Development of a passive sampling methodology for measurement of time-averaged nutrient concentration in stormwater flow and receiving waters

缺乏具有适当空间和时间尺度的当前和历史营养监测数据一直是加拿大和国际上为控制流域富营养化而制定环境保护和管理战略的累积影响评估和制定战略的一个障碍。进行水质采样的难度和费用无疑是造成监测记录不佳的原因之一。这项拟议研究计划的总体目标是开发和测试一种改进的采样方法，用于流出物和径流中选定的营养污染物。 研究目标： 短期： 开发一种创新、简单和可靠的采样方法，用于被动检测和量化雨水流和接受水中的时间平均营养物质浓度(硝酸盐和磷酸盐)。被动意味着该方法将不需要电源、数据记录器或水样采集来确定时间平均浓度。重点将放在量化间歇降水事件排放到受纳水域的平均营养浓度的方法上。该方法最初将在受控实验室条件下开发，模拟雨水收集系统的环境条件。 长期： 将被动采样方法与常规流量监测相结合，用于研究雨水营养污染物在接受水环境中的质量负荷。例如，研究内容包括：土地利用类型和土地管理做法对雨水水质的影响和营养污染物进入接收水域的大量负荷，以及测量接收水域内营养污染物分布的时空变化。 科学方法： 目的1：研究阴离子交换树脂膜在典型条件下对雨水中的硝酸盐和磷酸盐的捕集和保留作用。 目的2：研究典型雨水成分和环境条件下阴离子交换树脂膜上的离子交换反应动力学。在动力学研究的基础上，将硝酸盐和磷酸盐在离子交换树脂膜上的质量捕获量与采样水环境中营养物质的时间平均浓度联系起来。 目的3：通过与常规时间序列体积采样方法进行平行现场试验，研究被动采样方法在雨水收集系统中硝酸盐和磷酸盐浓度及质量流量研究中的应用。 目的4：探讨被动采样方法在受纳水环境营养盐质量流研究中的应用。特别是，调查使用抽样方法记录接受水中营养污染物的二维和三维分布情况。 新颖性和重要意义： 开发的被动采样方法将不需要电源、电子探头、触发机构、泵、容量采样或样品瓶。因此，该方法不会受到泵和样品系统中常见的故障和可靠性问题的影响，也不会受到基于离子特定电子探头的监测系统中常见的故障和可靠性问题的影响。此外，由于其简单性，建议的被动抽样方法将成本相对较低、可靠，并且易于在城市和/或偏远地区部署。因此，发展被动抽样方法有可能极大地促进在流域内建立更全面的营养监测网络，以改进环境评估和保护。

A lack of current and historical nutrient monitoring data with appropriate spatial and temporal scale has been a hindrance to cumulative effects assessments, and the development of environmental protection and management strategies for control of eutrophication in watersheds in Canada and internationally. The difficulty and expense of conducting water quality sampling has undoubtedly contributed to the poor monitoring record. The overall objective of this proposed research program is to develop and test an improved sampling methodology for selected nutrient pollutants in effluent and streamflow. Research Objectives: Short term: Develop an innovative, simple and reliable sampling methodology for passive detection and quantification of time-averaged nutrient concentration (nitrate and phosphate) in stormwater flow and within receiving waters. Passive meaning the method will not require a power supply, data logger or collection of water samples for the determination of time-averaged concentration. The focus will be upon a methodology for quantifying mean nutrient concentration in intermittent precipitation event-based discharges into receiving waters. The methodology will be initially developed under controlled laboratory conditions that simulate environmental conditions in stormwater collection systems. Long term: Apply the passive sampling methodology in conjunction with conventional flow monitoring for the study of stormwater nutrient pollutant mass loading into and within receiving water environments. For example studies such as: the influence of landuse types and land management practices upon stormwater quality and mass loading of nutrient pollutants into receiving waters, and measurement of spatial and temporal changes in nutrient pollutant distribution within receiving waters. Scientific Approach: Aim 1: Investigate the application of anion ion exchange resin membranes for the capture and retention of nutrient species (nitrate and phosphate) from stormwater under typical conditions within storm sewers and at stormwater outfalls. Aim 2: Investigate the kinetics of ion exchange reactions on anion exchange resin membranes for typical stormwater composition and environmental conditions. Based upon the kinetic studies, relate the mass capture of nitrate and phosphate on the ion exchange resin membranes to the time averaged nutrient species concentration in the sampled water environment. Aim 3: Investigate the application of the passive sampling methodology for study of nitrate and phosphate concentration and mass flow in stormwater collection systems by conducting parallel field tests with conventional time series volumetric sampling methods. Aim 4: Investigate the application of the passive sampling methodology for study of nutrient mass flow in receiving water environments. In particular, investigate the use of the sampling methodology to document two and three dimensional distribution of nutrient pollutants in receiving waters. Novelty and Significance: The passive sampling methodology developed will have no requirement for power supplies, electronic probes, trigger mechanisms, pumps, volumetric sampling or sample bottles. Hence the methodology will not be subject to the failures and reliability issues that commonly occur in pump and sample systems, or with ion specific electronic probe based monitoring systems. Further the proposed passive sampling methodology will be relatively low cost, reliable and easy to deploy in urban and/or remote locations due to its simplicity. Hence the development of the passive sampling methodology has the potential to greatly facilitate the establishment of much more comprehensive nutrient monitoring networks within watersheds for improved environmental assessment and protection.