Zhejiang Gongshang University

Ultrasound has the advantages of being environmentally friendly and enhancing the collision and aggregation of suspended particles, while the potential for microplastics (MPs) treatment in aqueous environments is yet to be explored.This study investigated the role of ultrasound in promoting the aggregation of MPs in aqueous environments to achieve their removal, and found that ultrasonic power, temperature, and time are key factors influencing MPs aggregation.Optimization achieved maximum aggregation rates of 64.8 % for PVC and 53.5 % for PE, and the optimal conditions for aggregation were ultrasound power of 230 W, 22 °C, ultrasound for 7 min, and ultrasound power of 153 W, 22 °C, ultrasound for 4 min, resp.Fourier transform IR spectroscopy and at. force microscopy analyses of the properties of MPs before and after aggregation revealed that ultrasonic input reduced the surface roughness of MPs from 676.6 nm to 499.7 and 107.1 nm, resp., accompanied by a reduction in elec. potential by 3.3-4.4 V, which was identified as the primary cause of aggregation.Theor. calculations indicated that the binding energies of PVC and PE were -12.82 and -7.75 kJ·mol^-1, resp., further confirming that electrostatic force play a dominant role in MPs interactions.Moreover, the differences in aggregation effects depended on variations in the physicochem. properties of different types of MPs.COMSOL simulations further validated the possible process of MPs aggregation induced by ultrasound in aqueous environments.This study offers new insights into the removal of MPs in aqueous environments and is expected to develop a green and efficient treatment technol.

In this study, a green method for collagen recovery from tuna processing waste utilizing a biocompatible ionic liquid-based aqueous two-phase system (ATPS) was established.The phase behavior of selected extractants, including choline-based ionic liquids (Ch-ILs) and the non-ionic surfactant Triton X-100 (TX-100), was systematically investigated and evaluated based on their phase diagrams, d. functional theory calculations, and NMR anal.Through optimization of single-factor experiments, the optimal ATPS was determined to consist of TX-100, [Ch][DHC], and water in a weight ratio of 16:30:54.Following ultrasonic treatment for 2 h at a solid-to-liquid ratio of 1:10, an average collagen yield of 16.61 ± 0.30 % was achieved without requiring tedious sample pretreatment steps.The purified collagen was characterized and validated through a series of spectral analyses, confirming that it maintained a relatively intact triple helix structure.It is noteworthy that the recovery and recycling rates for both [Ch][DHC] and TX-100 were evaluated during the extraction process, with results indicating that these rates exceeded 87.5 %.Addnl., the potential extraction mechanisms underlying the interactions between collagen and the studied ionic liquids were investigated using mol. docking simulations.This proposed extraction strategy aligns with principles of being environmentally friendly, safe, and sustainable-thereby enhancing its application prospects for effective treatment of tuna processing waste.

Nowadays, water pollution issues caused by antibiotics and heavy metals have become a focus of global concern, and it is greatly significant to develop effective methods to remove heavy metal and organic contaminant from wastewater. Herein, newly-designed Cu₂S/ZnIn₂S₄ p-n heterojunction with internal electric field is constructed by using epitaxial growth strategy. Importantly, lattice well-matched heterointerface between Cu₂S and ZnIn₂S₄ presents very low charge transfer resistance. Under the mediation of internal electric field, the generation and separation of photogenerated carriers are effectively improved, and the formation of hollow structure enhances visible light absorption capability. Benefiting from these changes, photogenerated electrons and holes can be directly involved in tetracycline (TC) degradation and Cr(VI) reduction, avoiding intermediate reaction processes. Under visible light illumination, thus, Cu₂S/ZnIn₂S₄ composite shows superb performance in the treatment of wastewater containing both antibiotic and Cr(VI). The removal efficiencies of TC and Cr(VI) are as high as 96.7% and 94.1% within 32 min, respectively. Interestingly, Cr(VI) reduction over Cu₂S/ZnIn₂S₄ is a stepwise process, and Cr(VI) is first reduced to Cr(V) and then transformed into Cr(III). Notably, Cr(V) with strong oxidation ability as transition intermediate can further promote antibiotic degradation.