Search Results (1,481)

Using native tree species, the phytostabilisation of toxic metals at former mining and industrial sites can provide ways to prevent metal spread and leaching into the environment and bring the sites back into the economic circuit. In this study, mixed afforestations with young trees from seven Central European species showing contrasted autecology (Picea abies (L.) Karst, Fagus sylvatica L., Acer pseudoplatanus L., Alnus incana (L.) Moench, Populus tremula L., Salix viminalis L. and Betula pendula Roth) were exposed during five years to mixed soil contamination (Zn/Cu/Pb/Cd = 1349/317/70/8 mg kg⁻¹). The uptake and allocation of the metals in root and shoot tissues, various functional traits and nutrient responses were compared. Despite high metal availability, all tree species showed low metal uptake and similar metal concentrations in their roots. The mobile metals (Zn, Cd) accumulated in the shoot and foliage of early-successional species with acquisitive ecological strategy only, whereas the late-successional species blocked the transfer of all metals from the roots to the aboveground organs. All species showed good tolerance to metal contamination, with large interspecific differences regarding the biomass production and some nutrient concentrations, in apparent relation to the varying species’ ecological strategies and independent of the metal treatment. Zn allocation within fine root tissues could enhance transient spatial and temporal metal immobilisation, especially when associated with protective or defence structures, which also contributed to metal detoxification. Higher transfer of mobile metals to aboveground organs in pioneer tree species was clearly related to their acquisitive ecological strategies, in the context of higher nutrient demand in foliage and lesser defence and protection of vegetative organs. The implications of findings for phytostabilisation applications are discussed. Full article

With the continuing intensification of modern agriculture, pesticides and antibiotics are extensively used to control pests and diseases, but their improper use and indirect inputs have resulted in widespread contamination of agricultural environments and food products. This review synthesizes how these contaminants enter agroecosystems, their occurrence across soils, waters and agricultural products, and the processes that redistribute residues across air–water–soil interfaces and into the soil–plant continuum. We summarize cross-media transport pathways (e.g., runoff/leaching, volatilization–deposition and irrigation-driven redistribution) and relate environmental exposure to plant uptake using a harmonized indicator set, including the bioconcentration factor (BCF), translocation factor (TF), octanol–water partition coefficient (log Kow) and soil organic carbon–water partition coefficient (Koc). We further discuss key determinants of crop accumulation, including compound-specific properties, soil characteristics and plant physiological traits, and highlight how these factors jointly shape residue profiles in edible tissues. Finally, we outline research priorities for source reduction, standardized multi-matrix surveillance, fate-to-uptake modeling, and microbiome-enabled remediation strategies to support pollution control, food safety and public health. Full article

Copper flotation tailings are produced in large quantities during ore beneficiation and smelting, yet remain underutilized and can act as persistent sources of potentially toxic elements. Here, we combined XRD-based mineralogical characterization, ICP-OES quantification, Tessier sequential extraction, and pH-dependent batch leaching to elucidate metal occurrence, mobility, and associated ecological risk in tailings from Tongling, Anhui Province. This study systematically analyzed the mineral composition, potentially toxic elements content, chemical fractions, leaching behavior, and ecological risks of copper flotation tailings from the Shuimuchong tailings reservoir in Tongling, Anhui Province. XRD and XRF analyses revealed that calcite, quartz, and garnet were dominant mineral phases in the tailings. Elevated levels of Cu, Cd, Pb, Zn, and As were detected, some of which surpassed both local background concentrations and national soil quality standards. Most potentially toxic elements primarily existed in the residual fraction, indicating low mobility. Leaching experiments revealed that Zn, Cu, and As showed enhanced release under acidic conditions, making them priority risk elements during tailings acidification. Pollution index and ecological risk assessments indicated that the tailings were heavily contaminated, with Cu and Cd as the main risk contributors. The Risk Assessment Code (RAC) evaluation showed that Cd had the highest bioavailability and ecological risk. By clarifying the behavior of pollutants, this study contributes to the effective regulation of environmental hazards and the sustainable use of tailing materials. Full article

