Search Results (177)

With increasing global challenges related to water scarcity and phosphorus depletion, the recovery and reuse of wastewater-derived nutrients offer a sustainable path forward. This study evaluates the dual role of lanthanides (Ce³⁺ and La³⁺) in recovering phosphorus from municipal wastewater and supporting corn (Zea mays) cultivation through lanthanide phosphate (Ln-P) and lanthanide-reclaimed wastewater (LRWW, wastewater spiked with lanthanide). High-purity precipitates of CePO₄ (98%) and LaPO₄ (92%) were successfully obtained without pH adjustment, as confirmed by X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS). Germination assays revealed that lanthanides, even at concentrations up to 2000 mg/L, did not significantly alter germination rates compared to traditional coagulants, though root and shoot development declined above this threshold—likely due to reduced hydrogen peroxide (H₂O₂) production and elevated total dissolved solids (TDSs), which induced physiological drought. Greenhouse experiments using desert-like soil amended with Ln-P and irrigated with LRWW showed no statistically significant differences in corn growth parameters—including plant height, stem diameter, leaf number, leaf area, and biomass—when compared to control treatments. Photosynthetic performance, including stomatal conductance, quantum efficiency, and chlorophyll content, remained unaffected by lanthanide application. Metal uptake analysis indicated that lanthanides did not inhibit phosphorus absorption and even enhanced the uptake of calcium and magnesium. Minimal lanthanide accumulation was detected in plant tissues, with most retained in the root zone, highlighting their limited mobility. These findings suggest that lanthanides can be safely and effectively used for phosphorus recovery and agricultural reuse, contributing to sustainable nutrient cycling and aligning with the United Nations’ Sustainable Development Goals of zero hunger and sustainable cities. Full article

Anthropogenic revegetation allows effective and timely soil development in mine restoration areas. The evaluation of soil quality is one of the most important criteria for measuring reclamation effectiveness, providing scientific reference for the subsequent management of ecological restoration projects. The aim of this research was to further investigate the influence of revegetation on mine-reclaimed soils in a semi-arid region. Thus, a coal-gangue dump within the afforestation chronosequence of 1 and 19 years in Shanxi Province, China, was selected as the study area. We assessed the physicochemical properties and nutrient stock of topsoils under four revegetation species, i.e., Pinus tabuliformis (PT), Medicago sativa (MS), Styphnolobium japonicum (SJ), and Robinia pseudoacacia ‘Idaho’ (RP). A two-way ANOVA revealed that reclamation age significantly affected SOC, TN, EC, moisture, and BD (p < 0.05), while the interaction effects of revegetation type and age were also significant for TN and moisture. In addition, SOC and TN stocks at 0–30 cm topsoil at the RP site performed the best among 19-year reclaimed sites, with an accumulation of 62.09 t ha⁻¹ and 4.23 t ha⁻¹, respectively. After one year of restoration, the MS site showed the highest level of SOC and TN accumulation, which increased by 186.8% and 88.5%, respectively, compared to bare soil in the 0–30 cm interval, but exhibited declining stocks during the 19-year restoration, possibly due to species invasion and water stress. In addition, an integrated soil quality index (ISQI) and the partial least squares structural equation model (PLS-SEM) were used to estimate comprehensive soil quality along with the interrelationship among influencing factors. The reclaimed sites with an ISQI value > 0 were 19-RP (3.906) and 19-SJ (0.165). In conclusion, the restoration effect of the PR site after 19 years of remediation was the most pronounced, with soil quality approaching that of the undisturbed site, especially in terms of soil carbon and nitrogen accumulation. These findings clearly revealed the soil dynamics after afforestation, further providing a scientific basis for choosing mining reclamation species in the semi-arid regions. Full article

