Antibiotic residues in aquatic environments pose severe ecological and public health threats, while sluggish photogenerated-carrier separation and inefficient molecular oxygen activation remain major obstacles for photocatalytic antibiotic degradation. Herein, an oxygen-vacancy-rich BiOI/BiOCl heterojunction photocatalyst was constructed through a one-pot solvothermal strategy for efficient visible-light-driven levofloxacin degradation. The optimized Ov-BiOCl-BiOI composite achieved 91.98% levofloxacin degradation within 90 min and maintained 84% degradation efficiency after five consecutive cycles, while also showing applicability toward representative fluoroquinolone antibiotics, including ciprofloxacin and norfloxacin. Comprehensive characterizations, including XRD, FTIR, SEM/TEM, XPS, EPR, Raman, PL, photocurrent response, EIS, and Mott-Schottky analyses, confirmed the successful formation of an intimate BiOI/BiOCl heterointerface, abundant oxygen-vacancy-related defect sites, suitable band-edge positions, enhanced visible-light harvesting, reduced charge-transfer resistance, and suppressed carrier recombination. XPS analysis and DFT calculations revealed directional electron transfer from BiOI to BiOCl, establishing an internal electric field that promotes spatial charge separation across the heterointerface. Radical-trapping and ESR experiments identified center dot O-2(-) as the dominant reactive species, with h(+) and O-1(2) serving as auxiliary oxidative species. Theoretical calculations further demonstrated that oxygen vacancies introduce additional electronic states near the Fermi level, strengthen O-2 adsorption, and elongate the O-O bond, thereby facilitating superoxide radical generation. The novelty of this work lies in the synchronous regulation of interfacial charge separation and surface O-2 activation through in situ coupling of oxygen vacancies with the BiOI/BiOCl heterojunction. This study provides both experimental evidence and theoretical insight for the rational design of defect-engineered bismuth-based photocatalysts for pharmaceutical wastewater remediation.

Understanding molecule-specific adsorption in functionalized MOFs is crucial for rational gas-separation design. Here, DFT calculations combined with interpretable descriptor analysis examined CO₂ and CH₄ adsorption in pristine and NH₂-functionalized MOF-5. Electrostatic potential, differential charge density, PDOS, and adsorption-energy analyses show that amino functionalization reshapes the electrostatic and electronic environment of MOF-5. CO₂ adsorption variations are associated with electronic-state modulation and interfacial charge redistribution. Within sampled configurations, PDOS shifts and charge variation Δq exhibit associations with adsorption energy. In contrast, CH₄ adsorption is less sensitive to global electronic-state shifts and is governed by local C–H···O hydrogen-bond-like interactions coupled with charge redistribution. Descriptor correlations and regression reveal distinct adsorption-energy regulation pathways for CO₂ and CH₄ in the dataset. These results suggest that amino functionalization can rebalance, rather than universally enhance, adsorption interactions in MOF-5, providing an interpretable structure–property analysis strategy extendable to functionalized MOFs.

The increasing demand for lithium has intensified interest in sustainable recovery from complex liquid resources, including salt-lake brines, geothermal waters, and oil and gas produced waters. Titanium-based lithium-ion sieves (Ti-based LIS) are promising adsorbents for selective lithium separation because their robust Ti–O frameworks, relatively low dissolution tendency, and Li+-recognition capability support repeated adsorption–regeneration operation. However, studies remain fragmented in linking local structure and interfacial ion-transfer mechanisms with engineering performance under realistic conditions. This review establishes an environmental chemical engineering-oriented, evidence-based structure–mechanism–regulation–application framework. Layered H2TiO3 and spinel H4Ti5O12 are compared in terms of framework topology, exchange-site accessibility, ion-transport pathways, adsorption performance, structural stability, and engineering applicability. Established Li+/H+ exchange and framework retention are distinguished from system-dependent interpretations involving structural memory, hydration-shell evolution, partial desolvation, intracrystalline or interlayer diffusion, defect-mediated transport, surface-hydroxyl chemistry, and local coordination environments. Multiscale regulation strategies are critically evaluated by linking precursor, lattice, defect, surface, morphology, pore-network, and composite-interface changes to mechanistic consequences, performance benefits, trade-offs, and failure risks. Intelligent design is presented as a cross-scale methodology integrating density functional theory, structured databases, machine learning, and experimental feedback for multi-objective material and process optimization. Practical applicability is assessed through condition-aware comparison, realistic-resource validation, shaping, regeneration, Ti dissolution, dynamic operation, process coupling, and standardized reporting. Key constraints include capacity–selectivity–stability trade-offs, limited real-brine and long-term dynamic evidence, and insufficiently standardized engineering data. Overall, this review integrates mechanistic understanding, multiscale regulation, engineering evaluation, and data-driven design to support sustainable lithium recovery using Ti-based LIS.

