This study evaluated the small-scale atmospheric dispersion performance of the Micro-SWIFT SPRAY (MSS) model and the GPU-accelerated QES model (GPU-QES) in the complex environment of a nuclear power plant site. Based on wind tunnel experimental data from the Sanmen Nuclear Power Plant, two typical wind direction dispersion scenarios were simulated by both models, and the results were compared in terms of wind field and concentration field predictions, including horizontal ground-level wind and concentration fields, as well as vertical wind speed and concentration profiles. The results indicated that GPU-QES outperformed MSS in wind speed prediction, especially in the areas between buildings, where the underestimation of wind speed is reduced by about 53%. Furthermore, GPU-QES simulated the three-dimensional wind field 450times faster than MSS, generating wind data over a 9km² area with 35million grid points in just 4s. In plume dispersion prediction, high-concentration areas were effectively reproduced by both models, but GPU-QES showed higher consistency with actual values in low-concentration regions. Statistical analysis revealed that both models meet internationally accepted model criteria. However, higher simulation accuracy was demonstrated by GPU-QES in most metrics, especially in the building ground area, where the fraction of predictions within a factor of two of the observations (FAC2) was 4.5% higher than that of MSS. Additionally, due to differences in the dispersion behavior behind buildings between MSS and GPU-QES, simulation accuracy was improved by averaging the results of both models (FAC2reached 71.8%). On the other hand, due to differences in concentration calculation methods, GPU-QES generated the plume approximately 48times faster than MSS. Therefore, a clear advantage was shown by GPU-QES over MSS in nuclear emergency response scenarios that required rapid and accurate predictions.

This study investigates the chemical composition and brown carbon (BrC) light-absorption characteristics of smoke particles from six industrial biomass boilers. The mass fractions of organic carbon (OC) and elemental carbon (EC) in the smoke particles were 1.96% and 0.78%, respectively, while water-soluble inorganic ions accounted for 46.3% of the mass. Significant differences in the chemical composition of smoke particles were observed across different boilers, influenced by factors such as fuel types, boiler loads, and dust removal techniques. Soot-EC from bag-filtered boilers exhibited a higher OC/EC ratio (10.8) compared to cyclone-filtered boilers (2.27). The carbon components were predominantly OC₂, OC₃, OC₄ and EC1, with a highly variable Char-EC/Soot-EC ratio (average: 18.7, range: 0.25~86.0). Water-soluble inorganic ions were primarily K⁺, Cl^-, Na⁺, SO₄^2- and Ca²⁺, constituting 81.0%~93.6% of the total ions. The spectral properties of BrC, including water-soluble organic carbon (WSOC) and methanol-soluble organic carbon (MSOC), showed limited correlation with boiler fuel, load, or dust removal method. The mass absorption efficiency at 365 nm (MAE₃₆₅) was closely related to the OC/EC ratio, suggesting a strong link between BrC photo-absorption capacity and combustion conditions. The mass absorption efficiency of WSOC (MAE_WSOC) from industrial biomass boiler was 4~5 times higher than that from biomass cookstoves and 5~9 times higher than open biomass combustion emissions, as reported in literature. The study elucidates the light absorption characteristics of brown carbon in smoke particles emitted from industrial biomass boiler and their correlation with combustion conditions.

This review summarizes the extracellular electron transfer mechanisms in anaerobic ammonium oxidation (anammox) systems and strategies for their enhancement, categorizing the influence mechanisms of carbon-based materials on anammox bacteria into three aspects: conductivity of carbon-based materials, functional groups on their surfaces, and interactions between microbial communities and extracellular polymeric substances. Studies have demonstrated that biochar, activated carbon, carbon nanomaterials, and iron-carbon composites can regulate the anammox process by mediating extracellular electron transfer. Carbon-based materials primarily enhance anammox performance through shortening reactor start-up periods, improving nitrogen removal efficiency, and alleviating pollutant inhibition effects. These materials not only effectively enrich microorganisms but also promote the stability enhancement of granular sludge, demonstrating significant application potential in anammox systems. Future research should focus on material modification to further improve the sustainability of carbon-based materials in practical applications.