In arid regions, soil salinization and inefficient water use are major challenges to sustainable agricultural development. Optimizing subsurface drainage system layouts is critical for improving saline soil reclamation efficiency. This study conducted field experiments from 2023 to 2024 to evaluate the effects of varying subsurface drainage configurations—specifically, burial depths (1.0–1.5 m) and pipe spacings (20–40 m)—on drainage and salt removal efficiency in silty loam soils of southern Xinjiang, aiming to develop an optimized scheme balancing water conservation and desalination. Five treatments (A1–A5) were established to measure evaporation, drainage, and salt discharge during both spring and winter irrigation. These variables were analyzed using a water balance model and multifactorial ANOVA to quantify the interactive effects of drainage depth and spacing. The results indicated that treatment A5 (1.5 m depth, 20 m spacing) outperformed all the others in terms of both the drainage-to-irrigation ratio (R_d/i) and the drainage salt efficiency coefficient (DSEC), with a two-year average R_d/i of 32.35% across two spring and two winter irrigation events, and a mean DSEC of 3.28 kg·m⁻³. The 1.5 m burial depth significantly improved salt leaching efficiency by increasing the salt control volume and reducing capillary rise. The main effect of burial depth on both R_d/i and DSEC was highly significant (p < 0.01), whereas the effect of spacing was not statistically significant (p > 0.05). Although the limited experimental duration and the use of a single soil type may affect the generalizability of the findings, the recommended configuration (1.5 m burial depth, 20 m spacing) shows strong potential for broader application in silty loam regions of southern Xinjiang and provides technical support for subsurface drainage projects aimed at reclaiming saline soils in arid regions. Full article

Xanthan gum (XG) is a biopolymer primarily composed of polysaccharides that is increasingly employed to stabilize problematic soils. Although promising results have been obtained in clayey soils, its effect on other geomaterials remains underexplored. This study investigates the impact of XG on the mechanical strength (q_u), stiffness (Go), and microstructure of compacted mixtures of soil and reclaimed asphalt pavement (RAP). A two-part mixing method was adopted: Initially, the XG was mixed with water to form a hydrosolution before mixing in the soil and subsequently combined with the soil–RAP mixture. Xanthan gum was incorporated at dosages of 0.5%, 1.0%, 1.5%, and 2.0% relative to the dry soil weight, while RAP contents were varied at 10%, 20%, and 30% on a dry soil basis. The compaction density was adjusted between 17 and 18 kN/m³, with an optimum moisture content of 18% as determined by the Proctor test. Specimens were cured in a humid chamber for 14 and 28 days. The experimental methodology included unconfined compression tests, ultrasonic pulse velocity measurements, and characterization using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM–EDS). The findings show that the mechanical strength of the soil–RAP mixture increased with the incorporation of up to 1% XG, which was identified as the optimal dosage. The strength values declined at higher dosages (1.5% and 2.0%). Moreover, the highest strength and stiffness were achieved with a 10% RAP content, while mixtures containing 20% and 30% RAP exhibited reduced performance. Microstructural analysis revealed that at 1% XG, there was a pronounced interaction between the XG and the soil–RAP matrix; however, as the RAP content increased, the larger voids present led only to a moderate interaction between the materials. Additionally, a correlation between the stiffness parameter (Go) and the unconfined compressive strength (q_u) was established, showing that the Go/q_u ratio was dependent on the percentage of XG yet remained independent of curing time—a finding that contrasts with previous correlations for this type of soil that were unaffected by other factors. Full article

Water scarcity has become an increasingly critical global issue, affecting various sectors, including industrial, domestic, and particularly agriculture. Agriculture, as the largest consumer of water due to its substantial water requirements for food production, faces significant challenges, which are expected to intensify with the growth of the global population. As a result, many countries have begun to explore innovative solutions to address this pressing problem, one of which is the reuse of wastewater for irrigation purposes. This approach has gained particular attention in viticulture, where water consumption is high, and the need for sustainable practices is paramount. This paper delves into the issue of water scarcity, focusing specifically on the winemaking sector. It reviews several studies investigating the potential of wastewater reuse for irrigating vineyards, highlighting both the promising benefits and the challenges associated with this practice. The findings suggest that using treated wastewater for irrigation in viticulture offers a viable solution to mitigate water shortages, particularly in regions facing severe droughts or limited freshwater resources. However, the successful implementation of this approach requires careful monitoring and management of several factors, including soil quality, plant health, fruit development, and the final wine product. Ensuring the safety and quality of the wine, as well as safeguarding consumer health, necessitates rigorous oversight to prevent any negative impacts from the use of reclaimed water. Full article

