High silica concentration in RO concentrate

Silica scaling is one of the major challenges in Reverse Osmosis (RO). The safe operation practice to keep silica concentration below 150 mg/L RO concentrate. This study addresses effects divalent cations such as calcium and magnesium on a seawater installation used pretreatment Eutectic Freeze Crystallisation (EFC). Results showed that absence antiscalant sustained approximately 280 concentrate possible without declining membrane permeability. At higher cations, permeability decreased. Membrane autopsy analysing destructed relatively low high after adding ions into solutions. It concluded limits can be extended for 6–8 h.