In this work, the co-precipitation method was used to prepare Fe-doped BiOCl-modified materials for visible photocatalytic degradation of ofloxacin in water by taking advantage of the property that the acidic nature of FeCl3 & sdot;6 H2O dissolved in water can improve the surface structure of the materials. In order to improve the problems of BiOCl's poor absorption of visible light and high compounding rate of electron-hole pairs, the transition atom Fe is introduced to add impurity energy levels in BiOCl, which effectively reduces the bandgap width of the material and promotes the photogenerated electron migration of the material, and it is calculated that after modification, the band gap of the material can be reduced to 2.79 eV, which is a decrease of 0.32 eV compared to the original BiOCl (3.11 eV). Fe acts as an electron trap to capture electrons in electron-hole pairs and slows down their complexation with holes, effectively enhancing the stability of carrier separation in the material. Through free radical quenching experiments and ESR assays, it is understood that superoxide radicals are one of the free radicals needed in that act in the reaction process, indicating that the efficient electron capture enables the electrons to better react with adsorbed oxygen to generate superoxide radicals, which enhances the oxidizing ability of the system. Meanwhile, the degradation ability of modified materials on ofloxacin has been studied. Compared to the original BiOCl, under the condition of adding 50 mg/100 mL, the degradation ability of modified materials on ofloxacin has significantly improved. After 100 min of light exposure, the degradation efficiency of OFL(10 mg/L) increased from 26.10 % to 88.02 %.

The photocatalytic hydrogel consisting of the modified graphite carbon nitride and calcium alginate was successfully prepared via gravity dripping for the photocatalytic degradation of pollutant. The removal rate of 150 mg center dot L-1 rifampicin reached 70.9 % within 20 min of dark reaction, 15 times higher than pure calcium alginate hydrogel. Subsequently, the removal rate of rifampicin increased to 95.7 % within 75 min of light irradiation reaction. The excellent catalytic activity of as-prepared hydrogel was attributed to the tripartite coupling effect of adsorption, dark degradation and photocatalysis. The free radical capture experiment and the theoretical calculations indicated that the abundant delocalized electrons around W-O group were the dominant reactive species in dark reaction, the electrophilic attack of center dot OH was the main drive force of photocatalytic degradation. The charge transport channel from WOCN to Ca2+ accelerated the carriers movement to the hydrogel surface and improved the photocatalytic performance. The theoretical calculations indicated that W-O group modification played a dominant role in the adjustment of the electronic structure of the photocatalytic hydrogel, followed by oxygen doping in the surface of carbon-rich cyanide group. The coupling effect of multi-site modification enhanced the catalytic activity of as-prepared hydrogel against various pollutants.

Oxygen vacancies could be induced into the heterojunction structure of BiOI/BiOBr via high-temperature calcination. Light absorption, charge transfer efficiency, photocatalytic activity, and mechanism are all intimately connected to oxygen vacancies. Density-functional theory simulations demonstrate that surface oxygen vacancies adsorb oxygen to active sites, whereas bulk oxygen vacancies activate oxygen adsorbed to the surface to reactive radicals. Meanwhile, the addition of oxygen vacancies efficiently reduces the effects of background ions and pH on tetracycline breakdown in the real aquatic environment. The experimental results are consistent with the DFT calculations. This paper presents a straightforward approach for creating heterojunction surface and bulk-phase oxygen vacancies, as well as an understanding of the many roles that different types of oxygen vacancies play in the photocatalytic degradation process.