Application of municipal reclaimed water to forests for water reclamation is a pragmatic approach that provides water and nutrients to soil and lowers the liability of reclaimed water disposal, yet little is known about the long-term impacts of reclaimed water amendment on forest soil chemical properties. We hypothesized that reclaimed water constituents will increase plant nutrient availability in soil with the magnitude of response depending on the facility establishment date. We collected samples from three mineral soil depths to 75 cm from treated and control plots at five water reuse facilities that represent a four-decade time series. Depth explained most of the observed variation. Several plant nutrients increased in soil at the different sites in response to reclaimed water treatments, including N, Ca, Fe, S, and B concentration as well as B content, while P was not significantly affected. Increases in cation concentrations positively correlated with pH and salinity. The treatment response was significantly greater at all facilities for total N, B and Na. However, the treatment response only occurred at long-established facilities for NO₃-N and Ca concentrations and for Fe and S content. The outcomes of this study are useful for guiding future management of soil at forest water reclamation facilities and for limiting the risk of downstream environmental impacts. Full article

The infiltration and water-holding properties of soil are essential for the efficient utilization of farmland water and the control of soil erosion. Soil amendments can enhance soil infiltration and storage capacity by increasing the cohesion between soil surface particles and maintaining a good soil structure. To understand the research status and development trend of soil amendments in improving soil infiltration and storage capacity, this study analyzed the annual publication volume, the major contributing institutions, the international cooperation relationships, and the research hotspots in this research field based on the Web of Science Core Collection database, using Citespace and VOSviewer software. The results showed that the number of publications on the application of soil amendments in improving soil infiltration and storage capacity had increased over the past two decades, with China, the United States, and Spain dominating in terms of publication volume and international influence. The current research hotspots mainly include soil aggregates, soil fertility, soil microorganisms, soil pore characteristics, organic amendments, and biochar. Future research should focus on the impact mechanisms of soil amendments, led by biochar, on reclaimed soil productivity when used to enhance soil infiltration and storage capacity. Additionally, further exploration should be conducted on the interaction between soil aggregates and surface runoff. Full article

Reclaiming land after mining activities and ensuring environmental protection are mandatory aspects of the decommissioning process for mining sites. Groundwater assessments, particularly those evaluating vulnerability to contamination using the DRASTIC rank method, are critical tools for guiding and controlling reclamation efforts. By analysing changes in hydrogeological and environmental factors, as well as parameter classes through sensitivity analyses, the DRASTIC method can be optimised to predict the effects of reclamation. Results indicate that reclamation typically decreases groundwater vulnerability, as evidenced by a shallower water table, reduced recharge volume, groundwater flow within new waste rock formations, changes in soil types, lower slopes, and reduced conductivity. Vulnerability changes during reclamation vary spatially, including both decreases and localised increases. Reclamation planning should prioritise groundwater vulnerability assessments to ensure effective land use and environmental protection. Modifications to groundwater-monitoring networks, especially in areas prone to flooding and significant surface changes, are also essential for comprehensive reclamation management. Full article

To thrive as a successful weed in natural pastures, a plant must have not only highly competitive ability, but also the resilience to endure environmental stress and rapidly reclaim space once those stressors diminish and the other non-stress-tolerant plants die. Acanthostyles buniifolius [(Hook. ex Hook. & Arn.) R.M.King & H.Rob.], known as chirca, is a widely spread weed in South American natural pastures. It is known for its remarkable ability to withstand environmental stress and flourish in environments with prevalent stressors. The study evaluated the memory effect of water stress (drought) in chirca plants. The experiment was conducted in a greenhouse in a randomized block design with three replications. Treatments included Control = control plants without water deficit kept at 100% of the soil water-holding capacity (WHC); Primed plants = plants that were primed with water stress at 141 days after emergence (DAE) and received recurrent stress at 164 DAE; Naïve plants: plants that only experienced water stress at 164 DAE. To reach water stress, plants were not watered until the soil reached 15% of the soil’s WHC, which occurred ten days after water suppression in the priming stress and nine days after water suppression in the second stress. During periods without restriction, the pots were watered daily at 100% of the WHC. Primed plants exposed to water deficit better-maintained water status compared to the naïve plants; glycine betaine is an important defense mechanism against water deficit in chirca; naïve plants have a higher concentration of proline than plants under recurrent stress, demonstrating the greater need for protection against oxidative damage and needs greater osmotic regulation. Recurrent water deficits can prepare chirca plants for future drought events. These results show that chirca is a very adaptative weed and may become a greater threat to pastures in South America due to climate change, especially if drought becomes more frequent and severe. Full article

