Browsing by Author "Cosgrove, Stephanie"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Application of activated carbon fabric for the removal of a recalcitrant pesticide from agricultural run-off
    (Elsevier, 2022-01-08) Cosgrove, Stephanie; Jefferson, Bruce; Jarvis, Peter
    Removal of pesticides from agricultural run-off close to the point of application has the potential to prevent or reduce the pollution of water sources used for drinking. This research considered the novel application of activated carbon (AC) fabric as a sorbent material for removal of pesticides from field run-off. AC fabric was tested for the removal of the molluscicide pesticide metaldehyde under a range of flow rates at both laboratory and pilot scale. Metaldehyde at an initial concentration of 10 μg/L was removed effectively from deionised (DI) water and real source water by the AC cloth under all conditions tested, reaching removal of 1375 and 876 μg/g (equivalent to 169 and 264 mg/m2), respectively. The adsorption followed pseudo-second order kinetics (k2 of 29.9 and 34.8 g/μg min for the AC fabric and GAC), providing rapid removal of metaldehyde within the first 5 min of contact. In single pass and flow through conditions, stabilised removal of 46% metaldehyde was achieved by the AC fabric bundle for treatment of 700 L of real water in a pilot scale flume. This equated to removal of 454 μg/m2, although significantly more removal would be expected over longer duration testing given the stabilised removal and the equilibrium capacity of the fabric seen during the batch isotherm testing. The work provides evidence to show that AC fabric could be used in the catchment to reduce peak loads of pesticides in sources used for drinking water.
  • Thumbnail Image
    ItemOpen Access
    A multi‐component method to determine pesticides in surface water by liquid‐chromatography tandem quadrupole mass spectrometry
    (Wiley, 2017-06-15) Ramos, Andre; Cosgrove, Stephanie; Villa, Raffaella; Jefferson, Bruce; Campo Moreno, Pablo; Jarvis, Peter; Whelan, Michael J.; Guymer, Ian
    Pesticide pollution of surface water is a major concern in many agricultural catchments The development of rapid and accurate methods for determining pesticide concentrations in water samples is, therefore, important. Here we describe a method for the simultaneous analysis of six pesticides (metaldehyde, quinmerac, carbetamide, metazachlor, propyzamide and pendimethalin) in natural waters by direct aqueous injection with liquid chromatography-tandem mass spectrometry. The method validation showed good linearity from 0.2 to 50.0 µg/L with correlation coefficients between 0.995 and 0.999. Method accuracy ranged from 84 to 100% and precision Relative standard deviation (RSD) from 4 to 15%. The limits of detection for the targeted pesticides ranged from 0.03 to 0.36 µg/L. No significant matrix effects on quantification were observed (t-test). The method was tested on water samples from a small arable catchment in eastern England. Peak concentrations for the determinands ranged from 1 to 10 µg/L.