Evaluation of polyferric silicate sulfate derived from rice husk for turbidity removal

Abstract

Rice husk is a natural material available in large quantities as agricultural waste. The rice husk is rich in silicon oxide which is up to 98% from the ash content. Burning rice husk generates rice husk ash (RHA) which is rich in silica. Thus, rice husk is an appropriate raw material to produce Inorganic Polymeric Coagulant which is polyferric silicate sulfate (PFSS). Sodium silicate produced from rice husk contain different silicon dioxide content, hence the best method to produce highest silicon dioxide content had been determined. Three different preparation method of sodium silicate was compared and the best method which produce highest silicon dioxide (12.13%) had been identified. In this project, the sodium silicate was used for production of polysilicic acid and the synthesis of PFSS coagulant. The PFSS coagulant was prepared by co-polymerization method. The synthesized coagulant, PFSS were successfully characterized by using Fourier Transform Infra Red (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The functional group and the crystallinity structure of PFSS that synthesized from rice husk has been successfully analyzed. XRD result confirmed that PFSS has crystalline material and amorphous material due to the presence of sharp peak and long broad peak. It was found that there exist strong diffraction peaks with 2ϴ values of 10.260˚, 9.613˚, 29.473˚, 22.738˚, 28.219˚ corresponding to the percentage of intensity were 100%, 91.7%, 51.0%, 50.6% and 48.6%. Then, SEM result shows that the morphological properties of PFSS are obviously seen arranged compactly with irregular granule units. At the end of the project, in comparison with the commercialized coagulant polyacrylamide (PAM), PFSS shows a better performance in turbidity removal. ©This item is protected by original copyright