Tetrabromobisphenol A (TBBPA), which is the most widely employed brominated flame retardant, and its alternative tetrachlorobisphenol A (TCBPA) are widely distributed in aquatic environments. In the present study, the hepatotoxicity induced by TBBPA and TCBPA was investigated in Rana nigromaculata, and the potential mechanisms were investigated with a particular focus on ROS (reactive oxygen species) -dependent mitochondria-mediated apoptosis. Healthy adult frogs were exposed to 0, 0.001, 0.01, 0.1, and 1 mg/L waterborne TBBPA and TCBPA for 14 days. The results showed that liver weight was significantly increased by 51.52%–98.99% in the 0.01, 0.1, and 1 mg/L TBBPA and TCBPA groups relative to the control. Histological examination revealed that the structure of the liver, to some extent, was influenced by TBBPA and TCBPA with nuclear shrinkage and mitochondrial swelling. Meanwhile, TBBPA and TCBPA have significantly increased the alanine transaminase level in serum and the content of ROS, while inhibiting the activity of superoxide dismutase in the liver. In addition, DNA fragments were observed in the TBBPA and TCBPA groups relative to the control. Expression of Cytochrome C was significantly increased by 1.13-, 1.38-, 1.60-, and 2.46-fold in 0.001, 0.01, 0.1, and 1 mg/L TBBPA, and by 1.26-, 1.51-, 2.14-, and 2.98- fold in 0.001, 0.01, 0.1, and 1 mg/L TCBPA, respectively, which indicated that TCBPA may be more toxic than TBBPA. Similarly, the ratio of Bax/Bcl-2 was increased in a dose-dependent manner. These results indicated that apoptosis in the ROS-dependent mitochondrial pathway mediates hepatotoxicity caused by TBBPA and TCBPA. The present study will facilitate an understanding of the toxicity mechanism of flame retardants.

Glyphosate (N-phosphonomethylglycine; GLP) and its main metabolite AMPA (aminomethylphosphonic acid), are frequently detected in relatively high concentrations in European agricultural topsoils. Glyphosate has a high sorption affinity, yet it can be detected occasionally in groundwater. We hypothesized that shrinkage cracks occurring after dry periods could facilitate GLP transport to greater depths where subsoil conditions slow further microbial degradation. To test this hypothesis, we simulated a heavy rainfall event (HRE) on a clay-rich arable soil. We applied 2.1 kg ha⁻¹ of 100% ¹³C₃, ¹⁵N-labeled GLP one day before the simulated rainfall event. Microbial degradation of translocated GLP over a 21-day period was assessed by quantifying ¹³C incorporation into phospholipid fatty acids. Microbial degradation potential and activity were determined by quantifying the abundance and expression of functional genes involved in the two known degradation pathways of GLP; to AMPA (goxA) or sarcosine (sarc). We confirmed that goxA transcripts were elevated in the range of 4.23 x 10⁵ copy numbers g⁻¹ soil only one day after application. The increase in AMPA associated with a rise in goxA transcripts and goxA-harboring microorganisms indicated that the degradation pathway to AMPA dominated. Based on ¹³C-enrichment 3 h after the HRE, fungi appeared to initiate glyphosate degradation. At later time points, Gram⁺-bacteria proved to be the main degraders due to their higher ¹³C-incorporation. Once GLP reached the subsoil, degradation continued but more slowly. By comparing GLP distribution and its microbial degradation in macropores and in the bulk soil, we demonstrated different time- and depth-dependent GLP degradation dynamics in macropores. This indicates the need for field studies in which soil properties relevant to GLP degradation are related to limiting environmental conditions, providing a realistic assessment of GLP fate in soils.

Compacted clay liners (CCLs) are extensively used as engineering barriers for groundwater and soil pollution. The existence of cracks/fractures in CCL caused by thermally induced shrinkage is reported to importantly damage the performance of the CCL. An analytical model is developed to study the effects of the cracks/fractures on the migration of organic contaminants through a composite liner system. Laplace transformation and Laplace inversion using the Stehfest method are adopted to derive the analytical solution, which is validated by the experimental data. The existence of crack shows a significant impact on the breakthrough curve and bottom flux of organic contaminants. Increasing the crack width from 1 to 25 mm results in an enhancement of contaminant bottom concentration by a factor of 280. Increasing the adsorption factor and degradation rate of contaminants can effectively improve the performance of the composite liner with cracks. The effects of degradation of contaminants on the breakthrough curve are found to be more significant for the case with a larger retardation factor. This may be due to the fact that increasing the retardation factor can significantly slow down the transport of contaminants, which may indirectly create a longer period for the degradation of contaminants.

