Yang Kai, Yu Jianwei, Guo Qingyuan, Wang Chunmiao, Xia Ping, Yang Y Jeffrey, Yang Min
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Beijing 100085, China.
University of the Chinese Academy of Sciences, Beijing 100019, China.
Environ Sci Eur. 2019 Jul 12;31:41. doi: 10.1186/s12302-019-0229-6.
To improve the microbial safety of drinking water, an arrangement of O-BAC with rear sand filtration (O-BAC-sand) has been proposed. In this study, efforts were devoted to evaluate the benefits and drawbacks of O-BAC-sand in a full-scale water treatment plant. The performance of the two configurations was compared in terms of particles, turbidity, COD and typical odorants and pesticides.
The O-BAC-sand yielded lower turbidity but higher COD (by approximately 7%) in the finished water than regular O-BAC (sand-O-BAC). Both systems removed odors in raw water; however, sand-O-BAC was more effective on septic and musty odorants. The total pesticide removals by sand-O-BAC and O-BAC-sand were 78% and 72%, respectively; though the latter had shorter activated carbon durable years.
The re-location of the sand filter would sacrifice the BAC efficiency in removals of organic matter and micropollutants. This tradeoff is a result of the loss of the particulate organic matter removal by sand filters, because locating the sand filter behind BAC causes particle load increase on BAC; some measures of enhanced coagulation should be suggested to improve the turbidity and particle removal. The study will be helpful for improvement of the O-BAC process in drinking water treatment.
为提高饮用水的微生物安全性，已提出一种后置砂滤的O-BAC工艺（O-BAC-砂）。在本研究中，致力于评估全尺寸水处理厂中O-BAC-砂工艺的优缺点。从颗粒、浊度、化学需氧量以及典型气味物质和农药方面对两种工艺配置的性能进行了比较。
与常规的O-BAC工艺（砂- O-BAC）相比，O-BAC-砂工艺产水的浊度较低，但化学需氧量较高（约高7%）。两种系统均能去除原水中的气味；然而，砂- O-BAC工艺对腐败和霉味物质的去除效果更好。砂- O-BAC工艺和O-BAC-砂工艺对农药的总去除率分别为78%和72%；尽管后者的活性炭使用寿命较短。
砂滤位置的改变会牺牲生物活性炭工艺去除有机物和微污染物的效率。这种权衡是由于砂滤器去除颗粒有机物的能力丧失所致，因为将砂滤器置于生物活性炭之后会导致生物活性炭上的颗粒负荷增加；应建议采取一些强化混凝措施来提高浊度和颗粒去除效果。该研究将有助于改进饮用水处理中的O-BAC工艺。
