To study the effect of H₂O₂ on the content and properties of humic acids (HAs) in lignites, the experimental conditions including oxidation time, H₂O₂ concentration, and the solid–liquid ratio were investigated. Under the optimum oxidation conditions, the contents of HAs of YL and HB lignite were 45.4 and 40.9%, respectively. The HAs extracted from oxidized and raw lignites were characterized and compared. The results showed that the HAs extracted from oxidized lignites contain more total acidic groups, carboxyl groups, and aliphatic carbon than that in HAs extracted from raw lignites, and their hydrophilic–hydrophobic index value is higher and thermooxidative stability is better than those in HAs extracted from raw lignites. In addition, the composition of polycyclic aromatic hydrocarbons and fluorophore types in HAs extracted from oxidized lignites are similar to the HAs extracted from raw lignites. The results indicated that the oxidation operation can increase the content of HAs in lignites, and simultaneously increase the content of oxygen-containing functional groups and biological activity of HAs, which provided a reference for the subsequent application of HAs.

The structural features of humic acids extracted from Zhaotong and Mile lignites were analyzed using comprehensive spectral analyses including UV-vis, FTIR, CP/MAS ¹³ C NMR, XRD and XPS.

In this work, industrial biomass power plant ash was used to synthesize the ZSM-5 zeolites for the first time with the original intention to turn value-added material into wealth, and then committed to adsorption performance testing. Typical chemical structure and morphology of ZSM-5 zeolite were identified by comprehensive technologies. Uniquely, it was found that there was a low pressure hysteresis loop which was caused by crossed 10-membered rings in the N₂ adsorption–desorption isotherm. To investigate the adsorption performance for dyes, the zeolite samples were used to remove cationic (MB) and anionic (CR) dyes from aqueous. The results demonstrated that when it came to adsorbing MB, the isotherm was in line with the Redlich–Peterson model (R² > 0.99), whereas it was matched up with the Sips model (R² > 0.99) for adsorbing CR. Kinetic models were assigned to the pseudo-second order equation (R² ≥ 0.99) along with remarkable intraparticle diffusion. In the end, thermodynamic parameters were ΔG⁰ < 0, and E_a > 0. Especially, adsorbing MB was ΔS⁰ > 0, and ΔH⁰ > 0, whilst adsorbing CR was ΔS⁰ < 0, and ΔH⁰ < 0, which indicates that electrostatic interaction plays a significant role in the whole process. All in all, this work might encourage novel attempts to dispose of industrial biomass ash.

In this study, response surface methodology (RSM) was adopted to investigate the optimization of process conditions for extracting humic acid (HA) from coal, aiming to enhance the yield of humic acid. Additionally, UV-vis spectroscopy, FTIR, XRD, TG-DTG, CP/MAS¹³CNMR, XPS, and molecular fluorescence were utilized to examine the properties of HAs. The extraction time significantly influenced the yield from Lishi weathered lignite, while the liquid-solid ratio had a significant impact on the yield from Wuhai weathered lignite. The interactive effect between factors did not have a significant effect on the yield. The optimal extraction conditions for Lishi humic acid (LSHA) were determined to be an extraction time of 4.4 h, NaOH concentration of 0.30 mol/L, and liquid-solid ratio of 21 mL/g, while those for Wuhai humic acid (WHHA) were 3.1 h, 0.21 mol/L, and 12 mL/g, respectively. Under these optimal conditions, the true yield values closely matched the predicted value obtained from the model optimization. Comparative analysis of the HAs revealed similarities in their chemical properties, including the degree of aromaticity, molecular weight, and distribution of functional groups. The aromaticity of WHHA was higher compared to that of LSHA. The higher hydrophilic-hydrophobic index of LSHA contributed to its relatively high biological activity compared to that of WHHA. Both humic acids belong to terrestrial humic acids. The results of the study provide a reference for further application of humic acid.

Four new naphthoquinones (1–4), including a dimeric one, shikometabolin G (1), together with six known ones (6–10), were isolated from the methanol extract of Onosma paniculatum. Their structures were established based on the analysis of NMR and MS spectroscopic data. All of the compounds were evaluated for inhibitory effects on NO production in murine macrophage RAW 264.7 cells. Compounds 2, 3, 5, 6, 7, 8, and 10 displayed good activity on the inhibition of NO production (IC₅₀ = 0.4–16.5 µM), suggesting the potential property of anti-inflammation. ^* These two authors contributed equally to this work.