Investigation of ZnO nanoparticles (nano-ZnO) and graphene quantum dots (GQDs) toxicology on dinoflagellate Gymnodinium helps to understand the effects of different surface characteristic nanoparticles on marine algae. The growth and biological responses of the algae exposed to 1, 10, 20 mg L⁻¹ nano-ZnO and GQDs in f/2 media were explored. Nano-ZnO showed slight effects on algal cells growth, while the growth inhibition rates of Gymnodinium increased as GQDs concentration increasing. Both nanoparticle treatments induced accumulation of reactive oxygen species and activated intracellular antioxidant defensive system, including SOD and ATPase, which were related to the two nanoparticles concentration. Under combined exposure of nano-ZnO and GQDs, the inhibitory effects decreased compared to the single GQDs and showed antagonistic effect. The addition of nano-ZnO could decrease the toxicity of GQDs due to aggregation and sedimentation interaction between nanoparticles. The morphologic change of the cells observed by SEM proved that nanoparticles adsorbed onto the cell surfaces and caused the cell shrinkage.

The idea of reusing municipal incinerator bottom ash (MIBA), the residue from incinerating municipal solid wastes, fits nicely in a circular economy scheme, which leads to an avoided impact of landfill disposal, and at the same time reduces the demand of natural resources. Past studies have attempted to add 20 to 60% MIBA for ceramic production, and resulted in some inspiring success. Focused on delivering quality interior and exterior floor tiles meeting industrial standards, this study investigated the operative conditions and the optimum amount of MIBA in the mix. In this study, only the kaolinite clay and MIBA were used. Before making specimens, raw materials of clay and MIBA underwent SEM, EDS, and TCLP tests to determine their chemical contents. Six sets of specimens with different replacement levels of MIBA (0%, 5%, 10%, 15%, 20%, and 30%) were then prepared. These specimens were fired at 1000°C, 1050°C,1100°C, and 1150°C and the products underwent a series of mechanical tests to verify their performance. NMR (nuclear magnetic resonance spectroscopy) were also used to determining the organic compound structure after each specimens’ crystallization. Research results showed that proper mix of MIBA up to 20% could result in quality tiles complying with specifications for interior and exterior flooring applications at certain kiln temperatures, while the specimens with 30% MIBA failed to meet either bending strength or size shrinkage requirement at all four kiln temperatures, and could not deliver a satisfactory result.

The need for environmental preservation requires civil engineering to reach new concepts and technical solutions aiming at the sustainability of its activities and products. In this context, this study aimed to evaluate the effect of using different types and percentages of vegetable particles on the physical, mechanical, and thermal properties of soil–cement bricks. Bamboo, rice husk, and coffee husk particles at 1.5 and 3% percentages and a control treatment not using the particle were evaluated. The chemical properties, shrinkage, compaction, consistency limits, and grain size were characterized for the soil; and the anatomical, chemical, and physical properties for the lignocellulosic particles. The bricks were produced using an automatic press and characterized after the curing process for density, water absorption, porosity, loss of mass by immersion, compressive strength, durability, and thermal conductivity. The increase in the lignocellulosic waste percentage caused a mechanical strength decrease and bricks’ porosity and water absorption increase. However, it caused a decrease in density and an enhancement in loss of mass and thermal insulation properties. The bricks produced with rice husk obtained the best results in terms of mechanical and thermal properties, and were still among the best treatments for physical properties, standing out among the lignocellulosic waste as an alternative raw material source for soil–cement brick production.

The Himalayan glaciers provide water to a large population in south Asia for a variety of purposes and ecosystem services. As a result, regional monitoring of glacier melting and identification of the drivers are important for understanding and predicting future cryospheric melting trends. Using multi-date satellite images from 2000 to 2020, we investigated the shrinkage, snout retreat, thickness changes, mass loss and velocity changes of 77 glaciers in the Drass basin, western Himalaya, India. During this period, the total glacier cover has shrunk by 5.31 ± 0.33 km². The snout retreat ranged from 30 to 430 m (mean 155 ± 9.58 m). Debris cover had a significant impact on glacier melting, with clean glaciers losing ~ 5% more than debris-covered glaciers (~ 2%). The average thickness change and mass loss of glacier have been − 1.27 ± 0.37 and − 1.08 ± 0.31 m w.e.a⁻¹, respectively. Because of the continuous melting and the consequent mass loss, average glacier velocity has reduced from 21.35 ± 3.3 m a⁻¹ in 2000 to 16.68 ± 1.9 m a⁻¹ by 2020. During the observation period, the concentration of greenhouse gases (GHGs), black carbon (BC) and other pollutants from vehicular traffic near the glaciers increased significantly. Increasing temperatures, caused by a significant increase in GHGs, black carbon and other pollutants in the atmosphere, are driving glacier melting in the study area. If the current trend continues in the future, the Himalayan glaciers may disappear entirely, having a significant impact on regional water supplies, hydrological processes, ecosystem services and transboundary water sharing.

