Rich Husk Ash Research Articles

Rice husk ash addition to acid red soil improves the soil property and cotton seedling growth

Red soil is characterized by poor physico-chemical properties and low nutrient availability. The present study aimed to examine rich husk ash (RHA) incorporation into red soil at various rates effects on its properties and the growth of cotton seedlings under a plug-seeding in tray experiment. Bulk density was decreased, and water holding capacity and total porosity were increased in red soil with increasing application rate of RHA. The addition of RHA counteracts the acidity of red soil and improves the nutrient availability to plants. The RHA incorporated soils favored the growth of cotton seedlings with improved shoot morphological traits and root architectures. The application rate at a volume ratio of 1:1 of RHA to red soil was found to be optimal for growing cotton seedlings in the present study. The mixture of RHA and red soil at a 1:1 volume ratio plus 2 g L−1 super absorbent polymers exhibited a high nursing seedling efficiency comparable to a commercial growing media under the condition of foliar application of mepiquat chloride at the one-true-leaf stage. RHA can be a promising substitute for peat as growing media for nursing cotton seedlings.

Green synthesis of mesoporous graphene oxide/silica nanocomposites from rich husk ash: Characterization and adsorption performance

Abstract Rice husk is an agricultural waste. Rice husk ash (RHA) is the main residue when rice husk is burned to produce biomass energy. The conversion of RHA into high-value-added products is a sustainable method and can help develop a circular economy. In this study, a graphene oxide/SBA-15 composite was synthesized from RHA. Experimental investigations revealed that the various oxygen-containing functional groups of the graphene oxide/SBA-15 composite resulted in considerably enhanced adsorption capacity. Furthermore, the composite possessed a pore volume of 0.978 cm 3/g, pore size of 10.5 nm, and surface area of 625 m2/g. The pore structure of the composite was mainly a hexagonal array of mesopores, which did not change with the addition of GO. TEM images revealed that the SBA-15 surface was homogeneously covered with GO flakes. Raman spectroscopy demonstrated that composite contained disordered carbon with a high degree of oxidation. The effects of adsorption conditions – adsorbent dosage, initial dye concentration, adsorption temperature, and solution pH – on the Rhodamine B adsorption of the graphene oxide/SBA-15 composite were investigated. The composite exhibited the highest adsorption capacity of 151.28 mg/g at 80 ∘ C. The adsorption was endothermic with enthalpy of 11.83 kJ/mol. The isotherm adsorption experiment revealed that the Langmuir model was the best fit for the adsorption results. Kinetic investigations revealed that the adsorption process followed the pseudo-second-order model. The adsorption rate was mainly controlled by the intraparticle diffusion step. Commercially available SBA-15 materials are expensive. This study provides an economically viable method of treating RHA that improves its potential for applications involving removal of dyes from wastewater.

Influence of rice husk ash on mechanical properties and fire resistance of recycled aggregate high-calcium fly ash geopolymer concrete

Abstract The use of recycled aggregates in geopolymer concrete provides an eco-friendly alternative for the construction industry. Since geopolymer concretes made with recycled aggregates generally have weaker internal structure compared with those using natural aggregates, SiO2-rich materials have therefore been used to improve the strength properties, one of which is the well-known nano-SiO2 (nS). However, because nS is not environmental friendly, other green SiO2-rich materials, such as rice husk ash (RHA) from agricultural wastes, are needed. The objective of this study is to investigate the effectiveness of replacing nano-SiO2 with rich husk ash for improving the performance of recycled aggregate geopolymer concrete (RAGC) made from high-calcium fly ash that is able to set and harden without heat curing. The mechanical properties and fire-resistant performance of RHA-added and nS-added geopolymer concretes were tested and compared. The results show that the addition of RHA is effective in improving the strengths of RAGCs, particularly when the SiO2/Al2O3 ratio is increased to 4.17. The 28-day compressive strengths of RAGCs containing RHAs ranged from 36.0 to 38.1 MPa due to the improved microstructure and denser matrix and were comparable to those of RAGCs made with nS. However, the inclusion of SiO2-rich materials had an adverse effect on the post-fire residual strength of geopolymer concretes made from recycled aggregates due primarily to the reduced porosity.

Properties of Cement Mortar with Different Blending Amount of Rich Husk Ash (RHA)

Abstract The morphology of rice husk ash (RHA) samples obtained at 400°C in a vertical high temperature furnace was characterized by scanning electron microscopy, and the effect of RHA on the mechanical behavior of cement mortar was studied. The RHA sample is slightly grey in color and there are some black particles. RHA samples have many sheets that are vertically and horizontally interlaced. The effect of RHA on the compressive and flexural strengths test for cement mortar has been investigated. The water absorption, mortar consistency, dry bulk density, and water permeability were tested. The compressive and flexural strengths decreased with the replacement of RHA. The mortar consistency improved, and water absorption increased. The dry bulk density of cement mortar decreased, and the water permeability increased. Because RHA is a resource containing properties that have the potential for categorizing it as waste, the comprehensive utilization of RHA is significant for improving environmental protection and gaining economic benefits.

