Biofilters are among the most popular nature-based systems for treating stormwater and delivering multiple environmental benefits. However, as a passive system, their performance tends to be inconsistent in removing emerging organic contaminants produced by anthropogenic activities that can be persistent, mobile, and toxic. Thus, in this study, real time control (RTC) of stormwater biofilters is introduced to enhance the removal of a diverse range of organic chemicals. Laboratory columns were employed to investigate the performance of five RTC strategies, i.e., dynamic soil moisture control (RTC-Moisture), infiltration rate control (RTC-IR), pre-drain (RTC-PreDrain), fully unsaturated (RTC-UnSat), and fully saturated (RTC-FulSat). These RTC strategies were tested under varying rainfall sizes, as well as dry and wet conditions. Additionally, the study examined the accumulation of organic chemicals in the media. The results revealed that RTC-Moisture, RTC-IR, and RTC-PreDrain were the top three performing strategies, which achieved a significantly higher removal rate than Non-RTC biofilters for the majority of tested organic chemicals (p-value < 0.05). The best RTC strategy, RTC-Moisture, not only had the highest overall performance (average removal rate of 76.1 %) but was also least affected by various rainfall events. Despite a better chemical removal found in RTC-Moisture and RTC-PreDrain, there was no significant overall increase in the accumulation of organic chemicals within the media (p-value > 0.05) when compared to Non-RTC biofilters. This may indicate that the biodegradation process could be promoted in the well-performing RTC biofilters. This study confirms the possibility of using RTC strategies to enhance organic chemical removal in stormwater biofilters.

中文翻译：

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实时控制雨水生物过滤器，提高有机化学物质的去除率


生物过滤器是最受欢迎的基于自然的系统之一，用于处理雨水并提供多种环境效益。然而，作为一个被动系统，它们在去除人为活动产生的新出现的有机污染物方面往往不一致，这些污染物可能是持久的、移动的和有毒的。因此，在本研究中，引入了雨水生物过滤器的实时控制 （RTC） 以增强对各种有机化学物质的去除。采用实验室色谱柱研究了动态土壤水分控制 （RTC-Moisture）、渗透速率控制 （RTC-IR）、预排水 （RTC-PreDrain）、完全不饱和 （RTC-UnSat） 和完全饱和 （RTC-FulSat） 5 种 RTC 策略的性能。这些 RTC 策略在不同的降雨量大小以及干燥和潮湿条件下进行了测试。此外，该研究还检查了有机化学物质在介质中的积累。结果显示，RTC-Moisture、RTC-IR 和 RTC-PreDrain 是性能最好的三种策略，对于大多数测试的有机化学品，它们的去除率明显高于非 RTC 生物过滤器（p 值 < 0.05）。最好的 RTC 策略 RTC-Moisture 不仅具有最高的整体性能（平均去除率为 76.1 %），而且受各种降雨事件的影响最小。尽管在 RTC-Moisture 和 RTC-PreDrain 中发现了更好的化学去除效果，但与非 RTC 生物过滤器相比，介质中有机化学物质的积累总体上没有显着增加（p 值 > 0.05）。这可能表明生物降解过程可以在性能良好的 RTC 生物过滤器中得到促进。本研究证实了使用 RTC 策略增强雨水生物过滤器中有机化学物质去除的可能性。