Elemental Characterization of Rice Husk Ash from Local Rice Species in South Eastern Nigeria

Abstract

Heavy metals such as Cr, Zn, As, Pb and Cu can be hazardous to health and the environment. The focus of this study is to investigate the trace metal constituents of rice husk ash (RHA) from Ikwo and Izzi rice clusters. RHA of Izzi CP, R8 and Ikwo CP rice husk species were sampled. Elemental characterization was done using X-ray fluorescence method. A total of 14 elements (K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Rb, As, Br, Sr and Ga) were detected in the rice husk species except in Izzi CP where Ga was not detected. The concentration of these elements in weight percent (wt. %) were compared with literature. Elements like, K, Ca, Fe, and Mn were found to be in negligible concentrations in all the samples while Ga, Rb, Cu, Cr, Zn, As and Ni were found to be well above the literature values. The X-ray fluorescence analysis of the samples showed that some toxic heavy metals like Cr, As, Ni, and Cu were of high concentrations compared to literature which for health reasons are not advisable to have long term exposure.

Microalgae Biomass Production from Rice Husk as Alternative Media Cultivation and Extraction of Phycocyanin Using 3D-Printed Ohmic Heating Reactor

“…The culture that contained different concentrations of rice husk extract and NaNO 3 was efficient for the growth of S. platensis biomass, which is an alternative to growing microalgae. This is because the rice husk has nutrients that are present in the extract, such as sources of SiO 2 , sources of C (starch), and traces of elements such as Ca, Mg, Fe, and Zn, mainly [48,49]. At an appropriate pH of 7.5, all the present conditions promote the growth of S. platensis using rice husk extract as a culture medium.…”

“…Enzymes commonly present in cyanobacteria are amylase, cellulases, and β-glucosidases; these types of enzymes could hydrolyze the glycosidic β bonds 1-4 of the chains of amylose and amylopectin present in the starch and could explain how S. platensis obtains glucose as a source of carbon. The presence of glucose can increase the yield of S. platensis biomass and increase the production of phycocyanin [48,49].…”

“…The presence of components such as nitrogen and a carbon source are essential for microalgae growth [48]. The trace metals are related to microalgae growth, especially the Fe 2+ , Cu 2+ , and Zn 2+ present in the RHE.…”

Geotechnical Characteristics of Benin Formation, Owerri Imo State, Nigeria

“…to a soil to alter its physical properties, whereas soil stabilization is the treatment of soils to enhance their performance and durability towards the point at which they are wholly suitable for construction beyond their initial classification [8,9,10,11]. Many soil materials, such as literite gravel and pizzollite, which are suitable for gravel road construction, are found in tropical areas around the world, including Nigeria [12]. When a lit includes a large number of clay components, its strength and stability under load cannot be guaranteed, especially when moisture is present [13].…”