The demand for scarce raw material has been increased with rise of construction. An ideal raw material is clay, which is abundantly used in manufacturing bricks. The proposed study aims at making a brick blocks with clay-free materials. Therefore, instead of clay, waste additives such as sludge waste, construction and demolition waste, and fly-ash are used as a binding material. These additives would contribute a better performance and properties without altering the desired strength. Sewage sludge is an important component of sewage disposal, but it is also ruinous to the environment. Construction and demolition (C&D) debris are a rising source of waste utilization. The objective of the proposed work is to eliminate the natural resources like clay and utilization of waste additives effectively in making brick blocks. The mix proportions are maintained at 30% sludge with 3:2:2, 2:3:2, and 2:2:3 (fly ash: cement: C&D), similarly, 40% sludge with 1:3:2, 2:3:1, and 3:2:1 and 50% sludge with 2:1:2, 2:2:1, and 1.5:1.5:2. The physicochemical properties include density, water absorption, pH, shrinkage, plasticity index, and efflorescence, and leaching characteristics were analyzed. Mechanical properties include compressive strength and thermal conductivity; mineralogical and microstructural analysis and durability aspects were carried out. The presence of organic matter influences the overall property. The stress distribution was induced by porosity and attained a maximum strength of 14.5 N/mm². Durability was influenced by compaction and temperature. At high temperature, the particles are well compacted. The concentrations of heavy metals are immobilized. Based on the above, it can be practically implemented in structures as well as in hidden masonry works.

Leather manufacturing is the process of transforming animal skin into high value-added commodity. As a crucial step in the leather producing process, conventional chrome tanning could lead to discharge of chromium contaminant due to the low efficiency of chromium uptake. In this paper, a series of polyethylene glycol triazine derivatives’ tanning agent (PT) with different molecule weight was synthesized with one-step method and applied in the main tanning of hide. The chemical structure of the PT was detected by FT-IR and ¹H-NMR. The application experimental results indicated that after 16% of PT tanning at pH of 6, the wet-white was endowed with shrinkage temperature over 80°C and thickening rate over 108%. The experimental results indicated that the PT tanning leather not only have a better physical and mechanical properties than commercial triazine derivatives tanning agent, but also the leather is endowed with the effects of outstanding thermal properties. Considering that the pickling process became unnecessary, a large number of neutral salts could be avoided, the chromium load in spent liquor decreased from 1288 mg/L to 0, and the total dissolved chlorine in spent liquor decreased from 15,360 to 9581 mg/L; no toxic and harmful substances such as chromium and aldehyde are introduced into the tanning process. Compared with the leather tanned with commercial triazine derivatives’ tanning agent, the leather tanned with PT showed a similar overall tanning properties and better environmental friendliness, which makes PT matches the integral requirements of the modern sustainable leather industry.

Aedes aegypti is the main vector of yellow fever, chikungunya, Zika, and dengue worldwide and is managed by using chemical insecticides. Though effective, their indiscriminate use brings in associated problems on safety to non-target and the environment. This supports the use of plant-based essential oil (EO) formulations as they are safe to use with limited effect on non-target organisms. Quick volatility and degradation of EO are a hurdle in its use; the present study attempts to develop nanoemulsions (NE) of Trachyspermum ammi EO and its constituent thymol using Tween 80 as surfactant by ultrasonication method. The NE of EO had droplet size ranging from 65 ± 0.7 to 83 ± 0.09 nm and a poly dispersity index (PDI) value of 0.18 ± 0.003 to 0.20 ± 0.07 from 1 to 60 days of storage. The NE of thymol showed a droplet size ranging from 167 ± 1 to 230 ± 1 nm and PDI value of 0.30 ± 0.03 to 0.40 ± 0.008 from 1 to 60 days of storage. The droplet shape of both NEs appeared spherical under a transmission electron microscope (TEM). The larvicidal effect of NEs of EO and thymol was better than BEs (Bulk emulsion) of EO and thymol against Ae. aegypti. Among the NEs, thymol (LC₅₀ 34.89 ppm) had better larvicidal action than EO (LC₅₀ 46.73 ppm). Exposure to NEs of EO and thymol causes the shrinkage of the larval cuticle and inhibited the acetylcholinesterase (AChE) activity in Ae. aegypti. Our findings show the enhanced effect of NEs over BEs which facilitate its use as an alternative control measure for Ae. aegypti.