Department of Civil & Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, United States.
Department of Civil & Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, United States.
Water Res. 2016 Nov 15;105:85-96. doi: 10.1016/j.watres.2016.08.033. Epub 2016 Aug 20.
With widespread occurrence of pharmaceuticals and personal care products (PPCPs) in the water cycle, their presence in source water has led to the need to better understand their treatability and removal efficiency in treatment processes. Fifteen indicator compounds were identified to represent the large number of PPCPs reported worldwide. Criteria applied to determine the indicator compounds included PPCPs widely used, observed at great frequency in aqueous systems, resistant to treatment, persistent in the environment, and representative of classes of organics. Through a pilot plant investigation to understand the optimal combination of unit process for treating PPCPs, 12 treatment trains with their additive and synergistic contributions were investigated; processes included dissolved air flotation (DAF), pre- and intermediate-ozonation with and without HO, intermediate chlorination, dual media filtration, granular activated carbon (GAC), and UV/HO. Treatment trains that achieved the greatest removals involved 1. DAF followed by intermediate ozonation, dual media filtration, and virgin GAC; 2. pre-ozonation followed by DAF, dual media filtration, and virgin GAC; and, 3. DAF (with either pre- or intermediate oxidation) followed by dual media filtration and UV/HO. Results revealed significant removal efficiencies for virgin GAC (preceded by DAF and intermediate ozonation) and UV/HO with an intensity of 700 mJ/cm, where more than 12 of the compounds were removed by greater than 90%. Reduced PPCP removals were observed with virgin GAC preceded by pre-ozonation and DAF. Intermediate ozonation was more effective than using pre-ozonation, demonstrating the importance of this process targeting PPCPs after treatment of natural organic matter. Removal efficiencies of indicator compounds through ozonation were found to be a function of the O rate constants (k). For compounds with low O rate constants (k < 10 Ms), HO addition in the O reactor was required. Of the 15 indicator compounds, tri(2-chloroethyl) phosphate (TCEP) and cotinine were observed to be the most recalcitrant. Although UV/HO with elevated intensity (700 mJ/cm) was effective for PPCP removals, energy requirements far exceed intensities applied for disinfection.
由于药品和个人护理产品（PPCPs）在水循环中广泛存在，它们在原水中的存在导致需要更好地了解它们在处理过程中的可处理性和去除效率。确定了 15 种指标化合物来代表全球范围内报告的大量 PPCPs。应用于确定指标化合物的标准包括广泛使用的 PPCPs、在水系统中经常观察到、对处理具有抗性、在环境中持久存在以及代表有机化合物类别的化合物。通过中试研究了解处理 PPCPs 的最佳单元工艺组合，研究了 12 种具有附加和协同作用的处理工艺；这些过程包括溶气浮选（DAF）、预氧化和中间氧化（带或不带 HO）、中间氯化、双介质过滤、颗粒活性炭（GAC）和 UV/HO。实现最大去除率的处理工艺包括 1. DAF 后接中间氧化、双介质过滤和新鲜 GAC；2. 预氧化后接 DAF、双介质过滤和新鲜 GAC；3. DAF（带预氧化或中间氧化）后接双介质过滤和 UV/HO。结果表明，新鲜 GAC（DAF 和中间氧化前）和强度为 700 mJ/cm 的 UV/HO 的去除效率显著，其中超过 12 种化合物的去除率超过 90%。在新鲜 GAC 前接预氧化和 DAF 的情况下，观察到 PPCP 的去除率降低。中间氧化比预氧化更有效，这表明在处理天然有机物后，该工艺对 PPCPs 的靶向处理非常重要。通过臭氧氧化去除指示化合物的效率被发现是 O 速率常数（k）的函数。对于 O 速率常数低（k < 10 Ms）的化合物，需要在 O 反应器中添加 HO。在 15 种指示化合物中，三（2-氯乙基）磷酸酯（TCEP）和可替宁被认为是最难去除的。尽管用较高强度（700 mJ/cm）的 UV/HO 对 PPCP 的去除是有效的，但能源需求远远超过用于消毒的强度。
