Ethanol-based thermochemical liquefaction is a promising route for converting microalgae into liquid fuels; however, nitrogen enrichment in the bio-oil severely limits its fuel quality and downstream upgrading. This study investigated how residual Fe3O4 NPs from upstream magnetic harvesting regulate nitrogen transformation during ethanol liquefaction of microalgae. Liquefaction experiments were conducted at 220-260 °C with a fixed Fe3O4 NP loading of 5 wt%. Product distributions, ethanol incorporation, and molecular compositions of the oil phase were analyzed by GC-MS and FT-ICR MS, complemented by DFT calculations. The bio-oil yield ranged from 55.29 to 78.08 wt%, increasing from 68.93 to 78.08 wt% at 260 °C with Fe3O4. Carbon balance analysis showed that up to 4.97 g of ethanol was incorporated into the products, contributing to both increased oil yield and active hydrogen supply. DFT calculations confirm that Fe3O4 promotes ethanol dehydrogenation, while FT-ICR MS reveals decreased abundance and unsaturation of nitrogen-containing compounds after Fe3O4 addition. Fe3O4 primarily influences nitrogen transformation by facilitating the generation of reactive hydrogen species from ethanol, thereby promoting hydrogenation of nitrogen-containing compounds. However, its contribution to overall nitrogen removal was limited, with the relative nitrogen content decreasing from 7.72 wt% to 6.74 wt% at 260 °C. Overall, residual Fe3O4 was compatible with ethanol liquefaction and influenced both bio-oil formation and nitrogen transformation, offering insight into integrating upstream magnetic harvesting with downstream thermochemical conversion.

Effective wastewater treatment is critical for environmental protection and resource recovery. Carbon quantum dots (CQDs), notably biomass-derived carbon quantum dots (BCQDs), have emerged as promising nanomaterials owing to their favorable physicochemical properties and environmental sustainability. This review examines BCQD formation from carbohydrate, protein, and lignin precursors. The molecular oxidation, radical-mediated oxidation, and physical shearing pathways are discussed with the key cross-linking reactions that drive nanodot growth. The existing separation techniques based on different parameters are systematically classified with emphasized advantages or disadvantages. The role of BCQDs in the whole process of wastewater treatment is summarized, and the detection and removal mechanisms and patterns were clarified. Especially, radioactive ion detection, photocatalytic degradation of complex pollutants such as heavy metals and plastic, membrane treatment, and antibacterial in wastewater are covered. New ideas and insights for the future applications of BCQDs in wastewater management are expanded.

The effect of selective catalytic reduction (SCR) system on condensable particulate matter (CPM) emission was thoroughly studied on a 50 kW one-dimensional combustion furnace, by preparing different monolithic SCR catalysts. Under VWTi and Cu-VWTi, removal rate of CPM was 3.2% and 10.0%, and that was 30.4% and 46.2% for organic CPM, respectively. This was mainly due to its high temperature and active SCR catalysts for catalytic oxidation of numerous organic CPM, with Cu-VWTi demonstrating superior catalytic activity. Cu-VWTi owned a larger pore volume and average pore size. Its good crystallinity promoted the formation of rutile TiO2 and more oxygen vacancies. The stronger electron transfer of Cu2+ + V4+ -><- Cu+ + V5+ also boosted its redox ability. Nevertheless, owing to oxidation of SO2 to SO3 and conversion of injected ammonia to NH4+, concentration of inorganic CPM increased after SCR. The inorganic CPM was mainly composed of NH4+ and SO42-while organic CPM was majorly hydrocarbons, esters and polycyclic aromatic hydrocarbons (PAHs). Specifically, the composition distribution of PAHs was analyzed in detail. The total concentration of PAHs at SCR inlet was 1.480 mg/ Nm3 (mainly 4-ring and 5-ring), with a toxicity equivalence quantity (TEQ) of 0.942 mg/Nm3. More 6-ring PAHs would be generated through polymerization reaction during SCR system. But for VWTi and Cu-VWTi, the PAH concentration reduced to 1.074 mg/Nm3 and 0.994 mg/Nm3, respectively, and the TEQ declined to 0.832 mg/ Nm3 and 0.015 mg/Nm3. The SCR with Cu-VWTi could dramatically decrease the TEQ of PAHs in CPM.

