Phosphogypsum (PG), an industrial solid waste produced from the wet phosphoric acid process, has seriously damaged the ecological environment. Its comprehensive utilization rate needs to be improved urgently. In this paper, the chemical enhancement effect of solid waste PG on expansive soil, known as engineering cancer, was investigated through systematic macroscopic and microscopic experiments. The positive and negative environmental impacts of the PG modifier were also comprehensively analyzed. Laboratory soil test results show that PG mixed with expansive soil can change the consistency limit of expansive soil, effectively increase the soil strength by 2-3 times and reduce the expansion of expansive soil to 62%. Therefore, it can be considered to be applied to the improvement of expansive soil roadbed. However, when the dosage is too high, it may be affected by the dissolution of PG, and the improvement effect is relatively decreased. The optimal dosage of PG is 15%. XRD, XRF, SEM and MIP microcosmic tests show that the mineral composition, element content and porosity of the expansive soil have changed after the addition of PG. Its microstructure is much tighter. Through TCLP test, the environmental effects of heavy metals caused by resource utilization of PG modified expansive soil were evaluated. In this study, only Cr element exceeded 2.6% slightly when the content of PG was 25%. The analysis found that the engineering properties of expansive soil were effectively improved, resulting in the effective solidification of heavy metals in PG.

Permafrost regions of Qilian Mountains in China are rich in gas hydrate resources. Once greenhouse gases in deep frozen layer are released into the atmosphere during hydrate mining, a series of negative consequences occur. This study aims to evaluate the impact of hydrate thermal exploitation on regional permafrost and carbon budgets based on a multi-physical field coupling simulation. The results indicate that the permeability of the frozen soil is anisotropic, and the low permeability frozen layer can seal the methane gas in the natural state. Heat injection mining of hydrates causes the continuous melting of permafrost and the escape of methane gas, which transforms the regional permafrost from a carbon sink to a carbon source. A higher injection temperature concentrates the heat and causes uneven melting of the upper frozen layer, which provides a dominant channel for methane gas and results in increased methane emissions. However, dense heat injection wells cause more uniform melting of the lower permafrost layer, and the melting zone does not extend to the upper low permeability formation, which cannot provide advantageous channels for methane gas. Therefore, a reasonable and dense number of heat injection wells can reduce the risk of greenhouse gas emissions during hydrate exploitation.

The improper disposal of discarded electronic and electrical equipment raises environmental and health concerns, spanning air pollution to water and soil contamination, underscoring the imperative for responsible management practises. This review explores the complex composition of discarded printed circuit boards (DPCBs), crucial components in electronic devices. Comprising substrates, electronic elements and solder, DPCBs showcase a heterogeneous structure with metal (30.0-50.0%) and non-metal (50.0-70.0%) fractions. Notably abundant in precious metals such as Au, Ag, and Pd, DPCBs offer a compelling avenue for recycling initiatives. The inclusion of heavy metals and flame retardants adds complexity, necessitating environmentally sound disposal methods. Ongoing research on smart disassembly, utilising 3D image recognition technology, underscores the importance of accurate identification and positioning of electronic components (ECs). The targeted approach of smart disassembly, centred on valuable components, highlights its significance, albeit with challenges in equipment costs and capacity limitations. In mechanical disassembly, techniques such as grinding and heat application are employed to extract ECs, with innovations addressing gas emissions and damage induced by overheating. Chemical disassembly methods, encompassing epoxy resin delamination and tin removal, present promising recovery options, whilst the integration of chemical and electrochemical processes shows potential. Efficient sorting, encompassing both manual and automated methods, is imperative post-disassembly, with smart sorting technologies augmenting accuracy in the identification and categorisation of ECs. In addition, explorations into NH3/NH4+ solutions for selective metal recovery underscore challenges and stress the necessity for meticulous process optimisation in environmentally sustainable PCB recycling. Challenges and future perspectives have also been expounded.

