title: The performance of passive flow monitors and phosphate accumulating passive samplers when exposed to pulses in external water flow rate and/or external phosphate concentrations.
abstract: Passive samplers are typically calibrated under constant flow and concentration conditions. This study assessed whether concentration and/or flow pulses could be integrated using a phosphate passive sampler (P-sampler). Assessment involved three 21-day experiments featuring a pulse in flow rate, a pulse of filterable reactive phosphate (FRP) concentration and a simultaneous concentration and flow pulse. FRP concentrations were also determined by parallel grab sampling and the P-sampler calibrated with passive flow monitors (PFMs) and direct measurement of flow rates. The mass lost from the PFM over the deployment periods predicted water velocity to within 5.1, 0.48 and 7.1% when exposed to a flow rate pulse (7.5-50 cm s(-1)), concentration pulse (5-100 μg P L(-1)), or both simultaneously. For the P-sampler, good agreement was observed between the grab and passive measurements of FRP concentration when exposed to a pulse in flow (6% overestimation) or concentration (2% underestimation).
authors.affiliation: The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 39 Kessels Rd. Coopers Plains, QLD 4108, Australia. d.obrien2@uq.edu.au
authors.forename: Dominique
authors.initials: D
authors.lastname: O'Brien
authors.forename: Darryl
authors.initials: D
authors.lastname: Hawker
authors.forename: Melanie
authors.initials: M
authors.lastname: Shaw
authors.forename: Jochen F
authors.initials: JF
authors.lastname: Mueller
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D010710:Phosphates / Q000032:analysis*; D014872:Water Movements; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D010710:Phosphates; D014873:Water Pollutants