Although treated wastewater (TWW) is increasingly being used to irrigate urban landscapes in arid regions like Qatar to preserve scarce freshwater resources, little is known about its long-term ecological impacts. The effects of extended irrigation with TWW on the composition of weed communities and soil characteristics in urban turfgrass systems were assessed in this study for a full year period. Three turfgrass fields in public parks in Doha that are not distant and similar in turf species and type of management were chosen. One of them has received regular tap water, and the other two had received a period of two years or a period of seven years irrigation with TWW. Due to nutrient availability in TWW, long-term irrigation improved turfgrass performance but drastically changed the structure and composition of the weed communities. More weed diversity and abundance were observed under irrigation with TWW, coinciding with cumulative increases in soil salinity [from 265 µS/cm for soil irrigated with regular tap water to about 1799 µS/cm for soil long-term irrigated with treated wastewater] and nutrient levels. Dactyloctenium aristatum and Euphorbia prostrata were dominating the field under TWW irrigation, while Cyperus rotundus prevailed better under regular tap-water irrigation. Crucially, build-up of toxic elements was found in the turfgrass, but not harmful. Overall, the findings showed that although TWW is a useful source for maintaining urban green spaces in arid regions, its long-term use necessitates cautious management to reduce weed growth and adaptation. Maintaining sustainable and healthy urban landscapes may be aided by using salt-leaching irrigation techniques and seasonal blending with freshwater. Full article

Brazilian soils are prone to a gradual decline in fertility due to intensive agricultural activity combined with natural weathering, which increases the demand for chemical fertilizers. Among potential alternatives, soil remineralization using crushed rock is a promising strategy. Silicate agrominerals (SAs) applied as soil remineralizers have attracted attention due to their ability to supply plant-available nutrients while reducing dependence on conventional mineral fertilizers. This study evaluated the potential of residues from six quarries in Brazil as soil remineralizers as a regulatory screening assessment. Samples were subjected to mineralogical, petrological, and chemical characterization using an integrated approach, including X-ray diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), and leaching experiments. XRD analysis revealed that anorthite and augite were the major minerals present in the mining waste. These minerals are less resistant to weathering, which enhances the release of macro- and micronutrients, essential for the development of various crops. Chemically, the samples were dominated by SiO₂, Fe₂O₃, and Al₂O₃, with the sum of bases (K₂O + CaO + MgO) ranging from 11.92% to 16.85%, meeting Brazilian standards for use as a soil remineralizer. Leaching results revealed that pH responses varied significantly among the studied samples for the filler particles, with an alkaline shift reaching values above 9.0 after 72 h. In contrast, the powder particle size samples showed no significant variation between the different materials tested, maintaining nearly constant pH levels throughout the period. This preliminary evaluation demonstrates that mining tailings from Brazilian quarries have potential as a sustainable soil remineralizer. This approach not only offers an alternative for soil fertilization but also promotes waste management and circular economy practices, although further studies are needed to assess long-term effectiveness and safety. Full article

Soil salinity poses a major challenge to agricultural productivity, especially threatening food security in arid and semi-arid areas. Traditional soil reclamation methods, such as leaching, chemical amendments, and drainage engineering, usually need large amounts of water, involve high costs, and can lead to environmental problems. This review compiles existing knowledge on innovative strategies for managing saline soils, focusing on buried interlayer systems that use materials like straw, sand, gravel–sand mixtures, and biochar. These interlayers improve soil hydraulic properties by preventing capillary rise, encouraging salt leaching, and reducing surface salt buildup. Biochar stands out as a particularly useful material because of its stability, large surface area, porosity, and high cation exchange capacity. These features help improve soil structure, increase water retention, and effectively retain sodium. Evidence from lab and field tests shows that buried biochar layers can stop salt from moving upward, aid in desalinating the root zone, and boost crop yields. While straw and sand interlayers show potential in reducing salinity, biochar is noted for its multifunctionality and long-term effectiveness in addressing salinity problems. The success of buried biochar systems depends on several factors, including the properties of the biochar, how much is used, how deep it is buried, and the specific soil and climate conditions. This review highlights how these systems work, compares their performance, and points out research gaps, advocating for their potential as a sustainable, resource-efficient way to manage salinity and improve soil health over the long term. A substantial proportion of the existing evidence is derived from controlled laboratory studies, and the buried biochar layer approach remains an emerging technique that requires further validation under field conditions. Still, significant knowledge gaps persist regarding long-term performance and water-salt dynamics, while site-specific soil variability and scalability challenges may limit the effective implementation of biochar interlayer systems under field conditions. Full article