This study employs density functional theory (DFT) calculations combined with wavefunction analysis to dissect the thermal decomposition pathways of lignin through cyclohexadienone-type (CHD) intermediates. Using 4(phenoxymethyl)phenol as a model dimer representing lignin's structural motif, systematic investigations are conducted into intra- and intermolecular reaction pathways during pyrolysis. The results demonstrate that both intra- and intermolecular hydrogen transfer processes occur, yielding CHD intermediates. Significantly, the intermolecular hydrogen transfer pathway exhibits a lower energy barrier, indicating its preferential contribution to intermediate formation under pyrolysis conditions. A comparative energetic analysis of cleavage pathways reveals that the cyclohexadienone intermediate-mediated cleavage (CHDM) occurs with substantially reduced energy barriers compared to direct bond scission, establishing CHDM as the kinetically favorable pathway. The addition of hydroxyl-containing compounds, such as phenol, glucose, and levoglucosan, further decreases the energy barriers for the cleavage of CHD intermediates by forming six-membered ring transition states. Among these intermediates, levoglucosan and glucose exhibit the most pronounced synergistic effects in facilitating barrier reduction. Electron localization function (ELF) analysis provides mechanistic insight, showing that hydroxyl groups enhance hydrogen atom mobility and promote alpha-O-4 bond cleavage by modulating electron density distribution at the reaction site.

Escalating global plastic pollution has resulted in the pervasive accumulation of microplastics (MPs) in aquatic environments. Due to their strong pollutant adsorption capacity and difficulties in recovery, MPs pose severe challenges to conventional water treatment technologies. Microalgae, characterized by high environmental adaptability and robust metabolic capabilities, exhibit significant potential for MP bioremediation. This review systematically elucidates the interaction mechanisms between microalgae and MPs, bioremediation strategies, and downstream co-conversion pathways. Specifically, extracellular polymeric substances (EPS) secreted by microalgae act as key drivers for hetero-aggregation, facilitating interfacial adhesion via charge neutralization and hydrogen bonding. The size ratio of MPs to algal cells regulates aggregation behavior: comparable sizes promote co-sedimentation, whereas significantly larger MPs obstruct light, and nanoscale particles induce cytotoxicity. MP toxicity is further modulated by particle concentration and the degree of aging. Conversely, microalgae accelerate MP degradation through physical abrasion and enzymatic hydrolysis. Effective bioremediation requires matching the surface properties of algal strains with MPs, regulating biofilm formation, and balancing hydrodynamic shear forces. Regarding resource recovery, the co-pyrolysis or liquefaction of algal biomass and MPs reduces nitrogen- and oxygen-containing impurities in bio-oil via the hydrogen-donor effect of MPs. This process can also yield porous carbon with a high specific surface area or fluorescent carbon quantum dots. However, current research faces notable limitations. Most studies on toxicity and degradation rely on static, single-species systems that fail to simulate realistic hydrodynamic parameters (e.g., flow velocity and turbulence intensity) and the synergistic effects of co-existing pollutants (e.g., heavy metals and pharmaceutical compounds). Furthermore, co-conversion technologies are limited by discontinuous operation and a lack of robust models correlating feedstock ratios with product quality. Future research should prioritize the development of multi-algal synergistic remediation systems and the introduction of dynamic flow simulations to replicate real aquatic environments. Remediation efficacy must be evaluated under multi-pollutant conditions. Additionally, developing multi-stage continuous-flow reactors with optimized catalysis is crucial. Ultimately, these efforts will bridge the gap between remediation and resource utilization, promoting the transition of bioremediation technology from laboratory research to industrial application.