Reclaimed water irrigation is increasingly being applied to address global water scarcity, yet its long-term effects on soil nitrogen cycling and salinity dynamics, particularly in agricultural and agroforestry systems, remain complex and insufficiently understood. Understanding these impacts is crucial for developing sustainable practices that optimize resource use while ensuring the long-term health and viability of agricultural and agroforestry systems. This study employs genetic-algorithm-optimized random forest models (GA-RF1 and GA-RF2) to examine the dynamics of nitrogen indicators (NO₃⁻-N, NH₄⁺-N, and TN) and salinity indicators (EC and Cl⁻) under reclaimed water irrigation. The models achieved high predictive accuracy, with NSE values of 0.918, 0.946, 0.936, 0.967, and 0.887 for NO₃⁻-N, NH₄⁺-N, TN, EC, and Cl⁻, respectively, demonstrating their robustness. Key drivers of nitrogen indicators were identified as irrigation duration (years), fecal coliform levels, and soil depth, while salinity indicators were primarily influenced by land use type and the chemical composition of reclaimed water, including chemical oxygen demand, total phosphorus, and total nitrogen. Spatial analysis revealed significant nitrogen and salinity accumulation in surface soils with extended irrigation, particularly in farmland, where NO₃⁻-N and NH₄⁺-N peaked at 25 mg/kg and 15 mg/kg, respectively. EC exceeded 700 µS/cm during early irrigation stages but remained within crop tolerance levels. Conversely, grassland and woodland exhibited minimal nitrogen and salinity accumulation. These findings underscore the need for targeted management strategies to mitigate nitrogen and salinity buildup, particularly in farmland, to ensure long-term soil health and productivity under reclaimed water irrigation systems. Full article

Pharmaceutical and personal care products (PPCPs) have the characteristics of environmental persistence, bioaccumulation, and high toxicity, and their environmental behavior has attracted the attention in the process of sewage resource utilization in recent years. In this study, four kinds of irrigation water sources (the primary treated water of rural domestic sewage (RDS) R1, the secondary treated water of RDS R2, the ecological pond purified water R3 and river water (CK) and three kinds of water level regulations (low-, medium- and high-water level regulation of W1, W2, and W3) were set to study the migration law of 22 kinds of PPCPs in rural domestic reclaimed water (RDRW), paddy soil and rice plants. Five rice plant and soil samples were, respectively, taken from each treatment using the five-point sampling method in this study. The samples were pretreated using the solid-phase extraction (SPE) method. After pretreatment, PPCPs were quantitatively analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The objective of the research was to explore the distribution patterns in soil-crop system, further evaluating the ecological risks of PPCPs in soil and rice plants under the regulation of RDRW irrigation. The results showed that 21 kinds of PPCPs were detected in RDRW and CK, among which the concentration of ofloxacin (OFL) was the highest. Fifteen kinds of PPCPs were detected in paddy soil and rice grain, among which atenolol (ATE) content was relatively higher. Compared with CK, the total content of PPCPs in the soil surface layer (0–20 cm) was the highest under RDRW irrigation. The impacts of different water level regulations on the PPCPs content between soil profile and rice grain were not significant. In addition, the reduction rate of 15 PPCPs in soil under RDRW irrigation was greater than 85%, and the bio-concentration factor (BCF) of PPCPs in rice grain was less than 0.1. The ecological risk assessment showed that ibuprofen (IBU) was a high-risk substance pollutant, triclocarban (TRIC) was a medium-risk pollutant, ofloxacin (OFL) was a low-risk pollutant, while the other PPCPs were all risk-free pollutants under RDRW irrigation. Therefore, R3 water sources can be selected for direct agricultural irrigation, while direct irrigation of R1 and R2 water sources should be avoided. Full article

