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Heavy metal contamination of soil has become one of the most important environmental problems worldwide. Heavy metals can affect growth and lead to changes in microbial community composition, which could influence the growth of crops in the soil. In this study, we conducted an experiment to investigate the distribution profile of heavy metals and bacterial communities in soil with the effects of slag and/or water on the top of the soil. Extra heavy metals, acting as selective pressure, led to the loss of sensitive taxa, with tolerant or less sensitive taxa being more abundant in the community. The results showed that the addition of slag on the top of soils did not change the diversity of bacteria but influenced the relative abundance of indigenous members in the community. Water addition, however, improved the homogeneity of the environment vertically in the soil, which consequently led to a lower variation in the bacterial community. This study mimicked the scenario of tailings and abandoned mines in nature, and aimed to study the effects of mines on the soil microbial community with the influence of precipitation on the distribution of heavy metals in the soil. With the effect of precipitation, the transportation of heavy metals in the slag may influence the local bacterial community and subsequently undermine the quality of soil for agriculture. These observations provide evidence of the effects of heavy metals on the soil around abandoned mines without any treatment. Mining causes both heavy metal and water pollution, which may lead to the accumulation of heavy metals in plants and agricultural production. Therefore, it is necessary to take care of tailings with proper procedures instead of exposing them to nature. [ABSTRACT FROM AUTHOR]

Purpose: The research examines the variation of soil erodibility index and physical characteristics due to iron placer mining activities and assesses the environmental impact of mining project by using MICOLD matrices. Methods: The research employed field samplings, laboratory analysis, and statistical analysis to study the variation of soil erodibility index and physical characteristics caused by iron placer mining activities. The study collected soil samples from the study area and conducted laboratory analysis to examine the physical and chemical properties of the soil. Statistical analysis was performed to analyze the data and identify the variation in soil erodibility index compared to natural conditions. Also, by modifying ICOLD matrices, environmental impact assessment of the project was evaluated. Results: The results of the paper indicate that there are significant differences between treated and untreated soils in terms of physical and chemical properties. The soil erodibility property (Ks) differs by −14.71% from natural conditions in top soils, although not significant statistically. In subsoil, Ks, clay, sand, Sp, Cu, Zn, Mn, Fe, and K differ significantly from untreated conditions (−43.38%, 35%, −15.07%, 5.28%, −192.50%, −242.55%, −101.86%, −333.34%, and −31.41%). The matrix of prediction and identification of the impacts related to the implementation of the mining project was created in two phases (construction phase and exploitation phase), the results of which show the total points in the construction phase and the exploitation phase have positive impacts and are equal to +71 and +171, respectively. Conclusions: The study examines the effects of iron placer mining operations on soil erosion characteristics and erodibility and suggests environmentally friendly solutions for minimizing the effects of mining on soil erosion. The research findings highlight the importance of considering physical characteristics of soils such as texture, infiltration, bulk density, and soil erodibility in evaluating the performance and efficiency of any project implemented on the Earth's surface. It emphasizes the need for designing well‐operated devices and structures with little environmental damage to promote eco‐innovation and green growth. The paper suggests that the environment is the most critical aspect of green surface mining, followed by efficiency and safety, and highlights the importance of microorganisms in mining environments and their role in constructing and producing primary succession for plant communities. [ABSTRACT FROM AUTHOR]

Background and aims: The addition of organic fertilizers and sheep slat manure have important effects on soil quality in alpine mining areas, but how they affect soil physicochemical properties and microorganisms is not yet known. Methods: The current study employed field-controlled experiments and high-throughput sequencing technology to investigate differences in soil physicochemical properties, microbial community structures, and diversity under four treatments: no fertilization (CK), 100% sheep manure (SM), a combination of 50% sheep manure and 50% commercial organic fertilizer (MF), and 100% commercial organic fertilizer (OF). Results: Aboveground biomass increased by 191.93, 253.22, and 133.32% under SM, MF and OF treatments, respectively, when compared to CK treatment. The MF treatment resulted in significantly higher soil total nitrogen, total phosphorus, organic matter, and available nitrogen content compared to other treatments. Soil total nitrogen content, total phosphorus content, organic matter, available nitrogen content and available phosphorus content were 211, 120, 380, 557, and 271% higher, respectively, under the MF treatment than the CK treatment. Different nutrient additions significantly influenced soil microbial community composition. The SM and MF treatments notably increased soil bacterial and fungal community Operational Taxonomic Units (OTUs) indices and Chao 1 indices, while nutrient addition had no meaningful effect on the Simpson indices for microbial communities. There was a highly significant positive correlation between aboveground biomass and observed soil nutrient content. Conclusion: The combined application of sheep manure and commercial organic fertilizer is more conducive to improving soil quality and enhancing plant productivity in alpine mining areas. [ABSTRACT FROM AUTHOR]

As a result of the mining activities carried out in the Jiu Valley, tailings dumps resulted. Currently, some of these tailing dumps are greened, some are inactive, and some of them are still active within operational exploitation perimeters. In order to capture the negative effects of these deposits, in this work an assessment of the degree of contamination will be carried out and the level of geo-accumulation of heavy metals will be determined in the soil in the area of the Old Funicular dump, an inactive one for about 12 years. The dump was formed following the deposition of tailings resulting from coal mining in the Uricani mine. The main purpose is to identify the types and concentrations of heavy metals present in the soil and determine the level of accumulation of these metals in a certain area. The study involved the collection of soil samples from 17 sampling points, followed by detailed chemical analyses to determine the concentrations of heavy metals present in the soil at the tailings dump. The results indicated variable levels of heavy metal contamination, with concentrations exceeding the normal value of these heavy metals in soil in certain areas. The geo-accumulation index (Igeo) was calculated to assess the degree of accumulation of each heavy metal in soil. The Igeo values obtained varied from slightly polluted to moderately polluted, suggesting a significant influence of mining activities on the soil in this area. The conclusions of the study emphasize the need to implement phytoremediation measures and continuous monitoring to prevent ecological and human health risks. [ABSTRACT FROM AUTHOR]

A number of species have developed detoxification strategies that allow them to accumulate high amounts of heavy metals in their tissues and grow despite a high heavy metal (HM) concentration in soils. Thus, they are considered hyperaccumulator or accumulator species, attractive for phytoremediation purposes. Families reported to contain a high number of hyperaccumulator species are Asteraceae, Euphorbiaceae, Rubiaceae, Fabaceae, Scrophulariaceae, Myrtaceae, Proteaceae, Caryophylaceae, and Tiliaceae. Indeed, the family Scrophulariaceae has a large extension, with Buddleja, Eremophila, Scrophularia, and Verbascum being some of the best-known genera containing species used for medicinal purposes. This review focuses on identifying the species used in folk medicine that belong to these four genera and can accumulate high concentrations of heavy metals (HMs). Additionally, the human health risks related to the consumption of HM hyperaccumulator species are discussed, as well as the feasibility of plant tissue culture to provide safe vegetal material for medicinal uses or to estimate the intrinsic potential of species for phytoremediation purposes. The following species have demonstrated the ability to accumulate HMs and grow in mine or HM-polluted soils, as well as use in traditional medicine: Buddleja asiatica, B. cordata, B. davidii, B. lindleyana, B. macrostachya, B. paniculata, B. scordioides, Eremophila latrobei, Scrophularia canina subsp. bicolor, S. ningpoensis, S. striata, Verbascum bombyciferum, V. olympicum, V. phrygium, and V. thapsus. In some of these species, antioxidant machinery has been proven to participate as a defense strategy against exposure to high HM concentrations. Consuming plants that accumulate high amounts of HMs has been described as a potential risk to human health. Plant tissue culture has also been established in a few of these species, whether to propagate or use them as a bioactive phytochemical source. Promoting safety and quality control related to the HM concentrations in the tissues of these plants used by populations for curative purposes is necessary. Further research must be carried out on several species for phytoremediation purposes. [ABSTRACT FROM AUTHOR]