To evaluate the potential of aerogel materials for selectively recovering Cu2+ from highly acidic wastewater, the adsorption behavior of Cu2+ by bis-pyridine N-functionalized cellulose (PEIPD/CMC) aerogel was systematically investigated. Characterization of structural and chemical properties of the absorbent revealed that the bis-pyridine N plays a crucial role in the adsorption process. The PEIPD/CMC aerogel exhibited excellent adsorption capacity and selectivity for Cu2+ in multi-component acidic solutions (Cu2+/Zn2+/Pb2+), achieving a maximum adsorption capacity of 1.19 mmol/g at pH = 2. The adsorption process was well-described by the pseudo-second-order model and the Langmuir model, indicating monolayer chemisorption. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses confirmed the involvement of bis-pyridine N groups in the adsorption of heavy metals. To further elucidate the interaction mechanisms between PEIPD/CMC and heavy metals at the microscopic level, Molecular dynamics (MD) simulations and Density functional theory (DFT) were conducted. MD simulations revealed that the adsorption process is predominantly governed by chemisorption, with the binding strength of the adsorbent to heavy metals following the order Cu2+ > Zn2+ > Pb2+. DFT calculations provided direct evidence of the chelation mechanism, highlighting the role of energy and electron transfer in the selective adsorption of Cu2+. These findings conclusively demonstrate that bis-pyridine N is the key functional group responsible for the selective adsorption of Cu2+.

In order to address the issue of protonation of functional groups and structural instability on the surface of aerogel due to strong acidic wastewater, a three-dimensional bis-pyridine N cellulose aerogel [PEIPD/carboxymethyl cellulose (CMC)] with protonation resistance was prepared in this paper by grafting pyridine onto polyethylenimine. The adsorption capacity for Cu2+ of the as-prepared aerogel is as high as 1.64 mmol/g (pH 5) and is maintained well in high-acidity solutions (1.15 mmol/g at pH = 2). It reveals high selectivity, splendid anti-interference ability, and also reliable on the recycle performance. Through the zeta potential tests, this adsorbent reveals a rather low zero charge point (pH(pzc) = 2.2). The adsorption of Cu2+ on the adsorbent is consistent with the pseudo-second-order kinetic model and the Langmuir model, suggesting that the adsorption process is dominated by chemisorption in a monolayer. The characterizations by Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy proved pyridine N as responsible binding sites, based on which two possible mechanisms are proposed, including chelation and cation-pi interaction. Density functional theory calculations are further used to precisely investigate the pathway. By comparing the binding energies, molecular electrostatic potentials, electron densities, and differential charge densities, the bis-pyridine N functional group is finally determined to be of much higher affinity to Cu2+ following chelation reaction as designated. By integrating bis-pyridine N with the CMC and understanding their crucial roles, this will provide significant insights into the rational design of aerogel adsorbents to enhance the recovery of Cu from strongly acidic wastewaters.

In this study, an Fe-La-CS adsorbent with a reticulated structure was prepared by an in situ method, which was able to adsorb arsenate efficiently over a wide pH range of 3–11. The incorporation of iron and lanthanum ions broadened the tolerant pH range of the adsorbent compared with chitosan beads (CS). Arsenic was mainly present in the pH range of 3–9 as two forms, H2AsO4− and HAsO42−. Calculations using the density-functional theory (DFT) showed that in the Ligand interactions and electrostatic interactions dominate in the pH range, with surface precipitation, and hydrogen bonding interactions playing a facilitating role. The background ions mainly compete with arsenic adsorption for electrostatic interaction sites. However, due to the different valence states of the background ions, the competition intensity is different. Such as low valence state representative ions Na+, K+ competitiveness is weak, and arsenic competition adsorption first occupy different adsorption sites, therefore, from the quantum chemistry and molecular dynamics point of view of Na+, K+ on arsenic adsorption almost no effect. Cl−, SO42− will have some influence on arsenic adsorption because of the same charge with arsenic, but the charged amount is smaller than arsenic and the molecular structure is different from that of arsenic, so the influence is not very big. In summary, the material design of Fe-La-CS adsorbent has great potential and theoretical significance for selective purification of heavy metal wastewater at wide pH.

With regard to the catalysts for NH3 selective catalytic reduction (NH3-SCR), the acid sites distribution can affect the adsorption of reactants and formation of intermediates, thus determining the reaction routines. In this work, a representative acidic component, monoclinic-WO3 (m-WO3), was used to probe the combination strategy of experimental and theoretical research, aiming at systematic understanding on the full-process mechanisms. Macro-scale characterizations, Temperature Programmed Desorption (TPD) and Temperature Programmed Reduction (TPR), are associated with the Density Functional Theory (DFT) calculations, by which W ion (Lewis acid site) is affirmed as the active sites. By comparing the energy barriers of possible pathways with DFT calculations, we identify that NH2NO and NHNOH are responsible active intermediates. Both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) pathways may take place on acid sites and the former on Lewis acid site is optimal, which agrees well the in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) analysis. This study offers a reasonable prototype for precisely examining the correlation between the catalyst and mechanisms of NH3-SCR catalysts.

