In this study, we aimed to magnetically separate phosphate from natural water and change its source-to-sink conversion to prevent eutrophication. To this end, a promising material in terms of phosphate removal efficiency and magnetic separability was developed. Nine types of magnetic composite P-removal agents were prepared by changing the types of metal salts (i.e., Zn 2+ , Cu 2+ , Mg 2+ , Al 3+ , Fe 3+ , Zr 4+ , Y 3+ , Ce 3+ , and La 3+ ), and the optimal agent was determined to be La 3+ /poly (acrylamide-co-acryloyloxyethyl thimethylammonium chloride)/Fe 3 O 4 [La 3+ /CPAM/Fe 3 O 4 ] based on phosphate removal efficiency. The optimal synthesis conditions, including reaction time (4 h), reaction temperature (65°C), and the content of metal salts (12.96 mmol), were determined. The synthesized material was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometry. The results showed that the material featured a core–shell structure and exhibited good magnetic response. The experimental results showed that the removal process was rapid and completed within 20 min. Moreover, the material could greatly reduce P concentration, with phosphate removal efficiency reaching 90.07%. This material could effectively separate phosphate under the action of an external magnetic field and change the source-to-sink conversion of P, thereby preventing the risk of eutrophication.
Wang Yunyun,Yang Xinyan,Dai Jiangdong,Yan Yongsheng,Jiang Yinhua,Chen Li
Cellulose aerogels (CA) were widely used in the adsorption field due to high porosity, ultra-light quality, high-proportioned surface area. This article used a 3D La-CA-based adsorbent to improve wastewater eutrophication. Filter paper as cellulose source was applied and lanthanum was doped. Batch adsorption experiments showed that the maximum phosphate adsorption capacity could reach 54.377 mg g −1 (pH = 3.0). At the same time, the leaching of the lanthanum of the adsorbent was negligible, which proves good stability. In particular, the 3D La-CA presented an overall cylindrical monolith and would be easily separated from water compared with the powdery adsorbent. The adsorption performance of La-CA was not significantly affected by the competitive ions (F − , SO 4 2− , Cl − , NO 3 − ) and could still maintain 84.8% after 5 cycles. And mechanism analysis suggested that the 3D La-CA had a specific affinity with phosphates, through electrostatic attraction and inner-sphere complexation. In general, these 3D La-doped cellulose aerogels would provide new possibilities for the practical application of adsorbents in phosphate adsorption.
危险品化学品经营许可证（带存储）