This work aimed to explore safe techniques for the utilization of farmland surrounding mining areas contaminated with heavy metals—specifically cadmium (Cd) and lead (Pb)—in order to achieve food security in agricultural production. A potato variety (Qingshu 9) with high Cd and Pb accumulation was used as the test crop, and seven treatments were set up: control (CK), special potato fertilizer (T1), humic acid (T2), special potato fertilizer + humic acid (T3), biochar (T4), calcium magnesium phosphate fertilizer (T5), and biochar + calcium magnesium phosphate fertilizer (T6). The remediation effect of the combined application of different passivators on the accumulation of cadmium and lead in potatoes in the contaminated soil of a mining area was studied. The results showed that, compared with CK, all passivator treatments improved the physical and chemical properties of the soil and reduced the available Cd and Pb content in the soil and in different parts of potatoes. The T6 treatment yielded the most significant reduction in the available Cd and Pb content in the soil, the Cd and Pb content in the potato pulp, and the enrichment factor (BCF) and transfer factor (TF) of the potatoes. Compared with T4 and T5, the content of available Cd in the soil decreased by 1.22% and 4.71%, respectively; the soil available Pb content decreased by 3.13% and 3.02%, respectively; the Cd content in the potato pulp decreased by 68.08% and 31.02%, respectively; and the Pb content decreased by 31.03% and 20.00%, respectively. The results showed that the application of biochar combined with calcium magnesium phosphate fertilizer had a better effect in terms of reducing the available Cd and Pb content in the soil and the Cd and Pb content in the potato flesh compared to their individual application. Biochar and calcium magnesium phosphate fertilizer can synergistically increase the content of soil available nutrients and reduce the activity of heavy metals in the soil to prevent the transfer and accumulation of cadmium and lead to potatoes, as well as improve their yield and quality. The results of this study provide technical support for safe potato planting and agricultural soil management. [ABSTRACT FROM AUTHOR]

This work assessed the activity concentrations of 238U(226Ra), 232Th, and 40K and their associated radiological risks due to exposure to soil and consumption of food crops in Babban Tsauni artisanal gold mine, Gwagwalada, Nigeria, using the gamma spectrometry technique. The mean activity concentrations of 226Ra, 232Th, and 40K in the mine soil were 60.2 ± 9.9, 161.4 ± 16.2, and 664.6 ± 138.2, while they were 46.4 ± 4.9, 79.9 ± 39.3, 266.4 ± 185.4 for tubers and 46.9 ± 15.7, 100.5 ± 35.8, 311.4 ± 132.7 (Bq/kg) for grains, respectively. The results reveal that the activity concentrations of radionuclides in all samples exceeded the recommended values set by United Nations Scientific Committee on the Effects of Atomic Radiation (33, 45, and 420 Bq/kg) except 40K, which fell within the acceptable limit in all food crop sample types. Estimated results for radiological hazard parameters, radium equivalent, annual effective dose due to ingestion, and excess life cancer risk were within safe limits, while the annual effective dose due to external gamma radiation in soil and annual gonadal equivalent dose were significantly high in all investigated samples; these call for constant radiological monitoring. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate soil properties and Eragrostis tef (teff) growth on Technosols produced from coarse and fine coal wastes from Moatize Mine, Mozambique. The experiment was performed in triplicate in 30 L containers filled with different substrate conditions, composed of fine coal waste, coarse coal waste, agricultural soil, and sewage sludge as an organic matter source. The soil analyses included bulk density, available water capacity, permeability, and fertility. Plant growth was monitored for biomass production and plant tissue composition. All the substrates presented a good available water capacity and a proper drainage condition. Regarding soil fertility, there were shortages of potassium and boron in the substrates composed exclusively of coal wastes, which was reflected in the composition of the plant tissue. Even so, plant growth was statistically equivalent to the control in all conditions, except for the substrate produced exclusively with fine coal waste and sewage sludge, which presented a better performance. Technosols are an alternative for reducing the final mine waste volume, and Eragrostis tef is used as a means for land use after the mining process, with social gains, and as a tool in an ecological process for restoring coal mining sites. [ABSTRACT FROM AUTHOR]

In the context of mining applications and the increasing demand for high load-bearing soils, utilizing weak soils poses a significant challenge. This study investigates the effectiveness of geosynthetics in stabilizing weak soils through numerical modeling using Abaqus software (R2016X)and validation via laboratory model testing. We examined the impact of various geosynthetic lengths and embedment depths across three soil types: clay loam (ML), sand (SM), and well-graded sand (SW). Our results reveal that ML and SM soil types exhibit local shear failure, while SW soil types demonstrate general shear failure. Notably, the bearing capacity of soils increases with coarser particle sizes due to higher Meyerhof parameters, leading to soil failure at lower settlements. Optimal geotextile embedment depths were determined as H/B = 0.125 for ML soil, H/B = 0.250 for SM soil, and H/B = 0.5 for SW soil. Additionally, the effect of geotextile length on bearing capacity is more pronounced in ML soil, suggesting greater effectiveness in fine-grained soils. The optimal geotextile lengths for installation are approximately 1.5 times the width for ML soil, 1.0 times for SM soil, and 1.0 times for SW soil. We also found that SW soil typically fails at lower settlements compared to ML and SM soils. Consequently, geotextile placement at shallower depths is recommended for SW soil, where the soil experiences higher tension and pressure. These findings contribute to enhance soil stabilization and load management in mining geotechnics. [ABSTRACT FROM AUTHOR]

Fungal communities are important components of soil biology and play crucial roles in multiple ecosystem functions and services; therefore, they can be used as effective indicators of soil function in stockpiled reclamation soils. We profiled the fungal communities of seven stockpiles of different ages (0.5, 1.5, 2, 5, 7, 11, and 28 years old) at various soil depths (0–300 cm) in two oil sand extraction locations in northern Alberta. Fungal communities of the stockpiles differed from the communities in the nearby undisturbed reference soils. The differences with the reference soils were more pronounced for the oldest and some of the younger stockpiled soils. Similar to previous studies, there was a decrease in fungal richness and overall diversity with increasing stockpile depth. Furthermore, soil stockpiling generated a shift in the functional composition based on inferred fungal guilds and trophic modes. Ectomycorrhizal fungi decreased and saprotrophic fungi increased in the stockpiles relative to the reference soils. Such a shift may have important implications for ecosystem functions and services associated with fungal communities, such as litter decomposition and plant growth promotion, when these stockpiles are used to reclaim ecosystems. Our results align with previous research identifying the negative effects of stockpiling on soil microbial communities, shed light on the soil functions that may be affected by this disturbance and their consequences for ecosystem functioning, and reflect the high sensitivity of fungal communities to soil disturbances like stockpiling. [ABSTRACT FROM AUTHOR]

During the ongoing studies designed to examine the fungal diversity present within the abandoned and flooded Escádia Grande gold mine (Góis, Portugal), we repeatedly isolated several specimens belonging to a Penicillium species. Molecular phylogenetic analysis, coupled with morphological observations, positioned this fungus within subgen. Penicillium sect. Paradoxa, series Atramentosa, pinpointing its identity as Penicillium mexicanum (the first record for mining soils and the country). Given the limited research conducted on Penicillia isolated from similar environments, the species genome was sequenced utilizing the Oxford Nanopore® MinION™ methodology and studied through bioinformatic analysis. The obtained genome has a size of 29.62 Mb, containing a 47.72% GC content, 10,156 genes, with 44 rRNAs and 178 tRNAs/tmRNAs, providing the first genomic resource for this microorganism. Bioinformatic analysis allowed us to identify multiple genomic traits that can contribute towards this species survival in these extreme environments, including the presence of high levels of major facilitator transporters (MFS), Zn (2)-C6 fungal-type DNA-binding domains, P-loop containing nucleoside triphosphate hydrolases, specific fungal transcription factors and sugar transporters. Furthermore, putative advantageous metabolic traits, such as methylotrophy, assimilatory nitrate and sulfate reduction abilities, were also detected. In addition, the results also highlighted a strong genomic and metabolic organization and investment towards arsenic detoxification (transport and oxidation). Lastly, thirty-two putative biosynthetic gene clusters were predicted, including some with high similarity values to monascorubrin, nidulanin A, histidyltryptophanyldiketopiperazine/dehydrohistidyltryptophanyldiketopiperazine/roquefortine D/roquefortine C/glandicoline A/glandicoline B/meleagrine, YWA1 and choline. Overall, this study expands the current Penicillia knowledge from mining environments while also enhancing our understanding regarding fungal arsenic resistance. [ABSTRACT FROM AUTHOR]

