Abstract

• This work concerns with the synthesis and characterization of rice husk silica (RHS) from rice husk ash (RHA) and its utilization for porous ceramic candle filter. Ma Naw Thukha rice husk was used to prepare RHA, by calcinations of rice husk (RH) at 700 C for 6 h. Preparation of silica powder was carried out from RHA by using precipitation method. The silica from RHA was extracted by 2.4 M NaOH for 3 h and then precipitated by adding concentrated H2SO4.The characterization of sample was carried out by modern techniques (SEM, FT IR, XRD, EDXRF) and determination of physicochemical properties using conventional methods. SEM micrograph indicates sponge like nature. XRD diffractogram exhibits an indication of amorphous silica. From FT IR spectral assignment, the band at 1150 to 1000 cm-1 indicates the stretching vibration of Si-O (asym) band in Si-O-Si group. From EDXRF analysis, the highest relative abundance of silica was found to be 99.33 % in RHS. The yield percent of RHS was found to be 52.7 %. Ceramic candle filter (CCF) was prepared by using the raw materials such as RHS, sand, char and clay. The physicochemical properties of CCF were also determined by conventional methods. The performance of ceramic candle filter (CCF) made from a mixture of sand, char, natural clay and RHS in removing chloride from sodium chloride solution was investigated. Removal of chloride ion from sodium chloride solution was studied with different parameters (flow rate for 100 mL fraction: 5, 10, 15, 20, 30, 40, 60 min; different concentrations: 100,200 and 400 ppm). Determination of chloride ion in sodium chloride solution was determined by argentometric method. From the results, the optimum condition for ceramic filter was found to be 69.58 mgg-1 of sorption capacity at a flow rate of 20 min for 100 mL fraction. Removal of chloride ion from lakes of Naung Bo Village (NB) and San Pyaw Village (SP), Naung Bo Group, Ka Wa Township, Bago Region was carried out. From the results, ceramic candle filter (CCF) was found relatirly as an effective adsorbent for saline water treatment.