To precisely control the denitrification process such that NO₃^--N is reduced solely to NO₂^--N without further reduction to N₂, short-term aeration was implemented to enhance the nitrate-to-nitrite transformation ratio (NTR) of denitrifying phosphorus-accumulating organisms (DPAOs). The results demonstrated that after aeration intensification, phosphorus removal efficiency in the reactor improved (from 84.62% to 88.34%). When aeration durations were set at 5, 10, and 15minutes, the NTR values reached 36.09%, 89.14%, and 91.86%, respectively. However, extending aeration to 20minutes resulted in elevated effluent nitrate concentrations (10.11mg/L). As aeration duration increased, the content of pre-anoxic electron donors (PHBs) gradually diminished, which was identified as the primary reason for nitrite accumulation. Furthermore, aeration induced an increase in the relative abundance of DPAOs while decreasing that of endogenous denitrifying glycogen-accumulating organisms (DGAOs). Based on the outcomes of the partial denitrification coupled with phosphorus removal (PDPR) process, the feasibility of implementing the N-PDPR-Anammox process in practical engineering applications was discussed.

In order to strengthen the rapid and stable formation of hydrostatically oxygenic photogranules (HSP), a strategy of inoculating Oscillatoria sp., a typical kind of filamentous cyanobacteria, into activated sludge at the early stage of cultivation was proposed. The photogranulation process, morphology, extracellular polymeric substances contents, surface thermodynamics properties and microbial community were analyzed to elucidate the mechanism for efficient photogranulation in R1 (cultivated with Oscillatoria sp.). Results showed that the mixed liquid suspended solid of mature HSP in R1 (2.17g/L) was larger than that in R2 (cultivated without Oscillatoria sp.) (2.03g/L), and the surface of HSP in R1 was smoother. Values of PN/PS in R1 (2.01) was slightly larger than R2 (1.45) on 30d, implying that inoculating Oscillatoria sp. enhanced the hydrophobicity of granular sludge. Furthermore, results showed that the interfacial free energy was strengthened in R1 with the potential energy barrier of 2616.75kT, which was lower than the potential energy barrier in R2 (5037.85kT). The EPS producing bacteria were enriched and the relative abundance of enzymes related to EPS production was increased by 8%~156% in HSP after being strengthened by Oscillatoria sp. Overall, inoculating filamentous cyanobacteria Oscillatoria sp. into activated sludge facilitated the attachment and aggregation between bacteria and microalgae in HSP, contributing to the rapid development of HSP.

This review summarized the research progress on mixotrophic metabolic mechanisms of anaerobic ammonium-oxidizing bacteria (AnAOB), and provided perspectives on future research directions and highlighted the engineering implications. Current studies indicated that the mixotrophic metabolism of AnAOB could be influenced by factors such as the C/N ratio, organic matter concentration and types. However, the metabolic rates and micro-mechanisms of different AnAOB strains in metabolizing small organic molecules (e.g., acetate, propionate) remain unclear. In recent years, advanced ¹³C isotope labelling technology (DNA-SIP) and single-cell techniques have provided novel approaches to elucidate the pathways of small organic molecules uptake and metabolism in AnAOB. Multi-omics analysis showed that AnAOB fix inorganic carbon through the reductive acetyl-CoA pathway and harboured multiple pathways for small organic molecules metabolism, including denitrifying nitrate to ammonium (DNRA), formate metabolism, acetate metabolism, propionate metabolism, and the tricarboxylic acid cycle, yet the specific mechanisms remain controversial. Future research could focus on the electron transfer mechanisms, endogenous organic matter utilization strategies, and small organic molecules assimilation capabilities in the mixotrophic metabolism of AnAOB, aiming to optimize the enrichment and nitrogen removal performance of AnAOB, and expand their application potential in complex wastewater treatment.

Feammox functional microorganisms were enriched from anaerobic digestion sludge with NH₄⁺-N and Fe(Ⅲ) supplementation and their long-term nitrogen removal performance was evaluated. Feammox activity was detected on day 66and remained stable in subsequent batches. The relative abundances of the potential Feammox functional bacteria Geobacter and Anaeromyxobacter increased by 457-fold and 11.6-fold, respectively. Metagenomic analysis revealed a significant increase in the total relative abundance of functional genes associated with three nitrite transformation pathways: ammonia oxidation to nitrite (amo, hao), nitrite denitrification to nitrogen gas (nirSK, norB, nosCZ), and nitrite reduction to ammonium (nirABD, nrfAH). The addition of the electron shuttle AQDS promoted extracellular electron transfer and enhanced the ammonia removal efficiency by 17.8%.