Aim The aim of this study is to engineer Pantoea dispersa MSC14 into a strain capable of producing lycopene and to enhance its lycopene content. Methods and results Our laboratory isolated the strain P. dispersa MSC14 from petroleum-contaminated soil in a mining area. Whole-genome sequencing confirmed the existence of a carotenoid synthesis pathway in this strain. This study employed an optimized CRISPR/Cas9 system to perform a traceless gene knockout of the lycopene cyclase gene crtY and to overexpress the octahydrolycopene dehydrogenase gene crtI in the P. dispersa MSC14. This strategic genetic modification successfully constructed the lycopene-producing strain MSC14-LY, which exhibited a notable lycopene content with a biomass productivity of 553 μg of lycopene per gram dry cell weight (DCW). Additionally, the components of the lycopene fermentation medium were optimized using Plackett–Burman design and response surface methodology. The average lycopene content was increased to 5.13 mg g −1 DCW in the optimized LY fermentation medium. Through genetic engineering, P. dispersa MSC14 was transformed into a strain capable of producing lycopene, achieving a yield of 5.13 mg g−1 DCW after medium optimization. Conclusions Genetic engineering successfully transformed P. dispersa MSC14 into a strain capable of producing lycopene, achieving a yield of 5.13 mg g−1 DCW after medium optimization. [ABSTRACT FROM AUTHOR]

The present study holds significant implications, as it aims to investigate the comparative effect of biochar, zeolite, and bentonite minerals on the stabilization of Ni fractions, bioaccumulation, translocation indices, and the reduction in their absorption by pakchoi in smelter- and mine-contaminated soils. The results, which are of great interest, showed that the maximum fresh and dry biomasses of pakchoi were observed up to 28.21 and 18.43% for smelter-polluted soil and 61.96 and 67.90% for mine-contaminated soil amended with zeolite compared to the control. Applying zeolite increased pakchoi chlorophyll SPAD values 1.17-fold in smelter soil and 1.26-fold in mine-polluted soil. The highest Ni immobilization in smelter and mine soil was observed at 76.8 and 85.38% with the application of bentonite, which increased soil pH and CEC. The application of biochar, bentonite, and zeolite reduced the Ni residual, oxidizable, and acid-soluble fractions, but biochar and bentonite increased the reducible fraction of Ni in smelter soil. The highest reduction in Ni in the shoot and root was noted as 82.08 and 68.28% of smelter-polluted soil and 77.25 and 89.61% of mine-polluted soil with bentonite compared to control soil. Overall, it has been concluded that biochar, zeolite, and bentonite can be successfully used to mitigate the Ni concentration in smelter- and mine-polluted soil and reduce uptake by vegetable crops. [ABSTRACT FROM AUTHOR]

In this review, I examined the number, distribution, and metal concentrations of all known metal hyperaccumulator plants from Indonesia. In total, 72 hyperaccumulator taxa were found: 19 accumulated Ni, 42 accumulated Al, 7 accumulated Cu, 2 accumulated Zn, and 2 accumulated Co in addition to Ni. There were six hypernickelophores with greater than 1% foliar nickel and with potential for agromining. Less than 10% of the hyperaccumulator species were single island endemics, and only one had an endangered status. Given that many species were only recorded from locations with mining activity, conservation assessments and actions should urgently be undertaken. There are undoubtedly many more hyperaccumulators to be found across Indonesia that will be discovered with further inter‐disciplinary surveys. [ABSTRACT FROM AUTHOR]

Dry riverbeds can transport mining waste during torrential rain events, disseminating pollutants from mining areas to natural ecosystems. This study evaluates the impact of these mine wastes on soils, sediments, and runoff/pore water in the La Carrasquilla dry riverbed (southeastern Spain). An integrated approach utilizing geochemical and mineralogical techniques was employed, analyzing water, soil, and sediment samples from both the headwater and mouth of the riverbed. Soil profiles and pore water were collected at 30 cm, 60 cm, and 90 cm deep, alongside sediment and runoff water samples. The assessment of metal(loid) contamination focused on arsenic, cadmium, chromium, copper, iron, nickel, manganese, zinc, and lead, utilizing sequential extraction to evaluate metal partitioning across soil phases. Various pollution indices, including the contamination factor (Cf), pollution load index (PLI), potential ecological risk index (RI), and metal(loid) evaluation index (MEI), were employed to classify contamination levels. The highest level of contamination was reported in the headwater, which suggested anthropogenic activities linked to the presence of mining residues as the major source of metal(loid)s. However, an active deposition of As, Cd, Cu, Fe, Mn, and Zn was reported in the topsoil at the mouth. In the headwater, a quartz and muscovite-rich zone exhibited the highest Cf for Pb (1022), primarily bound to the soil residual fraction (62.8%). At the headwater and mouth, pore water showed higher concentrations of sulfate, Ca, Na, Cl, Mg, and Mn and higher salinity than acceptable limits for drinking water or irrigation established by the World Health Organization. Runoff-water metal concentrations surpassed established guidelines, with MEI values indicating significant contamination by cadmium (36.1) and manganese (19.0). These findings highlight the considerable ecological risk of Pb and underscore the need for targeted remediation strategies to mitigate environmental impacts in the Mar Menor coastal lagoon. [ABSTRACT FROM AUTHOR]

The blooming industrialization and urbanization is leading to increased mining operations. These intensified mining activities emit heavy metals into the environment, posing serious threats to ecosystems. Hence, this study focused on assessing heavy metal pollution in mining soil, utilizing mosses as bioindicators. The ecological risk, geo-accumulation factor, and contamination factor have been calculated to know the harmful effect of heavy metals on ecosystem. The study covered three distinct mining sites of eastern India within Odisha: Jajpur's Sukinda Valley (SP1, Cr), Keonjhar's Joda-Barbil (SP2, Fe and Mn), and Sundargarh's Koira-Joda (SP3, Fe). The collection of 48 soil samples through random sampling revealed significant variations in heavy metal concentrations. SP1 recorded Cr concentration of 6572 ± 445 mg/kg and Ni of 8042.47 ± 501.38 mg/kg, surpassing eco-toxicological levels. The storage site in SP2 exhibited the highest Fe concentration at 9872 ± 502 mg/kg, and Mn levels in SP3 were at 7884 ± 432 mg/kg. Storage areas in all three regions held the highest concentrations of heavy metals. Mosses in studied area demonstrated as potential bioindicators for monitoring heavy metal pollution. EF and Igeo assessments showed Cd, Pb, Hg, and other heavy metal contamination compared to earlier investigations. This study indicated higher ecological risks for Pb, As, Cu, Ni, and Zn. The Hyophila involuta accumulates Mn, Cr, Cd, Pb, Fe, and Hg, while Barbula arcuata accumulates Mn, As, and Cu in SP1. Hyophila involuta and Trematodon longicollis accumulate Mn, Cr, Cd, Pb, Fe, Hg, and Zn in SP2. Trematodon ambiguous accumulates Cd, Fe, and Ni, while Fissidens diversifolius accumulates Mn, Cr, Hg, As, Cu, and Zn in SP3. These findings emphasize the necessity of monitoring heavy metal pollution in contaminated zones using moss as a potential bioindicator. [ABSTRACT FROM AUTHOR]

Active vegetation restoration plays an important role in the improvement in soil organic matter (SOM), including the carbon (C), nitrogen (N) and phosphorus (P) sequestration of degraded mining ecosystems. However, there is still a lack of understanding of the key drivers of SOM pool size and dynamics in active vegetation restoration. For this study, soil was collected from five different sites (Xiaoxian, Dingyuan, Chaohu, Tongling and Dongzhi), four habitats (platforms, slopes, steps and native areas) and two soil layers (0–20 cm and 20–40 cm) in limestone mines of Anhui province to quantify the spatial distribution of SOM contents and their stoichiometric characteristics and influential factors. It was found that the top soil in Chaohu had the highest significant C, N and P contents in the ranges of 14.95–17.97, 1.74–2.21 and 0.80–1.24 g/kg, respectively. Comparing the stoichiometric ratios of the different sites revealed significant differences in C:N and N:P ratios, but C:P ratios were relatively consistent. In particular, the C:N and C:P ratios in deep soil were higher than those in top soil, whereas the N:P ratio in deep soil was lower than that in top soil, suggesting that soil N is a major limiting factor in the top soil. The SOM content did not differ significantly between the three reclaimed habitats, but was significantly higher than that in the native habitat, suggesting that mine restoration has significantly enhanced SOM accumulation. Further analysis showed that nutrient availability and enzyme activity are important factors affecting soil C, N and P content in top soil, while the relationship gradually weakens in deep soil. This was attributed to active anthropogenic management and conservation measures during the early stages of reclamation. This study shows that the ecological recovery of the mining area can be enhanced by implementing differentiated vegetation planting strategies and anthropogenic management on different habitats in the mining area. [ABSTRACT FROM AUTHOR]

