Magnetic rice husk ash 'cleanser' as efficient methylene blue adsorbent

Burning of agricultural residues has been a prevalent cause of environmental concern especially in developing countries. In the Philippines, rice husks are usually burned in open air and either usually left in the field or rarely collected to be sold in the wet market as a cleanser. Hence in this study, an alternative use of this burning residue (rice husks ash, RHA) for removal of dyes from aqueous solutions was explored. Yet, its applications in real wastewater will be difficult in its pristine powdered form. Therefore, the RHA was functionalized with Fe₃O₄ to become inherently magnetic (MRHA), providing relative ease in handling. The RHA used was obtained from the local markets of Davao City, Philippines. Systematic adsorption studies on the effects of contact time, solution pH, solid/liquid ratio, and feed concentration were conducted. MB adsorption was Langmuir-type and followed a pseudo-second-order rate model. Its adsorption rate is significantly fast (<i>t</i> = 10 min, <i>k</i>₂ = 0.015 g mg^-1 min^-1) with high <i>q_m</i> (150.5 mg g^-1). MRHA was highly stable and reusable (> 10 cycles) demonstrating its high potential as an economical alternative for treatment of dye contaminated wastewater.

Characterization Nanofillers from Agriculture Waste for Polymer Nanocomposites Reinforcement

The current development of the packaging industry is increasing as well as the dependence of non-renewable oil-based materials encouraging researchers to look for alternative polymeric strengthening materials from biomass. Especially used from agricultural waste because it is cheap and widely available in nature and it can be renewed. In this study, agriculture waste used were rice husk and rice husks ash that prepared as organic nanofillers for the development of polymer nanocomposites. XRF analysis showed that rice husk ash has the highest silica (SiO2) content of 89. 835%, while rice husk has SiO2 contents of 82.540%. From XRD analysis on 2 theta there is a crystalline silica region at 22° and this analysis shows the sample is amorphous. FTIR analysis showed Si-H at peak 2339 cm−1 in rice husk and 2129 cm−1 for rice husk ash.

Characterization of Silica Extracted from Rice Husk Ash Wastes Doped by Tin Dioxide for Wave Guide Material

A series of experiments is made to produce silica, mixing with tin dioxide (SnO2), and characterizing for application of waveguide device. Silica xerogels (SX) are prepared from raw materials derived from rice husks ash (RHA), which abundant in South East Sulawesi. The synthesis conditions have been optimized to obtain the ash of rice husks with the maximum silica content. SnO2 are prepared from a commercial powder. The ceramic waveguide materials are produced by mixing SX and SnO2 with various composition. The mixtures are molded to form the rectangular shape of 20 mm, 40 mm, and 5 mm in size. The samples will be sintered at different level of temperatures (from 300°C to 1200°C) by using microwave heating system as well as electric furnace. The microstructural of sintered samples were characterized on the basis of the experimental data obtained using densification measurement method (Archimedes method), crystallization (X-ray diffraction, XRD), microstructure (Scanning electron microscope, SEM). Optical and related properties such as the functional groups, structure, and absoption were characterized by using FTIR, Infrared and Raman Spectroscopy and absorption (UVVis). The permittivity and permeability will be calculated from S-parameters determined by using Vector Network Analyzer (VNA). Characterization results are presented in this paper and the others are will be published in another separated papers. Furthermore, the relationship between properties with SnO2 content and sintering temperature is also studied.