Estimation of the quantity of liquid exuded by a loaded sludgy or pasty waste

摘要

In the disopsal of sludge or pasty wastes,the liquid contained in a loaded waste will exude.The quantity of liquid exuded will be a function of initial content,waste consistency,applied stress and time.In order to determine the amount of liquid,we have designed a new oedometer was designed to perform consolidation tests on large dimension specimens ( phi 250 mm,height <= 60 mm).Several tests on three types of waste have bene performed.Settlement and amount of exuded liquid from both upper and lower drainage interfaces has been measured under different normal stresses and initial water contents.The hydraulic conductivity was also measured.To estimate the exuding potential of a given waste,a method to determine the amount of extractable liquid (qf) for an infinite time is proposed.This mehtod presents the advantage of considerably reducing the required time for consolidation tests.Given the density and height of a sludgy layer located at a given depth,the paper shows that it is possible to determine the total amount of liquid that will be expected at large times.