Vaughan Ronald L, Reed Brian E
Department of Civil and Environmental Engineering, University of Missouri-Columbia, Columbia, MO 65211-2200, USA.
Water Res. 2005 Mar;39(6):1005-14. doi: 10.1016/j.watres.2004.12.034.
The objective of this research was to model As(V) removal onto a iron oxide impregnated activated carbon (FeAC) using the surface complexation model (SCM) approach. As(V) removal by FeAC was due to the impregnated Fe oxide, not the base carbon material and was a strong function of pH. The two-monoprotic site-triple layer model adequately described As(V) removal using 2 fitting parameters compared with the 3 parameters needed for the diprotic site model. This, along with a better representation of the recognized As(V) removal mechanism (ligand exchange with -OH) as well as the acid-base behavior makes the two-monoprotic approach the better model for As(V) removal by the impregnated iron oxide although the diprotic model was able to describe the pH dependent removal of As(V). Both models were also able to predict As(V) removal at different adsorbent/adsorbate ratios using K(As) determined from a single FeAC adsorption experiment. Thus, fewer adsorption experiments are required in order to model As(V) removal in equilibrium and column systems. The results described in this work will be used as a foundation in developing a dynamic model to predict As(V) adsorption in a fixed-bed adsorber.
本研究的目的是使用表面络合模型（SCM）方法对负载氧化铁的活性炭（FeAC）上砷（V）的去除进行建模。FeAC对砷（V）的去除归因于负载的氧化铁，而非基础碳材料，并且是pH的强函数。与双质子位点模型所需的3个参数相比，双单质子位点 - 三层模型使用2个拟合参数就能充分描述砷（V）的去除。这一点，连同对公认的砷（V）去除机制（与 -OH的配体交换）以及酸碱行为的更好表示，使得双单质子方法成为负载氧化铁去除砷（V）的更好模型，尽管双质子模型能够描述砷（V）去除对pH的依赖性。两个模型还都能够使用从单个FeAC吸附实验确定的K(As)预测不同吸附剂/吸附质比例下砷（V）的去除。因此，为了对平衡和柱系统中砷（V）的去除进行建模，所需的吸附实验更少。本工作中描述的结果将作为开发动态模型以预测固定床吸附器中砷（V）吸附的基础。
