Polypyrrole-functionalized sea urchin-like MnO2 as the carrier for anchoring CuCo2S4 (MnO2-PPy@CuCo2S4) was prepared and utilized to activate peroxymonosulfate (PMS) for degradation of typical antibiotics in water. The physicochemical properties of the resulting catalyst were characterized and analyzed by means of SEM, TEM, EDS, XRD, FT-IR, XPS, etc. The results showed that MnO2-PPy with unique structure and surface active groups created favorable conditions for anchoring CuCo2S4, which not only improved the dispersion of CuCo2S4, but also greatly enhanced the catalytic performances of the composite catalyst due to the synergistic effects between the three. The maximum removal of sulphamethoxazole (SMX), norfloxacin (NOR), oxytetracycline (OTC) and carbamazepine (CBZ) (10mg/L) in aqueous solution could reach up to 100%, 92.3%, 89.0% and 85.5% within 40min, respectively. Unique three-dimensional heterojunction and the enriched reactive sites enhanced electron transfer, which greatly promoted the redox cycles of Mn3+/Mn4+, Co2+/Co3+ and Cu+/Cu2+ and resulted in radical and non-radical pathways especially 1O2 and O2•− dominated the degradation of antibiotics. Moreover, the MnO2-PPy@CuCo2S4+PMS system exhibited satisfactory environmental applicability such as a wide pH application range (3.0-10.0), high removal in complex water matrices and good reusability. Furthermore, the possible degradation mechanisms and pathways of the MnO2-PPy@CuCo2S4+PMS system for antibiotics were proposed and the ecological toxicity of degradation intermediates was explored. Besides, the three-dimensional molding catalysts including the porous tablet-structured MnO2-PPy@CuCo2S4 and polyurethane sponge-loaded with MnO2-PPy@CuCo2S4 were constructed and evaluated their catalytic activity and potential in practical applications.
Tar removal remains a critical challenge in the thermochemical conversion of biomass, as its presence compromises syngas quality and threatens downstream pipelines. Microwave-driven steam reforming (SR) has garnered significant attention owing to its capacity to lower activation energy and mitigate carbon deposition. In this study, LaNiO3-σ perovskite oxygen carries (OCs) with distinct morphologies and physicochemical properties were successfully synthesized for microwave-driven chemical looping SR (CLSR) of toluene. By optimizing the steam-to-carbon (S/C) ratio, the toluene carbon conversion and the hydrogen yield were maximized while maintaining excellent stability throughout the CLSR redox cycles. During the SR reaction, the B-site metal Ni underwent highly dispersed exsolution. Leveraging the synergy between the microwave-driven non-thermal plasma and the OCs active sites, a toluene carbon conversion of 95.08% and a hydrogen yield of up to 147.78 mmol/g were achieved. The OCs demonstrated outstanding cyclic stability over 20 consecutive cycles. This work provides a novel strategy for designing catalysts for microwave-assisted tar steam reforming and highlights their potential for the efficient ex-situ conversion of tar.
The persistent occurrence of environmentally harmful halophenols (HPs) in aquatic ecosystems necessitates their efficient extraction and determination. Herein, a carboxyl-functionalized magnetic covalent organic framework (mCOF-d-COOH) was readily constructed via a monomer truncation-induced defect engineering strategy, and applied for magnetic solid-phase extraction (MSPE) of HPs in environmental waters. Compared to the defect-free counterpart, defect-induced carboxyl groups in the framework enhanced the hydrophilicity and introduced abundant active sites, endowing mCOF-d-COOH with improved extraction efficiency. Coupled with high-performance liquid chromatography (HPLC), the proposed method delivered low limits of detection (0.02–0.08 ng mL–1), high enrichment factors, broad linear ranges, and excellent reusability over 30 cycles. Mechanism analysis demonstrated that the adsorption behavior of mCOF-d-COOH toward HPs was driven by the synergistic interactions including π-π stacking, van der Waals interactions, electrostatic attraction, and hydrogen bonding, with electrostatic attraction and hydrogen bonding being the dominant contributors. This work demonstrates that the monomer truncation-induced defect engineering provides a facile and feasible approach to constructing functionalized COFs, and offers a reliable platform for monitoring trace HPs in environmental waters.
Contamination of agricultural soils by heavy metal(loid)s (HMs) has become a complex environmental issue involving food security, soil functions, ecological risk, and public health. Research priorities in this field have gradually shifted, yet the temporal correspondence between knowledge evolution and policy agendas remains insufficiently understood. To address this gap, this study integrated bibliometric analysis, policy text coding, and temporal mapping to link research hotspot evolution with policy milestones across four governance dimensions. The analysis included 10,008 Web of Science Core Collection publications from 2000 to 2025 and policy texts on agricultural soil pollution prevention and control. The results showed that knowledge production concentrated in a limited number of countries and institutions, with China as the dominant contributor. Research hotspots expanded from pollution identification, spatial distribution, and characterization of HMs to risk governance, including source apportionment, risk assessment, remediation, and soil health. Temporal mapping and sensitivity analyses showed that selected source-control and risk-assessment burst terms generally entered active phases before the corresponding policy anchors, whereas land use and safe-use and remediation-related terms showed weaker, mixed, or anchor- and keyword-sensitive temporal patterns. Collectively, the analysis suggested a stepwise temporal pattern in selected dimensions, from research-topic accumulation to later policy institutionalization, but this pattern should be interpreted as exploratory temporal correspondence rather than causal evidence. This study provides an analytical framework for examining the structural temporal correspondence between research and governance agendas. Future research should integrate policy-implementation data and field evidence to examine the institutional implications and management effects of these temporal patterns.
The anaerobic/oxic/anoxic (AOA) process is a promising strategy for carbon-efficient biological nutrient removal, but how carbon availability relates to nutrient-removal stability and microbial responses under simplified continuous-flow operation remains insufficiently understood. This study established a single-sludge-recirculation continuous-flow AOA system for treating sodium acetate-based synthetic low-strength wastewater and evaluated its nutrient removal performance and microbial response. The reactor was operated for approximately 200 d and achieved stable organic matter and nitrogen removal, with average removal efficiencies of 88.00% ± 7.70% for COD, 96% ± 7% for NH4+-N, and 91.53% ± 7.05% for TN. In contrast, phosphorus removal was less stable and showed considerable temporal fluctuations, particularly during the later operational period. Spatial profiles showed rapid COD uptake and phosphorus release in the anaerobic zone, efficient ammonium oxidation with limited NOx−-N accumulation in the oxic zone, and further TN reduction in the post-anoxic zone despite only minor liquid-phase COD depletion. This indicates that post-anoxic nitrogen removal may primarily rely on internal carbon utilization. The enrichment of denitrification-associated genera, including Azospira and Dechloromonas, and the persistence of low-abundance nitrifying populations were consistent with the observed nitrogen transformation pattern. However, sludge bulking, TP fluctuations, and the absence of stable granulation revealed operational stability limitations. The single-sludge-recirculation AOA configuration provides a simplified route for improving carbon utilization in AAO-oriented upgrading, while sludge structure and phosphorus removal stability require further optimization.