Chemical and Microstructural Effects of Different Calcinating Temperatures on Selected Pozzolans

Recent researches show that agricultural wastes can be reuse as pozolans; this contributes to our environmental sustenance. The need to successful carry out proper analysis contributes significantly to improving the overall use of the discovered pozolans. Therefore, this research aims to investigate the micro-structural and chemical analysis of some selected pozzolans at different calcinating temperatures. Rich husk ash (RHA), groundnut shell ash (GSA), locust beans pod ash (LBPA) and bamboo leaf ash (BLA) were obtained; their chemical and microstructural analysis at different calcinating temperatures (500°C, 600°C and 700°C) were carried out using X-ray fluorescence and scanning electron microscope. The results show that the optimum calcinating temperatures considering the microstructure and chemical composition of RHA, BLA and LBPA were 700°C, 500°C and 600°C respectively. These pozzolans were also classified according to ASTM 618 requirement.

Effect of rich husk ash stabilization on solute transport in a lead-contaminated soil

Effect of rich husk ash stabilization on solute transport in a lead-contaminated soil

Effect of natural fiber types and sodium silicate coated on natural fiber mat/PLA composites: Tensile properties and rate of fire propagation

In this study, 3 types of natural fibres, i.e. jute, sisal and abaca, were plain weaved to fibre mat. Before weaving, the fibres were treated with 5% NaOH to remove hemi cellulose and lignin. The weaving was performed by hand using square wooden block fit with nails for weaving using one and two types of natural fibres as weft and warp fibre to produce natural fibre mat. The fibre mat was also impregnated in sodium silicate solution extracted from rich husk ash. The pH of the solution was adjusted to pH 7 using H2SO4 before impregnation. After predetermined time, sodium silicate was gelled and deposited on the mat. The fabric mat and sodium silicate coated mat were then impregnated with PLA solution to produce prepreg. Dried pepreg was laminated with PLA sheet using compressing moulding machine to obtain natural fibre mat/PLA composite. The composite containing abaca aligned in longitudinal direction with respect to tension force enhanced Young's modulus more than 300%. Fibre mat composites with abaca aligned in longitudinal direction also showed tensile strength enhancement nearly 400% higher than neat PLA. After coating with sodium silicate, the tensile modulus of the composites was found slightly increased. The silicate coating was disadvantage on tensile strength of the composite due to the effect of sodium hydroxide solution that was used as solvent for silicate extraction from rice husk ash. However, sodium silicate could retard rate of fire propagation about 50%compare to neat PLA and about 10% reduction compared to fibre mat composites without sodium silicate coated fibre mat.

Production and characterization of rich husk ash particulate reinforced AA6061 aluminum alloy composites by compocasting

Rice husk ash (RHA) is a potential particulate reinforcement to produce aluminum matrix composites (AMCs) economically. Compocasting method was applied to produce aluminum alloy AA6061 reinforced with various amounts (0, 2%, 4%, 6% and 8%, mass fraction) of RHA particles. The prepared composites were characterized using X-ray diffraction and scanning electron microscopy. X-ray diffraction patterns of AA6061/RHA AMCs revealed the presence of RHA particles without the formation of any other intermetallic compounds. The scanning electron micrographs showed a homogeneous distribution of RHA particles all over the aluminum matrix. Intragranular distribution of RHA particles was observed. Further, RHA particles were bonded well with the aluminum matrix and a clear interface existed. The reinforcement of RHA particles enhanced the microhardness and ultimate tensile strength (UTS) of the AMCs. The tensile behavior is correlated to the microstructure of the AMCs.

Microstructure and reactivity of rich husk ash

Rice husk ash (RHA) is bio-organic nano SiO2 produced by controlled burning of rice husk and has high pozzolanic activity. The present paper is aimed at revealing the origin of high specific surface area and high pozzolanic activity of RHA by exploring its structure at micro and nano level. Rice husk calcined at 500, 600, 700 and 800°C, was tested for compressive strength and X-ray diffraction (XRD) analysis while Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM) analysis were carried out on selected samples of RHA. From the XRD analysis and compressive strength test results, it can be concluded that the optimum combustion temperature for obtaining highly reactive RHA is 600°C. SEM and TEM images showed that RHA has three layered structure i.e. inner, outer and interfacial with honeycombed and interstitial pores. These pores are actually the main reason for very large specific surface area and very high chemical activity of RHA.