The premature failure or early deterioration of mine haul roads due to increasing problems of overrutting, potholes, and excessive settlement is a major issue. These problems mainly arise from the mismatch of overburden soil strength and stresses exerted by moving dumpers, inadequate compaction of soil, and improper assessment of the load–deformation characteristics of overburden soil under repeated loading. In the past, several research studies have been conducted; however, most of the studies are related to the geotechnical characterization and stabilization of mine overburden soil. In this study, the deformation characteristics, i.e., plastic and resilient deformations, of an overburden soil extracted during mining operations have been addressed, taking into account the influence of varying compaction densities, cyclic deviatoric stress, and loading frequencies. Compaction density notably affects soil strength, with 5.82% and 16.4% increases in density resulting in 23%–48% and 297%–410% strength gains, respectively. Meanwhile, cyclic deviatoric stress and confining pressure primarily influenced the axial strain behavior of mine overburden soil subjected to cyclic loading. At higher compaction densities, higher resilient modulus values were obtained. For a confining pressure of 48 kPa, increases of 5.82% and 16.4% in compaction density resulted in an increase in the resilient modulus by 32.6%–48.9%, 36.5%–67.6%, and 73%–201.3%, for increasing levels of cyclic deviatoric stress. The plastic deformations obtained were also notably high. Thus, mine overburden soils with high resilient modulus values can still experience premature failure, owing to the significant accumulation of plastic strain under high repeated deviatoric stresses. From the analysis of test results, three-parameter strain models have also been developed as a function of the number of load repetitions and the applied cyclic deviatoric stress to predict the rutting phenomenon in overburden soil at different compaction densities, applied cyclic deviatoric loads, and loading frequencies. [ABSTRACT FROM AUTHOR]

While tire wear particles (TWP) have been estimated to represent more than 90% of the total microplastic (MP) emitted in European countries and may have environmental health effects, only few data about TWP concentrations and characteristics are available today. The lack of data stems from the fact that no standardized, cost efficient or accessible extraction and identification method is available yet. We present a method allowing the extraction of TWP from soil, performing analysis with a conventional optical microscope and a machine learning approach to identify TWP in soil based on their colour. The lowest size of TWP which could be measured reliably with an acceptable recovery using our experimental set-up was 35 µm. Further improvements would be possible given more advanced technical infrastructure (higher optical magnification and image quality). Our method showed a mean recovery of 85% in the 35–2000 µm particle size range and no blank contamination. We tested for possible interference from charcoal (as another black soil component with similar properties) in the soils and found a reduction of the interference from charcoal by 92% during extraction. We applied our method to a highway adjacent soil at 1 m, 2 m, 5 m, and 10 m and detected TWP in all samples with a tendency to higher concentrations at 1 m and 2 m from the road compared to 10 m from the road. The observed TWP concentrations were in the same order of magnitude as what was previously reported in literature in highway adjacent soils. These results demonstrate the potential of the method to provide quantitative data on the occurrence and characteristics of TWP in the environment. The method can be easily implemented in many labs, and help to address our knowledge gap regarding TWP concentrations in soils. [ABSTRACT FROM AUTHOR]

Microbially Induced Calcite Precipitation (MICP) has emerged as a promising technique for bio-cementation, soil improvement, and heavy metal remediation. This study explores the potential of Bhargavaea beijingensis, a urease-producing bacterium, for these applications. Six ureolytic bacteria were isolated from calcareous bricks mine soil and screened for urease and calcite production. B. beijingensis exhibited the highest urease activity and calcite precipitation. Urease activity, calcite precipitation, sand solidification, heavy metal removal efficiency, and compressive strength were evaluated. It showed significant heavy metal removal efficiency, particularly highest for HgCl2. Mortar blocks treated with B. beijingensis or its crude enzyme exhibited improved compressive strength, suggesting its potential for bio-cementation. Crack remediation tests demonstrated successful crack healing in mortar blocks using the bacterium or its enzyme. This study identifies B. beijingensis as a novel and promising MICP agent with potential applications in bio-cementation, soil improvement, and heavy metal remediation. Hence, B. beijingensis diversified abilities prove superior performance compared to commonly used strains like Bacillus subtilis and Shewanella putrefaciens in bio-cementation applications. Its high urease activity, calcite precipitation, and heavy metal removal abilities make it a valuable candidate for sustainable and eco-friendly solutions in various fields. [ABSTRACT FROM AUTHOR]

Purpose: This is a retrospective study of one-stage anterior sagittal sphincter saving anorectoplasty (ASSSARP) for repairing rectovestibular fistula (RVF) including operative details and postoperative complications, functional and cosmetic outcome. Patients and methods: Records of 41 cases of RVF, managed between April 2010 and September 2019 by one-stage ASSSARP, were reviewed. Preoperative preparation, both early and late postoperative care & complications, hospital stay, and functional & cosmetic outcomes were reported. Results: The mean age was 6.6 months. Vaginal tear occurred in 5/41 cases, and distal rectal tears in 4/41 cases. Thirteen patients suffered mild superficial wound inflammation; while Skin dehiscence; occurred in five patients. No colostomy or redo was needed. The mean hospital stay was 6.1 days. Mean follow-up was 43.13 months; (Range; 24–100 months). Subclinical anal stricture was detected in six patients. Constipation occurred in 14 cases. Soiling grade I occurred in five patients. Thirty-two patients reached past the age of three years; two of whom showed cough/diarrhea incontinence. Conclusion: One-stage ASSSARP is safe and gives functional and cosmetic results comparable to other techniques. It provides better access during RVF repair. The avoidance of muscle incision protects against muscle breakdown, if infection sets in, and thus against incontinence. It avoids the morbidity, cost and psychological burden of performing a three-stage repair. [ABSTRACT FROM AUTHOR]

Plant–soil interactions of endangered species with a high-priority conservation status are important to define in situ and ex situ conservation and restoration projects. The threatened endemic Coincya transtagana, thriving in the southwest of the Iberian Peninsula, can grow in metalliferous soils. The main goal of this study was to investigate the behavior of this species in soils rich in potentially toxic elements in the abandoned Aparis Cu mine. Soil samples were characterized for physicochemical properties and multielemental composition, as well as biological activity, through an analysis of enzymatic activities. Plant biomass was assessed, and multielemental analysis of the plants was also performed. The mine soils had slightly basic pH values and were non-saline and poor in mineral N-NH4, with medium-to-high organic matter concentration and medium cation-exchange capacity. In these soils, dehydrogenase had the highest activity, whereas protease had the lowest activity. The total concentrations of Cu (1.3–5.9 g/kg) and As (37.9–118 mg/kg) in soils were very high, and the available fraction of Cu in the soil also had high concentration values (49–491 mg/kg). Moreover, this study shows for the first time that C. transtagana had high uptake and translocation capacities from roots to shoots for Cu, Ni, and Cr. Although Cu in the plants' aerial parts (40–286 mg/kg) was considered excessive/toxic, no signs of plant toxicity disorders or P uptake reduction were detected. This preliminary study revealed that C. transtagana is Cu-tolerant, and it could be used for phytoremediation of soils contaminated with potentially toxic elements, while also contributing to its conservation. [ABSTRACT FROM AUTHOR]

In this article, a numerical calibration procedure for undrained cyclic triaxial tests is presented to evaluate the liquefaction potential in sand and silt samples from mining tailings in northern Chile. The numerical modeling of an axisymmetric specimen involved two stages: isotropic consolidation using the Hardening Soil Small (HSS) model and a cycling phase employing the UBC3D-PLM model to simulate the onset of liquefaction using the criterion that the excess pore pressure ratio R u should exceed 0.8. The results demonstrate that the UBC3D-PLM modeling calibrated with experimental data from cyclic triaxial tests effectively represents the excess pore pressure in both sandy and silty soils from mining tailings. The accuracy of the modeling decreases when a single set of parameters is applied to the same soil at different cyclic stress ratios (CSR), highlighting the need for specific calibrations for each loading. [ABSTRACT FROM AUTHOR]

