Technical optimization of batch membrane processes for the purification from residual heavy metal contamination of a pretreated marine sediment

In this paper an innovative process for the purification from heavy metals of marine sediments by membrane processes is presented. Since membranes hardly work on raw streams, especially on those having high suspended solids value such as marine sediments, a pretreatment process is necessary. In the examined case, centrifugation by a hydrocyclone appeared to be very efficient in removing the sand and was adopted. The remaining stream (silt) was then processed by a batch membrane process, capable to separate the organic and inorganic pollutants from the water. Pilot tests were carried out in order to estimate the membrane performances, such as the maximum recovery value, the typical rejection values, the permeate and the critical fluxes.