In machine vision-based online monitoring of microalgae, bubbles cause significant physical occlusion and optical refraction, leading to prediction distortion in traditional deep learning models. To overcome this optical interference bottleneck, this study proposes a dual-channel residual network with a mask mechanism (RES-MM) and evaluates its performance against a standard 18-layer residual network (RES-18) and an attention-enhanced residual network (RES-ATT) under varying bubble interferences, specifically non-bubble, single-bubble, and multi-bubble conditions. Results indicate that while traditional models suffer notable prediction distortion in the presence of bubbles—with RES-18 experiencing substantial performance degradation under Multi-B conditions (coefficient of determination (R²) dropping to 0.667, normalized root mean square error (NRMSE) rising to 54.59%)—RES-MM maintains high robustness. By leveraging dual-channel feature decoupling, RES-MM sustains an R² of 0.865 and restricts NRMSE to 34.80% under Multi-B scenarios, effectively mitigating distortions at extreme concentrations. Furthermore, feature visualization using Gradient-weighted Class Activation Mapping (Grad-CAM) confirms that RES-MM can effectively isolate gas-phase noise and focus on valid microalgal features, providing reliable algorithmic support for high-precision bioprocess monitoring.

Naphthalene was the primary component of polycyclic aromatic hydrocarbons (PAHs) from coal-fired flue gas. The Cu-doped VWTi catalyst with CTAB-remodification was prepared by sol-gel method, and its naphthalene oxidation activity was assessed, which exhibited the CO2 yield of approximately 65% and naphthalene conversion rate of 100% at 320 degrees C. Moreover, the naphthalene degradation under different SO2 concentrations was explored in depth, where SO2 rarely affected the naphthalene conversion but caused an obvious decline in CO2 generation. Significantly, the SO2 poisoning characteristics of the modified VWTi catalyst were explained by a series of characterization techniques such as FTIR, TG, XRD, N2 adsorption-desorption isotherms, SEM, XPS, H2-TPR, EPR, and in situ DRIFTS. Results illustrated that SO2 was oxidized to SO3, and the formed metal sulfates were adhered to the catalyst surface, which could clog the catalyst pores, cover the active sites, break the surface lattice oxygen, and cut down the low-temperature reduction performance. The introduction of SO2 tended to consume more active metals (V5+, W6+, and Cu+) and oxygen vacancies, resulting in the production of more basic hydroxyl groups. This promoted the chemisorption to naphthalene, restrained its deep oxidation to CO2, and led to the accumulation of more anhydride byproducts on the catalyst surface. This work provided insights into the SO2 poisoning mechanism of naphthalene oxidation on VWTi-based catalysts.

This study investigates the pyrolysis characteristics of reed bamboo and red fir wood to predict their fast pyrolysis product yields.Initially,the physicochemical properties of the raw biomass,including their thermogravimetric behavior,were analyzed.Fast pyrolysis experiments were subsequently performed in a horizontal fixed-bed reactor to examine the influence of temperature,residence time,and feedstock particle size on the yields of solid,liquid,and gaseous products.Finally,a neural network-based model was developed to rapidly and accurately predict the three-phase product yields under various reaction conditions,integrating data from this study with previously reported findings for different biomass types.The results reveal that the pyrolysis of reed bamboo and red fir wood proceeds through four main stages:drying;decomposition of hemicellulose and cellulose;decomposition of lignin;and subsequent low decomposition of the char residue.During the primary decomposition stage,macromolecules like cellulose break down into smaller molecules,with levoglucosan as a major product.As the pyrolysis temperature increases from 350 to 650℃,the solid char yields for both biomass types decrease significantly.At higher temperatures,secondary cracking of pyrolysis vapor is intensified,leading to a lower liquid yiled and a higher gas yield due to the formation of non-condensable gases.Furthermore,extending the pyrolysis residence time enhanced the extent of reaction,promoting further cracking of chemical bonds within the char matrix and residual polymeric materials,thereby releasing more volatile gases.Consequently,the solid yield decreases and the gas yield increases.Additionally,an increase in feedstock particle size impedes intra-particle heat transfer,resulting in incomplete pyrolysis.As a result,higher solid char yields and lower liquid and gas yields are observed,as the particle core does not reach the optimal pyrolysis temperature.An artificial neural network(ANN)model was developed using a combined dataset comprising 28 experimental runs from this study and 62 data points from the literature.The data were split into training and testing sets with a 7∶3 ratio.The model architecture comprised a single hidden layer with 14 neurons,utilizing the logistic-sigmoid activation function.The RMSprop optimizer was employed for training,with a learning rate of 0.000 9 and a smoothing parameter of 0.9.The developed ANN model demonstrated high accuracy,with regression coefficients(R)for the predicted solid,liquid,and gas yields at 0.971,0.966,and 0.974,respectively.When validated against the experimental data from this study,the average relative errors between the predicted and actual yields for the three phases were 5.25％,5.44％,and 5.23％,respectively,confirming the model's strong predictive capability.