This study investigated the impacts of reclaimed water (RW) irrigation on soil properties and landscape plant growth in a coastal monsoon city over a 13-month period. Soil properties in plots irrigated with RW and tap water (TW) were monitored monthly, including electrical conductivity, total nitrogen, total phosphorus, soil organic matter, and overall variations of soil enzyme activities. The results show that RW irrigation led to increased fluctuations in soil salinity indicators, with higher peaks during periods of low rainfall. Rainfall can efficiently mitigate the salinity increase associated with RW irrigation, highlighting the influence of monsoon climate variability on salinity dynamics. RW application increased soil total nitrogen and organic matter and decreased soil total phosphorus. This suggests that RW irrigation induces complex nutrient interactions within the soil–plant system. Furthermore, RW irrigation promoted the activities of soil enzymes related to carbon, nitrogen, and phosphorus cycling, indicating potential alterations in nutrient bioavailability. Plant growth responses varied among species, with Nephrolepis cordifolia and Cordyline fruticose exhibiting signs of salt stress, especially in the initial months of planting in RW plot. Other species demonstrated greater tolerance to RW irrigation, suggesting the importance of species selection for sustainable landscape management with RW. This study demonstrates the challenges and opportunities associated with RW utilization for urban greening. Full article

In arid and semi-arid zones, reclaiming/restoring salt-affected soil is considered a significant challenge because of the limited amount of water available for soil washing. The reclaimed salt-affected soil is regarded as a valuable resource for increasing the production of food and feed. In the current study, soil electrokinetics (SEK) under pulsed-mode electric field operation was used to evaluate and optimize energy use efficiency for reclaiming salt-affected soils, which is one of the electro-agric technology branches that was suggested in 2021 to address the water crisis in arid and semi-arid regions. Under a fixed applied voltage of 5 V, or 1 V/cm, the calcareous, highly salinized soil under investigation was reclaimed. A 25% reduction in applied voltages with time OFF set at 15, 30, 60, and 120 min and a 50% reduction with time OFF set at 15, 30, 60, and 120 min were the two pulsed electric field techniques that were examined. The findings demonstrated that the removal of Na⁺ surpasses half (50%) in the majority of pulsed-mode studies. By decreasing the removed K⁺, which is crucial for plant growth, the pulsed modes of electric fields 25 and 50% showed an economic advantage over the control experiment, which operated with a continuous electric field. Throughout the control experiment, very little Ca²⁺ was removed. However, the amount of Ca²⁺ removed rose when the electric field’s pulsed mode was applied, and the removal percentages were higher for the pulsed 50% strategy than the pulsed 25% strategy. In nearly every segment of every experiment (control, pulsed 25%, and pulsed 50%), the pH levels exceeded the initial value of 8.05. The pulsed 25% strategy of the OFF time showed an improvement in current passing at the longest interval of 120 min; the pulsed 50% strategy of the OFF time showed an improvement in current passing at the shorter and longer intervals of 15, 60, and 120 min; however, the interval of 30 min had a negative effect. The cumulative EO flow at the time OFF interval of 60 min was improved by the pulsed 25% strategy throughout the first seven days of operation, and by the end of the trial, the control experiment exhibited high values. The highest values, however, were displayed by the pulsed 50% field at the time OFF interval of 60 min. The anolyte pH decreased for the majority of the time OFF intervals over the first seven days of the trial for both the 25% and 50% pulsed strategies. Lastly, in order to minimize the overall energy consumption, it is strongly advised that the pulsed mode of the electric field be used while reclaiming salt-affected soil. Full article

