Chemical discharge into water has contaminated various locations globally, endangering humans and aquatic life. Industries, farms, wastewater treatment plants, and stormwater overflows release chemicals. The European Union has set pollutant concentration criteria in drinking, surface, and groundwater to reduce water pollution. To comply with these limits, analytical detection methods must be rapid, reliable, and able to identify even minute levels of chemicals. Agriculture uses pesticides to keep crops safe from illnesses, insects, and weeds. Few chemicals work, while the remainder sink into the soil and damage ground and surface water. Due to the growing emphasis on scene analytes over chromatographic approaches, new pesticide evaluation methods have been prioritized. This report summarises various electrochemical pesticide detection studies in a simple and targeted manner. This study examines the electrochemical detection of carbamates, organophosphorus, organochlorine, pyrethroids, and pyrethrins. Electrochemical diagnostic methods, electrode materials, electrolyte and pH of interesting samples, and sample matrices are examined. This paper will also discuss current advances in the respected study, analytical obstacles, and future opportunities. Many electrochemical investigations and analytical data are summarised in this article, which also describes the linear dynamic range of concentration and limit of detection for electrochemical pesticide sensing. This review discusses electrochemical pesticide sensing advances in the utilization of various nanomaterials.

To comprehensively consider the influence of boundary conditions, non-Darcy flow, load forms, and soil stratification on soil consolidation, a one-dimensional soil consolidation equation is established. By subdividing the soil layer and employing time discretization, the nonlinear consolidation equation is linearized, resulting in an analytical solution for layered soil foundation at any given time. Subsequently, an iterative approach for time solution is employed to obtain a semi-analytical solution. The correctness of the solution is verified by comparison with solutions based on Darcy's flow and the semi-analytical method under traditional drainage boundary conditions. Subsequently, the influence of interface parameters, loading conditions, flow index, and other factors on consolidation characteristics is analyzed. The results indicate that higher interface parameter values for continuous drainage boundaries correspond to faster average consolidation rates for stratified soil foundations, while these parameters have little effect on the time required for complete consolidation of the soil layers. Improved boundary drainage performance amplifies the influence of exponential flow on pore water pressure and average consolidation degree. Conversely, poor boundary drainage performance diminishes the impact of exponential flow on soil consolidation, rendering it negligible. Moreover, faster loading rates accentuate the influence of the flow index on the average consolidation degree defined by pore pressure.

Trichlorobenzenes (TCBs), comprising the isomers 1,2,3-, 1,2,4-, and 1,3,5-TCB, disrupt metabolic processes by inducing liver enzymes involved in xenobiotic metabolism, suggesting a broad toxicological impact. Specifically, exposure to TCBs is associated with significant organ-specific toxicities, such as increased liver and kidney weights in rodents and cytotoxic effects in mammalian cells, which include DNA damage without metabolic activation. Used extensively in industrial and agricultural sectors, TCBs are prevalent pollutants in various ecosystems, including air, food, surface water, groundwater, sediment, soil, and sewage. This is a concern because of their tendency to accumulate in lipid-containing tissues of animals and humans and potentially serious risks to human health and ecosystems. Information showing the presence of TCBs in food, drinking water, and even human breast milk underscores the need for ongoing assessment of the extent of these contaminants in food to measure the potential exposure to these chemicals. TCBs are extracted from various food sample matrices, and then instrumental analysis is performed, typically gas chromatography (GC) coupled with a variety of detectors. This review discusses the occurrence and risk assessment of TCBs in foods, as well as the toxicology and analytical methods related to TCBs.

In this study, the segment joint and ring joint of the lining of the straight-jointed tunnel are simplified as an equivalent open cylindrical shell with a small central angle and an equivalent closed cylindrical shell with a small width, and the lining of the straight-jointed tunnel is thus simplified as an equivalent continuous periodic shell (ECPS) described by the cylindrical shell theory. Since the ECPS lining is periodic along the longitudinal direction, the tunnel-soil system can thus be treated as a periodic system, which is referred to as the periodic tunnel-soil system (PTSS) in this study. Based on the proposed ECPS lining model, an analytical method for the tunnel with the ECPS lining (ECPS tunnel) under seismic waves is established in this study. By employing the periodicity condition for the PTSS as well as the wave function expansion method, the representation for the wave field in the soil is established. With the aforementioned cylindrical shell theory and Fourier series expansion method, the convolution type constitutive relation for the ECPS lining and the Fourier space equations of motion are derived. By using the soil-lining continuity condition and aforementioned formulations for the ECPS lining and soil, the coupled Fourier space equations of motion for the PTSS are established, with which the response of the ECPS lining and scattered waves in the soil can be determined.

