Sedimentary characteristics of suspensions in London Stormwater

The paper reports the results of an investigation into the size and compositional variations of suspended solids during storm-runoff events in an urban catchment. Particle-size analysis indicates that the mass-size distribution for suspended sediments is typically bimodal, although the relative size, breadth and location of the peaks varies through the cycle and from one storm to another. The importance of particle aggregation on the size distributions is discussed and the role of organic particulates in this relation examined. The elemental composition is dominated by silicon and aluminium with the mineralogy being dominated by impure mixtures of quartzo-feldspathic material.The observed textural, compositional and mineralogical variations have been used as diagnostic properties in the identification of source materials and their transport history through the catchment.