Background: Heavy elements such as antimony greatly affect the environment and living organisms. Antimony is discharged into the environment by mining and industries that use it as pesticides and flame retardants. This activity can lead to environmental pollution, water and soil contamination. Antimony can also accumulate in living organisms and cause negative health effects, such as damage to the respiratory system and skin, and growth abnormalities of animals and plants. Methods : The primary objective of this investigation was to explore the teratogenic impact of the antimony heavy metal on histological structure of the liver in adult rabbits ( Oryctolagus cuniculus ). The study included adult white rabbits divided into several groups: the first one is the control group injected with physiological saline (0.09% NaCl), the other group injected with 20 mg/kg antimony, and the last injected with 30 mg/kg antimony over a 30 -day period. Following this, postmortem procedures were conducted to extract and fix the liver organ, and tissue sections were prepared. Result : The results revealed significant histological changes, including distortion and rupture in Glisson's Capsule, leading to the formation of a sub -capsular space due to its separation from hepatocytes. Additionally, alterations in the radial organization of hepatocytes and pyknosis in the nuclei were observed, characterized by a dark color and reduced size. Karyolysis, where nuclei completely disappeared, and hydropic degeneration in hepatocytes with swollen appearance and dark nuclei due to fluid accumulation were noted. Moreover, an increase in Kupffer cells and blood congestion in the central vein, resulting in dilation compared to the control group, were observed. Conclusion : Overall, the treatment with antimony at 20 and 30 mg/g doses for 30 days show profound teratogenic effects on the histological structure of the liver in adult rabbits. These effects are represented by the destruction of various parts of liver, in addition to changes in arrangement, and distortion and rupture of the cells. Furthermore, an increase in Kupffer cells and blood congestion were also recorded.

Tibetan Plateau (TP) is known as the water tower of Asia, and glaciers are solid reservoirs that can regulate the amount of water. Black carbon (BC), as one of the important factors accelerating glacier melting, is causing evident environmental effects in snow and ice. However, a systematical summary of the potential sources, analytical methods, distributions, and environmental effects of BC in snow and ice on the TP's glaciers is scarce. Therefore, this study drew upon existing research on snow and ice BC on glaciers of the TP to describe the detection methods and uncertainties associated with them to clarify the concentrations of BC in snow and ice and their climatic effects. The primary detection methods are the optical method, the thermal-optical method, the thermochemical method, and the single-particle soot photometer method. However, few studies have systematically compared the results of BC and this study found that concentrations of BC in different types of snow and ice varied by 1-3 orders of magnitude, which drastically affected the regional hydrologic process by potentially accelerating the ablation of glaciers by approximately 15% and reducing the duration of snow accumulation by 3-4 days. In general, results obtained from the various testing methods differ drastically, which limited the systematical discussion. Accordingly, a universal standard for the sampling and measurement should be considered in the future work, which will be beneficial to facilitate the comparison of the spatiotemporal features and to provide scientific data for the model-simulated climatic effects of BC.

The behavior and fates of environmental pollutants within the cryosphere and the associated environmental impacts are of increasing concerns in the context of global warming. The Tibetan Plateau (TP), also known as the Third Pole, represents one of the most important cryospheric regions in the world. Mercury (Hg) is recognized as a global pollutant. Here, we summarize the current knowledge of Hg concentration levels, pools and spatio-temporal distribution in cryospheric environments (e. g., glacier, permafrost), and its transfer and potential cycle in the TP cryospheric region. Transboundary transport of anthropogenic Hg from the surrounding heavily-polluted regions, such as South and Southeast Asia, provides significant sources of atmospheric Hg depositions onto the TP cryosphere. We concluded that the melting of the cryosphere on the TP represents an increasing source of Hg and brings a risk to the TP environment. In addition, global warming acts as an important catalyst accelerating the release of legacy Hg from the melting cryosphere, adversely impacting ecosystems and biological health. Furthermore, we emphasize on the remaining gaps and proposed issues needed to be addressed in future work, including enhancing our knowledge on some key release pathways and the related environmental effects of Hg in the cryospheric region, integrated observation and consideration of Hg distribution, migration and cycle processes at a key region, and uses of Hg isotopic technical and Hg models to improve the understanding of Hg cycling in the TP cryospheric region.

In the past decade, approximately 17 % of the world's photovoltaic capacity has been installed in China, especially in the northwestern desert areas. The impacts of the construction and operation of large-scale photovoltaic power plants (PPPs) on local ecological environments have become urgent scientific issues regional environmental protection decision-making. To quantitatively evaluate the local environmental impacts of the construction and operation of PPPs in the desert oasis region, thermal infrared and multispectral sensors mounted on unmanned aerial vehicles (UAVs) as well as X-ray fluorescence spectrometers and soil sensors were used in this study to monitor a large PPP in Northwest China. We found that the construction and operation PPPs can promote biological soil crust development and vegetation growth and can thus improve the soil texture and nutrition. However, the Ca, S and Cl concentrations were found to be 3, 5 and 1.7 times higher inside the PPP area than outside the PPP area, respectively. In addition, the soil salinization is also more severe inside the PPP area. In future studies, it is essential to further elucidate the impacts of PPP operations and agricultural on desert ecosystems.