ABSTRACT

Stormwater biofilters operate in alternating wet-dry cycles and subjects processes to distinct environmental conditions, particularly, moisture content. Pollutants in residual water may undergo chemical or biological transformation during the dry phase and affect pollutant removal. The study aims to analyse filter water content during dry-cycle. Ten Perspex bioretention columns (94 mm internal diameter) were fed with tapwater at 100 mL/min for three hours and the filters were left to dry for 40 days. Filter material samples were obtained at different depths after different number of dry days (0–40 days) and were tested for moisture content. Top 5 cm had moisture content decreased to wilting point (6% degree of saturation) while deeper layers stabilised at higher degrees (40%). A mathematical model developed indicates significant amounts of moisture being held in the filter during the dry-phase, indicating potential impact on pollutant removal performance of the filter.

摘要

雨水生物过滤器在交替的干湿循环中运行，并使过程受到不同的环境条件，特别是水分含量。残留水中的污染物在干燥阶段可能会发生化学或生物转化，从而影响污染物的去除。该研究旨在分析干循环期间过滤器的含水量。10 根有机玻璃生物保留柱（内径 94 毫米）以 100 毫升/分钟的流速注入自来水三小时，然后将过滤器晾干 40 天。在不同干燥天数（0-40 天）后在不同深度获得过滤材料样品，并测试其水分含量。顶部 5 厘米的含水量降低到枯萎点（6% 的饱和度），而更深的层稳定在更高的程度（40%）。