A biochar-supported green nZVI (G-nZVI@MKB) composite was synthesized using mango kernel waste with “dual identity” as reductant and biomass of biochar. The G-nZVI@MKB with a Fe/C mass ratio of 2.0 (G-nZVI@MKB2) was determined as the most favorable composite for hexavalent chromium (Cr(VI)) removal. Distinct influencing parameters were discussed, and 99.0% of Cr(VI) removal occurred within 360 min under these optimized parameters. Pseudo-second order kinetic model and intra particle diffusion model well depicted Cr(VI) removal process. The XRD, FTIR, SEM and XPS analyses verified the key roles of G-nZVI and functional groups, as well as the primary removal mechanisms involving electrostatic attraction, reduction, and complexation. G-nZVI@MKB2 exhibited a good stability and reusability with only a 16.4% decline in Cr(VI) removal after five cycles. This study offered evidence that mango kernel could be recycled as a beneficial resource to synthesize green nZVI-loaded biochar composite for efficient Cr(VI) elimination from water.

The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid (IL) were investigated. The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL. As the water concentration increased to 65 mg·g–1, the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%, and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201. When the concentration of impurities increased to a critical value, the chloroaluminate IL began to deactivate, leading to a decrease in naphthalene conversion. The critical concentrations for ethanolamine, water, methanol, ether, and diisopentyl sulfide were 33 mg·g–1, 65 mg·g–1, 67 mg·g–1, 87 mg·g–1, and 123 mg·g–1, respectively. Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation. The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy. 2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better, but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks. 2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL. With the increase in water concentration, the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid, and the Lewis acid gradually decreased, while the Brønsted acid showed a change of increasing first and then decreasing.

Visible-light-driven photocatalysis is a promising technology for the treatment of dye wastewater. In this work, a novel photocatalyst of K-doped g-C3N4 loaded on magnetic attapulgite (ATP) (Kω-g-C3N4@ATP-Fe3O4) with excellent visible light photocatalytic properties and stability were successfully prepared and characterized. The removal efficiency of Kω-g-C3N4@ATP-Fe3O4 for malachite green (MG) was studied, and the degradation mechanism was analyzed and proposed. It was found that the K5-g-C3N4@ATP-Fe3O4 photocatalyst possessed excellent degradation efficiency of over 98.0% for the MG dye wastewater under optimal conditions. Moreover, the K5-g-C3N4@ATP-Fe3O4 materials possessed good recyclability with a removal rate over 82% after 4 cycles. Under visible light condition, the K5-g-C3N4@ATP-Fe3O4 photocatalyst produce radicals of ·OH and ⋅O2− to degrade the MG dyes, which was supported by EPR and radical trapping experiments. In addition, the LC-MS analysis interpreted the degradation pathways and intermediates of MG in the solution. The findings in this work indicate that the prepared photocatalytic material has excellent degradation efficiency for MG and can be applied in dye wastewater treatment.

Selective electrodialysis (SED) has surfaced as a highly promising membrane separation technique in the realm of acid recovery owing to its ability to effectively separate monovalent ions through the utilization of a potential difference. However, the current SED process is limited by conventional commercial monovalent cation permselective membranes (MCPMs). This study systematically investigates the use of an independently developed MCPM in the SED process for acid recovery. Various factors such as current density, volume ratio, initial ion concentration, and waste acid systems are considered. The independently developed MCPM offers several advantages over the commercial monovalent selective cation-exchange membrane (CIMS), including higher recovered acid concentration, better ion flux ratio, improved acid recovery efficiency, increased recovered acid purity, and higher current efficiency. The SED process with the MCPM achieves a recovered acid of 95.9% and a concentration of 2.3 mol·L–1 in the HCl/FeCl2 system, when a current density of 20 mA·cm–2 and a volume ratio of 1:2 are applied. Similarly, in the H2SO4/FeSO4 system, a purity of over 99% and a concentration of 2.1 mol·L–1 can be achieved in the recovered acid. This study thoroughly examines the impact of operation conditions on acid recovery performance in the SED process. The independently developed MCPM demonstrates outstanding acid recovery performance, highlighting its potential for future commercial utilization.

Biological solubility is one of the important basic parameters in the development process of poorly soluble drugs, but the current measurement methods are mainly based on a large number of experiments, which are time-consuming and cost-intensive. There is still a lack of effective theoretical models to accurately describe and predict the biological solubility of drugs to reduce costs. Therefore, in this study, osaprazole and irbesartan were selected as model drugs, and their solubility in solutions containing surfactants and biorelevant media was measured experimentally. By calculating the parameters of each component using the perturbed-chain statistical associating fluid theory (PC-SAFT) model, combined with pH-dependent and micellar solubilization models, the thermodynamic phase behavior of the two drugs was successfully modeled, and the predicted results were in good agreement with the experimental values. These results demonstrate that the model combination used provides important basic parameters and theoretical guidance for the development and screening of poorly soluble drugs and related formulations.

