This study conducted a comprehensive analysis of the carbon components in $\mathrm{PM}_{2.5}$ particulate matter in Linfen City for the year 2020. Utilizing the thermal-optical transmittance (TOT) method, the mass concentrations of organic carbon (OC) and elemental carbon (EC) in $\mathrm{PM}_{2.5}$ were quantitatively assessed. Findings revealed seasonal variations in the concentrations of $\mathrm{OC}$ and EC. Specifically, concentrations in spring were registered at $4.45 \mu \mathrm{g} / \mathrm{m}^3$ for OC and $1.03 \mu \mathrm{g} / \mathrm{m}^3$ for EC; in summer, these were $3.89 \mu \mathrm{g} / \mathrm{m}^3$ and $0.74 \mu \mathrm{g} / \mathrm{m}^3$; in autumn, $6.01 \mu \mathrm{g} / \mathrm{m}^3$ and $1.30 \mu \mathrm{g} / \mathrm{m}^3$; escalating significantly in winter to $16.76 \mu \mathrm{g} / \mathrm{m}^3$ for OC and $4.24 \mu \mathrm{g} / \mathrm{m}^3$ for EC. This seasonal trend highlighted a notable peak in winter, with OC concentrations being 4.31 times, and EC concentrations 5.73 times, those observed in summer. The correlation analysis between OC and EC demonstrated the highest correlation in winter $\left(\mathrm{R}^2=0.961\right)$, suggesting similar sources for these components in the colder months, followed by autumn $\left(\mathrm{R}^2=0.936\right)$ and spring $\left(\mathrm{R}^2=0.848\right)$, with the least correlation observed in summer $\left(\mathrm{R}^2=0.584\right)$. The EC tracer method, employed to estimate secondary organic carbon (SOC) concentrations, indicated a seasonal pattern in SOC levels, with the highest concentrations occurring in winter, thereby suggesting a significant secondary pollution impact during this period. Moreover, the study identified meteorological conditions, particularly long-distance horizontal transport, as a primary influencer of winter pollution levels in Linfen City.

Utilising scanning electron microscopy (SEM) and X-ray powder diffraction (XRD), the morphological and phase composition characteristics of waste incineration fly ash were meticulously analysed. Morphological evaluations revealed a predominant presence of irregularly shaped particles, encountering a spectrum of structures inclusive of polycrystalline polymers and amorphous forms. Additional particle shapes encompassed polygons, strips, blocks, and flakes, while a notable high porosity between particles and a markedly rough surface were observed. Despite the scarcity of complete crystals within the ash, the majority manifested as polycrystalline polymers and amorphous forms, indicating the structural complexity intrinsic to waste incineration fly ash. Through the deployment of chemical continuous extraction technology, forms, migrations, and transformation laws pertaining to rare earth elements (REEs) in fly ash were elucidated. In three fly ash samples analysed for REEs, the most abundant state was identified as the residual, succeeded by the Fe-Mn oxide-bound state and minimally, the carbonate-bound state. Amongst all REEs, Ce exhibited the highest prevalence, followed by La, Y, Nd, Gd, and other elements. Furthermore, the source of waste and the respective incineration process markedly influenced REEs content.

This research delineates a numerical elucidation concerning the flow through an embankment, utilising PLAXIS2D software, and underscores the pivotal influence of soil composition—encompassing gravel, sand, and clay—on the structural resilience of embankments during seismic events. Different material models, incorporating the UBC3D-PLM for sand and the Hardening Soil (HS) small constitutive models for gravel and clay, were strategically employed to replicate embankment behaviours, ensuring a meticulous simulation of distinct soil types. The objective herein was to scrutinise the impact of dynamic loads and soil typologies on pertinent variables: settlements, lateral displacements, and excess pore water pressure engendered within the embankment. A comprehensive series of 2D finite element models, each representative of a specific soil type, were formulated and subsequently subjected to an earthquake record for dynamic analysis. It was discerned that embankments constituted from sand and gravel exhibited a pronounced settlement under dynamic loads, relative to those formulated from clay, primarily attributable to the absence of cohesion forces, augmented porosity, and diminished energy dissipation efficacy. Such factors render sand and gravel more prone to compression and settlement upon exposure to dynamic loads. Moreover, embankments fabricated from sand were identified to generate superior pore pressures compared to their clay or gravel counterparts, a phenomenon attributable to sand’s compressibility which can engender augmented volumetric strains and initiate pumping phenomena, thereby elevating pore pressures. In contrast, gravel and clay materials demonstrated enhanced drainage capabilities and reduced compressibility, facilitating the proficient dissipation of excess pore pressures.