Left–right (LR) asymmetry disorders present a complex etiology, with genetic factors emerging as a primary contributor. This study aims to explore the genetic underpinnings of chromosomal variants and individual genes in fetuses afflicted with prenatal LR asymmetry disorder. Through a retrospective analysis conducted between 2020 and 2023 at Tongji Hospital, Huazhong University of Science and Technology, genetic outcomes of LR asymmetric disorder were scrutinized utilizing copy number variation sequencing (CNV-seq) and whole exome sequencing (WES) methodologies. With a combination of CNV-seq and WES, 5 fetuses in 17 patients with LR asymmetry had chromosomal or genetic variants. CNV-seq revealed a 16p11.2 microdeletion syndrome in a situs inversus fetus presenting pathogenic and a 2q36.3 microduplication syndrome in a fetus with Heterotaxy presenting a variant of uncertain significance (VUS). WES identified NM_198075.4:c.755del in the LRRC56 gene and NM_001454.4:c.865_868dup in the FOXJ1 gene in two situs inversus cases, along with two variants in DNAH5 in two other fetuses. Further bioinformatics scrutiny was conducted to assess the protein structure and function prediction of these variants, ultimately indicating their potential pathogenicity. The study highlights that fetuses with LR asymmetric disorders may have copy number variants, underscoring the significance of mutations in LRRC56 and FOXJ1 in the development of LR asymmetry disorders.

The pyrolysis of flue-cured tobacco stalks (TS) faces challenges such as low bio-oil value and utilization efficiency. Existing studies have overlooked the anatomical heterogeneity of tobacco stalks, thereby limiting the directional regulation of high-value components, such as nicotine and phenolic compounds. This study divides TS into the husk (TSH), xylem (TSX), and pith (TSP), and investigates their physicochemical properties, pyrolysis behavior (through TGA and fixed-bed pyrolysis experiments), and interactions. Additionally, DFT calculations are used to elucidate the catalytic mechanism of K+/H+ on nicotine cracking. The main findings are as follows: (1) TSH contains the highest nicotine and KCl content, TSX accounts for 67.39 wt% of the dry weight of TS, and due to its high volatile content and low ash content, it has an advantage in bio-oil production, while TSP has a higher sugar content; (2) TSX dilutes the potassium concentration in TSH and TSP, reduces the catalytic effect of potassium, and delays small molecule cracking, shifting the maximum weight loss rate temperature from 308 °C to 338 °C; (3) GC-MS results show that nicotine yield peaks at 550 °C for TS, with nicotine yield higher than that of TSH. TSX has a higher phenolic yield, and K+ in TSH and TSP promotes the condensation of phenolics into biochar (XPS confirms an increase in sp2 carbon); (4) DFT calculations demonstrate that the synergistic effect of K+/H+ lowers the C4-C7 bond dissociation energy of nicotine by 39 %, catalyzing nicotine cracking, and more pyridine derivatives are observed in the bio-oil.

As the particular zero-dimensional carbon nanomaterial, carbon dots(CDs) have attracted great attention in the field of photocatalysis due to their advantages such as efficient utilization of visible light, rapid transport of charge carriers, and adjustable energy level configuration. This paper classifies large-scale synthesis methods into solid-phase, liquid-phase and gas-phase production based on the different states of the reaction medium, and innovatively analyzes their economy. These CDs are generally without post-treatment, and their photocatalytic performance is not satisfactory. Heteroatom doping and surface modification are utilized to adjust the photocatalytic properties of CDs. The former changes the internal structure and optical properties, while the latter mainly enhances the stability. Although the two means have outstandingly improved the catalysis of CDs in recent years, the existing reviews lack a discussion of the mechanisms by which CDs play multiple roles in photocatalytic CO2 reduction. From the perspective of the mechanism of photocatalytic CO2 reduction, it’s found that CDs utilize their unique optical properties to broaden the absorption range of catalysts, and can also serve as photocatalysts or co-catalysts to improve the photocatalytic efficiency by broadening the available light range, reducing carrier recombination, enhancing CO2 adsorption capacity, adjusting the morphology of catalysts and multiple synergies. Finally, the challenges and opportunities are analyzed, and the future development prospects are projected, providing new ideas for promoting the industrial preparation and photocatalytic applications of CDs.

