Salinization of road base aggregates poses a critical challenge to the performance of coastal roads, as the intrusion of chlorine salts adversely affects the stability and durability of pavement structures. To investigate the cyclic behavior of salinized road base aggregates under controlled solution concentration, c, and crystallization degree, omega, a series of unsaturated cyclic tests were conducted with a large-scale triaxial apparatus. The results showed that variations in solution concentration had a negligible influence on the resilient modulus of road base aggregates, and no significant differences were observed in their shakedown behavior. However, the long-term deformational response of the aggregates was affected by the precipitation of crystalline salt. At low crystallization degrees, a significant increase in accumulated axial strain and a decrease in resilient modulus were observed with increasing omega. Once the crystallization degree exceeded a critical threshold (omega(c)), there was a reduction in accumulated strain and an increase in resilient modulus. The precipitation of crystalline salt also disrupted the shakedown behavior of road base aggregates. During the nascent stages of crystallization (omega < 0.33), the presence of fine crystalline powders and clusters in the saltwater mixture destabilized the soil skeleton, resulting in a transition from the plastic shakedown stage to the plastic creep stage. This poses potential risks to the long-term characteristics and durability of the road base courses.

Sudden temperature drops cause soils in natural environments to freeze unidirectionally, resulting in soil expansion and deformation that can lead to damage to engineering structures. The impact of temperature-induced freezing on deformation and solute migration in saline soils, especially under extended freezing, is not well understood due to the lack of knowledge regarding the microscopic mechanisms involved. This study investigated the expansion, deformation, and water-salt migration in chlorinated saline soils, materials commonly used for canal foundations in cold and arid regions, under different roof temperatures and soil compaction levels through unidirectional freezing experiments. The microscopic structures of saline soils were observed using scanning electron microscopy (SEM) and optical microscopy. A quantitative analysis of the microstructural data was conducted before and after freezing to elucidate the microscopic mechanisms of water-salt migration and deformation. The results indicate that soil swelling is enhanced by elevated roof temperatures approaching the soil's freezing point and soil compaction, which prolongs the duration and accelerates the rate of water-salt migration. The unidirectional freezing altered the microstructure of saline soils due to the continuous temperature gradients, leading to four distinct zones: natural frozen zone, peak frozen zone, gradual frozen zone, and unfrozen zone, each exhibiting significant changes in pore types and fractal dimensions. Vacuum suction at the colder end of the soil structure facilitates the upward migration of salt and water, which subsequently undergoes crystallization. This process expands the internal pore structure and causes swelling. The findings provide a theoretical basis for understanding the evolution of soil microstructure in cold and arid regions and for the management of saline soil engineering. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

The degree of soil salinization is still on the rise. In saline environments, NaCl is the main substance that causes plant salt damage, with the toxicity of ions under salt stress primarily involving sodium (Na+) or chloride (Cl-). However, fewer studies have focused on Cl- stress. This study investigated the differences in the growth and physiology of five blueberry varieties under Cl- stress, aiming to understand the mechanisms of Cl- tolerance and the physiological responses to Cl- stress in these varieties. Five blueberry varieties ('Northland', 'PL19', 'Duke', 'Reka', and 'Bonnie') were used as test materials. This study examined the changes in growth and physiological indices of blueberry plants under different concentrations of Cl- (A1-A6: 50, 100, 150, 200, 250, and 300 mmol/L) treatments. A control treatment (CK) was included to serve as a baseline for comparison. We comprehensively evaluated the Cl- tolerance of these five varieties to screen for chlorine-tolerant varieties. This study examined the concentration-dependent changes in growth and physiological indices of blueberry plants, including plant height, leaf area, chlorophyll content, electrical conductivity, levels of soluble sugar (SS), malondialdehyde (MDA), proline (Pro), and soluble protein (SP), as well as the activities of superoxide dismutase (SOD) and catalase (CAT). The results revealed that as the Cl- concentration increased, the growth of all blueberry varieties was inhibited; plant height, leaf area, and chlorophyll content consistently declined, whereas electrical conductivity showed a steady increase. SS and MDA content exhibited a biphasic response, with an increase at lower Cl- concentrations followed by a decrease at higher concentrations. The activities of SOD and CAT in 'Duke' consistently increased with rising Cl- levels. In 'PL19' and 'Reka', chlorophyll content decreased with increasing Cl-, while their proline content rose initially and then declined. In contrast, the other varieties generally showed an increasing trend in proline content. Similarly, the soluble protein content of 'Northland' and 'PL19' increased at lower Cl- levels and decreased at higher concentrations, whereas 'Bonnie', 'Duke', and 'Reka' displayed an overall declining trend. Principal component analysis indicated that the Cl- tolerance of the blueberry varieties ranked as follows: 'Duke' > 'Bonnie' > 'Reka' > 'PL19' > 'Northland'. These findings lay a foundation for blueberry cultivation in saline-alkaline soils and support the selection and development of new, chlorine-tolerant varieties.

