Using artificial fluorescent particles as tracers of livestock wastes within an agricultural catchment

Abstract

Evidence for the movement of agricultural slurry and associated pollutants into surface waters is often anecdotal, particularly with relation to its 'particulate' components which receive less attention than 'bio-available' soluble phases. To assess the extent of movement of slurry particles artificial fluorescent particles were mixed with slurry and applied to a field sub-catchment within a headwater catchment. Particles were 2-60 μm in diameter and two different densities, 2.7 and 1.2 g cm(-3) representing 'inorganic' and 'organic' material. Water samples from the field and catchment outlet were collected during two storm events following slurry application and analysed for particle and suspended sediment concentrations (SSC). SSC from the field and catchment outlet always formed clockwise hysteresis loops indicating sediment exhaustion and particles of the two densities were always found to be positively correlated. Particles from the field formed clockwise hysteresis loops during the first discharge event after slurry application, but anti-clockwise hysteresis loops during the second monitored event which indicated a depletion of readily mobilisable particles. Particles from the catchment outlet always formed anticlockwise hysteresis loops. Particle size became finer spatially, between field and catchment outlet, and temporally, between successive storm events. The results indicate that slurry particles may be readily transported within catchments but that different areas may contribute to pollutant loads long after the main peak in SSC has passed. The density of the particles did not appear to have any effect on particle transport however the size of the particles may play a more important role in the 2-60 μm range.

Chiral, fluorescent microparticles constructed by optically active helical substituted polyacetylene: preparation and enantioselective recognition ability

“…Fluorescent technology has been extensively used in a diverse number of signicant elds such as diagnostics, 1 biological imaging, 2 recognition/sensing, 3 detection, 4 analytical techniques, 5 and environmental sciences. 6 The generally utilized uorophores include organic dyes, 7,8 quantum dots (QDs), 9,10 metal particles, 11 and conjugated polymers. 12 For the rst three categories, their dispersion properties are not highly satisfactory, so they are frequently encapsulated by or immobilized on other materials (polymers, silica, etc.)…”

Seasonal Accumulation and Depletion of Local Sediment Stores of Four Headwater Catchments

“…However, much of this work has been focused on individual discharge events [10][11][12], or has been in predominately agricultural areas [4,6,7,[11][12][13], in small hillslope plots [11] or in areas with drastically different physiographic and climatic regimes [7,14,15]. A few longer studies looking at multiple time scales have shown considerable temporal variation in sediment patterns.…”

Recent advances and future directions in soils and sediments research

“…Blake et al 1999;Saari et al 2010), and in developing new tracers, such as rare earth elements (REE) and natural and artificial fluorescence (e.g. Polyakov and Nearing 2004;Granger et al 2007Granger et al , 2011Stevens and Quinton 2008;Spencer et al 2011). Many of these newer tracers are showing considerable promise, particularly for tracing sediment movement on hillslopes, although further refinement and testing are required to prove their suitability at medium to large spatial scales such as the landscape and river basin scales, and at the interface between freshwater and brackish/saltwater environments.…”