Feasibility of developing a passive sampler for sampling heavy metals in BMPs for stormwater runoff management

Structural Best Management Practices (BMPs) have been used for stormwater treatment and management for several decades. How to monitor these BMPs performance reliably and economically is a challenge. This paper reports the feasibility of developing a flow through passive sampler (PS) based on Amberlite IRC748 ion exchange resin operated in kinetic regime for sampling heavy metals in BMPs (infiltration systems) for stormwater treatment and management. Tests were conducted using batch reactors and laboratory-scale BMPs. Batch reactor results indicate that PSs performed desirably with consistent and rapid metal uptake, and thus, the resin-based PS is feasible to be used for stormwater sampling. In lab-scale BMPs tests, the resin PSs were employed for sampling influent and effluent of BMPs loaded with synthetic stormwater for storm durations of 0.5, 3, and 12 hours. The removal efficiency of heavy metals in the BMPs as predicted by PSs was very similar to the actual treatment efficiencies obtained from control BMPs, with errors ranging from -5% to 2%, indicating that the PSs can be used for sampling stormwater and monitoring BMPs. The next step for this sampler will be to develop a method for evaluating the volume of water passing the PS during the sampling period.