Sulphide soil is an organic soil characterised by high water content and poor geotechnical properties. When excavated, it oxidises and becomes an environmental hazard due to leached metals and acid drain. To avoid excavation, methods for utilizing more sulphide soil as a subgrade material are being developed. However, precise characterisation of sulphide soil is challenging, as its inherent properties make it prone to sample disturbance, introducing large scatter into geotechnical test results. To minimise the scatter in laboratory test results, a portion of the characterisation could be based on reconstituted samples. This study explores the applicability of the slurry deposition method to produce homogeneous, repeatable and representative sulphide soil samples. The reconstituted samples were assessed by comparing their initial index properties and triaxial behaviour against those of the intact samples. The index properties of the tested reconstituted samples precisely and accurately matched the average results of the intact samples. The undrained triaxial behaviour and derived critical state line of the reconstituted samples and the intact samples were found to be comparable. Neither type of sample reached critical state in drained triaxial testing. In conclusion, this study suggests that the slurry deposition method is suitable for reconstituting sulphide soil samples. Full article

Soil and water contamination with high nutrient concentrations from swine farms poses a risk to human and animal health. This study investigated the effects of biochar derived from young aromatic coconut husk (CH), coconut shell (CS), and their mixture (CHCS) on nutrient retention in biochar-amended soil columns for variable synthetic swine wastewater (SW) loading based on water use for piglets and fattening stalls. A 0.9 L leaching test column contained 3 g of each biochar type mixed with 300 g of soil. It was loaded daily with synthetic SW for 42 days at loading rates of 30 mL/day (piglet SW) and 60 mL/day (fattening SW). CH-amended soil was then selected to investigate the effect of rainfall rates at 0 (R0), 25 (R25), 70 (R70) and 140 (R140) mL/4 days on soil nutrient retention. Leachate was collected every 7 days to analyze nitrogen and phosphorus concentrations. The results showed that CH-amended soil had the highest retention of total nitrogen (TN) and phosphate among all treatments. For piglet SW, TN retention in CH-amended soil was 1.4–1.6 times higher than with CS and CHCS treatments, probably due to enhanced ammonium retention on exchangeable sites associated with the high cation exchange capacity of CH. High phosphate retention in CH-amended soil was linked to Ca²⁺ release from CH, facilitating phosphate precipitation. Moreover, CH-amended soil at R25 showed the highest ammonium retention but inhibited seed germination. Overall, CH-amended soil effectively retained nutrients and was suitable as a seedling growth medium, except under the R25 rainfall condition. Full article

Improving nitrogen (N) use efficiency in olive cultivation is essential to address the environmental burden of N fertilizers, whose recovery efficiency rarely exceeds 55%. This study evaluates the agronomic and environmental performance of chabazite-rich zeolite as a soil amendment to enable 50% N-fertilizer reduction in olive growing. A seven-year field experiment (2017–2023) was conducted at two sites in Emilia-Romagna (Italy)—one irrigated (Brisighella) and one rainfed (Bertinoro)—comparing four autochthonous varieties under zeolite amendment (ZEO, 50% N) versus conventional fertilization (CNT, 100% N). Vegetative growth, productive parameters, oil quality and environmental impacts (Life Cycle Assessment, ISO 14040/44) were monitored. Under irrigation, ZEO maintained vegetative and productive equivalence with CNT, sustaining commercially viable yields (0.5–2.3 t ha⁻¹). Under rainfed conditions, variety-specific responses emerged: Colombina exhibited 126.2% greater trunk diameter and near-universal fruiting competence (88.9% vs. 29–35% productive plants) under ZEO, while Capolga showed treatment convergence. LCA revealed higher per-unit environmental impacts for ZEO during early orchard phases due to front-loaded extraction burdens, progressively offset by annual N-input reductions. These findings demonstrate that zeolite amendment enables agronomically viable 50% N-fertilizer reduction, with efficacy modulated by water regime and genotype. Full article