At this time in Indonesia, much illegal sand mining is negatively impacting the environment. One area where many Illicit mining activities are found is the Gantar area and its surroundings, West Java Province. Sand mining activities using an open pit mining system. The open pit mining system degrades soil quality by mining sand. This study uses laboratory analysis by measuring the physical, chemical, and mineralogy of soils. The purposive sampling method is used to sample post-mining ex-sand mining soil samples in Gantar District, West Indramayu Regency, West Java Province. Physical soil quality measurement is characterized by increased bulk density, particle density, fine fractions (clay and silt), and decreased porosity and permeability. Chemical examination showed a decrease in C-organic, N-organic, P, and K concentrations (available) and base saturation; however, the CEC level increased. The results showed that sand mining activities have degraded soil quality in the former sand mining area in Gantar District, West Java, Indonesia. This research makes a major contribution to policymakers to pay attention to post-mining activities so that the decline in soil quality can be avoided. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) in temperate forests is a crucial part of the global C cycle. The C and nitrogen (N) inputs may greatly increase in forest ecosystems affected by atmospheric CO2 concentration, N deposition, and other climate change, which may further affect SOC dynamics in temperate forests. Nevertheless, how C and N inputs interact to influence the soil priming effect (PE) in the organic and mineral layers of temperate forests remains unclear. Here, we used easily available C and N sources, such as 13C‐glucose with 2% SOC contents and ammonium nitrate (input C:N ratio = 10), to examine the effects and mechanisms of exogenous C and N inputs on soil CO2 production and PE in both soil layers of a temperate forest. Our research revealed that exogenous C input caused a positive PE in both soil layers, with the mineral layer showing a larger PE per unit of SOC than the organic layer (OL). Although C input increased C loss from native SOC, soil net C accumulation still increased. The C and N inputs decreased the soil PE in both soil layers, suggesting that N input alleviates substrate N limitation and weakens microbial N mining in both soil layers. Meanwhile, the C and N inputs increased the exogenous C remaining in the organic layer, which was beneficial for soil C sequestration. Compared to the organic layer, the response of the mineral layer to C and N inputs was weaker. This study suggests that C and N interact to affect PE on SOC decomposition and this interaction should be considered in modeling and prediction of soil C cycling. [ABSTRACT FROM AUTHOR]

Evaluating the impact of vegetation types and reclamation methods on soil organic carbon and nitrogen in carboniferous spoil heaps is critical for selecting the best vegetation type and reclamation method to improve ecosystem services in a changing climate. This paper presents the relationship between vegetation types (woodland, forbland, and grassland) and reclamation techniques (barren rock, topsoil application, succession, and cultivation) on soil organic carbon (SOC) and total nitrogen (TN) in developing soils on carboniferous rocks in coal mine heaps. Soil samples were collected from the litter layer (Oi + Oe) and the A horizons (0–10 cm). The results revealed that vegetation types and reclamation methods significantly affected SOC and TN stocks. Woodland exhibited higher SOC and TN in the Oi + Oe horizons than other vegetation types. Topsoil application and cultivation resulted in the highest SOC and TN stocks in the A horizons (0–10 cm) under woodland and forbland compared to succession on bare carboniferous rock. In grassland, there was no significant difference in SOC stock under topsoil application and cultivation; however, significantly higher TN stock was observed in the 0–10 cm areas with topsoil application compared to succession on bare carboniferous rock. Based on the results, topsoil application is recommended to improve SOC if the mining site is restored using woodland. Conversely, grassland exhibits a similar amount of SOC stock with or without topsoil application. Considering the difficulty of obtaining topsoil, we suggest that grasses are optimal for SOC stock in the studied mining sites, followed by forbs. [ABSTRACT FROM AUTHOR]

Soil is a crucial component in achieving sustainable development goals due to its significant role in addressing environmental challenges. It is essential to differentiate soils that have similar management requirements. This necessity has prompted soil scientists to employ numerical classification models to categorize soils based on their similarities. In this study, we utilized two types of clustering models, traditional and modern, to classify soils from certain areas of the Qazvin Plain. Using one-way and two-way clustering models, we grouped 297 soils from the region based on a comprehensive set of their morphological, physicochemical, and environmental attributes. The classifications derived from these two models were assessed using internal and external evaluation indicators, with the distribution map of soil subgroups serving as a ground truth reference map. The results indicated that the hierarchical clustering model, with a lower Davis-Bouldin index (DB: 1.38) and a higher adjusted Rand index (ARI: 0.49), outperformed the biclustering model. However, the classifications from the bidirectional clustering model corresponded reasonably well with the topographical and soil changes in the region, as evidenced by the higher Shannon’s difference index in the bidirectional clustering model (1.82) compared to the hierarchical clustering model (1.62). Overall, the study’s findings underscore the utility of the co-clustering model as a contemporary data mining technique for soil classification and identification of soil management similarity patterns. [ABSTRACT FROM AUTHOR]

The non‐Lambertian surface features varying particle size and discrete distribution, resulting in reflectance to be unevenly distributed in different directions. Mine soil with a high content of coarse particles and non‐uniform particle distribution exhibits significant non‐Lambertian properties on its surface. Consequently, not only vertical observation of the reflectance spectra but also multi‐angle reflectance spectra are related to the physical and chemical properties (e.g. soil organic carbon, moisture content and particle size) of mine soil. Understanding the bidirectional reflectance distribution of mine soil with various particle sizes is essential for accurately estimating soil properties using spectroscopy. Current estimations of soil properties using spectroscopy mainly focus on vertical observations, overlooking the bidirectional reflectance characteristics. This study reports the bidirectional reflectance distribution of mine soil with various particle sizes. Furthermore, the performance of different bidirectional reflectance distribution function (BRDF) models in simulating the bidirectional reflectance of mine soil with various particle sizes was evaluated. Soil samples from three typical mine areas were collected and sieved into seven particle sizes ranging from 25 to 3500 μm. The bidirectional reflectance in the Vis–NIR wavelength region was measured in a laboratory using the Northeastern University bidirectional reflectance measurement system. The performance of five BRDF models (isotropic multiple scattering approximation, anisotropic multiple scattering approximation, H2008, H2012 and SOILSPECT) in modelling the bidirectional reflectance distribution of mine soil with different particle sizes was compared. Sobol's sensitivity indices were used to quantify the contributions of the parameters in the BRDF models. The results showed that (1) small mine soil particles (25 μm) exhibited greater reflectance than large particles (3500 μm). Large particles (3500 μm) exhibited backward scattering, whereas small particles (25 μm) exhibited extremely forward scattering characteristics because of the high silicon dioxide content; (2) the SOILSPECT model outperformed the other BRDF models in simulating the bidirectional reflectance of mine soil and had the smallest root mean square error (0.004–0.04); (3) the single‐scattering albedo (ɷ) parameter had the greatest contribution in the SOILSPECT model. Four parameters in the phase function (b, b′, c and c′) effectively indicated the scattering behaviour of mine soil with different particle sizes. These findings improve our understanding of the scattering characteristics of mine soil with various particle sizes and can be used to improve the accuracy of extracting particle size and other soil properties from mine soil. [ABSTRACT FROM AUTHOR]

Although molecular characterization of soil organic carbon is crucial for understanding its dynamics, studies on reclaimed coal mine soil are comparatively limited. Therefore, the primary objective of this study was to ascertain the influence of tree species on the soil organic carbon content and molecular characteristics of soil organic carbon in a chronosequence of reclaimed coal mine soil. To investigate the effects of reclamation time on soil organic carbon characteristics, a chronosequence of three coal mine soil was used, each exhibiting different ages of reclamation: 8, 14, and 25 years. Along a re-vegetation age gradient of 8 to 25 years, the total soil organic carbon content increased. Within the 25 years of restored soil, the FTIR absorption intensities were lowest within the range of 2,920 and 2,850 cm−1, while they were highest within the range of 1,685, 1,425, and 1,285 cm−1which indicates presence of aromatic C=C. This shows that aromatic compounds contributed more significantly to the composition of soil organic carbon compared to aliphatic structures. Based on molecular characteristics, it is suggested that the soil organic carbon in 25-year old revegetated coal mine soil consists of aromatic and recalcitrant carbon. Among three tree species Dalbergia sissoo can be used for reclamation as quality and quantity of carbon found was higher under this tree species. In conclusion, the results indicated that the molecular properties of soil organic carbon were extremely important for understanding the dynamics of soil organic carbon in a restored coal mine soil chronosequence. [ABSTRACT FROM AUTHOR]

The transfer of arsenic (As) from soil to plant could be significantly influenced by soil parameters through regulating soil As bioavailability. To distinguish the bioavailable As provided by soil and the As uptaken by plants, herein two different soil bioavailable were defined, namely potential soil bioavailable As (evaluated through the bioavailable fraction of As) and actual soil bioavailable As (assessed through plant bioaccumulation factor, BF, and BFavailable). To identify the dominant soil parameters for the two soil bioavailable As forms, soil and plant samples were collected from a former As mine site. The results showed that the potential bioavailable As only accounted for 1.77 to 11.43% in the sampled soils, while the BF and BFavailable in the sampled vegetables ranged from 0.00 to 1.01 and 0.01 to 17.87, respectively. Despite a similar proportion of As in the residual fraction, soil with higher pH and organic matter (OM) content and lower iron (Fe) content showed a higher potential soil bioavailable As. Correlation analysis indicated a relationship between the soil pH and potential soil bioavailable As (r = 0.543, p < 0.01) and between the soil Fe and actual soil bioavailable As (r = − 0.644, p < 0.05, r = − 0.594, p < 0.05). Stepwise multiple linear regression (SMLR) analysis was employed to identify the dominant soil parameters and showed that soil pH and phosphorus (P) content could be used to predict the potential soil bioavailable As (R2 = 0.69, p < 0.001). On the other hand, soil Fe and OM could be used to predict the actual soil bioavailable As (R2 = 0.18–0.86, p < 0.001–0.015, in different vegetables). These results suggest that different soil parameters affect potential and actual soil bioavailable As. Hence, soil Fe and OM are the most important parameters controlling As transfer from soil to plant in the investigated area. [ABSTRACT FROM AUTHOR]

