Copper release kinetics during the iron oxide transformation in the presence of fulvic acid and humic acid [富里酸和胡敏酸对水铁矿转化过程中铁氧化物上铜释放动力学特性的影响]

作者：Lu Y.; Liang Y.; Lu G.; Shi Z.^*

来源：Acta Scientiae Circumstantiae, 2021, 41(2): 607-615.

DOI：10.13671/j.hjkxxb.2020.0190

• Cu
• Ferrihydrite
• Hematite
• Iron oxide transformation
• Natural organic matter
• STEM

Natural organic matter (NOM) and heavy metals (HMs) can both participate in the iron oxide transformation process in HM contaminated soils. However, there is still a lack of knowledge concerning the HM release kinetics during the iron oxide transformation especially under the influence of NOM. In this study, iron oxide transformation was conducted in the presence of Cu and two types of representative NOM, fulvic acid and humic acid (FA and HA). Release kinetic experiments were conducted for the iron oxides at various aging times to elucidate the influence of NOM on the Cu release during the iron oxide transformation process. A stirred-flow (SF) system and a pH of 5.5 were set to imitate the natural dynamic solid-liquid reaction process. Results showed that the leachability of Cu decreased during the iron oxide transformation, while NOM increased Cu leachability compared with the non-NOM treatment. The spherical aberration corrected scanning transmission electron microscopy (Cs-STEM) showed that Cu could be incorporated into the iron oxide nano particles to sequester Cu in iron oxides, while both FA and HA resulted in the ellipsoidal particles with a loose structure, which provided abundant sites for Cu adsorption. Overall, the different leachability of Cu was mainly due to the aging of Fe oxides, not to the aging of Cu-NOM complexes. Results in this study would help to get a better understanding of the environmental behaviors of Cu during the iron oxide transformation process in the presence of NOM, and also, shed lights on the nano scale mechanism of Cu and C interaction with iron oxides.

• 出版日期2021
• 单位华南理工大学