Soil thallium (Tl) contamination is of major public concern but little is known about soil Tl ecological toxicity or potential ecological remediation strategies. Here, two soil animal species with different ecological niches, Folsomia candida and Enchytraeus crypticus, were used to test Tl toxicity and modification by exogenous organic materials (i.e. maize straw and biochar). The endpoints of Tl ecotoxicity to F. candida and E. crypticus were studied at two biological levels, i.e., the individual (body Tl concentrations) and the population (survival, reproduction, and growth). Thallium concentrations in F. candida and E. crypticus increased with increasing soil Tl concentration, and their survival and reproduction rates decreased with increasing soil Tl concentration. The LC50 value of Tl effects on F. candida mortality (28 d) was 24.0 mg kg-1 and the EC50 value of reproduction inhibition was 6.51 mg kg-1. The corresponding values were 4.15 mg kg-1 and 2.31 mg kg-1 respectively for E. crypticus showing higher sensitivity to soil Tl than F. candida. These effective values are comparable to or much lower than the environmental Tl concentrations in field soils, suggesting high potential ecological risk. Both biochar and straw can decrease animal body Tl concentrations in different ways, i.e. reducing Tl availability or offering clean food sources, and addition of exogenous organic materials clearly mitigated Tl ecotoxicity in highly polluted soil. The results highlight the potential Tl ecological risk to soil animals and the potential use of organic materials to control the toxicity.

Accurate prediction of cadmium (Cd) ecotoxicity to and accumulation in soil biota is important in soil health. However, very limited information on Cd ecotoxicity on naturally contaminated soils. Herein, we investigated soil Cd ecotoxicity using Folsomia candida , a standard single-species test animal, in 28 naturally Cd-contaminated soils, and the back-propagation neural network (BPNN) model was used to predict Cd ecotoxicity to and accumulation in F. candida . Soil total Cd and pH were the primary soil properties affecting Cd toxicity. However, soil pH was the main factor when the total Cd concentration was < 3 mg kg −1 . Interestingly, correlation analysis and the K-spiked test confirmed nutrient potassium (K) was essential for Cd accumulation, highlighting the significance of studying K in Cd accumulation. The BPNN model showed greater prediction accuracy of collembolan survival rate ( R 2 = 0.797), reproduction inhibitory rate ( R 2 = 0.827), body Cd concentration ( R 2 = 0.961), and Cd bioaccumulation factor ( R 2 = 0.964) than multiple linear regression models. Then the developed BPNN model was used to predict Cd ecological risks in 57 soils in southern China. Compared to multiple linear regression models, the BPNN models can better identify high-risk regions. This study highlights the potential of BPNN as a novel and rapid tool for the evaluation and monitoring of Cd ecotoxicity in naturally contaminated soils.

Two novel koninginin derivatives, koningipyridines A and B ( 1 and 2 ), along with four known compounds ( 3˗6 ) were isolated from the EtOAc extract of the endophytic fungus Trichoderma koningiopsis SC-5. Among them, koningipyridine A featured an unprecedented pentacyclic ketal skeleton with the formation of a fascinating 6/6/5/6/5 fused ring system and shared a characteristic pyridine core, which represents the first example of nitrogen-containing koninginin-type natural product. Moreover, koningipyridine B was the first member in the koninginin family sharing a unique 6/6/5 dihydropyridine skeleton, and it was suggested to be the critical biosynthetic precursor of koningipyridine A. The structures of 1 and 2 were elucidated by the interpretation of 1D and 2D NMR spectroscopy, HRESIMS data, as well as theoretical calculations of 13 C NMR and electronic circular dichroism (ECD). Moreover, all isolates were screened for antimicrobial activities against Staphylococcus aureus , MRSA, and Escherichia coli as well as the cytotoxic effects against three cancer cell lines (A549, Hela, and HepG2). Graphical Abstract

High pressure wet ball milling and thermal polycondensation are used to prepare W-doped O-bridge carbon nitride (WOCN) for the rapid catalytic degradation of antibiotic rifampicin (RIF).

