Journal of Environmental Management最新文献

This preliminary study examines how beaver engineering affects river condition in England and can be measured in relation to Biodiversity Net Gain (BNG) using the River Condition Assessment (RCA) methodology. Paired river reaches with (impact) and without (control) beaver engineering were compared at eight sites across southern England. At two sites, beavers were enclosed; at six, they were free-living. Two additional sites supported free-living beavers but without beaver engineering, so impact and control reaches could not be distinguished. Three hypotheses were tested: (i) in lowland English rivers, beaver engineering improves river condition as measured by the RCA; (ii) the magnitude of improvement depends on baseline river condition; and (iii) improvements in river condition are linked to increases in the presence and abundance of specific physical habitats. Findings from paired sites indicated that beaver-engineered reaches were generally assessed by the RCA to be in better condition than control reaches, supporting hypothesis (i), especially where control reaches were assessed to be overdeep (due to past management). Furthermore, the degree to which condition improved across paired reaches was inversely related to the condition of the control reach, supporting hypothesis (ii). Ten physical features showed significantly higher abundances in beaver-impacted reaches, while other physical features showed similar abundances in control and impact reaches, supporting hypothesis (iii). Although conducted in lowland, predominantly pastoral landscapes, the sites captured a typical range of environmental settings for beaver engineering and this preliminary study demonstrates that the RCA can effectively measure the influence of beaver engineering on river condition. These results provide a foundation for future research and offer practical guidance for considering beaver reintroduction as a nature-based tool for achieving Biodiversity Net Gain in development planning.

Combined sewer overflows (CSOs) represent a major challenge for urban water management, as they intermittently discharge untreated wastewater and stormwater to the receiving water bodies. Nature-based solutions (NbS), such as treatment wetlands (TWs), offer a sustainable alternative, but full-scale evidence, particularly aerated TWs operating under highly variable CSO conditions, remains extremely limited. The present study addresses this gap through a two-year evaluation of a full-scale aerated TW treating CSOs upstream of the Merone WWTP (Italy). The system was evaluated for conventional pollutants, nutrients, heavy metals, organic micropollutants, pathogens, and microplastics. Results demonstrate that forced aeration enables stable treatment performance under high hydraulic and pollutant loading rates, achieving median removals of 85.3% for COD, 89.0% for BOD₅, 95.6% for TSS, and 66.6% for ammonium nitrogen. High retention of particle-associated metals (Pb, Cu, Zn, Al) and microplastics (70-90%) highlights the dominant role of filtration and sorption processes, while compound-specific behavior governed organic micropollutant removal. Pathogen reductions ranged from 0.5 to 2 log units, indicating effective attenuation but confirming that additional disinfection would be required for water reuse applications. Additionally, an adaptive aeration strategy based on real-time COD monitoring is proposed, showing the potential to reduce aeration demand to approximately 10% of CSO event duration. This approach could lower aeration energy consumption by about 43 MWh y^-1, without compromising treatment reliability. Overall, the findings confirm the feasibility of aerated TWs as robust NbS for CSO management, highlighting the potential of sensor-supported, demand-based aeration to enhance wetland performance and operational sustainability in future large-scale applications.

Organic substitution technology is regarded as a key pathway for achieving sustainable agricultural development. However, systematic quantitative analyses examining the effects of different organic substitution ratios on maize productivity in China remain scarce. Therefore, following the PRISMA guidelines, we screened 235 studies for a meta-analysis to systematically assess the effects of different organic substitution ratios on grain yield (GY), water productivity (WP), nitrogen uptake (NU), and N losses, while exploring key associated factors. Organic substitution significantly increased GY (1.6%, 95% confidence interval (CI): 0.7-2.4%), WP (2.2%, 95%CI: 0.2-4.4%), and NU (2.7%, 95%CI: 1.3-4.3%), with the effects were most pronounced when the substitution ratio was 20-40%. Climatic conditions with mean annual temperature of 7-12 °C and mean annual precipitation >550 mm were more favorable for increasing production and efficiency. The greatest increases in GY, WP, and NU were observed in slightly acidic and nutrient-sufficient medium soils. The most significant increase in maize productivity was observed with nitrogen application rate of 180-240 kg ha^-1 and irrigation, and was further amplified in spring maize cropping system with planting density >7 × 10⁴ plants ha^-1. The increments of GY, WP, and NU were amplified when organic fertilizer N > 2.5%, organic fertilizer C > 50%, and organic fertilizer C:N > 30. Furthermore, a substitution ratio of 20-40% clearly reduced N losses. The optimal substitution intervals for the Northeast, Northwest, Southwest, North, and Southeast regions were 25.6-39.8%, 27.9-42.8%, 22.8-39.5%, 19.9-41.5%, and 37.5-58.1%, respectively. Organic substitution technology effectively enhances crop productivity and reduces N losses in China's maize production, providing valuable insights for sustainable production. The most notable issue is that the robustness of this study's conclusions may be limited due to the high heterogeneity of the sample and the reliance on variance estimation. Future research requires methodological breakthroughs to improve its extrapolation value.

