|Title||Effect of humic acid on uranium(VI) retention and transport through quartz columns with varying pH and anion type|
|Affiliation||Sichuan Univ, Inst Nucl Sci & Technol, Key Lab Radiat Phys & Technol, Minist Educ, Chengdu 610064, Sichuan, Peoples R China.|
China Acad Engn Phys, Inst Nucl Phys & Chem, Mianyang 621900, Peoples R China.
Peking Univ, Coll Chem & Mol Engn, BNLMS, Beijing 100871, Peoples R China.
|Publisher||JOURNAL OF ENVIRONMENTAL RADIOACTIVITY|
|Citation||JOURNAL OF ENVIRONMENTAL RADIOACTIVITY.2017,177,142-150.|
|Abstract||Humic acid (HA)1 is ubiquitous in the environment and is an important factor in the migration behavior of U(VI) in the geological medium. The present work investigated the effect of HA on the migration behavior of U(VI) using quartz column experiments at different pH values and in the presence of various anions. The U(VI) adsorption characteristics and speciation were also studied to illuminate' further the migration behavior of U(VI). Our results indicated that, at pH 6.0, HA slightly increased the migration velocity of U(VI) during the initial phase and reduced the quantity of eluted U(VI) because of the formation of HA-U(VI). The relative concentration (c/c(o)) of U(VI)was higher in the HA-U system at pH 8.0 than that at pH 5.0 because of the higher solubility of HA in basic solutions and the difference in charge of HA-U(VI). In the U-HA-anion system at pH 6.0, the breakthrough pore volumes (PVs(2)) of U(VI) in electrolytes containing Cl- and SO42- anions (PV = 8) are much higher than for solutions containing phosphate (PV = 3), while the HA migration behavior was not significantly affected by the type of anion. Thus, the fast migration of U(VI) under HA and phosphate was attributed to phosphate rather than HA. This result suggests that phosphate should be given more attention in predictions of U(VI) migration, especially in regions with high groundwater phosphate content. (C) 2017 Elsevier Ltd. All rights reserved.|
|Appears in Collections:||化学与分子工程学院|