Weikang Zheng,Boyan Wang,Zhenzhong Liu,Hongwei Yang,Zhanli Chen,Xiangrong Sun
Microplastics (MPs) in the aqueous environments has attracted widespread attention because of its potential risk to human health.Its high stability makes it difficult to be degraded and long term presence in the environment. Therefore, it is crucial to find an efficient and clean technology to remove microplastics in water. The advanced electrocatalysis oxidation process (AEOP) shows great potential for application. In this work, We focused on preparing Ti/Sb-SnO 2 electrodes doped with different rare earth elements (La, Ce, Sm or Nd) as active layer by sol-gel method. The electrooxidation system has efficiently degraded MPs in aqueous solution. The optimal parameters for the removal of MPs were electrode spacing of 1.5 cm, current density of 46.67 mA·cm −2 , Na 2 SO 4 electrolyte concentration of 0.22 mol·L −1 , and initial solution pH of 7. After 3 h, MPs removal rate by Ti/La-Sb-SnO 2 system reached 28.3 %, which was higher than the Ti/Ce-Sb-SnO 2 , Ti/Sm-Sb-SnO 2 , Ti/Nd-Sb-SnO 2 and Ti/Sb-SnO 2 electrode, the removal rates were increased by 8.23 %, 10.13 %, 16.28 % and 77 %, respectively. Electrochemical performance tests and •OH (Hydroxyl radicals) generation results indicated that the surface of Ti/La-Sb-SnO 2 electrode had abundant active sites, which promoted the formation of •OH to degrade microplastics effectively. In summary, the rare earth element-doped Ti/Sb-SnO 2 electrode provides crucial technological support for the electrooxidative removal of microplastics from water.
The flotation of molybdenite particles smaller than 20 μm is inefficient primarily due to the reduction in overall hydrophobicity as particle size decreases. However, previous studies mainly focused on interfacial regulation of molybdenite faces or edges individually, resulting in unsatisfactory recovery and high collector consumption. In this work, an attempt was made to regulate the interfacial properties of both faces and edges synchronously to achieve highly efficient beneficiation of molybdenite fines utilizing a new compound collector consisting of emulsified kerosene and fatty alcohol polyoxyethylene ether phosphate (AEOP). The flotation results demonstrated that the compound collector was more superior than single collector in flotation, which promoted the flotation recovery greatly compared to emulsified kerosene or AEOP. In addition, the synergistic effect of kerosene and AEO-3P was much stronger than that of kerosene and AEO-9P. The results of zeta potential, electrochemical tests and scanning electron microscopy energy dispersive spectrometer (SEM-EDS) indicated that AEOP species preferentially adsorbed on edges, which enhanced the adsorption of emulsified kerosene droplets on edges via intermolecular interactions. Moreover, a portion of AEOP combined with kerosene droplets adsorbed on the molybdenite faces. X-ray photoelectron spectroscopy (XPS) results suggested that the phosphoric acid groups in AEOP bonded with Mo sites on edges. The contact angle results further confirmed that the compound collector synergistically acted on both faces and edges to improve its hydrophobicity. This work provides an innovative perspective to design effective compound collector for the flotation of molybdenite fines in future.
危险品化学品经营许可证（带存储）