Reasonably using reclaimed water (RW) for irrigation can help to alleviate water scarcity, while also providing both environmental and economic benefits. However, there is limited information regarding the potential impact of RW irrigation on the nutrients of saline–alkali soils and their microbial communities. This study investigates the effects of RW irrigation on saline–alkali soil properties and microbial communities using a 16S rRNA sequence analysis. The results show that the pH and electrical conductivity (EC) are significantly lower in RW treatment (p < 0.05). Compared to the saline–alkali soil that was not irrigated with RW (CK), the EC value decreased by 42.15–45.76%, in both 0–20 cm and 40–60 cm depth. RW exhibited a significant increase in the abundance of Actinobacteria (32.32–33.42%), Chloroflexi (7.63–15.79%), Firmicutes (9.27–10.42%), and Ascomycota (89.85–95.95%). Bacterial richness and diversity were significantly enhanced after RW irrigation (p < 0.05). At the genus level, the dominant bacterial genera included Bacillus, Penicillium, Aspergillus, and Talaromyces. Differences in the microbial community were observed between the two treatments and among soil depths within each treatment (p < 0.05). A network analysis indicated that the internal relationships among bacterial communities become more complex following RW irrigation, whereas the internal connections within fungal communities tend to become more simplified. A redundancy analysis (RDA) showed that soil microbial communities were directly influenced by EC, total nitrogen (TN), and available potassium (AK). Partial least squares path modeling (PLS-PM) results indicated that soil salinity and available nutrients were the most significant factors influencing the microbial community structure. Together, these results indicate that RW irrigation has a positive impact on ameliorating soil salinity and enhancing microbial community diversity in saline–alkali soils. These findings provide valuable insights for the future agricultural utilization of saline–alkali land. Full article

During coastal reclamation processes, land use conversion from natural coastal saline/sodic soils to agricultural land changes the soil’s physicochemical properties. However, the impact of soil structure evolution on soil hydraulic properties (SHPs, e.g., hydraulic conductivity and soil water retention curves) during long-term reclamation has rarely been reported. In this study, we aimed to evaluate the effect of reclamation duration and land use types on the soil aggregate stability and SHPs of coastal saline/sodic soils and incorporate the aggregate structures into the SHPs. In this study, a total of 90 soil samples from various reclaimed years (2007, 1960, and 1940) and land use patterns (cropland, grassland, forestland, and wasteland) were taken to analyze the quantitative effects of soil saline/sodic characteristics and the aggregate structure on SHPs through pedotransfer functions (PTFs). We found that soil macroaggregate contents in the old reclaimed areas (reclaimed in 1940 and 1960) were significantly larger than those in the new reclamation area (reclaimed in 2007). The soil saturated hydraulic conductivity (K_s) of forestland was larger than that of grassland in each reclamation year. Soil structure contributed to 22.13%, 24.52%, and 23.93% of the total variation in K_s and soil water retention parameters (α and n). The PTFs established in our study were as follows: log(K_s) = 0.524 − 0.177 × ${\mathrm{Y}}_{k_3}$ − 0.093 × ${\mathrm{Y}}_{k_1}$ + 0.135 × ${\mathrm{Y}}_{k_4}$ − 0.054 × ${\mathrm{Y}}_{k_2}$, 1/α = 477.244 − 91.732 × ${\mathrm{Y}}_{{\alpha }_2}$ − 81.283 × ${\mathrm{Y}}_{{\alpha }_4}$ + 38.106 × ${\mathrm{Y}}_{{\alpha }_3}$, and n = 1.679 − 0.086 × ${\mathrm{Y}}_{n_2}$ + 0.045 × ${\mathrm{Y}}_{n_1}$ − 0.042 × ${\mathrm{Y}}_{n_3}\left(\mathrm{Y}\mathrm{a}\mathrm{r}\mathrm{e}\mathrm{p}\mathrm{r}\mathrm{i}\mathrm{n}\mathrm{c}\mathrm{i}\mathrm{p}\mathrm{a}\mathrm{l}\mathrm{c}\mathrm{o}\mathrm{m}\mathrm{p}\mathrm{o}\mathrm{n}\mathrm{e}\mathrm{n}\mathrm{t}\mathrm{s}\right)$. The mean relative errors of the prediction models for log(K_s), 1/α, and n were 79.30%, 36.1%, and 9.89%, respectively. Our findings quantify the vital roles of the aggregate structure on the SHPs of coastal saline/sodic soils, which will help us understand related hydrological processes. Full article