Tetrabromobisphenol A (TBBPA) is a brominated flame retardant, which is widely present in the various environmental and biological media. The knowledge on the contamination of TBBPA in Weihe River Basin is still limited. In order to know the pollution level and distribution of tetrabromobisphenol A (TBBPA) in the Weihe River Basin, a total of 34 sediment samples and 36 water samples were collected from the main stream and tributaries of the WeiHe River Basin, and the concentration of TBBPA in the samples was analyzed by high-performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC-ESI-MS). The detection frequency of TBBPA in sediments and water samples was 61.8% and 27.8%, respectively; the TBBPA concentrations in sediments and water samples were in the range of not detected (N.D.)–3.889 ng/g (mean value of 0.283 ng/g) and N.D—12.279 ng/L (mean value of 0.937 ng/L), respectively. Compared with other areas in China, the residues of TBBPA in the Weihe River Basin were at a relatively low level. The spatial distributions of TBBPA in surface sediments and water indicated that the local point-input was their major source. This is related to the proximity of some sampling sites to industrial areas and domestic sewage discharge areas. The insignificant correlation between TBBPA and total organic carbon (TOC) indicated that TBBPA in sediments is not only influenced by TOC but also affected by atmosphere and land input, wet deposition, and long-distance transmission. The potential risks posed by TBBPA in water and sediment were characterized using the risk quotient (RQ) method. The calculated RQ for TBBPA was less than 0.01, showing that the ecological risk due to TBBPA was quite low for aquatic organisms.

In this study, the interaction between the humus and two antibiotics was studied by UV-Vis spectroscopy to describe the interaction mechanism and the effects of different environmental factors on the mechanism. Results showed that humic acid (HA) containing more aromatic groups was easily associated with antibiotics. In the HA-OTC, with the increase of the concentration of OTC, there were obvious absorption peaks in the 230–260 nm and 330–360 nm range, and the absorption band of the HA ultraviolet spectrum underwent a slight blue shift and the absorption intensity increased, demonstrating that a new ground state complex was generated. In the HA-SD, with the increase of SD concentration, an aromatic structure absorption peak appeared in the 190–220 nm range, and the peak value increased and the absorption band underwent a red shift, and the aromatization of HA decreased, which enhanced the interaction between the antibiotics and HA. With the increase of pH, the absorption band of HA, HA-OTC and HA-SD ultraviolet spectrum suffered a blue shift, the degree of polymerization of HA molecules decreased, and the number of adsorption binding sites increased, which resulted in the interaction of HA with antibiotics being enhanced. The absorption band of HA, HA-OTC and HA-SD displayed a red shift with the increase of ionic strength, which indicated that the repulsion within HA particles was weakened, and the molecular polymerization was strengthened and therefore, the interaction between antibiotics and HA was inhibited. The UV characteristics of the HA, HA-OTC and HA-SD systems were insensitive to the temperature. This study lays the foundation for better studying the effect of humus on the distribution of antibiotic residues in the environment.

In order to prepare parabolic superhydrophobic materials, copper meshes were used as the substrate and ultrasonic etching and oxidative corrosion were carried out with FeCl₃ solution and H₂O₂ solution, respectively, and then the surface was modified with stearic acid (SA). The topological structure and surface wettability of the prepared mesh were characterized by fluorescence microscope, scanning electron microscopy and contact angle measurement. Finally, the as-prepared copper meshes were applied to oil-water separation. The results showed that the micro-nano-mastoid structure on the surface of the copper mesh was flaky bulges, forming a rough structure similar to a paraboloid. When the oxidative corrosion time of H₂O₂ was 1 min, it is more beneficial to increase the hydrophobicity of the surface of the copper mesh and increase the contact angle of water droplets on the surface of the membrane. Additionally, based on superhydrophobic materials of the parabolic copper mesh, the static contact angles of the water droplets, engine oil and carbon tetrachloride with the surface were approximately 153.6°, 5° and 0.1°, respectively and the sliding angle of the water droplets with the surface were approximately 4.9°. The parabolic membrane was applied to discuss the separation efficiency of different oils with deionized water and the separation efficiency was obtained as benzene > carbon tetrachloride > oil > machine oil. Therefore, based on the research, the parabolic superhydrophobic material has good efficiency of oil-water separation.

As one of the most widely used brominated flame retardants, hexabromocyclododecane (HBCD) is found widely in the environmental media. In this study, the content and spatial distribution of HBCD and risk posed by HBCD in surface sediment in the Weihe River Basin in Northwest China were investigated. The HBCD concentration ranged nd–4.04 ng/g dw with the mean was 0.45 ng/g dw. The major source of HBCD in surface sediment was local point discharge. The distribution profiles of α-, β-, γ-HBCD were 24.7–87.9%, 0–42.0%, and 0–67.1%, respectively. Specially, α-HBCD was the dominating isomer in most sample sites. This differed significantly from that in HBCD technical product, which might be attributed to the different degradation rates and inter-transformation of the three HBCD isomers. Risk quotient method was used to assess the potential risk posed by HBCD in sediment. HBCD do not pose strong risks to aquatic algae organisms in the Weihe River Basin.

The sorption of hexabromocyclododecanes (HBCDs) on sediment affects the fate and transport of HBCDs in rivers. The sorption of HBCDs on sediment from the Weihe River was investigated by performing batch equilibration experiments, and the effects of changing the pH ionic, strength, and humic acid concentration (HA) on sorption were evaluated. The obtained results indicated that fast rather than slow sorption was the dominant process. Nonlinear sorption isotherms were acquired, and the Freundlich (R² 0.94–0.98) and Langmuir (R² 0.95–0.99) models both described the sorption of HBCDs well. The adsorption capacity for α-HBCD, β-HBCD, and γ-HBCD were calculated using the Langmuir model, and were 443.56, 614.29 and 1146.37 mg/kg, respectively. Thermodynamic analysis shows that HBCDs sorption on sediment is a spontaneous exothermic process. HBCDs sorption was affected by the HA concentration and ionic strength. The amounts of HBCDs sorbed to the sediment decreased as the ionic strength increased, and first increased and then decreased as the HA concentration increased. Changes in pH did not clearly affect the sorption of HBCDs. Synchrotron radiation Fourier-transform infrared spectra (SR-FTIR) was used to characterize the adsorption mechanism, and the obtained result indicated that hydrophobic interactions dominated the mechanism involved in HBCDs sorption on sediment.