Per- and polyfluoroalkyl compounds (PFASs) have been used industrially worldwide and are persistent organic pollutants in many soils. Twenty eggs laid by synchronized adults of the collembolan Folsomia candida were added to each Petri dish containing compressed soil substrate mixed with perfluorooctanoic acid (PFOA), heptafluorobutyric acid (PFBA), or 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (F-53B), and after 25 d of exposure the number hatched declined on average by 6.9%?49.7%, 10.3%?24.1%, and 3.4%?18.6%, respectively. PFASs delayed the peak of hatching by one day, and at different concentrations reduced the number of eggs hatched during the peak by 16.7%?30% and 23.3%?43.2% in PFOA and PFBA treatments, respectively. In the presence of F-53B the number of eggs hatched declined by 73.3% but the number of individuals increased by 29.3% at higher concentrations. The characteristics of egg hatching were stable and sensitive to PFASs, and may be suitable for use as indicators in the screening of contaminated soils for environmental risk assessment.

A single hydrothermal reaction was used to create BiOI/BiOBr composites, which demonstrated good sunlight-driven photocatalytic degradation activity of tetracycline (TC) over a broad pH range and the degradation efficiency can be stable at about 90%. Moreover,·O2- has been identified as the most important active ingredient in the photocatalytic system. Density functional theory (DFT) calculations were used to investigate the electron transfer mechanism of BiOX heterojunctions on a molecular scale, as well as to propose possible photocatalytic degradation mechanisms and reaction sites for tetracycline in different deprotonated forms at a wide range of pH values. The quantitative structure-activity relationship (QSAR) was also used to assess the toxicity of the intermediates. In summary, this study presents new concepts for investigating the photodegradation behavior of antibiotics throughout a wide pH range, which is predicted to be employed for surface water remediation.

Soil pollution represents a threat to soil biodiversity and to soil and human health. However, many ecotoxicological issues, such as the impact of heavy metal pollution on the soil mite community and its spatial distribution in areas with complex environmental factors, are not fully understood. Here, an investigation was conducted in an arable area (about 11 km2) enclosed by surrounding mountains. The study area was contaminated with potentially toxic metals derived from copper smelting that was functioning for over 10 years. The area comprised four land use types: woodlands, dry fields, paddy fields, and wastelands, and was divided into 141 study sites each with an area of 6.25 ha. The soil metal (Cu, Zn, Pb, and Cd) contents, pH, and organic matter were determined and their distributions were established. Furthermore, soil mite (Acari) community properties (species richness, individual abundance, and Shannon–Wiener diversity index) were determined, and the distributions of total species number and abundance were ascertained. Soil metal pollution strongly reduced soil mite community, but the effects depended on mite groups or species and their sensitivity to different metals as well as land use types. CANOCO analysis revealed that the order Oribatida was more highly correlated with soil metal contents, whereas the other three orders responded to soil metal contents depending on land use types, mite properties, or metals. SADIE method indicated that the coordinate relationship between mite species number and metal concentration was more negative (4–25% of the study sites) than positive (4–12%). The metal pollution levels in the soil were evaluated by single and integrated pollution and ecological risk indices.

In this work, a hydrophilic polypyrrole carboxymethyl cellulose aerogel (PPY/CMC) with a 3D structure was prepared via in-situ polymerization of pyrrole monomers with carboxymethyl cellulose as the substrate. The adsorption experiments showed that tetracycline can be effectively removed in a wide range of pH (4-10), and the adsorption capacity was 689.39 mg/g when the pH value was 6. The pseudo-second-order kinetic and Langmuir models better fitted the kinetic and isotherm data, which revealed that the adsorption was homoge-neous and dominated by chemisorption. The experiment of adsorption thermodynamics showed that the adsorption process was spontaneous and endothermic. Zeta potential, FT-IR and XPS results indicated that the adsorption mechanism included pi-pi EDA interaction, hydrogen bonding and electrostatic interaction. Through Density Functional Theory (DFT) and Frontier Orbital Theory (FOT) simulation, the microscopic adsorption mechanism was further explored on the molecular and electronic scales. It is confirmed that TC was adsorbed onto PPY/CMC aerogels mainly through pi-pi EDA interaction in sandwich (S) configuration and parallel-displaced (PD) configuration, thus ensuring high adsorption efficiency. Compared with various adsorbent materials re-ported recently, the PPY/CMC aerogels have the advantages of higher adsorption capacity, excellent pH buff-ering capacity, simple preparation process and quickly removal of pollutants.