Among various bio-oil production technologies, thermochemical liquefaction is more suitable for processing high-moisture biomass like microalgae. When organic solvents such as ethanol replace water as the medium, the incorporation of reactive solvents and differing separation procedures cause significant variations in the distribution of liquefaction products and nitrogen (N). Understanding N transformation characteristics is essential for N removal from bio-oil. In this study, a systematic comparison of hydrothermal liquefaction (HTL) and solvothermal liquefaction (STL) was conducted, with the nitrogen content in each product quantified to elucidate its migration behavior under different reaction media. Special emphasis was placed on the identification of N species in bio-oil using GC-MS and FT-ICR MS. It was found that part of the ethanol reacts with acidic intermediates via esterification/transesterification, resulting in significantly higher oil yields in STL than in HTL at the same temperature. Additionally, the hydrogen-donating effect of ethanol further enhances bio-oil quality. After HTL, over 40 % of the N migrates to the aqueous phase, whereas after STL, due to the absence of an aqueous phase, most of the N accumulates in the bio-oil, resulting in a higher relative N content (8.42 % - 9.36 %). Nitrogen in STL-derived bio-oil is predominantly in the form of heterocyclic compounds, with a higher saturation level compared to hydrothermal bio-oil. This study provides a novel understanding of solvent-mediated N transformation mechanisms, laying a theoretical foundation for the production of low-nitrogen, high-quality biooil.

A series of widely utilized VWTi catalysts doped with Fe, Ce and Cu were synthesized by sol-gel method to effectually oxidize naphthalene from flue gas. Results manifested that Cu-VWTi catalyst presented the fairly higher COx (CO + CO2) generation and nearly 90 % naphthalene was converted at 258 degrees C. Characterization techniques coupled with density functional theory (DFT) computations supported that Cu served as the most promoting additive, which was primarily interrelated to the formation of more oxygen vacancies and stronger electron transfer of Cu2+ + V4+ Cu+ + V5+ that introduced higher proportion of V5+ as well as surface active oxygen. Basic sites on catalyst surface were found to be momentous for the adsorption of naphthalene, on which naphthalene would be quickly converted to naphthol. Meanwhile, fewer basic sites on Cu-VWTi catalyst weakened the naphthalene chemisorption (adsorption energies of -0.58 eV) and facilitated its deeper oxidation to COx. The oxidation pathway was proposed through in-situ DRIFTS and GCMS as follows: naphthalene -> naphthol -> 1,4-naphthoquinone -> phthalic anhydride -> benzoic acid -> maleic anhydride -> COx/H2O. Furthermore, phthalic anhydride was proven to be the critical intermediate according to experiment of TG-FTIRMS and calculation of reaction heat (Delta H). Nevertheless, naphthalene was prone to undergoing polymerization reaction to produce higher-ring anthracene. These were the key to thoroughly getting rid of naphthalene.

The removal of naphthalene is important but deficient, so that the available V-W/Ti catalysts (1.0 wt% V2O5/ TiO2) were prepared for its efficient abatement in this work. Especially, influences of different existence status of vanadium species on naphthalene elimination were investigated via changing the pH value of precursor solution. With the increase of precursor solution acidity, more highly polymeric vanadium species were formed on the catalyst surface. The redox capability was enhanced markedly as a consequence of the stronger electron transfer between V/W and Ti that induced more surface active oxygen and V5+, whereas the catalytic activity was obviously boosted and almost 90 % conversion of naphthalene was achieved at 293 degrees C. Moreover, the weaker chemisorption between naphthalene and V-W/Ti catalyst allowed the deeper conversion to COx. GC-MS manifested that naphthalene seemed to be an organic component that was difficult to be totally degraded. Naphthalene oxidation was in the following pathway of naphthalene -* 1,4-naphthoquinone -* phthalic anhydride -* phthalates -* benzene -* benzoquinone -* maleic anhydride -* COx/H2O. The opening of aromatic ring in phthalic anhydride and benzene ring in benzene were proven to be the rate-controlling step based on in-situ DRIFTS results. The key of naphthalene oxidation was the complete degradation of various intermediates.