Despite being essentially water-free, nominally anhydrous minerals such as plagioclase and pyroxene represent the biggest reservoir of water in most lunar rocks due to their sheer abundance. Apatite, which incorporates F, Cl, and OH into its mineral structure as essential crystal components, on the other hand, is the only other volatile-bearing phase common in lunar samples. Here, we present the first coordinated study of volatiles (e.g., H2O, Cl, F, and S) in nominally anhydrous minerals combined with isotopic measurements in apatite from the ancient lunar basalt fragments from meteorite Miller Range (MIL) 13317. Apatite in MIL 13317 basalt contains similar to 2000 ppm H2O and has an elevated SD values (+ 523-737 parts per thousand), similar to Apollo mare basalts, but has high delta Cl-37 values (+ 29-36 parts per thousand), similar to apatite found in several KREEP-rich samples. MIL 13317 is unique compared with other lunar basalts; it has both elevated SD and delta Cl-37 values currently only observed in highlands sample 79215 (a granulitic impactite). Based on measurements of H2O in nominally anhydrous minerals and in apatite, the source magma of MIL 13317 basalt is estimated to contain similar to 130-330 ppm H2O. Assuming reasonable levels of partial melting of the lunar mantle and magmatic degassing during eruption of the basalt, the Moon contained at least one reservoir with < 100 ppm H2O, a delta D value of < 0 parts per thousand similar to carbonaceous chondrites, and extensively fractionated Cl isotopes prior to 4.332 Gyr, the crystallization age of the MIL 13317 basalt.

Large quantities of chlordecone-based insecticides were produced and used throughout the world. One of its most important uses was to control the damage caused by Cosmopolites sordidus in banana-growing regions. In the islands of Martinique and Guadeloupe, 18,000 ha of farmland are potentially contaminated. Despite the key role played by soil macrofauna in agroecosystems, there are currently no data on their contamination. The aim of this study was to explore the fate of chlordecone (CLD) and its transfer to different organisms of the soil food web. Seven species of invertebrates representing different taxonomic groups and trophic levels of the soil communities of Martinique were targeted and collected in six experimental banana fields, with a level of contamination within a range of values classically observed. Soil samples and macrofauna from the study sites were analysed for CLD and chlordecol (CLDOH) its main transformation product. The contamination of the soil fauna were related to delta 15N 15 N (trophic level), proportion of soil ingestion (diet) and types of epidermis (mucus or exoskeleton) in order to study the different mechanisms of macrofauna contamination. Presence of CLD and CLDOH could be quantified in all the soil organisms from contaminated fields. Results showed a significant relationship between the CLD contamination of detritivorous and the ash content of their faeces, suggesting that soil ingestion was the main contamination pathway. In contrast, the exoskeleton-bearing diplopod Trigoniulus coralinus and the soft-bodied earthworm Eudrilus eugeniae, both detritivores with a comparable diet, had similar contamination levels, suggesting that the type of tegument has little influence on bioaccumulation. At the scale of the entire trophic network, a significant relationship was uncovered between delta 15N 15 N values and CLD contamination of the fauna, therefore providing some in situ evidence for a bioamplification process along the soil food chain.

