Matamoros Victor, Bayona Josep M
Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain.
Environ Sci Technol. 2006 Sep 15;40(18):5811-6. doi: 10.1021/es0607741.
Removal efficiency and elimination rates of 11 pharmaceuticals and personal care products (PPCPs)were measured in two subsurface horizontal flow constructed wetlands (SSFs) characterized by different water depths (i.e. 0.3 and 0.5 m) in a 2-year study. Dissolved and particulate phases of wastewater and gravel samples were collected and analyzed. The PPCP influent concentration ranged from 1 to 25 microg L(-1). The best removal efficiency was found in the shallower bed SSF due to its less negative redox potential. PPCPs were classified in four groups according to their removal behavior: (i) the efficiently removed (>80%) namely caffeine, salicylic acid, methyl dihydrojasmonate, and carboxy-ibuprofen, (ii) the moderately removed (50-80%) namely ibuprofren, hydroxy-ibuprofen, and naproxen, (iii) the recalcitrant to the elimination namely ketoprofen and diclofenac, and,finally, (iv) compounds that were eliminated by hydrophobic interactions namely polycyclic musks (i.e. galaxolide and tonalide). These compounds were removed more than 80% from the effluent but occurred at high concentrations (up to 824 microg kg(-1)) in the gravel bed. Accordingly, their elimination by sorption onto the organic matter retained is the predominant removal mechanism. Furthermore, the constructed wetland clogging appears to induce a negative effect in the PPCP degradation in the SSF evaluated. The PPCP elimination classified as efficiently and moderately removed through the shallow bed fitted to either zero- or a first-order areal kinetics. Finally, the apparent distribution coefficients between suspended solids (Kd'ss) or gravel bed (Kd'gb) and water were determined in the different sampling points of the wetland obtaining values comparable to the described previously for sewage sludge.
在一项为期两年的研究中，对两个具有不同水深（即0.3米和0.5米）的地下水平流人工湿地（SSF）中11种药物和个人护理产品（PPCP）的去除效率和消除率进行了测量。收集并分析了废水和砾石样品的溶解相和颗粒相。PPCP进水浓度范围为1至25微克/升。由于较浅床层的人工湿地氧化还原电位负值较小，因此在该湿地中发现了最佳去除效率。根据PPCP的去除行为将其分为四类：（i）高效去除（>80%）的即咖啡因、水杨酸、甲基二氢茉莉酮酸酯和羧基布洛芬，（ii）中度去除（50-80%）的即布洛芬、羟基布洛芬和萘普生，（iii）难消除的即酮洛芬和双氯芬酸，以及最后（iv）通过疏水相互作用消除的化合物即多环麝香（即佳乐麝香和吐纳麝香）。这些化合物在流出物中的去除率超过80%，但在砾石床中的浓度很高（高达824微克/千克）。因此，它们通过吸附到保留的有机物上而被消除是主要的去除机制。此外，在所评估的地下水平流人工湿地中，人工湿地堵塞似乎对PPCP的降解产生负面影响。通过浅床高效和中度去除的PPCP符合零级或一级面积动力学。最后，在湿地的不同采样点测定了悬浮固体（Kd'ss）或砾石床（Kd'gb）与水之间的表观分配系数，得到的值与先前描述的污水污泥的值相当。