Two mineral-based solid residues, namely coal gangue (CG) and phosphorus tailings (PT), two of the largest solid waste streams in the mining industry, were used as the sole metal feedstocks to fabricate a novel MgCaFeAl layered double hydroxide (LDH-GT) via a 700 °C calcination, acid leaching and hydrothermal coprecipitation route, with simultaneous synthesis of white carbon black from the reaction byproducts. Under optimized conditions (total metal load is 150 mg kg⁻¹, LDH-GT dose is 0.09 g, pH from 6 to 7), the synthesized material achieved concurrent immobilization efficiencies of 76.28%, 99.96%, and 99.95% for Cr (VI), Cd (II) and Ni (II), respectively, within a 24 h reaction period. TCLP leachability decreased by 82 to 91% relative to the untreated soil. After three wetting, drying and freeze–thaw cycles, the leached concentrations of all three metals remained below 0.3 mg L⁻¹, confirming excellent long-term stability. Mechanistic analyses revealed that Cr (VI) was mainly sequestered through interlayer anion exchange and surface complexation, whereas Cd (II) and Ni (II) were immobilized via isomorphic substitution into the LDH lattice, precipitation as carbonates, and incorporation into Fe/Mn oxides. A 7-day mung bean bioassay showed that LDH-GT amendment increased seed germination from 50% to 73%, enhanced root and shoot biomass by 1.1- to 1.6-fold, and decreased plant Cr, Cd, and Ni contents by over 80%. The 16S rRNA sequencing further demonstrated that LDH-GT reversed the decline in microbial α diversity induced by heavy metal stress, restored aerobic chemoheterotrophic and sulfur cycling functional guilds, and reduced pathogenic signatures. This study provides the demonstration of a waste-to-resource LDH that achieves efficient, durable remediation of multi-metal-contaminated soils, offering a scalable route for coupling solid waste valorization with in situ site restoration. Full article

Utilising highly mineralised mine water for drip irrigation of desert vegetation in mining areas represents a crucial approach to alleviating freshwater scarcity and achieving mine water resource utilisation. However, high salt inputs may pose risks of salt return to root zones and deep accumulation. To ensure the safe and effective utilisation of mine water, laboratory 45 cm soil column infiltration tests (freshwater, 8, 12, 16 g L⁻¹) were conducted in the heavily saline-affected desert vegetation zone of Dananhu, Hami, Xinjiang, alongside 2023–2024 field drip irrigation trials (8, 12, 16 g L⁻¹). This study established a ‘soil column inversion–field validation–scenario optimisation’ framework (16 g L⁻¹) and field drip irrigation trials (8, 12, 16 g L⁻¹) during 2023–2024. A multi-scale HYDRUS-1D/3D simulation framework—‘soil column inversion–field validation–scenario optimisation’—was established to quantify water–salt transport processes in the root zone and optimise emitter flow rates. HYDRUS-1D demonstrated excellent fitting for soil moisture content, wetting front, and salinity distribution (R² = 0.964–0.979, 0.995–0.998, 0.791–0.898). Following parameter migration, HYDRUS-3D achieved R² values of 0.834–0.949 for simulating field-scale stratified salinity. Overall desalination occurred in the 0–80 cm soil profile over two years. Within the 0–40 cm root zone, reduction rates decreased with increasing irrigation salinity: 45.77% (2023) and 59.64% (2024) under 8 g L⁻¹ treatment, significantly higher than the 24.24% and 30.91% reductions observed at 16 g/L (p < 0.05). During the high-temperature period of July–August, transient salt accumulation occurred in the 0–10 cm surface layer, while the 80–120 cm zone exhibited cumulative risk. Scenario simulations indicated that increased dripper flow rates expanded the wetted zone horizontally but weakened vertical leaching. The 2.0–2.4 L h⁻¹ range demonstrated superior overall performance in balancing root zone desalination rates and irrigation uniformity. The study recommends targeting root-zone salinity stability through a combination of moderate leaching, summer transpiration suppression, and seasonal flushing/natural leaching, alongside prioritising low-to-medium flow emitters. This approach synergistically reduces both surface salinity return and deep accumulation risks. Full article

