As a result of rice grain processing, a big amount of waste (up to 20%) is produced. It is mainly rice hulls. The main components of rice hulls are cellulose, lignin and mineral ash. The mineral ash quantity in rice hulls varies from 15 up to 20%, by weight of the rice hulls. The mineral ash consists of amorphous silica (opal-type). Due to the high content of silica in rice hulls, the material burns with difficulty under natural conditions, and it is biodegradably destroyed only with difficulty, when composted. Utilization of rice hulls then becomes an ecological problem due to huge rice production and its continuous growth. At the same time, the annual quantity of silica content in rice hulls is comparable with the quantity of amorphous silica produced as a mineral resource. The issue of manufacturing cellular glass silica construction materials from rice hulls as a renewable resource is discussed in this paper. The utilization technology is based on an amorphous silicon oxide with the use of energy from the combustion of the organic component of rice hulls.
The paper analyzes a solution in green manufacturing of foamed or cellular ceramics. The objective of this study was to determine the technical solution for rice husk ash and “tales” of mixed glass cullet reusing based on the specific properties of these materials for creation of spherical holes inside ceramic using the process of coalescence of cellular glass. The paper reports on experimental results obtained from the production of lightweight cellular glass granules produced using glass cullet and rice husk ash. Lightweight cellular glass granules were mixed with clay, pressed and fired in air at 920°C. Clay sintering and the formation of ceramic were followed with the coalescence of cellular structure of glass granules and with the formation of spherical hollows inside the matrix. Density and strength of the fired ceramic bodies were determined. It is observed that the lightweight ceramics with density 900 ÷ 920 kg/m3 possess a compressive strength of about 5 MPa that is acceptable for bricks or tiles manufacture. The utilization of amorphous silica waste for lightweight ceramics manufacture helps in reducing waste disposal concerns and costs associated, and also transforms the waste into an alternative raw material with added value, moreover making the final product cheap.
In the last decades, the amount of municipal sewage sludge generation rate has drastically increased due to population growth, spatial sewerage system development, and implementation of new treatment techniques. Nowadays, it is considered a globally prominent issue. Municipal sewage sludge contains pathogenic bacteria and viruses along with heavy metals, poorly biodegradable organic compounds, pharmaceuticals, and microplastics, which make its utilization management quite difficult. Landfill placement of sewage sludge is the most widely used technique worldwide, but is obsolete and inefficient, and accompanied by significant risk of environmental pollution with high logistics expenditure. Moreover, landfill placement means that all residual energy and potential material reuse applications are lost. The introduction of modern treatment techniques can solve the problem with sewage sludge generation, but it results in strong energy consumption increase of energy consumption. Modernization and operational policies based on circular economy principles are focused on relevant sewage sludge utilization issues with the potential use of waste-to-energy and recycling applications. The paper presents a methodological approach of cradle-to-grave assessment of sewage sludge treatment process based on energy and material flow analysis. The proposed methodology is studied within the real operational activities of big-scale wastewater treatment plants of two of the largest cities of Russia-Ekaterinburg and Perm. This investigation provides an efficient managerial tool for sustainable development that can be used by wide range of stakeholders.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.