Water, Air, & Soil Pollution最新文献

Wastewater generated during tunnel construction and tunnel cleaning contains diverse pollutants that may pose significant environmental risks if discharged without proper treatment. This review systematically summarizes the sources, characteristics, characterization methods, and treatment technologies of tunnel-related wastewater from an engineering perspective. Tunnel construction wastewater typically exhibits high suspended solids (73–6250 mg/L), elevated pH values (up to 13), ammonia nitrogen, and metal ions, whereas tunnel wash wastewater is dominated by traffic-related organic micropollutants, including polycyclic aromatic hydrocarbons (≤ 4 μg/L), nonpolar oil (≤ 70 mg/L), and trace metals (1.2–27,000 μg/L). Conventional and advanced characterization techniques, ranging from routine physicochemical parameters to spectroscopic and chromatographic analyses, are critically reviewed with emphasis on their analytical capabilities, limitations, and practical applicability. Treatment technologies based on physical, chemical, biological, and membrane processes are systematically evaluated. Chemical coagulation–flocculation can achieve suspended solids removal efficiencies exceeding 90%, while integrated treatment systems combining coagulation, filtration, and membrane processes demonstrate superior performance, enabling more than 99% removal of salts and metals and meeting reuse standards under complex operating conditions. Unlike previous reviews that focus on individual technologies or specific pollutants, this review provides a critical, side-by-side comparison of tunnel wastewater characterization and treatment approaches, highlighting their engineering applicability, operational robustness, and inherent limitations under realistic construction scenarios. Key technical challenges and future research directions toward sustainable and adaptable tunnel wastewater management are also discussed.

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Combined pollution by antibiotics and microplastics poses a significant threat to aquatic ecosystems and human health. Polystyrene (PS), a typical microplastic widely detected in aquatic environments, interacts with the sulfonamide antibiotic sulfathiazole (STZ) and thereby impacts wastewater treatment processes. In this study, a novel magnetic biochar (MBC) was synthesized via co-precipitation. Its performance in removing STZ in the presence of PS was systematically evaluated using experimental and theoretical calculation methods. The MBC exhibited excellent superparamagnetism (saturation magnetization: 11 emu·g⁻¹) and a high specific surface area (703 m²/g). In a single-pollutant system (STZ only), the MBC achieved an STZ adsorption capacity of 39.3 mg·g⁻¹. In contrast, the coexistence of PS in the STZ-containing system exerted a promotional effect, increasing the STZ adsorption capacity to 42.5 mg∙g⁻¹ (removal rate > 98%), with optimal performance under neutral conditions (pH 5.00–7.00). Notably, the MBC also maintained high efficiency in PS removal (up to 98%) while eliminating STZ. Kinetic analysis revealed that STZ adsorption in the single-pollutant system relied on hydrogen bonding and π-π conjugation. However, in the co-pollutant system (PS + STZ), PS formed complexes with STZ. These complexes anchored to the hydrophobic regions of the MBC, while the polar groups of STZ bound to the polar sites of the MBC, further enhancing the stability of PS-MBC binding. This is the first study to clarify that PS promotes STZ adsorption on MBC through complex formation, while also enabling efficient PS removal. It bridges the existing knowledge gap in the mechanism of co-pollutant removal and provides a feasible strategy for the synergistic elimination of antibiotics and microplastics.

Small lakes and ponds are often of critical ecological and economic importance. At the same time, they are increasingly impacted by anthropogenic activities, leading to eutrophic or hypertrophic conditions. These are typically accompanied by increasing primary production, nutrient, and detritus accumulation. Owners and stakeholders are often challenged to decide on feasible and appropriate measures for lake restoration. Addressing one of these measures, this study explores passive sediment aeration through oxygen slow-release from a calcium peroxide (CaO₂) formulation amended at the sediment surface. Compared to other peroxides, CaO₂ has a slow dissociation rate, which may enhance organic matter degradation and microbial activities over months. This study investigates the application of a CaO₂-based lake restoration agent (CLRA) by a fine-scale dissection of its application to an eutrophic lake sediment. Using laboratory sediment columns, a dose–response approach, fine-scale microsensor analytics, and 16S rRNA gene amplicon sequencing, we provide evidence for an increased oxygen availability within sediments while other biogeochemical parameters remained unaffected. Significant impacts on sediment height were not detected, and microbial diversity remained stable across depths and CLRA dosages. However, characteristic shifts in microbial communities in upper sediments, specifically within aerobic heterotrophs and carbohydrate-degrading taxa within the Gammaproteobacteria, Bacterioidota and others were clearly detected. The findings provide first detailed insights into the sedimentary and microbiological impacts of a CaO₂ formulation applied in lake restoration. Better understanding the mechanisms and ecosystem impacts of CLRA applications will be vital for the implementation of effective and ecologically sound lake restoration strategies.