More and more attention has been paid to condensable particulate matter (CPM) since its emissions have surpassed that of filterable particulate matter (FPM) with the large-scale application of ultralow-emission reform. CPM is a gaseous material in the flue stack but instantly turns into particles after leaving the stack. It is composed of inorganic and organic components. Organic components are an important part of CPM, and they are an irritant, teratogenic, and carcinogenic, which triggers photochemical smog, urban haze, and acid deposition. CPM organic components can aggravate air pollution and climate change; therefore, consideration should be given to them. Based on existing methods for removing atmospheric organic pollutants and combined with the characteristics of CPM organic components, we provide a critical overview from the aspects of (i) fundamental cognition of CPM, (ii) common methods to control CPM organic components, and (iii) catalytic oxidation of CPM organic components. As one of the most encouraging methods, catalytic oxidation is discussed in detail, especially in combination with selective catalytic reduction (SCR) technology, to meet the growing demands for multipollutant control (MPC). We believe that this review is inspiring for a fuller understanding and deeper exploration of promising approaches to control CPM organic components.

Adsorption is one of the most promising strategies for heavy metal removal. For Hg(II) removal, mineralized Ca-based shell-type self-assembly beads (MCABs) using alginate as organic polymer template were synthesized in this work. The adsorbent preparation consists of gelation of a Ca-based spherical polymer template (CAB) and rate-controlled self-assembly mineralization in bicarbonate solution with various concentrations. The comparative study demonstrates that 1% (MCAB-1) is the optimal concentration of bicarbonate. Based on this condition, the maximum adsorption capacity (48 ± 4 mg/g) of MCAB-1 was observed at pH = 5 in a batch test, which was 2.67 times more than that of the unmodified one, CAB, at 18 ± 1 mg/g. Long-duration (10 h) adsorption tests showed that MCAB-1 exhibited remarkable performance stability and anti-wear ability (43.2% removal efficiency and 74.3% mass retention, compared to 2.7% and 38.6% for CAB at pH = 3, respectively). The morphology determination showed that a shell-type porous amorphous carbonate layer was formed at the surface of the organic polymer template by rate-controlled self-assembly mineralization. This transition not only promotes the pore structure and activated cation binding functional sites, but also improves the anti-wear ability of materials effectively.

Biomass gasification co-firing is a technology that can be implemented instantly in almost all coal-fired power plants in a relatively short period to reduce the consumption of fossil fuel. Most studies have focused on improving the system according to variations in the gasification conditions, biomass types, co-firing ratio, and boiler loads. However, the whole system process analysis and structural improvement based on the matter and energy of the co-firing system require further investigation. In this study, a novel biomass air-steam circulating fluidized bed gasification co-firing system based on waste heat and flue gas water recovery with different cofiring ratios (approximately 10 %-40 %) was simulated and compared with the original air gasification cofiring system using Aspen Plus software. The impacts of recovered water participate in gasification process and the optimal steam to biomass ratio (S/B) when it varied from 0.5 to 2, on the syngas quality, thermal characteristics of flue gas, recovered water, coal consumption, exergy loss, and efficiency of the system were analyzed. Compared with the air gasification co-firing system, the results showed that the N2 content in syngas reduced from 41.14 % to 28.92 %, and the heat yield of syngas increased by 7.73 %, along with a 110 t/h recovered water surplus at a 40 % co-firing ratio when steam to biomass ratio was equal to 1. The maximum coal saving amount was 2.26-9.11 t/h and the volume of atmospheric pollutants emissions, such as carbon dioxide (CO2), sulfur oxides (SOx) and nitrogen oxides (NOx), reduced by 0.95 %-6.02 %, 0.91 %-0.95 %, and 11.38 %- 36.47 % at a co-firing ratio of approximately 10 %-40 %. Furthermore, the exergy loss can be reduced by 4.35 %-10 % with a 1.72 %-3.96 % increase in exergy efficiency, indicating that the new system mode improves the comprehensive performance of the co-firing system.