A novel efficient phosphate adsorbent (CF-La) was synthesized by treating activated carbon fibers using lanthanum with impregnation method. The adsorption isotherms, adsorption kinetics, one-way experiments, and actual water sample tests were carried out. The adsorption isotherm studies demonstrated that the adsorption process conforms to the Langmuir model, indicating monolayer adsorption, with the maximum adsorption capacity of 5.78mg/g at 333K. Kinetic analyses revealed that the adsorption process follows the pseudo-second-order kinetic model, involving both physical and chemical adsorption mechanisms. The pH and competitive ions experiments indicated that the best adsorption effect was achieved under neutral environment, and the best adsorption result was achieved under neutral condition. The effects of five anions on CF-La were in the following order: S^2- > SO₄^2->CO₃^2-> Cl^-≈NO₃^-. The recyclability assessment through five adsorption-desorption cycles showed that CF-La retained >80% adsorption and desorption efficiency. By conducting characterization with SEM and BET on the modified material before and after, it is confirmed that lanthanum has been successfully loaded onto the surface. Analysis of the materials before and after adsorption using XPS and FTIR indicates that the synthesized material features a mesoporous structure, and the presence of lanthanum in two different oxidation states on the surface is beneficial for enhancing the adsorption efficiency. The experiment on sample water verified that CF-La showed excellent adsorption performance on inorganic phosphorus and organic phosphorus in Chaohu Lake, Anhui Province, and the water samples from Chaohu Lake in summer and winter could be reduced to within the threshold of cyanobacterial bloom after adsorption for 10h.

A composite material (CBC-nZVI) was synthesized by green reduction of Artemisia arenaria extract to produce nanoscale zero-valent iron (nZVI), which was subsequently loaded onto biochar derived from waste corn straw. This composite was employed for the removal of hexavalent chromium (Cr(Ⅵ)) from aqueous solutions. The study investigated the adsorption kinetics and thermodynamics, as well as the effects of pH, dosage, and coexisting ions on Cr(Ⅵ) removal by CBC-nZVI. The material was characterized using SEM, FTIR, XRD, and XPS to elucidate the Cr(Ⅵ) removal mechanisms. The adsorption kinetics of Cr(Ⅵ) onto CBC-nZVI fit best with the Elovich model, indicating that intraparticle diffusion was the rate-controlling step. The adsorption isotherm fitted the Freundlich model, indicating that the adsorption was a spontaneous endothermic and entropy-increasing process. The Cr(Ⅵ) removal efficiency improved with increasing reaction temperature, material dosage, and solution acidity. Under optimal conditions (298K, pH 2, and dosage of 1.0g/L), 100% removal efficiency was achieved for a Cr(Ⅵ) concentration of 30mg/L. The presence of coexisting cations or anions in the solution inhibited the removal of Cr(Ⅵ) by the CBC-nZVI to varying degrees, with the order of inhibition being Cd²⁺>Mg²⁺>Ca²⁺>Cu^2-, and CO₃^2->Cl^->NO₃^->SO₄^2-. The results of characterization of CBC-nZVI and batch adsorption experiments showed that the Cr(Ⅵ) removal mechanism by CBC-nZVI involves electrostatic adsorption, chemical reduction, functional group complexation, and precipitation. nZVI reduces adsorbed Cr(Ⅵ) to Cr(Ⅲ), which is then removed through surface complexation with functional groups and co-precipitation with Fe(Ⅲ) as Cr(Ⅲ)-Fe(Ⅲ) complexes. The loaded nZVI and CBC exhibited a synergistic effect in the removal of Cr(Ⅵ) by the composite material.

To solve the problems of high synthesis cost and lack of specific adsorption sites on traditional zeolites surface, polydopamine-modified coal gangue based zeolite was successfully synthesized by combining alkali melting hydrothermal method and impregnation coating method using coal gangue as raw material and dopamine as the polymerization monomer and applied for efficient adsorption of Cd(Ⅱ) from aqueous solution. The adsorption performance was investigated by batch adsorption experiments, and adsorption mechanism was revealed by SEM-EDS and XPS method. The results showed that polydopamine coating significantly improved the adsorption capacity of coal gangue-derived zeolite. The adsorption process conformed to the Langmuir adsorption isotherm model and pseudo-second-order model, suggesting that Cd(Ⅱ) adsorption by Zeolite@PDA was monolayer and chemical adsorption, and the theoretical maximum adsorption capacity could reach 130.89mg/g, which was two times as high as that of Zeolite (q_max=66.49mg/g). Thermodynamic studies indicated that Cd(Ⅱ) adsorption by Zeolite@PDA was a spontaneous, endothermic process with increased disorder at the solid-liquid interface. SEM-EDS and XPS analysis showed that cation exchange between Na⁺and Cd(Ⅱ) as well as surface complexation between surface functional groups and Cd(Ⅱ) played a primary role for Cd(Ⅱ) removal.