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The purpose of this study was to evaluate the phytoremediation potential of aquatic plant water fern (Azolla pinnata R.Br.) in treating sugar mill wastewater by removing key pollutants. The experiment was conducted over 20 days at using different concentrations of sugar mill wastewater. The results showed that 75% sugar mill wastewater concentration gave maximum removal efficiencies of 91.13% for BOD, 84.91% for COD, 93.73% for TKN, and 93.17% for P. A first-order reaction-based kinetic model was applied to describe the removal kinetics, showing strong correlations (R² values between 0.88 and 0.99) for all measured parameters. As well, the highest fresh biomass (104.38 g), relative growth rate (1.61 mg/g/d), and total chlorophyll content (3.36 mg/g fresh weight) were observed at this concentration. The absorption coefficient (μ) for the key pollutants was also calculated to further understand the system’s efficacy. The results showed that A. pinnata is highly effective in reducing organic and nutrient pollutants from sugar mill wastewater. The proposed model suggests that this phytoremediation approach could be implemented as a cost-effective and sustainable method for mitigating industrial wastewater pollution. The study demonstrates that A. pinnata is a natural, low-cost solution for treating sugar mill wastewater.

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ZnO and Mg doped ZnO nanoparticles (NPs) were synthesized via chemical reduction technique, which were used as photocatalysts for the photodegradation of chlorpyrifos pesticide in aqueous media. The morphological study presented that ZnO NPs has hexagonal and spherical shape while Mg doped ZnO has needle like irregular structure. The XRD pattern demonstrates the crystalline size of ZnO and Mg doped ZnO NPs having diameter 31 and 34.30 nm, respectively. FTIR spectra showed peaks at 703, 419 and 1391–1448, cm⁻¹, which represent the metal oxide nanoparticles. The photocatalytic degradation study demonstrated that ZnO and Mg doped ZnO NPs degraded about 94 and 97% pesticide within 25 min, respectively. The effect of various parameters like irradiation time, pH, initial pesticide concentration and catalyst dosage on the photodegradation of pesticide were also studied. The recovered and re-recovered ZnO and Mg doped ZnO NPs were also significantly degraded the chlorpyrifos pesticide in aqueous media. Further, both types of NPs exhibited promising bioactivity and Antileishmanial activities.

Soil pollution is usually associated with biodiversity loss. However, soils enriched with zinc, lead and cadmium can support unique vegetation such as calamine grasslands, which are priority habitats for nature conservation programmes. This study investigates a declining calamine grassland in Northern France, which developed in the 1960s in the immediate vicinity of a former smelting plant. It was initially dominated by two locally rare and absolute metallophyte dicot species, Armeria maritima and metal-hyperaccumulating Arabidopsis halleri, in association with Agrostis capillaris. From then on, the grassland gradually declined and developed into a meadow, largely dominated by a tussock-forming grass: Arrhenatherum elatius. Possible explanations include landscaping, a decrease in soil metal concentrations or the replacement of pioneer species by later successional species. To better understand the causes of the decline and to discuss restoration strategies, we carried out an ecological study including: (1) compilation of available data to reconstruct the history of the site, (2) chemical analysis of soil element concentrations, (3) functional analysis of potential plant-plant interactions, and (4) a 7-year restoration experiment including vegetation monitoring. The results suggest that in the absence of significant anthropogenic disturbance, while soil metal concentrations remain elevated, grassland decline is best explained by plant successional dynamics. Accordingly, repeated disturbances, such as the removal of A. elatius tussocks by annual mowing of the vegetation with organic matter removal, not only stopped the expansion of A. elatius but also allowed a partial recovery of the calamine grassland.

