Ultrafiltration (UF) and microfiltration (MF) are theoretically the best pre-treatment upstream reverse
osmosis, removing from the feed water most of the potential elements responsible of desalinating membranes
fouling such as particles, turbidity, bacteria and large molecular weight organic maters. Those clarification
membranes reduce also significantly the silt density index below 3 (100%) [1–6] and generally below 2. Many
papers present results about the efficiency of UF/MF regarding clarification efficiency.