通过向合成铜氨络合废液中添加镁离子Mg2+和磷酸根离子34PO?,可以实现络合离子的解离,从而实现铜与氨氮的同步脱除.据此建立了两段式鸟粪石结晶法(TSSF),用于去除铜及氨氮.其中,第一段添加90%药剂(MgCl2及Na2HPO4),第二段添加剩余10%药剂.考察磷源及镁源添加量、pH、反应时间对铜及氨氮去除率的影响.结果表明,TSSF法对铜、氨的去除性能优于一段式沉淀法.在n(NH3-N):n(Mg):n(P)=1:1.2:1.5(摩尔比)、pH=9、反应时间30 min情况下,铜及氨氮的去除率分别为98.9%和99.96%.采用铜氨络合物与鸟粪石对氨氮的竞争机制解释了TSSF法对铜、氨的高效去除,并采用基于计算及优势相图的热力学分析手段进一步阐明了铜氨络合离子的解离机制.此外,X射线衍射分析(XRD)及能谱分析(EDS)结果也证实了鸟粪石的形成及铜的沉淀,揭示了铜及氨氮从液相到固相的转变过程.
Mg2+ and PO43+were added into the synthetic wastewater, leading to the dissociation of the complex ions in the wastewater, and resulting in removal of copper and ammonia therein. The effects of agents addition amount, pH, and reaction time on the removal efficiency of copper and ammonia were investigated. In particular, two-sectional struvite formation (TSSF) process was established for copper and ammonia removal. MgCl2 and Na2HPO4 were added by following 90% addition in the first section and remained 10% in the second during the TSSF process. Compared with one sectional struvite formation, TSSF possessed much better performance. Under condition ofn(NH3-N):n(Mg):n(P)=1:1.2:1.5 (molar ratio), pH=9, and reaction time of 30 min, the removal efficiencies of copper and ammonia were 98.9% and 99.96%, respectively. The enhanced performance of TSSF is explained by the competition of ammonia by copper?ammonia complexes and struvite. The dissociation of copper?ammonia complexes is further demonstrated by thermodynamic equilibrium analysis, on the basis of calculations and establishment of predominance phases diagram. Moreover, XRD and EDS analyses further confirmed the formation of struvite and precipitation of copper, which prove the transmission of copper and ammonia from liquid phase into solid phase.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%