Emerging contaminants (ECs) are a diversely mounting group of chemicals and biological compounds found in air, water, and soil, which include pharmaceuticals, personal care products, per- and poly-fluoroalkyl substances (PFASs), microplastics, endocrine-disrupting chemicals, and various other industrial compounds. Unlike conventional pollutants, ECs are usually unregulated, found in very small amounts, and can persist and build up in living organisms, resulting in toxic risks for both ecosystems and human health. These contaminants originate from various anthropogenic activities and enter the environment through wastewater, stormwater, landfill leaching, and atmospheric deposition. This article documents a holistic literature review of ECs available from the last five years, covering classification, sources and pathways of contamination, and environmental behavior, while assessing their ecological, human health, and socioeconomic impacts. Advances in detection, including high-resolution mass spectrometry, non-target screening, real-time sensors, and AI-assisted monitoring, are addressed. Management strategies including advanced oxidation, membrane filtration, electrochemical treatments, and nature-based solutions are explored. It also analyses global and regional policy frameworks, highlighting regulatory gaps and the need for standardized monitoring. The study emphasizes integrated, multidisciplinary approaches combining scientific innovation, sustainable chemical design, predictive modeling, and public engagement. Synergizing technology, governance, and prevention could reduce the risks related to ECs and protect the environment. The novel contribution is an end-to-end, decision-oriented synthesis that links what monitoring can reliably infer to be feasible, integrated control strategies and sustainability outcomes, supporting risk-based prioritization, targeted pollution treatment, and prevention-focused management. Full article

The reflectivity of the bare soil surface (BSS) is influenced by soil type, moisture, salinity, tillage, erosion, and other factors. To investigate the direct impact of erosion on the spectral characteristics of the BSS (SCBSS), a study site in the forest-steppe zone (Mtsensk district, Oryol Oblast, Russia), unaffected by salinity, carbonates, gypsum, and other factors, was selected. To suppress the influence of moisture and tillage, a multitemporal soil line (MSL) construction method was selected, which averages the influence of these factors, using the effect of big data. It was possible to reduce the influence of various factors on the SCBSS to two: zonal soil types and the extent of soil degradation from erosion (erosion degree). Soil types and erosion degree were determined by a ground survey with excavation of 488 pits/soil profiles. It was found that the relationship of soil types on the SCBSS has the form of a second-degree polynomial with a determination coefficient of R² = 0.95. Spectral reflectance decreases across the zonal series of soils: sod-podzolic, light gray forest, gray forest, dark gray forest, podzolized chernozem, leached chernozem, typical chernozem, and meadow-chernozem soils. The influence of erosion leads to a linear increase in reflectance for each soil type in the following erosion degree series: non-eroded, slightly eroded, moderately eroded, and strongly eroded. Superimposing two functional relationships yields a distribution in the form of a polynomial ladder. This distribution maintains the general trend of a polynomial decrease in soil reflectance across the zonal series with stepwise deviations at the erosion degree. The polynomial ladder allows us to demonstrate how the erosion degree can change the spectral characteristics of one soil type to those of another. Full article

