Environmental Microbiology Research Group, School of Biological Sciences, The University of Auckland, Private Bag 92-019, New Zealand.
Environmental Microbiology Research Group, School of Biological Sciences, The University of Auckland, Private Bag 92-019, New Zealand.
Water Res. 2014 Feb 1;49:406-15. doi: 10.1016/j.watres.2013.10.023. Epub 2013 Oct 31.
Contaminants associated with stormwater are among the leading causes of water quality impairment in urban streams. Multiple device treatment systems are commonly installed with the aim of reducing contaminant loads within stormwater discharge. However, the in situ performance of such systems remains poorly understood. We investigated the efficacy of an advanced stormwater treatment system by monitoring biofilm associated metals and biofilm bacterial community composition at multiple locations through the treatment system (which included rain gardens, grassy swales, a stormwater filter and a wetland) and in the receiving stream above and below the stormwater discharge. Changes in bacterial community composition were assessed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and concentrations of biofilm associated metals monitored by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Significant differences in bacterial community composition were detected throughout the stormwater network. Bacterial communities gradually changed towards a community more similar to that within the receiving stream and the discharge of treated stormwater had little effect on the composition of bacterial communities in the receiving stream, suggesting the effective conditioning of water quality by the treatment system. Concentrations of some biofilm-associated metals declined following sequential treatment, for example copper (73% reduction), zinc (48% reduction) and lead (46% reduction). In contrast, levels of arsenic, cadmium, chromium and nickel were not reduced by the treatment system. We demonstrate that biofilm bacterial community composition is a sensitive indicator of environmental changes within freshwater ecosystems and an efficient indicator to monitor water quality in enclosed stormwater networks where traditional biological indicators are not available.
与雨水相关的污染物是造成城市溪流水质受损的主要原因之一。为了降低雨水排放中的污染物负荷，通常会安装多种设备处理系统。然而，这些系统的原位性能仍未得到充分了解。我们通过监测生物膜相关金属和生物膜细菌群落组成，在处理系统（包括雨水花园、草地洼地、雨水过滤器和湿地）和雨水排放上方和下方的接收溪流中的多个位置，调查了一种先进的雨水处理系统的效果。通过自动核糖体基因间隔区分析（ARISA）评估细菌群落组成的变化，并通过电感耦合等离子体质谱（ICP-MS）监测生物膜相关金属的浓度。在整个雨水网络中都检测到细菌群落组成的显著差异。细菌群落逐渐向与接收溪流中更相似的群落变化，并且处理后的雨水排放对接收溪流中细菌群落的组成几乎没有影响，这表明处理系统有效地调节了水质。一些生物膜相关金属的浓度在连续处理后下降，例如铜（减少 73%）、锌（减少 48%）和铅（减少 46%）。相比之下，砷、镉、铬和镍的水平并未被处理系统降低。我们证明，生物膜细菌群落组成是淡水生态系统内环境变化的敏感指标，也是监测封闭雨水网络水质的有效指标，在这些网络中传统的生物指标不可用。