In 2020, the world witnessed an unprecedented event: the outbreak of the COVID-19 pandemic, leading to significantly curtailed human activities. This study sought to elucidate the potential spatial ramifications of this on land surface temperatures (LSTs) in the renowned tourist locale of Kuta, Bali, Indonesia. Landsat 8 satellite imagery from 2019-2021, complemented by spatial data from local agencies, was employed for this analysis. LST processing was achieved through the calculation of Spectral Radiance/Top of Atmosphere, Brightness Temperature, and the conversion of Brightness Temperature to actual LST. In 2019, observed LSTs in Kuta District varied from 20.1℃ to over 32℃, with the predominant temperature range being 28.1℃ - 31.99℃, covering an expansive 1487.03 ha or 70.26% of the entire area. By 2020, a notable decline was discerned with temperatures peaking at 27.99 ℃ and the most prevalent temperature range being 24.1℃ - 27.99℃, encompassing an area of 1105.46 ha (52.23%). Contrarily, 2021 experienced an upswing, with the apex temperature touching 31.99℃, and the dominant temperature bracket being 28.1℃ - 31.99℃, spanning 974.90 ha (46.06%). A discernable correlation was identified between tourism activities and LST fluctuations, with temperature reductions conspicuous in zones endowed with tourism amenities.

Safety of reservoir dams remains pivotal for societal stability, underscoring the significance of efficient emergency management strategies. This investigation focuses on Naban Reservoir, where the BREACH model was employed to simulate potential dam failures. By integrating one-dimensional and two-dimensional modeling approaches, a mathematical representation was developed to scrutinize flood progression in the adjacent region. Correlation coefficients for the devised model ranged from 0.945 to 0.986, with relative errors of -13.72%, -0.23%, -17.41%, and -15.44%. Comparisons indicated that observed flow rates align closely with simulated rates. Notably, significant land slippages surrounding the reservoir were not detected, implying that an enhanced downstream surge due to an upstream collapse is unlikely. Nevertheless, a breach in the main dam could result in catastrophic outcomes for downstream zones, particularly affecting infrastructure and communities along the Shangsi and Zaimiao Basins. Critical observation zones, such as Siyang Town in Shangshi County, Zaimiao Town in Shangshi County, and Nakan Town in Ningming County, were identified, emphasizing the need for enhanced precautionary measures to safeguard human lives, property, and societal stability. This research has paved the way for a novel flood early warning system tailored for the Naban Reservoir, ensuring timely predictions and alerts. Such advancements augment the disaster prevention capacity, offering valuable insights for mitigating risks in small to medium-sized reservoirs.

Emerging as an efficient, cost-effective, and environmentally sound approach, electrochemical treatment methods hold significant promise for sustainable remediation and wastewater treatment. This review elucidates recent progress in electrochemical techniques used for site decontamination and wastewater management. It elucidates the fundamental electrochemical processes, detailing the principles of electrocoagulation, electroflocculation, electrochemical membranes, electrochemical oxidation (EO), and advanced oxidation processes (AOPs). The broad applicability of these methods for contaminant removal, inclusive of heavy metals, organic pollutants, complex organic compounds, and suspended particulate matter, is underscored. Notwithstanding, the adoption of these techniques encounters notable challenges. These involve the heterogeneity of soil conditions, the presence of intricate contaminant mixtures, and the risk of electrode fouling and degradation. Suggestions for overcoming such challenges include refining the comprehension of electrochemical treatment processes in field-scale applications, investigating innovative electrode materials, and developing advanced modeling and simulation tools. This review offers a robust overview of electrochemical treatment strategies for sustainable wastewater management and can guide researchers, engineers, and policymakers towards the successful adoption and implementation of these techniques to meet environmental challenges and foster sustainable water management.