Extraction of sodium silicate from rice husk and application of PFSS in coagulantion process

Abstract

Rice husk is also called rice hull, is the coating on a seed or grain of rice. It was formed from hard materials, including silica and lignin, to protect the seed during the growing season. The burning of rice husk can produce rice husk ashes (RHAs). The RHAs were higher in silica contents, i.e. 90% of amorphous silica. This project aims to prepare the sodium silicate from rice husk ashes and its applications in coagulation process for turbidity removal. In this research, the rice husk was heated in the muffle furnace to obtain the rice husk ashes (RHAs). Three different method of sodium silicate production were runs during this experiment, the purposed were too compared the silica oxide (SiO2) content between the three method which were produced the higher yields of silica oxide (SiO2). Between the three methods, method two produced the highest percentages yields of silica oxides (SiO2) which values 12.9570 %. Different synthesis parameters such as effect of calcination temperature and sodium hydroxide concentration on percentage of silica oxide (SiO2) was varied. The best calcination temperature was at 650◦C and the percentages yields of silica oxides was found to be 12.958 %. Besides, at 1.0 M of sodium hydroxide concentration (NaOH) the silica oxides content was found to be the highest among the others. The coagulation performance of PFSS was evaluated. The coagulation study using the jar test was carried out. The purpose of coagulation study was to estimate the minimum coagulant dose required to reduce the turbidity of wastewater. Furthermore, different coagulation parameters such as initial pH, coagulant dosage and settling time were studied. Lastly, at the end of this project it was expected that the optimum coagulant dosage was at 250 mg/l, with initial pH of 6.5 and at 25 minutes of settling time to reduce the turbidity of kaolin in water completely.