To optimize the use of chlorine saline soils commonly found in many coastal areas, ground granulated blast furnace slag (GGBS) and calcium carbide residue (CCR) were used in this study to stabilize/solidify these soils. This study aims at evaluating the suitability of GGBS-CCR as industrial by-products in improving the mechanical behaviors of chlorine saline soil in comparison with the use of Portland cement (PC) as a traditional binder. The optimal proportion of the binder was determined by the unconfined compressive strength, conductivity, and leaching characteristics. Moreover, the water stability coefficients, collapse coefficients and microscopic characteristics of the solidified soil were evaluated. The results reveal that when the ratio of GGBS to CCR in the binder is 4:1, the 28-day unconfined compressive strength reaches 4.53 MPa, and the leaching of chloride ions is reduced by 94.1 %. The excellent water stability and reduced collapsibility further indicate that GGBS-CCR is a preferable binder for solidifying saline soil compared to PC. Furthermore, microscopic analysis revealed that chloride ions in the saline soil were involved in the hydration reaction to form Friedel's salt.

In this study, the level of toxic metals and organochlorine pesticides (OCPs) in the simulated leachate of the soil of a cocoa farm and a nearby river was investigated. Potential mutagenic and genotoxic effects of the river and simulated leachate were evaluated using Ames Salmonella fluctuation assay (Salmonella typhimurium strains TA100 and TA98) and SOS chromotest (Escherichia coli PQ37), respectively. The level of copper, cadmium, arsenic, chromium, nickel, lead, and iron in both the simulated leachate and the river sample was higher than the allowable maximum standard. The concentration of total OCPs was 9.62 and 108.89 mu g/L in the river sample and simulated leachate, respectively. The concentrations of total hexachlorocyclohexanes and dichlorodiphenyltrichloroethane were significantly higher than the standards. Dichlorodiphenyltrichloroethane was the main pollutant in the two samples. Data from the Ames Salmonella fluctuation assay indicated that the tested samples were mutagenic. Similarly, the data from the SOS chromotest corroborate the Ames assay's result. In the E. coli PQ37 system, the two samples induced significant SOS response, an indication of genotoxicity. Comparing the two microbial assays, the E. coli PQ37 showed a slightly higher sensitivity than the Ames Salmonella assay for the detection of genotoxins in the present study. The chemical and organic constituents of the samples were believed to induce these reported genetic and mutagenic effects. These results showed the environmental pollution caused by the indiscriminate use of pesticides in cocoa farming and the potential effects the pollutants might have on exposed aquatic organisms and the human populace.

The extensive use of pesticides has led to the contamination of natural resources, sometimes causing significant and irreversible damage to the environment and human health. Even though the use of many pesticides is banned, these compounds are still being found in rivers worldwide. In this review, 205 documents have been selected to provide an overview of pesticide contamination in rivers over the last 10 years (2014-2024). After these documents were examined, information of 47 river systems was organized according to the types of pesticides most frequently detected, including organochloride, organophosphorus, and pyrethroid compounds. A total of 156 compounds were classified, showing that 46% of these rivers contain organochlorine compounds, while 40% exhibit organophosphorus pesticides. Aldrin, hexachlorocyclohexane, and endosulfan were the predominant organochlorine pesticides with concentration values between 0.4 and 37 x 105 ng L-1. Chlorpyrifos, malathion, and diazinon were the main organophosphorus pesticides with concentrations between 1 and 11 x 105 ng L-1. Comparing the pesticide concentrations with standard guidelines, we found that the Ganga River in India (90 ng L-1), the Owan and Okura Rivers in Nigeria (210 and 9 x 103 ng L-1), and the Dong Nai River in Vietnam (68 ng L-1) exceed the permissible levels of aldrin (30 ng L-1).

