Effect of Rice Husk Ash Gel on the Properties of Integral Membrane from a Blend of Polysulfone/ Chitosan/ Polyvinyl Alcohol

Abstract

Rice Husk Ash (RHA) can produce 85-95% of amorphous silica with burning temperature of 350-750ÛC, while crystalline silica is produced when burning temperature is above 800ÛC. Due to high content of silica, RHA is utilized in many applications as adsorbents, fillers for membrane and activated carbon. In this research silica gel was extracted from RHA by using acid-leaching process and it was used as cross-linking agent for integral membrane of polysulfone/chitosan/ polyvinyl alcohol. The silica gel was dried and characterized using X-Ray Diffractometer (XRD) and X-Ray Fluorescence (XRF). The silica gel was added at various concentration (0wt%, 0.05wt% and 0.1wt%) into the membrane formulations. The membrane was characterized using Fourier Transform Infrared Spectroscopy (FTIR) the performance was measured through pure water flux performance. The result from XRD and XRF showed that 76.85% of silica presence in the gel. The cross linking of membrane was occurred as displayed through the detected Si-O-C bond around 1107cm-1 from FTIR analysis. Furthermore, membrane with RHA gel at concentration 0.1wt% (MA) and 0.05wt% (MB) portrayed lower water flux compared to membrane from pure polymer blend showed that membrane has attained the integral stability through the cross-linking process. The concentration of RHA silica gel added also effect the performance of the pure water flux, as MA with 0.1wt% of RHA silica gel showing lower flux compared to MB with 0.05wt% silica gel. Therefore, results showed the potential of silica gel from RHA to be incorporated into membrane formulation to increase the physical properties and performance of the membrane for effective filtration process. This finding shown that the performance of membrane can be further studied with higher silica gel concentration and evaluated for water-oil separation process.