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流出物和溪流中选定营养污染物的采样方法。**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：*将被动采样方法与传统的流动监测相结合，研究雨水营养污染物在接收水环境中的质量负荷。例如：土地利用类型和土地管理措施对雨水水质和接受水中营养污染物质量负荷的影响，以及在接受水中营养污染物分布的时空变化的测量。**科学方法：*目标1：调查阴离子交换树脂膜在典型条件下在雨水管和雨水排放口捕获和保留雨水中营养物质(硝酸盐和磷酸盐)的应用。*目标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。*目标3：通过与传统的时间序列体积采样方法进行平行的实地测试，研究被动采样方法在研究雨水收集系统中的硝酸盐和磷酸盐浓度和质量流动方面的应用。*目标4：调查被动采样方法在研究受水环境中营养物质流动的应用。特别是研究如何使用抽样方法来记录营养污染物在接收水中的二维和三维分布。**新颖性和意义：*所开发的被动抽样方法将不需要电源、电子探头、触发装置、泵、体积取样或样本瓶。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.