Freeze-thaw cycles and compactness are two critical factors that significantly affect the engineering properties and safety of building foundations, especially in seasonally frozen regions. This paper investigated the effects of freeze-thaw cycles on the shear strength of naturally strongly chlorine saline soil with the compactness of 85%, 90% and 95%. Three soil samples with different compactness were made. Size and mass changes were measured and recorded during freeze-thaw cycles. Shear strength under different vertical pressures was determined by direct shear tests, and the cohesion and friction angle were measured and discussed. Microstructure characteristic changes of saline soil samples were observed using scanning electron microscopy under different freeze-thaw cycles. Furthermore, numerical software was used to calculate the subsoil-bearing capacity and settlement of the electric tower foundation in the Qarhan Salt Lake region under different freeze-thaw cycles. Results show that the low-density soil shows thaw settlement deformation, but the high-density soil shows frost-heaving deformation with the increase in freeze-thaw cycles. The shear strength of the soil samples first increases and then decreases with the increase in freeze-thaw cycles. After 30 freeze-thaw cycles, the friction angle of soil samples is 28.3%, 29.2% and 29.6% lower than the soil samples without freeze-thaw cycle, the cohesion of soil samples is 71.4%, 60.1% and 54.4% lower than the samples without freeze-thaw cycle, and the cohesion and friction angle of soil samples with different compactness are close to each other. Microstructural changes indicate that the freeze-thaw cycle leads to the breakage of coarse particles and the aggregation of fine particles. Correspondingly, the structure type of soil changes from a granular stacked structure to a cemented-aggregated system. Besides, the quality loss of soil samples is at about 2% during the freeze-thaw cycles. Results suggest that there may be an optimal compactness between 90 and 95%, on the premise of meeting the design requirements and economic benefits. This study can provide theoretical guidance for foundation engineering constructions in seasonally frozen regions.

We compare the stable isotope compositions of Zn, S, and Cl for Apollo mare basalts to better constrain the sources and timescales of lunar volatile loss. Mare basalts have broadly elevated yet limited ranges in delta Zn-66, delta S-34, and delta Cl-37(SBC+WSC) values of 1.27 +/- 0.71, 0.55 +/- 0.18, and 4.1 +/- 4.0 parts per thousand, respectively, compared to the silicate Earth at 0.15, -1.28, and 0 parts per thousand, respectively. We find that the Zn, S, and Cl isotope compositions are similar between the low- and high-Ti mare basalts, providing evidence of a geochemical signature in the mare basalt source region that is inherited from lunar formation and magma ocean crystallization. The uniformity of these compositions implies mixing following mantle overturn, as well as minimal changes associated with subsequent mare magmatism. Degassing of mare magmas and lavas did not contribute to the large variations in Zn, S, and Cl isotope compositions found in some lunar materials (i.e., 15 parts per thousand in delta Zn-66, 60 parts per thousand in delta S-34, and 30 parts per thousand in delta Cl-37). This reflects magma sources that experienced minimal volatile loss due to high confining pressures that generally exceeded their equilibrium saturation pressures. Alternatively, these data indicate effective isotopic fractionation factors were near unity. Our observations of S isotope compositions in mare basalts contrast to those for picritic glasses (Saal and Hauri 2021), which vary widely in S isotope compositions from -14.0 to 1.3 parts per thousand, explained by extensive degassing of picritic magmas under high-P/P-Sat values (>0.9) during pyroclastic eruptions. The difference in the isotope compositions of picritic glass beads and mare basalts may result from differences in effusive (mare) and explosive (picritic) eruption styles, wherein the high-gas contents necessary for magma fragmentation would result in large effective isotopic fractionation factors during degassing of picritic magmas. Additionally, in highly vesiculated basalts, the delta S-34 and delta Cl-37 values of apatite grains are higher and more variable than the corresponding bulk-rock values. The large isotopic range in the vesiculated samples is explained by late-stage low-pressure vacuum degassing (P/P-Sat similar to 0) of mare lavas wherein vesicle formation and apatite crystallization took place post-eruption. Bulk-rock mare basalts were seemingly unaffected by vacuum degassing. Degassing of mare lavas only became important in the final stages of crystallization recorded in apatite-potentially facilitated by cracks/fractures in the crystallizing flow. We conclude that samples with wide-ranging volatile element isotope compositions are likely explained by localized processes, which do not represent the bulk Moon.