Legacy Ponds and Silo Wastes

Essentially, a PhD project is proposed to extend ‘measurement and modelling’ work, at the University of Leeds, into the use of acoustic backscatter as a method to characterise complex flocculated waste suspensions. A lot of fundamental analysis is required to quantitatively understand both the flocculation of fine magnox and the analysis of settling sludge systems with the acoustic backscatter array (ABA). The PhD will have two major research strands. Firstly, the project will characterise the flocculation of fine magnesium hydroxide with different commercial polymeric agents (e.g. floc size, shape and fractal dimensions). A fuller understanding of these systems is required; both to aid acoustical analysis, but also to help Sellafield assess the appropriateness of flocculation as a method to remove colloidal fines from pond effluent streams. Secondly, the PhD will measure the fundamental relationships between acoustic scattering strength, attenuation and velocity from these types of complex multicomponent species, to aid in developing analytical methods for the ABA. Importantly, the PhD will focus on how to link theoretical scattering-attenuation relationships (currently developed for hard-sphere glass type particles) for use with flocculated waste suspensions.