Application of optimized silica sediment to adsorb Na⁺ ion in seawater

We conducted the desalination process of seawater into clean water using silica produced from natural sediment. The sediment contains Si-O-Si and Si-OH groups in the silica to absorb NaCl substances in the seawater. Silica from natural sediment was purified from heavy metals using acid reflux and then measured physical and chemical characterization. The XRF analysis, calcination process, FTIR and AAS analysis were investigated to produce and optimize silica from a sediment sample. The application of silica was applied to absorb NaCl in Prigi Seawater. The results indicated the white silica adsorbent had a typical peak stretching vibration of Si–OH groups visible at wave number 3200-3400 cm⁻¹ as the potential situs of Na+ ion adsorbent. The effective temperature in the produced silica sediment was at 800°C with adsorbed Na⁺ ion on the artificial seawater of 25 mg/L (16.7%) while the Prigi seawater sample was 60.8 mg/L (10.7%). The produced silica can reduce the salt content of Prigi Seawater.