An environmentally friendly pore size-controlled, superhydrophobic polylactic acid (PLA) membrane was successfully prepared by a simpler freeze solidification phase separation method (FSPS) and solution impregnation, which has application prospects in the field of oil–water separation. The pore size and structure of the membrane were adjusted by different solvent ratios and solution impregnation ratios. The PLA-FSPS membrane after solution impregnation (S-PLA-FSPS) had the characteristics of uniform pore size, superhydrophobicity and super lipophilicity, its surface roughness Ra was 338 nm, and the contact angle to water was 151°. The S-PLA-FSPS membrane was used for the oil–water separation. The membrane oil flux reached 16,084 L·m⁻²·h⁻¹, and the water separation efficiency was 99.7%, which was much higher than that of other oil–water separation materials. In addition, the S-PLA-FSPS membrane could also be applied for the adsorption and removal of oil slicks and underwater heavy oil. The S-PLA-FSPS membrane has great application potential in the field of oil–water separation.

In this study, dendritic polyamine chitosan beads with and without 2-aminomethyl pyridine were facilely prepared and characterized. Compared to CN (without the pyridine function), more adsorption active sites, larger pores, higher nitrogen content, higher specific surface area, and higher strength could be obtained for CNP (with the pyridine function). CNP microspheres afforded a larger adsorption capacity than those obtained by CN for different pH values; further, the uptake amounts of Cu(II) were 0.84 and 1.12 mmol g⁻¹ for CN and CNP beads, respectively, at pH 5. The CNP microspheres could scavenge Cu(II) from highly acidic and salty solutions: the maximum simulated uptake amount of 1.93 mmol g⁻¹ at pH 5 could be achieved. Due to the strong bonding ability and weakly basic property of pyridine groups, the adsorption capacity of Cu(II) at pH 1 was 0.75 mmol g⁻¹ in highly salty solutions, which was comparative to those obtained from the commercial pyridine chelating resin M4195 (Q_Cu(II) = 0.78 mmol g⁻¹ at pH 1). In addition, a distinct salt-promotion effect could be observed for CNP beads at both pH 5 and 1. Therefore, the prepared adsorbent CNP beads can have promising potential applications in the selective capturing of heavy metals in complex solutions with higher concentrations of H⁺ and inorganic salts, such as wastewaters from electroplating liquid and battery industries.

In this study, novel physical blending modified membranes are prepared using the non-solvent induced phase separation method, the influences of nano-graphite and Poly(vinyl chloride) (PVC) incorporated into the hydrophobic performance of the polyvinylidene fluoride (PVDF) membrane were investigated. The composite membrane was prepared not only reduces the cost of producing PVDF membrane, but also enhances the hydrophobicity of the membrane. The addition of nano graphite and PVC accelerated the phase transformation of PVDF and changed the crystal structure of PVDF. Therefore, the surface roughness of the composite membrane is changed, and the hydrophobicity of the composite membrane is enhanced compared with the original PVDF membrane. the crystal structure and crystallinity of the composite membranes can be analyzed by WAXD and DSC, the surfaces morphology of the composite membranes were characterized by SEM and AFM, the wetting and hydrophobicity of the composite membrane by CA and SFE. The experimental results show that adding a small amount of nano inorganic substance (nano graphite) to the (PVDF-PVC) blend polymer is an effective method to prepare and improve the hydrophobic performance of the blend polymer membrane. The PVDF-PVC/nano-graphite prepared in the experiment not only improves the hydrophobic performance of the PVDF membrane, but also reduces the cost of the composite membrane through the addition of PVC. Meanwhile, the membrane has a durable self-cleaning performance, which widens the applications of PVDF membranes.

In this paper, the photocatalytic degradation efficiency of typical antibiotics (norfloxacin (NOR), sulfamethoxazole (SMX) and tetracycline hydrochloride (TCH)) by Ag/CNQDs/g-C₃N₄ under visible light irradiation was studied. Various strategies were applied to characterize the morphology, structure and photochemical properties of the Ag/CNQDs/g-C₃N₄ composites. The superior photocatalytic activity of Ag/CNQDs/g-C₃N₄ was attributed to the wide light response range and the enhancement of interfacial charge transfer. At the same time, the effect of the influence factors (pH, Humic acid (HA) and coexisting ions) on the antibiotics degradation were also investigated. Furthermore, the electron spin resonance (ESR) technology, free radical quenching experiments, LC/MS and DFT theoretical calculations were applied to predict and identify the active groups and intermediates during the photocatalytic degradation process. In addition, Ag/CNQDs/g-C₃N₄ exhibited the obvious antibacterial effect to Escherichia coli due to the addition of Ag NPs. This study develops a new way for the removal of emerging antibiotic pollution from wastewaters.

Semiconductor photocatalysis is an advanced oxidation process driven by solar energy which has widespread applications in the treatment of organic pollutants in liquid and gas phases. In this work, titanium dioxide nanoparticles modified with yttrium ions (Y³⁺) were prepared by a ball milling method. The effects of Y³⁺ mole fraction, ball-to-powder weight ratio, milling time and milling rate on the photocatalytic activities were evaluated by the degradation of methylene blue (MB) under UV light. Then Y³⁺/TiO₂ photocatalysts prepared at the optimized ball milling conditions were applied to treat shrimp wastewater under UV and visible light. Chemical oxygen demand (COD_Cr), 3D fluorescence spectroscopy and total organic carbon (TOC) were used to detect the water samples taken from the photocatalytic experiments. Experimental results showed that when the mole fraction was 2%, the ball-to-powder weight ratio was 4 : 1, milling time was 4 h and milling rate was 500 rpm, the reaction rate constant of MB degradation can reach up to 0.1112 min⁻¹ which was 4.2 times as fast as pure TiO₂. All Y³⁺/TiO₂ samples showed a red shift of absorption compared to pure TiO₂ and it led to a visible light absorption response. The content of surface oxygen vacancies has significantly increased and the BET specific area increased to 104 m² g⁻¹. The COD_Cr removal rates of shrimp wastewater were 43.8% and 37.5% for 2% Y³⁺/TiO₂ under UV and visible light, respectively. Besides, the TOC removal rates were 67.5% and 38.8%, respectively. Humic-like substances and fulvic-like substances in shrimp wastewater can be mineralized after 90 minutes irradiation.