Analysis of the nature of interaction between AlN nanocage and ibuprofen using quantum chemical study

Theoretical design of transition metal-doped oxo-triarylmethyl as a disposable platform for adsorption of ibuprofen

Emerging environmental contaminants have become a crucial environmental issue because of the highly toxic effluents emitted by factories. Ibuprofen (IBP), as a typical anti-inflammatory drug, is frequently detected in water sources. Therefore, its removal using various adsorbents has drawn great interest. Herein, the structural, electronic, energetic, and optical properties of pristine oxo-triarylmethyl (oxTAM) and transition metal-doped oxo-triarylmethyl (TM@oxTAM, TM = Sc, Ti, V, Cr, and Mn) for adsorption of the IBU drug were investigated using density functional theory (DFT) calculations implemented in Gaussian and VASP codes. Frontier molecular orbital (FMO), density of states (DOS), and electronic band structure results demonstrated that transition metal-doped oxTAM causes a significant reduction in the energy band gap (Eg) value of pristine oxTAM, with the highest decrease (30.14 %) in the case of Mn@oxTAM. It was found that transition metal doping onto oxTAM leads to an increase in the adsorption energies (1.20-2.64 eV) and charge density between transition metal and IBU. Natural bond orbital (NBO) analysis revealed that charge was effectively transferred from the IBU towards the transition metal, which was further analyzed by charge decomposition analysis (CDA). Furthermore, quantum theory of atoms in molecules (QTAIM), interaction region indicator (IRI), electron localization function (ELF), and radial distribution function (RDF) analyses revealed that the IBU is adsorbed on the Sc@oxTAM surface via covalent interactions, while electrostatic with partially covalent interactions are dominated in other IBU/TM@oxTAM complexes. The results suggest that TM doping on the oxTAM provides a new insight for developing photocatalyst-based covalent organic frameworks (COFs) to remove emerging pollutants in wastewater.

Persulfate-enhanced continuous flow three-dimensional electrode dynamic reactor for treatment of landfill leachate

Compared with sequencing batch reactor, continuous flow dynamic reactors are more conducive to promotion and application. In this study, the ability of a three-dimensional (3D) electrode dynamic reactor to remove pollutants in the landfill leachate was investigated, in which landfill leachate entered through continuous flow. Either increased of current density or the decreased of flow rate was conducive to the removal of pollutants. The optimal process parameters for current density and flow rate were 16 mA cm^-2 and 0.75 L h^-1, respectively. When the current density was constant at 16 mA cm^-2 and the flow rate was kept at 0.75 L h^-1, 60.02% of total organic carbon (TOC), 96.50% of chroma, 64.98% of chemical oxygen demand (COD) and 99.46% of ammonia nitrogen (NH₃-N) were removed. The characteristic peaks of refractory organic pollutants were reduced by 97.95%. After the reaction, the biological oxygen demand (BOD)/COD was increased from 0.24 to 0.32. As one of the emerging trace organics in landfill leachate, 85.90% of ibuprofen (IBU) was removed. The results showed that the 3D electrode dynamic reactor constructed in this study could reduce the TOC, refractory trace organic pollutant, NH₃-N and chroma in the landfill leachate. The 3D electrode dynamic reactor constructed in this research has application potential in the field of landfill leachate treatment.