Abstract

The aim of the study was to evaluate the effectiveness of the MIEX® resin sedimentation process, both new and repeatedly used in hybrid water treatment MIEX®DOC + microfiltration (MF) or ultrafiltration (UF) processes (repeatedly regenerated). The tests consisted of performing 1 h sedimentation of the suspension resin in nonflow conditions and analysis of supernatant water at different process durations. The suspension weight analysis was performed on filters (of porosity 0.45 μm) and granulometric analysis (using a laser granulometer) was accomplished as well. Particles size measurements showed that the average particle size (d50) of the new MIEX® Resin was approximately 120 μm. The repeated use of resin in the water treatment caused significant reduction in suspension grain size (d50 = 31 μm), which could be the result of their abrasion or crumbling during exploitation. The sedimentation for both types of resin was a very effective process. For a new resin just after 5 min of sedimentation, the process efficiency was 99%. For the repeatedly used, regenerated resin the process went forward at much slower rate and 99% effectiveness was obtained scarcely after about 11–12 min of sedimentation. It was established that particles of the new resin, larger than 50 μm, settled much faster than the corresponding particles of the regenerated resin. The smallest particles (<50 μm) settled faster and more effectively in the case of regenerated resin. The obtained test results allowed to determine the optimal sedimentation process parameters as well as the selection of particles with specific, the most favorable sizes (e.g., the rejection of the smallest particles to limit phenomena of blocking membranes used in hybrid water purification system MIEX®DOC + MF/UF).

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Authors (4)