Textile dyes are dramatic sources of pollution and non-aesthetic disturbance of aquatic life and therefore represent a potential risk of bioaccumulation that can affect living species. It is imperative to reduce or eliminate these dyes from liquid effluents with innovative biomaterials and methods. Therefore, this research aims to highlight the performance of Capparis spinosa L waste-activated carbon (CSLW-AC) adsorbent to remove Crystal Violet (CV) from an aqueous solution. The mechanism of CV adsorption on CSLW-AC was evaluated based on the coupling of experimental data and different characterization techniques. The efficiency of the CSLW-AC material reflected by the equilibrium adsorption capacity of CV could reach more than 195.671 mg·g–1 when 0.5 g·L–1 of CSLW-AC (Particle size ≤250 μm) is introduced into the CV of initial concentration of 100 mg·L–1 at pH 6 and temperature 65° C and in the presence of potassium ions after 60 min of contact time according to the one parameter at a time studies. The adsorption behavior of CV on CSLW-AC was found to be consistent with the pseudo-second-order kinetic model and Frumkin's linear isothermal model. The thermodynamic aspects indicate that the process is physical, spontaneous, and endothermic. The optimization of the process by the Box Behnken design of experiments resulted in an adsorption capacity approaching 183.544 mg·g–1 ([CV]=100 mg·L–1 and [CSLW-AC]=0.5 g·L–1 at 35 min). The results of the Lactuca sativa seeds germination in treated CV (70%), adsorbent solvent and thermal regeneration (more than 5 cycles), and process cost analysis (1.0484 $ L–1) tests are encouraging and promising for future exploitations of the CSLW-AC material in different industrial fields.

In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction, a large amount of phase equilibrium data was collected in the context of the actual process of butadiene production by acetonitrile. The accuracy of five prediction methods, UNIFAC, UNIFAC-LL, UNIFAC-LBY, UNIFAC-DMD, and COSMO-RS, applied to the butadiene extraction process was verified using partial phase equilibrium data. The results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing system. COSMO-RS predicted multiple systems showed good accuracy. And a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS method. The predicted phase equilibrium data were checked for consistency. The NRTL-RK and UNIQUAC thermodynamic models were used to correlate the phase equilibrium data. Industrial device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction process. The simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2% compared to that using the commercial simulation software Aspen Plus and its database. The average deviation was much smaller than that of the simulations using the Aspen Plus database (>10%), indicating that the obtained phase equilibrium data are highly accurate and reliable. The best phase equilibrium data and thermodynamic model parameters for butadiene extraction are provided. This improves the accuracy and reliability of the design, optimization and control of the process, and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.

The traditional automotive catalytic converter using commercial ceramic honeycomb carriers has many problems such as high back pressure, low engine efficiency, and high usage of precious metals. This study proposes a four-channel catalytic micro-reactor based on alumina hollow fiber membrane, which uses phase inversion method for structural molding and regulation. Due to the advantages of its carrier, it can achieve lower ignition temperature under low noble metal loading. With Pd/CeO2 at a loading rate of 2.3% (mass), the result showed that the reaction ignition temperature is even less than 160 °C, which is more than 90 °C lower than the data of commercial ceramic substrates under similar catalyst loading and airspeed conditions. The technology in turn significantly reduces the energy consumption of the reaction. And stability tests were conducted under constant conditions for 1000 hours, which proved that this catalytic converter has high catalytic efficiency and stability, providing prospects for the design of innovative catalytic converters in the future.

As promising catalysts for the degradation of organic pollutants, metal-organic frameworks (MOFs) often face limitations due to the particle agglomeration and challenging recovery in liquid-catalysis application, stemming from their powdery nature. Engineering macroscopic structures from pulverous MOF is thus of great importance for broadening their practical applications. In this study, three-dimensional porous MOF aerogel catalysts were successfully fabricated for degrading organic dyes by activating peroxymonosulfate (PMS). MOF/gelatin aerogel (MOF/GA) catalysts were prepared by directly integrating bimetallic FeCo-BDC with gelatin solutions, followed by freeze-drying and low-temperature calcination. The FeCo-BDC-0.15/GA/PMS system exhibited remarkable performance in degrading various organic dyes, eliminating 99.2% of rhodamine B within a mere 5 minutes. Compared to the GA/PMS system, there was over a 300-fold increase in the reaction rate constant. Remarkably, high removal efficiency was maintained across varying conditions, including different solution pH, co-existing inorganic anions, and natural water matrices. Radical trapping experiments and electron paramagnetic resonance analysis revealed that the degradation involved radical (SO4•−) and non-radical routes (1O2), of which 1O2 was dominant. Furthermore, even after a continuous 400-minute reaction in a fixed bed reactor at a liquid hourly space velocity of 27 h−1, the FeCo-BDC/GA composite sustained a degradation efficiency exceeding 98.7%. This work presents highly active MOF-gelatin aerogels for dye degradation and expands the potential for their large-scale, continuous treatment application in organic dye wastewater management.