Performansi pemisahan membran organosilika untuk desalinasi air rawa asin di kawasan lahan basah

Abstract

Both long dry season and seawater intrusion caused decreasing of water quality and impacted on water scarcity for tidal wetland area. Decreasing of water quality in tidal wetland is caused by salts tendency to build up in the groundwater due to water evaporation along dry season. Consequently, water is out of clean water feasibility criteria or even more as potable water. This work aims to investigate performance of organosilica membrane to separate between salt molecule and water molecule through desalination via pervaporation using organosilica membrane. Organosilica membrane was synthesized from TEOS precursor and citric acid organic catalyst in sol gel process including condensation and hydrolysis reaction and followed by reflux during 3 hours. Sol gel process was run into two varying temperature (0oC and 50oC). Also, resulting thin film from sol gel process was dip-coated onto membrane support and calcined at 250oC. Furthermore, tubular membrane was applied for desalination via pervaporation to separate between salt and water molecule at 60 oC wetland saline feed water. Results show increasing of water flux and salt rejection (> 90%) as varying function of reflux temperature at 0oC and 50oC. Stability (permeability) and separation performance were showed by highest water flux at 0oC (3,9496 kg m-1h-1). It indicated that carbon chain bonded in silica structure generates more robustness pore structure compared to pure silica structure. Therefore, silica-carbon chain is excellent as membrane for applying in desalination via pervaporation feeding by wetland saline water from South Kalimantan.