In Northeast China’s degraded croplands, nitrate (NO₃⁻-N) leaching is the dominant pathway for fertilizer-nitrogen (N) loss, which presents an increasing threat to the quality of groundwater. Conservation tillage, defined as no-tillage (NT) and straw retention, is a widely adopted management strategy to maintain cropland fertility in the black soil (BS) regions. At present, however, the impact of shifting from conventional to conservation tillage on the vertical distribution and regulatory mechanisms of NO₃⁻-N derived from applied fertilizer-N (F_NO3) remains poorly understood. Based on a 12-year field experiment, we integrated ¹⁵N-tracing field monitoring with ¹⁵N-paired-labeling incubation to quantify the vertical migration of F_NO3 into deep soil profiles, and specify the dominant processes regulating N retention and supply. Across the tested BS croplands, total NO₃⁻-N production rates (4.06–6.58 mg N kg⁻¹ soil day⁻¹) were faster than their consumption rates (0.36–0.92 mg N kg⁻¹ soil day⁻¹), leading to a net accumulation of NO₃⁻-N, and implying a potential for leaching of NO₃⁻-N, from the perspective of substrate availability. The results of the field ¹⁵N micro-plot experiment also indicated that, by maize maturity in the first growing season, an average of 7.5% of F_NO3 had migrated to the 80–100 cm soil layer. During the following two growing seasons, the maximum accumulation of F_NO3 had shifted downward to 140–160 cm and 180–220 cm, respectively. Such a pattern, particularly in light of the increased extreme precipitation in the studied regions, raises clear concerns about NO₃⁻-N leaching losses. Compared with conventional management, no-tillage with full-rate straw mulching decreased net rates of NO₃⁻-N production from 6.22 to 3.14 mg N kg⁻¹ soil day⁻¹. This reduction resulted from a decline in the gross oxidation of NH₄⁺-N to NO₃⁻-N (from 6.39 to 3.70 mg N kg⁻¹ soil day⁻¹) and an increase in DNRA (from 0.35 to 0.85 mg N kg⁻¹ soil day⁻¹), which collectively delayed the downward transport of F_NO3. Conservation tillage also increased the gross rate of heterotrophic nitrification (from 0.19 to 0.36 mg N kg⁻¹ soil day⁻¹) and its proportion relative to total nitrification (from 2.8% to 8.9%). Despite this shift, autotrophic nitrification remained the dominant process for NO₃⁻-N production in the tested BS croplands, likely due to a pH constraint on heterotrophic nitrification. With the increasingly widespread promotion of conservation tillage for soil fertility improvement, heterotrophic nitrification warrants greater attention, particularly in BS regions where pH < 6.5 and C/N contents are relatively high. Collectively, our findings provide a scientific basis for tailoring tillage practices to maintain sustainable agriculture in Northeast China. Full article

This research explores the use of industrial waste as an alternative to natural raw materials, promoting a circular economy in the construction sector. It specifically investigates the manufacturing of paving blocks using blast furnace slag and recycled aggregates. Paving blocks were produced without altering typical industry conditions, entirely replacing cement with alkaline-activated blast furnace slag. The study replaced natural aggregate in three proportions (20%, 50%, and 100%) with three types of recycled aggregates: concrete recycled aggregate (CA), masonry recycled aggregate (MA), and recycled mixed aggregate (RMA), in both coarse and fine fractions. The experimental procedure analysed the impact of recycled aggregates in an alkaline-activated slag matrix through three phases: characterising physical properties (mechanical properties, water absorption, density, abrasion resistance, and slip resistance), evaluating leaching behaviour, and conducting a life cycle analysis. The results of physical characterisation were statistically analysed using principal component analysis (PCA). The results obtained show the feasibility of manufacturing paving blocks with blast furnace slag by completely replacing the natural aggregate with the coarse fraction of the three recycled aggregates used and replacing up to 20% in the case of using the fine fraction. The properties of the paving blocks manufactured with slag depend mainly on the degree of substitution of natural aggregate with the recycled aggregate. All paving blocks can be considered environmentally safe from leaching according to the Dutch Soil Quality Decree. Paving blocks made from alkali-activated ground granulated blast furnace slag and recycled aggregates generate a lower carbon footprint compared to concrete paving blocks. Full article