Turning the dirt, we have cultivated back into soil is critical to securing our planetary future. The world’s principal existential challenges – food, water and energy security, climate change abatement, biodiversity protection and human health1 – are all underpinned by soil dysfunction. Yet, little is known about soil function, soil services and threats to soil, or how the state of our soils, determined by land use and land management, cause desertification and climate change. As greenhouse gases are transparent to incoming solar radiation, we must mitigate excess atmospheric heat by reducing the amount of organic matter mined from the soil, because when the sun’s rays fall on exposed, drained, baked dry soil, most of the solar radiation is converted from latent heat to sensible heat. Soil specific policy and legislation must be developed to regulate sources of excess sensible heat, consistent with limiting global temperature rise to 1.5°C above pre-industrial levels. Through soil security, we can deliver a better present and safeguard our planetary future. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effect of detoxifying substances on U(VI) removal by bacteria isolated from mine soil. The results demonstrated that the highest U(VI) removal efficiency (85.6%) was achieved at pH 6.0 and a temperature of 35 °C, with an initial U(VI) concentration of 10 mg/L. For detoxifying substances, signaling molecules acyl homoserine lactone (AHLs, 0.1 µmol/L), anthraquinone-2, 6-disulfonic acid (AQDS, 1 mmol/L), reduced glutathione (GSH, 0.1 mmol/L), selenium (Se, 1 mg/L), montmorillonite (MT, 1 g/L), and ethylenediaminetetraacetic acid (EDTA, 0.1 mmol/L) substantially enhanced the bacterial U(VI) removal by 34.9%, 37.4%, 54.5%, 35.1%, 32.8%, and 47.8% after 12 h, respectively. This was due to the alleviation of U(VI) toxicity in bacteria through detoxifying substances, as evidenced by lower malondialdehyde (MDA) content and higher superoxide dismutase (SOD) and catalase (CAT) activities for bacteria exposed to U(VI) and detoxifying substances, compared to those exposed to U(VI) alone. FTIR results showed that hydroxyl, carboxyl, phosphorus, and amide groups participated in the U(VI) removal. After exposure to U(VI), the relative abundances of Chryseobacterium and Stenotrophomonas increased by 48.5% and 12.5%, respectively, suggesting their tolerance ability to U(VI). Gene function prediction further demonstrated that the detoxifying substances AHLs alleviate U(VI) toxicity by influencing bacterial metabolism. This study suggests the potential application of detoxifying substances in the U(VI)-containing wastewater treatment through bioremediation. [ABSTRACT FROM AUTHOR]

Priming effects of soil organic matter decomposition are critical to determine carbon budget and turnover in soil. Yet, the overall direction and intensity of soil priming remains under debate. A second‐order meta‐analysis was performed with 9296‐paired observations from 363 primary studies to determine the intensity and general direction of priming effects depending on the compound type, nutrient availability, and ecosystem type. We found that fresh carbon inputs induced positive priming effects (+37%) in 97% of paired observations. Labile compounds induced larger priming effects (+73%) than complex organic compounds (+33%). Nutrients (e.g., N, P) added with organic compounds reduced the intensity of priming effects compared to compounds without N and P, reflecting "nutrient mining from soil organic matter" as one of the main mechanisms of priming effects. Notably, tundra, lakebeds, wetlands, and volcanic soils showed much larger priming effects (+125%) compared to soils under forests, croplands, and grasslands (+24...+32%). Our findings highlight that positive priming effects are predominant in most soils at a global scale. Optimizing strategies to incorporate fresh organic matter and nutrients is urgently needed to offset the priming‐induced accelerated organic carbon turnover and possible losses. [ABSTRACT FROM AUTHOR]

The reuse of heavy-metal hyperaccumulator waste has emerged as a critical constraint in the implementation of phytoremediation to control heavy-metal pollution. Ramie (Boehmeria nivea) is a well-established arsenic (As) hyperaccumulator that has been widely used in the remediation of As-contaminated sites in recent years. To facilitate multipurpose development and the recycling of ramie straw contaminated with heavy metals, a study investigated the preparation of hydrochar (HC) at different temperatures and assessed the feasibility of reintroducing the HC into the soil. The results indicated higher yields, increased nutrient contents, and reduced As percentage levels at a hydrothermal carbonization temperature of 240°C. Treatment with a 300 mmol/L sodium hydroxide solution resulted in the removal of As from HC, ranging from 77.06% to 87.60%, effectively facilitating the reuse of HC. The application of alkali-modification HC in As-contaminated soil not only enhances soil properties but also augments the potential population of dominant microorganisms that promote soil arsenic mobilization, thereby improving arsenic mobilization capacity in mining soil. This study offers a viable strategy for enhancing the phytoremediation efficiency of As-contaminated soil and establishing a recycling system for As hyperaccumulator resources in the future. [ABSTRACT FROM AUTHOR]

Lack of knowledge on phosphorus transport and retention in soils amended with polyaluminium chloride and anionic polyacrylamide water treatment residuals (PAC-APAM WTRs) makes it challenging to effectively utilize these materials as amendments in traditional soil-based media for stormwater bioretention systems to mitigate phosphorus pollution. This study investigated the impact of initial phosphorus concentration (C0), pH, and flow rate on phosphorus transport and retention in columns of three soil types amended with PAC-APAM WTRs under saturated hydraulic conditions. Results demonstrate that increasing C0 led to a decrease in the retardation factor (Rf) from 30.05 to 26.87, 12.64 to 9.10, and 12.27 to 6.68 in Soil 1 and PAC-APAM WTRs columns, Soil 2 and PAC-APAM WTRs columns, and Soil 3 and PAC-APAM WTRs columns, respectively. Similarly, increasing flow rate resulted in a decrease in Rf from 22.81 to 9.01, 11.14 to 4.74, and 16.13 to 7.57 in the respective columns. The adsorbed phosphorus mass per gram of media increased from 6.4 to 7.2 in Soil 1 and PAC-APAM WTRs columns and 7.6 to 9.8 in Soil 2 and PAC-APAM WTRs columns with increasing C0, but decreased from 16.3 to 8.0, 11.0 to 5.3, and 8.7 to 4.8 in the respective columns with increasing flow rate. No obvious trend was observed regarding the impact of pH on Rf and the adsorbed phosphorus mass. Future research should aim to elucidate the underlying mechanisms governing the comprehensive effects of C0, pH, and flow rate on phosphorus transport under field conditions. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the open‐cast mining activities, a large area in the Lusatian region in eastern Germany was left unproductive. Robinia pseudoacacia L. was planted within different ages in that large area as a short rotation coppice for woody biomass cultivation as well as to increase soil nutrients by increasing plant phosphorous (P) availability, accumulating organic matter input and biological nitrogen fixation. In this experiment, soil chemical analysis has been done to investigate the improvement and status of P in the mining soil depending on the ages of plantation (16, 17, 18, and 27 years old) of Robinia pseudoacacia L. The results show a higher P sorption in the oldest site, and the average P sorption capacity (PSC) obtained in the oldest site was 21.0 mmol Kg−1, which was 3–4 times higher than the youngest site. However, all the values were very low compared with the optimum plant growth level, and low P desorption indicates a low level of plant‐available P in the soil. The lower sorption properties with the small amount of oxalate iron (Feox) and oxalate aluminum (Alox) indicate the general P deficiency in the soil. However, a comparison from a previous study on the same experimental areas shows that not much improvement has occurred in soil P, and the change in soil P dynamics is very low. Nevertheless, the improvement of the values with increasing ages of Robinia pseudoacacia L. indicates that further improvement may be expected in soil nutrients with time. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge of remediating soil impacted by acid mine drainage (AMD) using an innovative and sustainable Technosol‐based approach to stabilize soil and facilitate vegetation recovery. The study assessed the effectiveness of Technosols made from recycled organic (water clarification sludge) and inorganic (siderurgical slags and red gypsum) wastes in mitigating the detrimental effects of AMD on soil properties, pore water chemistry, and plant growth through a 4‐month pot experiment. Technosols significantly improved soil health by neutralizing net acidity (296 mmol H+ kg−1), raising pH levels from extremely acidic (3.3) to mildly alkaline (7.7–8.0), and limiting the mobility of potentially toxic elements (PTEs). Dissolved Cu and Zn concentrations dropped from 80.21 and 72.08 mg L−1, respectively, to below 1 mg L−1 by the end of the monitoring period. The experiment identified several concomitant mechanisms of PTE retention, such as decreased dissolution of metal‐bearing minerals, precipitation reactions and adsorption onto Fe and Al (oxy)hydroxides. Aqueous speciation modelling indicated a decline in toxic metal forms (e.g. Al3+, AlSO4+, Cu2+, Zn2+ and H2AsO4−) in soil pore water after treatment, thus reducing phytotoxicity. Additionally, waste amendments enhanced nutrient availability, with nitrate concentrations reaching up to 417 mg L−1, supporting seed germination and seedling establishment. The most effective Technosol, combining water treatment sludge and white steel slag (60:40 w/w), enabled robust growth of Brassica juncea. Principal component analysis showed a strong correlation between healthy plant responses (survival rate, plant height, leaf number, biomass production) and improved soil pore water parameters (pH, PTEs, aluminium, calcium, bicarbonate and nitrate ions), highlighting the benefits of waste amendments. These findings underscore the potential of waste‐derived Technosols in stabilizing AMD‐impacted soils and promoting thriving plant growth. However, further validation in field trials with diverse plant species is recommended for real‐world applications. [ABSTRACT FROM AUTHOR]