This work presents a simplified method for the nonlinear analysis of the load-displacement response of piles in multi-layered soils. As a starting step, a new interface model based on the disturbed state concept (DSC) is put forth to simulate the interface shear stress-displacement relationship by considering the nonlinear hardening-softening behaviour. In the new model, input parameters can be conveniently calibrated using conventional interface shear tests or on-site tests. The good agreement between predictions and experimental data from interface direct shear tests validated the performance of the proposed DSC model. The DSC model performed better in terms of predictions when compared to the hyperbolic one. Next, the soil-structure interface model and bearing capacity theory are coupled to provide a theoretical framework for the analysis of pile load-transfer in saturated and unsaturated multi-layered soils, where the DSC model is employed to represent base resistance as well as skin friction. This work also discusses the profile of steady-state in-situ matric suction, soil-water characteristic curve, and pore-water pressure of unsaturated soils. The proposed method has the advantage of being used in practice as it is simple to obtain input parameters from laboratory tests, as well as Standard Penetration or Cone Penetration Tests. The proposed framework is finally applied to the analysis of five welldocumented case studies. The proposed approach and the static load test results from the field measurements are found to be in satisfactory agreement, indicating that the proposed method performs well. The proposed method is suggested to be utilised for preliminary analysis, planning a suitable programme of loading tests, as well as optimizing the pile design by back analysis of the load test results.

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.

Perfluoroalkyl acid analogs (PFAAs) are a class of chemically stable environmentally persistent organic pollutants (POPs) that are difficult to degrade and have a strong capacity to accumulate in the human body. PFAAs have been found to be biotoxic to humans and have been detected in various environmental media, especially in the cryosphere at trace concentrations. The cryosphere, sensitively responds to climate change, plays a crucial role in the global water, carbon and energy cycles. However, researches on cryosphere PFAAs especially in Tibetan Plateau (TP) is limited. Therefore, we summarize the physicochemical properties, physiological toxicity, spatiotemporal distribution, sources, diffusion and migration pathways, as well as analysis and removal methods of PFAAs in the cryosphere regions. The results show that PFAAs pollutants are mainly produced and distributed in the more economically developed countries in Europe and the United States, as well as in East Asia, and PFAAs can be transported by atmospheric circulation and water cycle to remote regions including cryosphere regions. The current detection methods for PFAAs in cryosphere need to be further refined for increased accuracy and convenience. There is also a need to develop more effective removal methods that will reduce the environmental and human threats posed by these PFAAs. Finally, we propose key scientific questions for future research in cryosphere including PFAAs redistribution influenced by cryosphere changes, human activities, and the interaction of other spheres.

Microplastic is an emerging contaminant of concern in soil globally due to its widespread and potential risks on the ecological system. Some basic issues such as the occurrence, source, and potential risks of microplastics in the soil are still open questions. These problems arise due to the lack of systematic and comprehensive analysis of microplastic in soils. Therefore, we comprehensively reviewed the current status of knowledge on microplastics in soil on detection, occurrence, characterization, source, and potential risk. Our review suggests that microplastics are ubiquitous in soil matrices globally. However, the research progress of microplastics in the soil is restricted by inherent technological inconsistencies and difficulties in analyzing particles in complex matrices, and studies on the occurrence and distribution of microplastics in soil environments remain very scarce, especially in Africa, South America, and Oceania. The consistency of the characteristics and composition of the microplastics in the aquatic environment and soil demonstrate they may share sources and exchange microplastics. Wide and varied sources of microplastic are constantly filling the soil, which causes the accumulation of microplastics in the soil. Studies on the effects and potential risks of microplastics in soil ecosystems are also reviewed. Limited research has shown that the combination and interaction of microplastics with contaminants they absorbed may affect soil health and function, and even migration along the food chain. The occurrence and impact of microplastic on the soil depend on the morphology, chemical components, and natural factors. We conclude that large research gaps exist in the quantification and estimation of regional emissions of microplastics in soil, factors affecting the concentration of microplastics, and microplastic disguising as soil carbon storage, which need more effort. (c) 2021 Elsevier B.V. All rights reserved.