基于水解-沉淀形态分布的金属盐混凝过程关键因子解析  

Analysis of key factors in the coagulation of metal salts based on the calculation of hydrolysis-precipitation distribution

作　　者：甘永海 张丽[1] 吴兵党 郑宏岑 张淑娟[1] Yonghai Gan;Li Zhang;Bingdang Wu;Hongcen Zheng;Shujuan Zhang(State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学环境学院,污染控制与资源化研究国家重点实验室,南京210023

出　　处：《中国科学：化学》2021年第4期458-467,共10页SCIENTIA SINICA Chimica

基　　金：国家重点研发计划(编号:2019YFC0408302);江苏省重点研发计划社会发展项目(编号:BE2018702)资助。

摘　　要：水解-沉淀是无机金属盐能够发挥混凝作用的关键过程.金属盐的价态、浓度、配体浓度以及水的p H均对混凝性能有着重要影响.为准确对比各种无机金属盐作为混凝剂的优劣势和适用范围,本文通过热力学平衡常数的计算,并与混凝实验相结合,解析和验证了铝、铁、钛和锆4种金属的无机盐在有/无配体情况下的沉淀区域图和水合/水解物种的形态分布,定量描述了多核水解产物在4种金属盐水解-沉淀过程中的贡献,并从溶液化学的角度揭示了水中常见配体影响混凝性能的内在机制.上述结果为无机金属盐混凝剂的研发和应用提供了理论基础,对于准确理解混凝性能和机制具有重要意义.Hydrolysis and precipitation are the key processes that determine the coagulation performance of inorganic metal salts. The valence and concentration of metal salts, ligands, and solution pH all influence the coagulation performance. In order to get a full picture on the pros and cons of various inorganic metal salts as coagulants, this paper conducted thermodynamic equilibrium calculations and coagulation experiments to analyze and verify the hydrolysisprecipitation areas and speciation of four inorganic metal salts(aluminum, iron, titanium, and zirconium) in the absence and presence of ligands. In addition, the contributions of polynuclear hydrolysates in the hydrolysis and precipitation of the four metal ions were quantitatively described. Furthermore, the underlying mechanisms of the effects of common aquatic ligands on coagulation performance were discussed from the perspective of solution chemistry. The above results provide a theoretical basis for the development and application of inorganic metal salt coagulants, and are of great significance for understanding the coagulation performance and mechanisms accurately.

关 键 词：铝盐 铁盐 钛盐 锆盐 混凝 配体 水处理 

分 类 号：TU991.22[建筑科学—市政工程]