The extensive use of antibiotic compounds has raised significant ecological concerns and potential threats to public health. In this study, a sandwich-structured Fe₃O₄-CeO₂/CNTs-Fe₃O₄-loaded carbon nanofiber mat was successfully fabricated through facile electrospinning coupled with subsequent thermal annealing, serving as an innovative three-dimensional adsorption-enhanced electro-Fenton cathode for the removal of amoxicillin (AMX) - a prevalent semi-synthetic β-lactam antibiotic. The results demonstrated that as-prepared electrode exhibited rapid AMX adsorption kinetics, attaining a maximum adsorption capacity of 229.9 mg g^-1. Remarkably, over 99% removal of AMX was achieved via a two-stage process: 20-min pre-adsorption followed by 60-min electro-Fenton oxidation. The developed electrode showed exceptional pH adaptability and operational durability, with low metal leaching observed across six consecutive reuse cycles. Mechanistic analysis revealed that the improvement of removal performance originated from synergistic interactions between adsorption of low-level AMX and enhanced degradation of hydroxyl radical (∙OH) electro-generated via as-prepared cathode. This study provides new insights into a binder-free "self-cleaning" electro-Fenton cathode for the removal of antibiotics wastewater.

Water pollution caused by dyes from the textile industry poses a serious environmental challenge, driving the development of efficient adsorbents and strategies for their reuse in water purification processes. In this work, a polar hydrophobic poly(ionic liquid), poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (Poly(DADMA)NTf₂), was synthesized, characterized, and used as adsorbent for the removal of two anionic textile dyes, Direct Red 80 (DR80) and Reactive Blue 5 (RB5), from water. Characterization results confirmed the successful synthesis and revealed high thermal stability (T_onset ≈ 421.6 °C) and a semi-crystalline nature. The aim is to develop a polar adsorbent, capable of exhibiting high extraction efficiencies in the removal of charged dyes from the textile industry, and electrochemically stable so that it can be recycled through electrochemical processes, which degrade the dyes with minimal adsorbent loss. Two different particle sizes, less than 0.071 mm and between 0.45 and 1.00 mm, were studied. The kinetic studies indicate that the adsorption equilibrium was achieved within 20 min for direct red 80 and 5 min for reactive blue 5, with maximum adsorption efficiency of 99.2% and 99.3%, respectively, using the smaller particles size. Generally, the adsorption mechanisms followed the Langmuir isotherm model, except for RB5 with larger Poly(DADMA)NTf₂ particles, where the Freundlich model provided a better fit. The poly(DADMA)NTf₂ was reused in eight successive adsorption cycles without intermediate regeneration. Regeneration was performed using three-dimensional (3D) electrochemical oxidation with a mixed metal oxide anode and a stainless-steel cathode. Under optimal conditions (35 mL solution, 1 mg/mL polymer concentration, 5 V potential, 0.04 M NaCl as the electrolyte), over 85.0% polymer adsorbent recovery was achieved after two regeneration cycles. However, the polymer's adsorption capacity slightly declined with each cycle, likely due to degradation during electrochemical oxidation. Although no clear trend was observed regarding dye order during reuse, Reactive Blue 5 consistently showed higher adsorption than Direct Red 80, across all cycles.

When treating low carbon (C)/nitrogen (N) municipal wastewater, it is still difficult to achieve efficient simultaneous nitrogen and phosphorus removal by relying only on raw water carbon sources. In this study, static magnetic fields (SMF) enhanced simultaneous partial nitrification endogenous denitrification phosphorus removal by aerobic granular sludge system was utilized to achieve highly efficient deep removal of nitrogen and phosphorus from low C/N municipal wastewater. The results of the microbial activity batch experiment indicate that SMF promoted the activity of ammonia-oxidizing bacteria (AOB) significantly more than nitrite-oxidizing bacteria (NOB) at 10 mT, while the opposite was true at 50 mT. Both phosphorus release and uptake activities were significantly enhanced with increasing SMF intensity. Long-term operational results showed that the partial nitrification and phosphorus removal performance was significantly enhanced in the low SMF intensity (10 mT), but the extent of performance enhancement diminished in the high SMF intensity (50 mT), compared to the control group. The high SMF intensity promoted the secretion of more extracellular polymeric substances (EPS), and the granules were encapsulated by dense, viscous substances, leading to the limitation of internal dissolved oxygen mass transfer, which in turn counteracted the microbial activity of the system. High-throughput sequencing results confirmed that the energy metabolism of the system was enhanced with the increase of SMF intensity, which in turn promoted the secretion of the EPS. The specific effects of SMF on microbial activity and EPS resulted in a Two-way synthesis effect in the long-term operation of the system.

