College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China.
College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang 550025, China.
Sci Total Environ. 2023 Feb 20;860:160289. doi: 10.1016/j.scitotenv.2022.160289. Epub 2022 Nov 19.
A large amount of wastewater containing nitrogen, phosphorus, and fluorine produces in the production of phosphate fertilizer. In this study, to simultaneously recover nitrogen and phosphorus from phosphorus-containing wastewater and realize the resource utilization of red mud and rape straw, red mud-modified rape straw biochar (RM/RSBC) was prepared by facile one step, and the physicochemical properties were characterized by Zeta potential, SEM-EDS, BET specific surface area (SSA), FTIR, XRD, and XPS. The adsorption performance and mechanisms of ammonium and phosphate onto RM/RSBC were explored through static, fixed-bed column adsorption, and practical wastewater experiments. The results showed that pH = 3.0 and 8.0 were favorable for the removal of phosphate and ammonium, respectively. The main adsorption mechanisms of ammonium and phosphate were the interaction between ammonium and surface functional groups and surface precipitation, respectively. The removal efficiencies of ammonium and phosphate by fixed-bed column adsorption mainly depended on the addition amount of RM/RSBC, the concentration of ammonium and phosphate, and the flow rate. The results of the germination experiment showed that adding > 0.5 wt% of RM/RSBC loaded with ammonium and phosphate promoted the growth of mung beans. This study shows that RM/RSBC can not only recover ammonium and phosphate in wastewater, but also realize the resource utilization of red mud and rape straw.
大量含有氮、磷和氟的废水会在生产磷肥的过程中产生。在这项研究中，为了从含磷废水中同时回收氮和磷，并实现赤泥和油菜秸秆的资源利用，采用简便的一步法制备了赤泥改性油菜秸秆生物炭（RM/RSBC），并通过 Zeta 电位、SEM-EDS、BET 比表面积（SSA）、FTIR、XRD 和 XPS 对其理化性质进行了表征。通过静态、固定床柱吸附和实际废水实验，探讨了 RM/RSBC 对铵和磷酸盐的吸附性能和机制。结果表明，pH = 3.0 和 8.0 有利于磷酸盐和铵的去除。铵和磷酸盐的主要吸附机制分别为铵与表面官能团的相互作用和表面沉淀。固定床柱吸附去除铵和磷酸盐的效率主要取决于 RM/RSBC 的添加量、铵和磷酸盐的浓度以及流速。发芽实验的结果表明，添加 > 0.5wt%负载有铵和磷酸盐的 RM/RSBC 可促进绿豆的生长。本研究表明，RM/RSBC 不仅可以从废水中回收铵和磷酸盐，还可以实现赤泥和油菜秸秆的资源利用。