After introducing heteroatoms into the carbon material skeleton, the performance of carbocatalyst during catalytic pyrolysis of biomass for monophenol production is significantly improved. Algae, as a carbon source with intrinsic nitrogen content, is well -identified as a suitable raw material for preparing heteroatom-doped carbocatalyst. The present study aimed to investigate the effects of different alkaline activation agents (KOH/NaOH) and gas atmospheres (N 2 /CO 2 ) during the carbonization -activation synthesis process of macroalgal biocharbased catalysts (MBBCs) on their properties and performances. Characterizations of carbocatalysts were carried out via BET and XPS analyses to investigate the porous structures and surface functional groups. Results showed that CO 2 , as a weakly oxidizing atmosphere, can promote the formation of porous structure of MBBCs. However, the promotion is not as strong as that of chemical activation agents (KOH/NaOH). Furthermore, KOH can promote the formation of porous structure more strongly than NaOH, but NaOH can substantially enhance the formation of surface oxygen-nitrogen groups compared to KOH. All the MBBCs exhibited the increment of monophenols in the bio-oil obtained from catalytic pyrolysis of wood dust, especially phenol, o -cresol, and pcresol. Amongst, the biochar-based catalyst activated with NaOH in CO 2 atmosphere was the most effective one in promoting monophenols content (up to 59.46 %). Compared with the control group (without catalyst), the phenol content was increased from 5.03 % to 19.40 %. Moreover, it is found that the catalytic performance was positively correlated with the C - O species percentage on the surface of MBBCs. The macroalgal biochar-based catalyst has an excellent catalytic performance, which is of great significance for achieving the complete utilization of algae and thereby improving the quality of catalytic pyrolysis products.

Textile dyes, including methylene blue (MB) and methyl orange (MO), pose a significant threat to water quality. This study delves into the competitive adsorption mechanisms pivotal for the concurrent removel of cationic MB and anionic MO dyes using nitrogen-rich seaweed-based carbon adsorbents. Synthesized through the pyrolysis and NaOH activation of Enteromorpha seaweed biomass, the preparation method is both uncomplicated and cost-effective, holding promising applications in industry. Characterization unveiled a commendable specific surface area of 911 m2/g, accompanied by abundant nitrogen- and oxygen-containing functional groups. Batch adsorption experiments showcased exceptional removal efficiencies surpassing 99.8% for both dyes. Molecular dynamics simulations offered valuable insights into the dynamic multi-stage adsorption behavior, while density functional theory calculations clarified the chemisorption-based interaction mechanism. Notably, MB displayed superior adsorption affinity compared to MO. An integrated adsorption mechanism was proposed, encompassing electrostatic attraction, migration, and enhanced chemisorptive binding of dye aggregates at active sites on the adsorbent surface. The innovative adsorption mechanism adopted by this carbon-based adsorbent prepared from nitrogen-rich seaweed can effectively remove cationic and anionic dyes, laying a solid foundation for future research on real water bodies with complex compositions.

The effective monitoring of microalgae cultivation is crucial for optimizing their energy utilization efficiency. In this paper, a quantitative analysis method, using microalgae images based on two convolutional neural networks, EfficientNet (EFF) and residual network (RES), is proposed. Suspension samples prepared from two types of dried microalgae powders, Rhodophyta (RH) and Spirulina (SP), were used to mimic real microalgae cultivation settings. The method's prediction accuracy of the algae concentration ranges from 0.94 to 0.99. RH, with a distinctively pronounced red-green-blue value shift, achieves a higher prediction accuracy than SP. The prediction results of the two algorithms were significantly superior to those of a linear regression. Additionally, RES outperforms EFF in terms of its generalization ability and robustness, which is attributable to its distinct residual block architecture. The RES provides a viable approach for the image-based quantitative analysis.