The escalating prevalence of heavy metal pollution from lead (Pb²⁺) and cadmium (Cd²⁺) threatens ecological security and public health, necessitating advanced multifunctional adsorbents. Herein, a thiol-functionalized Cu-MOF@biochar composite (SH-MOF@BC) was innovatively synthesized via hydrothermal method. Characterization (SEM-EDS, BET, XRD, FTIR) confirmed a multi-level pore architecture with ultrahigh surface area (379.05 m²/g), an average pore size of 2.2205 nm, and multi-elemental composition (C, O, P, Cu, S). Multi-active sites (-SH, -COOH, -OH, C=O) synergistically enhanced heavy metal sequestration. In batch adsorption tests, the material achieved High uptake of 262.72 (Pb²⁺) and 57.24 (Cd²⁺) mg/g in single-component systems, surpassing most advanced composites. Notably, in binary systems, Cd²⁺ coexistence enhanced Pb²⁺ uptake due to ion-specific binding, while the composite retained >81% capacity after five regeneration cycles. Langmuir and pseudo-second-order models indicate covalent-driven monolayer chemisorption.Thermodynamic analysis further indicated that the binding was spontaneous (ΔG⁰ < 0) and endothermic (ΔH⁰ > 0).XPS analysis identified sulfhydryl groups (-SH) as primary sites, forming stable metal-sulfide complexes (Pb-S, Cd-S). This work provides a scalable green strategy for multi-pollutant wastewater remediation aligned with sustainable chemistry principles.

Reliable real-time measurement of suspended sediment mass concentration (SSC) is essential for effective environmental monitoring and management. It is also important for the operation and maintenance of hydropower schemes, particularly in managing reservoir sedimentation and mitigating turbine abrasion. However, sensor readings are strongly influenced by variable sediment properties, particularly size and shape, hindering reliable monitoring. This study systematically investigates the effects of particle size (median particle diameter d₅₀ and Sauter Mean Diameter SMD) and shape (sphericity Ψ) on the responses of several turbidimeters and acoustic sensors (single- and multi-frequency), and develops methods for practical application. A customized recirculating cylindrical tank with a volume of 246 L and a maximum upward flow velocity of 0.2 ms^-1 enabled testing various natural and artificial particles (up to 2 mm) across SSCs from 0.5 to 25 gl^-1. We analyzed the specific outputs of the instruments, defined as the outputs divided by SSC, representing the calibration factors for each particle type. We found that for turbidimeters, the specific output scaled with inverse power-law relations of d₅₀ as well as SMD, and decreased nearly linearly with Ψ. SMD and Ψ proved effective for combining size/shape effects and representing shape-related output, offering a basis for generalized field calibration. We developed three generic models to predict sensor output conversion factors for improved real-time SSC monitoring and calibration. The best-performing data-driven model, applied to a natural sediment sample, showed good agreement for turbidimeters but overestimated acoustic sensor response, highlighting refinement needs. The findings advance the understanding of sensor responses and support the feasibility of generic prediction models across diverse sediment types and sensor technologies. This study contributes to better informed sensor selection and calibration, directly enabling more effective and sustainable monitoring and management of water and sediment resources.

Traditional Fenton reaction is limited by strict pH and iron sludge. integrating photo-Fenton enables operation under mild conditions. We report a one-step hydrothermal synthesis of Fe-modified Bi₂WO₆ (Fe-BWO) to create an efficient photo-Fenton synergistic system for ciprofloxacin (CIP) removal under visible light. The Fe-BWO system achieved 83.7 % CIP degradation in 1 h, surpassing standalone photocatalysis and homogeneous Fenton. The degradation rate was 6 times that of photocatalysis and 1.5 times that of homogeneous Fenton. Crucially, the system exhibited excellent stability, wide pH applicability, and low H₂O₂ consumption OH, and ·O₂^- were confirmed as major reactive species. Mechanistic studies indicate that the narrowed band gap promotes electron migration, while H₂O₂-induced surface microenvironment variation (attributed to Bi^(3-x)+ electron redistribution) is vital for molecular oxygen activation. This work offers novel insights into H2O2 activation and the impact of surface microenvironments in photo-Fenton processes.

Thallium (Tl) pollution poses severe environmental risks, with the steel industry being a significant contributor. However, the behavior and fate of Tl under the rapidly adopted dry flue gas desulfurization (FGD) process remain poorly understood. This study provides the first comprehensive substance flow analysis (SFA) of Tl in a full-scale steel plant utilizing dry FGD. Through integrated field sampling, chemical analysis, SFA, and thermodynamic simulations, we established a complete Tl flow network and elucidated its phase transformation mechanisms. The results revealed a total Tl input/output flux of 3325.50 and 3295.11 mg/t-crude steel, respectively. Notably, coke was identified as a major input source (21.15 %), alongside the circulating sintering head dust (40.62 %). More critically, sequential extraction demonstrated that Tl in dry FGD by-products (e.g., dusts) predominantly exists in the highly mobile and bioavailable exchangeable fraction (>50 %), indicating a substantially higher leaching and ecological risk than previously recognized. The primary output pathways were dust (37.01 %) and exhaust gas (14.34 %). Based on these findings, we evaluated emission reduction potentials via source control (e.g., raw material selection) and end-of-pipe treatment strategies. This work uncovers the unique drivers and heightened environmental risks of Tl in dry FGD steel plants, offering crucial insights for targeted pollution control and sustainable waste management in the evolving steel industry.