rich countries. Our results suggest that the environmental treaties signed by resource-rich countries may lead them to achieve sustainable development growth by 2030. Therefore, our results extend the environment literature and inform policymakers of the need to pay attention to the effects of signing environmental treaties on environmental protection.