To explore the effects of nitrogen (N) and phosphorus (P) nutrient gradients on morphological characteristics and biomass of fine root (≤2 mm) of plant surface layer (0-10 cm) in new coastal reclamation areas, Ligustrum lucidum was used as the test material and the fertilization method of ingrown soil cores (volume 196.25 cm³) was used to conduct nitrogen and phosphorus addition experiments on the soil core of the soil surface layer (0-10 cm) of L. lucidum. Suppose the fertilization gradient was 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 20 g per hole. The effects of N and P nutrients on the functional traits of fine roots in the soil surface were studied. The results were as follows: (1) Compared with the control, when 3 g N was applied, the length, surface area, volume, root length density, root surface area density, and biomass of fine roots increased significantly, with the increases of 62.39%, 120.87%, 169.97%, 59.19%, 106.99% and 102.75%, respectively; when 5-11 g N was applied, the above indicators gradually decreased. When the amount of N was applied greater than 11 g, no root grew. (2) When 3 g P was applied, the total length, surface area, volume, root length density, root surface area density and biomass of the root system significantly increased, with the increases of 77.37%, 111.15%, 147.50%, 73.87%, 97.88% and 98.05%. When the amount of P was applied greater than 5 g, the above indicators of fine roots gradually decreased, but there was no rootless situation. Fertilization caused significant changes in the morphological indicators and biomass of fine roots, and plants improved the ability to acquire soil nutrients by changing the structure of fine roots. Therefore, applying 3 g of Nor P respectively to the surface soil 1 m away from the trunk significantly can promote the growth of fine roots of L. lucidum. [ABSTRACT FROM AUTHOR]

Toxic element concentrations including As, Hg, Pb, Zn, Cr, Co, Cu, Cd, and Mn were assessed in lignite mining areas of the Kutch district of Gujarat. It was assessed mainly in land uses like reclaimed mine soil, core zone soil, roadside soil, and reference agricultural soil along the soil layer of different depths. Roadside soil has the highest concentration of mercury (5.36 mg/kg), arsenic (18.2 mg/kg), lead (34.5 mg/kg), and manganese (464 mg/kg). In comparison, the core zone soil has the highest concentration of zinc (93.4 mg/kg), chromium (52.3 mg/kg), cobalt (19.2 mg/kg), and cadmium (5.65 mg/kg), respectively. Numerous soil indices including contamination factor, geo-accumulation index, ecological risk factor (ERF), and ecological risk index (ERI) showed that the study area lies within the moderate contamination to very high contamination zone and moderately polluted to the unpolluted range. The (Eif) (Hg) for roadside soil and core zone soil indicated high potential ecological risk category, while reclaimed mine site indicated considerable potential ecological risk. The Eif (Cd) in all sites in the mining area (121–327) can be put under high potential ecological risk, and the rest of the metals (As, Pb, Zn, Co, Cu, Cr, and Mn) can be put under low ecological risk category. In the three sites (i.e., reclaimed mine site, roadside soil, and core zone soil), core zone soil of (10–20 cm) showed the highest ERI value of 660.48 (10–20 cm), indicating high ecological risk. Cd and Hg contribute to 48% and 38% of ERI value. Hierarchical cluster analysis (HCA) suggested that the Cu and Mn were closely linked with each other and derived from similar origin and geo-chemical composition. The results of this study interpreted that the soil near the lignite mining area was contaminated with toxic elements. It is, therefore, recommended that the routine toxic element monitoring in the soil sample of the examined area should be done, and remediation action should be advised to prevent the accumulation of toxic elements in the soil and further into the food chain. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phytoremediation is an in situ remediation and eco-friendly technique employing accumulator plant species to remove trace elements (TEs) from contaminated sites. Moreover, it has been demonstrated that both natural and synthetic amendments can enhance trace elements (TEs) phytoremediation from polluted soils through bioenergy crops. This work assessed the synergistic impact of two tested biochar (BC) from data palm (B1) and Prosopis (B2) (1.5%/ kg), citric acid (CA, 1.5 mmol/kg) and vermiwash (VW, 20 ml/kg) to enhance the remediation of tested TEs (Mn, Zn, Cd, Pb, Ni, Cu, and Fe) from Mahad AD'Dahab mine-contaminated soil by sorghum (Sorghum bicolor L.). The BC and CA amendments alone and combined with VW significantly augmented the proliferation and survival of sorghum grown in mine-contaminated soil. Considering the individual and combined applications of VW and BC, the influence on plant growth followed this order: K < VW < B2 < B1 < B1 + VW < B2 + VW < CA < CA + VW. Applying tested BC/CA and VW significantly increased chlorophyll compared to unamended soil. The outcomes revealed a substantial elevation in TE absorption in both shoot and root (p ≤ 0.05) with all tested treatments compared to the untreated soil (K). The combined application of CA and VW resulted in the most significant TE uptake of TEs at both the root and the shoot. Furthermore, adding CA or VW as a foliar spray enhanced the bioaccumulation factor (BCF) and translocation factor (TF) of studied metals. The combined addition of CA and foliar spraying of VW was more effective than the sole addition of CA or VW. Such increase reached 20.0%, 15.6%, 19.4%, 14.3%, 14.0%, and 25.6% of TF, and 13.7%, 11.9%, 8.3%, 20.9%, 20.5%,18.7%, and 19.8% of BCE for Cd, Cu, Fe, Mn, Ni, Pb, and Zn, respectively. This study highlights the efficiency of combining CA/BC with VW as a more viable option for remediating mine-contaminated soil than individual amendments. However, future research should prioritize long-term field trials to assess the efficiency of using citric acid and vermiwash for restoring contaminated mining soils. [ABSTRACT FROM AUTHOR]

Seed-based restoration in dryland environments is commonly limited by low and sporadic rainfall, extreme temperatures, and degraded soils. These challenges are exacerbated in dryland mine restoration sites where species are seeded onto mine waste substrates due to limited availability of topsoil. Native grasses are focal dryland and mine restoration species, though the ability to deliver seeds to targeted sites presents further constraints to seed-based restoration due to complex seed morphology and site attributes. Seed enhancement technologies (SETs) may help to mitigate environmental stressors and improving seed handling. In this study, SETs which promote seedling recruitment and/or address edaphic challenges while also improving seed morphology and handling were tested in four Australian native grasses (Cymbopogon ambiguus, C. obtectus, Eulalia aurea, and Eriachne obtusa). Flash flaming or acid digestion (depending on species), extruded seed pellets with or without the addition of topsoil, and flaming or acid digestion used in combination with extruded pellets (with or without topsoil) were evaluated on topsoil and mine waste substrates. Material treated with either flash flaming or acid digestion tended to produce similar maximum emergence (week 3), final emergence (week 14), and above-ground biomass (week 14) on both topsoil and mine waste when compared to the un-enhanced ('control') treatment. Extruded pellets enhanced emergence (maximum and final) on both soil types, though had no effect on biomass. Extruded pellets containing topsoil and/or when used in combination with flash flamed or acid digested florets, provided the most significant benefits to seedling emergence, particularly on mine waste soil. However, SETs were unable to mitigate the detrimental effects of mine waste substrates on seedling biomass. This study shows promise for improving seed-based restoration in post-mine and dryland environments using SETs, though also highlights potential limitations and the importance of understanding long-term (i.e., beyond emergence) plant recruitment outcomes in SET applications. [ABSTRACT FROM AUTHOR]

