Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008, China.
J Hazard Mater. 2012 Aug 30;229-230:170-6. doi: 10.1016/j.jhazmat.2012.05.089. Epub 2012 Jun 2.
Hydroxyapatite nanoparticle (nHAP) is increasingly being used to remediate soils and water polluted by metals and radionuclides. The transport and retention of Alizarin red S (ARS)-labeled nHAP were investigated in water-saturated granular media. Experiments were carried out over a range of ionic strength (I(c), 0-50mM NaCl) conditions in the presence of 10 mg L(-1) humic acid. The transport of ARS-nHAP was found to decrease with increasing suspension I(c) in part, because of enhanced aggregation and chemical heterogeneity. The retention profiles (RPs) of ARS-nHAP exhibited hyperexponential shapes (a decreasing rate of retention with increasing transport distance) for all test conditions, suggesting that some of the attachment was occurring under unfavorable conditions. Surface charge heterogeneities on the collector surfaces and especially within the ARS-nHAP population were contributing causes for the hyperexponential RPs. Consideration of the effect(s) of I(c) in the presence of HA is needed to improve the efficacy of nHAP for scavenging metals and actinides in real soils and groundwater environments.
羟基磷灰石纳米颗粒（nHAP）越来越多地被用于修复受金属和放射性核素污染的土壤和水。本文研究了茜素红 S（ARS）标记的 nHAP 在水饱和的颗粒介质中的迁移和滞留。在存在 10mg/L 腐殖酸的情况下，在 0-50mM NaCl 离子强度（I(c)）范围内进行了实验。发现随着悬浮液 I(c)的增加，ARS-nHAP 的迁移减少，部分原因是由于聚集和化学异质性增强。对于所有测试条件，ARS-nHAP 的保留剖面（RP）呈现出超指数形状（随着迁移距离的增加，保留率降低），表明在某些不利条件下发生了一些附着。集流体表面的表面电荷非均质性，特别是在 ARS-nHAP 群体内，是导致超指数 RP 的原因之一。需要考虑在 HA 存在下 I(c)的影响，以提高 nHAP 在实际土壤和地下水中去除金属和锕系元素的功效。
