Modelling of the Competitive Adsorption Between Micropollutants and Background Organics.

将理想吸附溶液理论应用于活性炭的多组分竞争吸附。对含溶质的假想原水进行了数值模拟，其单溶质体系的吸附等温线由Freundlich方程给出。结果表明，柱试验和批试验得到的总有机物吸附等温线有本质区别。模拟还表明，当原水稀释或浓缩时，间歇吸附等温线发生变化。建立了一个预测模型来描述原水稀释或浓度对总有机物间歇吸附等温线的影响。该模型成功地应用于天然水体中典型背景有机物腐殖酸的间歇吸附等温线实验，尽管腐殖酸的浓度是由TOC和UV吸附量等替代参数测量的，但基于IAS理论的数值模拟也表明，确定吸附相的扩散压力可以与吸附的总有机物量相关，并且当原水被稀释或浓缩时以及当某一组分的浓度稍微改变时，该相关性不改变。因此，组分在吸附相（活性炭）和液相之间的分配比可以与总有机物吸附量相关。基于后者的相关性，一个简单的，但非常实用的模型来描述的竞争影响的背景有机物上的活性炭吸附的微污染物。通过对氨基苯甲酸在含有中等浓度背景有机物的河水中的间歇吸附试验，验证了该模型的正确性。

IAS (Ideal Adsorbed Solution) theory was applied to a multi-component competitive adsorption on activated carbon. Numerical simulations were executed to the imaginary raw water containing solutes, the adsorption isotherm of which in their single-solute system is given by Freundlich equation. The result showed the essential difference between the adsorption isotherm of the total organics obtained by column tests and that obtained by batch tests. The simulations also showed that the batch adsorption isotherm changes when the raw water is diluted or concentrated. A predictive model was developed to describe the influence of dilution or concentration of raw water on the batch adsorption isotherm of the total organics. This model was successfully applied to the experimental batch adsorption isotherm of humic acid which is very typical background-organics in natural water, even though the concentration of humic acid was measured by surrogate parameters such as TOC and UV-adsorbance.Numerical simulations based on IAS theory also showed that the spreading pressure which specifies the adsorbed-phase can be correlated with the amount of the total organics adsorbed, and this correlation does not change when the raw water is diluted or concentrated and when the concentration of a certain component sligtly changes. Accordingly, the distribution ratio of a component between adsorbed-phase (activated carbon) and liquid-phase can be correlated with the amount of the total organics adsorbed. Based on the latter correlation, a simple but very practical model was developed to describe the competitive influence of background organics upon the adsorption of micropollutants onto activated carbon. This model was veryfied through the batch adsorption tests of paminobenzoic acid spiked into a river water which contains a moderate concentration of background organics.