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Urban NO₂ pollution poses major challenges to public health and environmental sustainability, particularly in rapidly expanding cities like Kanpur. Despite advances in remote sensing, limited attention has been given to the integration of high-resolution multispectral satellite data with advanced machine learning models for fine-scale NO₂ monitoring. This study addresses this gap by integrating Sentinel-2 spectral reflectance and Sentinel-5P NO₂ datasets through a Random Forest regression model to examine the spatial and temporal variability of NO₂ concentrations in Kanpur during 2024. The key objectives include identifying dominant temporal cycles, assessing spectral drivers, and evaluating model performance. Temporal analysis revealed distinct seasonal variation, with peak NO₂ in November and lowest levels in August, influenced by meteorological and anthropogenic factors. The 7th-degree polynomial model effectively captured these seasonal trends with best tradeoff between accuracy and complexity, while frequency-domain analysis detected dominant semi-annual and annual cycles. The Random Forest model achieved optimal performance with 50 trees with R² = 0.5442 and error of 7.2%). Spectral correlations indicated strong negative associations between NO₂ and Red Edge/NIR bands, underscoring vegetation’s mitigating role. In summary, this study demonstrates the effectiveness of integrating multi-sensor satellite data and machine learning for urban air quality estimation and offers a scalable, low-cost approach for data-scarce regions, supporting evidence-based pollution control and health planning.

The transport and retention behaviors of graphene oxide (GO) in saturated porous media were examined in systems containing heavy metals (Cd²⁺, Zn²⁺, Cr³⁺), with a focus on the effects of ionic strength (IS) and cation type. Both IS and cation type were found to be key factors governing GO retention. Notably, Cr³⁺ most effectively inhibited GO transport, a result attributed to its strong charge shielding and promotion of straining. At a low IS of 0.3 mM, the inhibitory effects of Cr³⁺, Cd²⁺, and Zn²⁺ on GO transport followed the Hofmeister series. Higher IS (3 mM) led to greater GO deposition. In the presence of 3 mM Cd²⁺ and Zn²⁺, the remobilization of retained GO was evidenced by double peaks in breakthrough curves, attributed to cation exchange and reduced IS, indicating reversible retention. In contrast, significant retention with no release (irreversible retention) occurred under Cr³⁺ even at a low IS (< 0.6 mM). Combined analysis of GO aggregation, interaction energy, and CFT confirmed that double-layer compression, cation bridging, and straining collectively governed GO retention, leading to retention profiles (uniform, exponential, or hyper-exponential) that depended on IS and cation type. These results are valuable for understanding the coupled environmental fate of GO and heavy metals in subsurface systems and are critical for assessing groundwater contamination risks under transient solution chemistry.

The need for clean water is the most basic human right. Water scarcity will be one important environmental problem of all countries in the future. Phosphorus in the water environment, come from some untreated industrial, agricultural and domestic wastewater, pose a significant threat to human health and and other biota due to their toxicity. In this study, the modified corn straw biochar (LBC) /sodium alginate (SA) composites (LBS) adsorbents were prepared to remove phosphate from water. The results showed that the best pyrolysis temperature of preparing LBS was 550 °C. When pH was 2 and mass ratio of 550LBC (at 550 °C)/SA was 0.3 g/0.3 g, the adsorption capacity and removal efficiency of phosphate by 550LBS were 61.4 mg/g and 92%, respectively. The adsorption of phosphate by 550LBS was consistent with Langmuir model and pseudo 1st order model (R² > 0.95), and reached adsorption equilibrium at 20 min, indicating that 550LBS was monolayer adsorption, physical adsorption was the main adsorption and chemical adsorption was the secondary adsorption. The adsorption of 550LBS was the protonation between surface hydroxyl group and H⁺, the phosphate adsorption of 550LBS was dominated by ligand exchange and electrostatic attraction. Compared with the maximum adsorption capacity of 550LBS, used 550LBS could be reused, the adsorption efficiency of adsorbents after three tests was still above 41%. This showed that reusability and renewability of 550LBS were good, and promotes its application in water purification processes.

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