Interlayer-free Silica Pectin Membrane for Wetland Saline Water via Pervaporation

Abstract

Wetland in South Kalimantan is one of surface water sources to provide clean water. However, seawater intrusion has spread into the wetland aquifer and reduce the quality of water. Silica-pectin membrane is a promising technology for desalination. The membranes were tested for desalination by pervaporation at room temperature (~25 °C). During pervaporation process, the water contacts to membrane and the separation is started to occurs as vapour phase by maintaining vacuum pressure (~1 bar). The permeate was collected in the cold trap after condensed using nitrogen liquid. The purpose of this research was to investigate the performance of interlayer-free silica pectin membrane for wetland saline water. Experimental results shows the fluxes of membrane are 0.35 and 0.19 kg.m-2 h-1 ( pectin 0%wt); 0.23 and 0.16 kg.m-2 h-1 (pectin 0.1%wt); 0.58 and 3.63 kg.m-2 h-1 (pectin 0.5%wt); 3.40 and 0.12 kg.m-2 h-1 (pectin 2.5%wt) calcined at 300 and 400 °C, respectively. Natural organic matter (NOM) and salt concentration in wetland saline water can reduce the fluxes up to (~98%). Nevertheless, overall salt rejection of membranes achieved >99%. It was found that low calcination gives better performance at high pectin concentration. While pectin concentration was limited at high calcination.