Institute of Hygiene and Environmental Medicine, RWTH Aachen University, Pauwelstr. 50, 52074, Aachen, Germany.
Environ Sci Pollut Res Int. 2013 Jun;20(6):3607-15. doi: 10.1007/s11356-012-1432-9. Epub 2013 Jan 9.
Due to concerns about ecotoxicological effects of pharmaceuticals and other micropollutants released from wastewater treatment plants, activated carbon adsorption is one of the few processes to effectively reduce the concentrations of micropollutants in wastewater. Although aimed mainly at apolar compounds, polar compounds are also simultaneously removed to a certain extent, which has rarely been studied before. In this study, adsorption isotherm and batch kinetic data were collected with two powdered activated carbons (PACs) to assess the removal of the polar pharmaceuticals 5-fluorouracil (5-Fu) and cytarabine (CytR) from ultrapure water and wastewater treatment plant effluent. At pH 7.8, single-solute adsorption isotherm data for the weak acid 5-Fu and the weak base CytR showed that their adsorption capacities were about 1 order of magnitude lower than those of the less polar endocrine disrupting chemicals bisphenol A (BPA) and 17-α-ethinylestradiol (EE2). To remove 90 % of the adsorbate from a single-solute solution 14, 18, 70, and 87 mg L(-1) of HOK Super is required for EE2, BPA, CytR, and 5-Fu, respectively. Effects of solution pH, ionic strength, temperature, and effluent organic matter (EfOM) on 5-Fu and CytR adsorption were evaluated for one PAC. Among the studied factors, the presence of EfOM had the highest effect, due to a strong competition on 5-Fu and CytR adsorption. Adsorption isotherm and kinetic data and their modeling with a homogeneous surface diffusion model showed that removal percentage in the presence of EfOM was independent on the initial concentration of the ionizable compounds 5-Fu and CytR. These results are similar to neutral organic compounds in the presence of natural organic matter. Overall, results showed that PAC doses sufficient to remove >90 % of apolar adsorbates were able to remove no more than 50 % of the polar adsorbates 5-Fu and CytR and that the contact time is a critical parameter.
由于担心医药和其他微污染物从污水处理厂释放对生态毒理学的影响，活性炭吸附是有效降低废水中微污染物浓度的少数工艺之一。虽然主要针对非极性化合物，但也会同时在一定程度上去除极性化合物，这在以前很少被研究过。在这项研究中，使用两种粉末状活性炭 (PAC) 收集了吸附等温线和批量动力学数据，以评估从超纯水和污水处理厂废水中去除极性药物 5-氟尿嘧啶 (5-Fu) 和阿糖胞苷 (CytR) 的效果。在 pH 值为 7.8 时，弱酸性 5-Fu 和弱碱性 CytR 的单溶质吸附等温线数据表明，它们的吸附容量比极性稍低的内分泌干扰化学物质双酚 A (BPA) 和 17-α-乙炔基雌二醇 (EE2) 低 1 个数量级。为了从单溶质溶液中去除 90%的吸附物，需要分别使用 HOK Super 活性炭吸附 14、18、70 和 87mg/L 的 EE2、BPA、CytR 和 5-Fu。研究了一种 PAC 溶液 pH 值、离子强度、温度和废水中有机物 (EfOM) 对 5-Fu 和 CytR 吸附的影响。在所研究的因素中，EfOM 的存在影响最大，这是由于 5-Fu 和 CytR 吸附的强烈竞争。吸附等温线和动力学数据及其与均相表面扩散模型的建模表明，在 EfOM 存在的情况下，去除百分比与可电离化合物 5-Fu 和 CytR 的初始浓度无关。这些结果与天然有机物存在时的中性有机化合物相似。总的来说，结果表明，足以去除 >90%非极性吸附物的 PAC 剂量，只能去除不超过 50%的极性吸附物 5-Fu 和 CytR，并且接触时间是一个关键参数。
