硫酸根含量对施氏矿物表面性质及相转化过程的影响  

Effect of sulfate content on surface properties and phase transformation of schwertmannite

作　　者：王超平 郭楚玲 陈锴 殷美玲 周玉婷 庄庆林 曹倩倩 WANG Chaoping;GUO Chuling;CHEN Kai;YIN Meiling;ZHOU Yuting;ZHUANG Qinglin;CAO Qianqian(The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters,Ministry of Education,School of Environment and Energy,South China University of Technology,Guangzhou 510006)

机构地区：[1]华南理工大学环境与能源学院,工业聚集区污染控制与生态修复教育部重点实验室,广州510006

出　　处：《环境科学学报》2024年第8期270-278,共9页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2023YFC3207304);国家自然科学基金(No.41931288)。

摘　　要：施氏矿物作为酸性矿山废水环境中最为常见的次生矿物,其亚稳态结构导致其容易发生矿相转变.除外部环境(如pH值、温度和共存离子等)之外,施氏矿物自身的硫酸根含量也会对其表面性质和稳定性造成影响.为此,本文采用快速化学法成功制备3种硫酸根含量不同的施氏矿物,并研究了它们的表面特性以及在酸性条件下的矿相转化过程.结果表明,随着硫酸根含量的降低,施氏矿物的表面位点密度、负电荷和酸碱缓冲能力均有所降低.在模拟老化环境条件下,3种施氏矿物的主要转化产物均为针铁矿,但转化速率不同:通过红外定量实验发现硫酸根含量较低的施氏矿物在矿物相变过程中能保持稳定的转化速率,而硫酸根含量较高的施氏矿物在硫酸根完全释放后转化速率减缓,从长期来看后者表现出更高的稳定性.本研究揭示了施氏矿物的硫酸根含量对其表面性质及矿相稳定性的影响,为深入了解其在酸性环境下的行为提供了新的视角和思路.As a widely spread secondary mineral in acid mine drainage environments,schwertmannite is susceptible to undergo mineral phase transformations due to its metastable structure.In addition to environmental factors such as pH,temperature,and coexisting ions,the sulfate content of schwertmannite also plays a significant role in determining its surface properties and stability.In this study,three types schwertmannite with different sulfate contents were successfully synthesized using a rapid chemical method.The study focused on investigating their surface characteristics and mineral phase transformation processes under acidic conditions.The findings revealed that as the sulfate content decreased,the surface site density,negative charge,and acid-base buffering capacity of schwertmannite all exhibited a corresponding decrease.In the simulated aging environments,it was observed that the primary transformation product of the three types of schwertmannite was identified as goethite.However,the transformation rates varied among the samples:infrared quantitative analysis showed that schwertmannite with lower sulfate content maintained a consistent transformation rate throughout the process,while schwertmannite with higher sulfate content experienced a deceleration in transformation rate after the complete release of sulfate.Over the long term,the latter demonstrated higher stability.This investigation sheds light on the impact of sulfate content in schwertmannite on its surface properties and stability.These findings offer new insights of how schwertmannite behaves in acidic environments.

关 键 词：施氏矿物 针铁矿 硫酸根含量 矿相转化 

分 类 号：X131[环境科学与工程—环境科学]