Premium
A Study of Chromium Adsorption on Natural Goethite Biomineralized with Iron Bacteria
Author(s) -
Zhenya SUN,
Chunshui ZHU,
Jiangbo HUANG,
Wenqi GONG,
Hesheng CHEN,
Shanbin MU
Publication year - 2006
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.2006.tb00280.x
Subject(s) - goethite , adsorption , chromium , chemistry , inorganic chemistry , redox , freundlich equation , metal , langmuir , metal ions in aqueous solution , chemical engineering , materials science , organic chemistry , engineering
Goethite, especially biogenic goethite, has high specific surface area and great capacity for the adsorption of many contaminants including metal ions and organic chelates. Chromium is a redox actively toxic metal ion that exists as either Cr III or Cr VI in nature, and as such it is essential to understand its behavior of adsorption on natural goethite mineralized by iron bacteria, as Gallionella and Leptothrix in water body. The adsorption of Cr 3+ and Cr VI on naturally biomineralized goethite is studied in this paper. The results show that both Langmuir and Freundlich adsorption isothermal models are able to accurately describe the adsorption of these two ions. Investigation of SEM/EDS, TEM/EDS indicates that the two ions do not adsorb homogeneously on goethite owing to the different microstructures of goethite, and that the microspherical goethite has a greater adsorption capacity for chromium ions than the helical one. XPS data show that redox reaction of chromium on the surface of biomineralized goethite takes place in the adsorption of both Cr 3+ and Cr VI . The Cr VI adsorbed on biogoethite is much easier to transform into Cr III than the oxidization of Cr III on the bio‐goethite.