Zanders J M
Landcare Research, Private Bag 3127, Hamilton, New Zealand.
Sci Total Environ. 2005 Mar 1;339(1-3):41-7. doi: 10.1016/j.scitotenv.2004.07.023.
Increasing pressure to mitigate pollution from urban stormwater and road run-off is generating interest in vegetative treatment systems. The treatment performance of these systems depends on the characteristics of the pollutants entering them--for example, whether metals are dissolved or particle bound, and the particle size. This study sought to provide information on the characteristics of sediment derived specifically from road-use activities. A length of roadside gutter was vacuumed repeatedly at 2-day intervals. The samples obtained were found to contain predominantly fine particles (52% <250 microm). Particles <250 microm had the highest metal contents: 181-212 mg Cu/kg, 1073-2080 mg Zn/kg and 251-334 mg Pb/kg. A high percentage of the total metal load was associated with particles smaller than 125 microm (64% of Zn, 57% of Cu and 46% of Pb). These <125-microm particles are generally predicted to be poorly trapped by vegetation. In this study, these smaller particles were also found to have a lower density (<2200 kg/m3) than normally modelled for sediment (>2600 kg/m3), and this may further reduce predicted trapping efficiencies. The impact of sediment entering vegetative treatment systems via aerial deposition is also discussed in terms of evaluating such systems for treatment performance.
减轻城市雨水和道路径流污染的压力不断增加，引发了人们对植被处理系统的兴趣。这些系统的处理性能取决于进入其中的污染物的特性——例如，金属是溶解态还是颗粒态，以及颗粒大小。本研究旨在提供有关专门源自道路使用活动的沉积物特性的信息。一段路边排水沟每隔两天用真空吸尘器反复清理一次。所获得的样本主要含有细颗粒（52%<250微米）。小于250微米的颗粒金属含量最高：铜181 - 212毫克/千克、锌1073 - 2080毫克/千克、铅251 - 334毫克/千克。总金属负荷的很大一部分与小于125微米的颗粒有关（锌的64%、铜的57%和铅的46%）。通常预计植被对这些小于125微米的颗粒捕获能力较差。在本研究中，还发现这些较小颗粒的密度（<2200千克/立方米）低于沉积物通常建模的密度（>2600千克/立方米），这可能会进一步降低预计的捕获效率。在评估植被处理系统的处理性能时，还讨论了沉积物通过大气沉降进入该系统的影响。
