考察了水力停留时间（HRT）对絮凝效果的影响 研究其对浸入式超滤膜污染的影响。湖中的地表水 加拿大安大略省使用聚合氯化铝（PACl）和铝进行凝固 硫酸盐（明矾）和三氯化铁。每个凝结水源都被送往多个实验室 不同水力停留时间（0-25分钟）的絮凝池。 水力停留时间对污垢速率、TOC去除和金属残留的影响 进行了评估。较长的HRT值显著降低了明矾和石灰的结垢率 然而，氯化铁对PACl的影响很小。HRT对TOC无影响 发现了去除，但金属残留量受HRT的显著影响 有些案子。包括4个参考文献、表格和图表。

The impact of hydraulic retention time (HRT) for flocculation was examined with respect to its impact on fouling of immersed ultrafiltration membranes. Surface water from Lake Ontario, Canada was coagulated using polyaluminum chloride (PACl), aluminum sulphate (alum) and ferric chloride. Each source of coagulated water was sent to multiple flocculation tanks with different hydraulic retention times varying from 0-25 minutes. The impact of hydraulic retention time on fouling rate, TOC removal and metals residuals was evaluated. Longer HRT values significantly lowered the fouling rates for alum and ferric chloride, however little impact was found for PACl. No impact of HRT on TOC removals was found, however metals residuals were significantly affected by HRT in some cases. Includes 4 references, tables, figures.