This research looks at how some plant species' development and metabolic characteristics are affected by heavy metal pollution in mining soils. Two mining sites provided soil samples, which were compared to control soil from a university campus. The growth, protein, carbohydrate, and proline content of the chosen species--Sorghum bicolor, Vigna mungo, Eleusine coracana, Brassica juncea, and Telfairia occidentalis--were assessed in a greenhouse environment. The findings showed that plants growing in polluted soils had lower amounts of protein and carbohydrates, and that Vigna mungo and Sorghum bicolor were more resistant to metal stress. In polluted soils, elevated proline buildup indicated a stress reaction. The research emphasizes the detrimental effects of heavy metal pollution on plant health and raises the possibility that tolerant species might be useful in phytoremediation. [ABSTRACT FROM AUTHOR]

This study aimed to examine the changes in selected soil properties at Lítov spoil heap (Sokolov, Czech Republic) and compare the current situation with the situation described twenty years ago. A total of 110 soil samples were taken at Lítov at the same sites as in 1998. The analyses of basic soil characteristics involved: exchangeable soil pH (pHKCl), organic carbon content (Cox), quality of humic substances (A400/A600), exchangeable acidity (Ea), and two types of aluminium contents in the soil. Changes in all soil characteristics between 1998 and 2018 were statistically evaluated, compared, and visualized using Geographical Information Systems (GIS). We have observed an increase of pHKCl, Cox and a slight improvement in humus quality compared to the results from 1998. The temporal changes of soil characteristics were evident in the whole area, and the influence of reclamation methods was also pronounced. Soil development close to the regional common natural conditions was found in the area where agricultural reclamation measures (i.e., covering with topsoil) were carried out. Furthermore, afforestation - mainly by deciduous trees - supported the improvement of soil characteristics favourable for plant growth. High pyrite content and marshland were identified as the main causes that led to vegetation cover mortality. [ABSTRACT FROM AUTHOR]

Coal mining causes surface subsidence, resulting in the loss of phosphorus from the soil surface and affecting crop growth. To provide a basis for the reclamation of soils in coal mining subsidence areas, using the Suntuan mine area in Huaibei City as an example, indoor soil cultivation experiments were conducted to investigate the effects of applying different types of phosphate rock powders (mechanically activated and nonmechanically activated), active minerals (zeolite, kaolin, bentonite) and phosphorus solubilizing microorganisms (Pseudomonas fluorescens, Aspergillus niger) on soil pH, available phosphorous content, and the conversion of soil phosphorus fractions. The results showed that the combined action of phosphate rock powder and phosphorus solubilizing bacteria could significantly improve the soil acidic environment. The application of phosphate rock powder, active minerals, and phosphorus solubilizing microorganisms can promote the release of available phosphorous in soil, and Aspergillus niger has a better effect than Pseudomonas fluorescens. Soil content of H2O-P, NaOH-Pi, NaHCO3-Pi, and HCl-P increased, NaOH-Po decreased, and some treatment groups had reduced Residual-P content. Together, phosphate rock powders, active minerals, and phosphorus solubilizing microorganisms can mitigate soil acidification, promote soil phosphorus release, result in the transformation of soil phosphorus fractions, and improve phosphate fertilizer utilization. [ABSTRACT FROM AUTHOR]

The province of García Rovira (Santander) has been the protagonist ofambitious road infrastructure projects, carried out through the figure of Temporary Authorization, for the extraction of construction materials used on the roads. The environmental liabilities represented in the soil by mining activities covered by Temporary Authorizations in the province were evaluated. Two projects associated with Temporary Authorizations were selected, in which the execution conditions were analyzed, and the closure and recovery plans of the intervened areas were compared. The projects SCR-08491 in El Término (Guaca) and LHO-14372 in the Servitá River Basin (Concepción) were selected, in which exploitation fronts and mining support areas devoid of vegetation cover, mainly abandoned mining infrastructure, were observed. It is concluded that the contractors focus mainly on complying with the exploitation plan, downplaying the execution of the closure, abandonment, and recovery phase ofthe intervened area. Inefficient control and monitoring of this type of projects by the environmental authority was evident. [ABSTRACT FROM AUTHOR]

Soils contaminated with multiple heavy metals pose a significant threat to human health and ecosystem functionality. Following a "treat pollution with waste" strategy, we synthesized Mg‐Fe‐Al ternary layered double hydroxides (LDHs) from waste Bayer red mud for the remediation of heavy metal contaminated soils. Characterization using XRD, FTIR, SEM and EDS methods revealed a characteristic layered structure rich in functional groups, offering reaction sites for heavy metal passivation. Passivation experiments showed that the application of Mg‐Fe‐Al LDHs (2.5 wt.%) reduced the availability of Pb (29.7%), Cd (64.1%) and Cu (66.0%) in contaminated soil from a sulphide iron ore area in southern Sichuan Province. Simulated acid rain experiments showed leachate concentrations of Pb, Cd, and Cu reduced by 43.3%, 72.7% and 42.4%, respectively. This work provides a reference for the development of high‐performance and environmentally friendly adsorption‐stabilizing materials for green remediation. [ABSTRACT FROM AUTHOR]

Phytoremediation is considered an effective strategy for remediation of heavy-metal-contaminated soil in mining areas. However, single-species plants cannot reach the highest potential for uptake of heavy metals due to inhibition of their growth by high concentrations of heavy metals in the soil. Therefore, this study has explored the effects of illite application and two plant species' co-cropping on soil quality, plant growth, and heavy metal transformation in a soil–plant system. The results reveal that the addition of 1% (mass fraction) of illite significantly enhances soil pH. The co-cropping of Ilex cornuta and Epipremnum aureum is beneficial for improving the organic matter content of the soil. The contents of EDTA-extractable Pb, Zn, and Cu were significantly reduced by 29.8–32.5%, 1.85–5.72%, and 30.0–32.9%, respectively, compared to the control. The co-cropping of Ilex cornuta and Epipremnum aureum promoted enrichment effects of Epipremnum aureum on Pb and Ilex cornuta on Cd (p < 0.05). The co-cropping pattern lowered the biomass of Ilex cornuta and Epipremnum aureum; however, co-cropping of Ilex cornuta and Epipremnum aureum promoted the elimination of Pb, Zn, Cu, and Cd from the soil at 13.0–75.8%, 11.1–38.2%, 8.39–88.4%, and 27.8–72.5%, respectively. It is concluded that illite application combined with co-cropping of Ilex cornuta and Epipremnum aureum is highly effective for the elimination of Pb, Zn, Cu, and Cd from contaminated soil. This study provides a theoretical basis and pathway for the restoration of heavy-metal-contaminated soil in mining with the application of bentonite combined with phytoremediation. [ABSTRACT FROM AUTHOR]

This study aims to contribute to the characterization of Katangese Copperbelt's (DR Congo) mining wastes and soils polluted with trace metals, using pollution indices and direct concentration measurements. This study also evaluated the use of these indices in assessing the success of remediation projects. Data from previous studies and samples collected from six types of discharge and one polluted soil were used to address the first objective. Soil and plant samples were collected at Kipushi and Penga Penga for the second objective. The results reveal very high concentrations of As, Cd, Co, Cu, Mn, Pb, and Zn in all mine tailings and polluted soils, compared with local references. The degree of contamination (DC) values (from 72 to 5440) and potential ecological risk (RI) values (from 549 to 162,091) indicate very high-risk situations associated with polluted discharges and soils. Regarding revegetation trials, the results show lower concentrations and RIs in tree rhizospheres compared with unamended areas at both sites. However, trace metal concentrations are higher in tree rhizospheres compared with local references, and RI values are in the considerable risk range for Penga Penga (RI = 533) and in the very high range (>1500) for Kipushi. Bioconcentration factor values are below 1, indicating low accumulation in roots, wood, and leaves, and low risk of contamination of the trophic chain. In this context, it seems that the pollution indices used are suitable for characterizing pollution and prioritization for remediation. However, there seems unsuitable for assessing the effectiveness of phytotechnology processes based on metal stabilization. Direct plant performance measurements combined with direct measurements of metals in substrates and plants to assess transfer and efficiency are more appropriate. [ABSTRACT FROM AUTHOR]