过滤是饮用水处理的一个基本过程。最近的隐孢子虫疫情突显了人们对过滤效率的担忧，尤其是对颗粒突破的担忧。突破与成熟阶段有关，在成熟阶段，由于去除不良，以及在流速变化期间，多达90%的突破发生。本研究旨在扩展这方面的知识，特别是通过确定流量何时发生变化。实验室试验是在一个启动流速为5 m/h的单滤柱上进行的。在过滤器运行期间，在不同的点瞬时引入各种流量增加，每次流量变化持续30分钟，之后流量恢复到启动值。 结果表明，流速变化会导致颗粒穿透率增加。这种影响在运行后期的流量变化和更大幅度的流量增加时更为明显。包括9个参考文献、表格、图表。

Filtration is an essential process in drinking water treatment.Recent Cryptosporidium outbreaks have highlighted concerns about filter efficiency and in particular particle breakthrough. Breakthrough has been linked to the ripening stage, when up to 90% of the entire breakthrough occurs, due to poor removal, and also during flow rate changes. This study aims to expand upon this knowledge, specifically by determining when flow rate changes occur. Laboratory experimentswere conducted on a single filter column which had a starting flow rate of 5 m/h. Various flow increases were introduced instantaneously at different points during the filter run with each flow change being 30 minutes in duration, after which the flow was returned to the starting value. The results show that flow rate changes cause an increase in particle breakthrough. This effect is more pronounced with flow changes later on in the runs and with higher magnitude flow rate increases. Includes 9 references, table, figures.