Recent developments in the reuse of agricultural residues/resources have led to environmental sustainability and cleaner technology emphasizing the utilisation of natural resources. Novel approaches to sustainable and energy conservations inter-relates the scientific and practical applications employed in engineering solutions. The increasing importance of biomass had led to an acute need for mitigating global sustainable problems. In the third world economics, Rice Husk (RH) collected from rice milling industry is considered as one of the abundant and invaluable agro-based residues. A focus on industrial food production and its sustainability is due to the generation of huge quantity of RH. The improper handling and disposal management of RH has resulted in environmental and population health risk, due to its large space occupancy and leaching. The effective utilization and study of rice husk in various industrial applications such as construction industry, energy production, water purification and soil stabilization have shown acceptable results. This review discusses the current research works focussing on the suitability of RH and its ash over a wide field of applications. Silica being the dominant content in RH and Rice Husk Ash (RHA) has attracted interest among the researchers to develop it into high strength composite materials, porous nanomaterials, a precursor of renewable energy and soil stabilising biochars. Replacement of fine aggregates with RHA has improved the strength and durability of the concrete. The RHA is also developed into an adsorbent and coagulant in water purification. The binding between the ions present in impure water and highly reactive silica bond enhances the removal efficiencies of metal ions in water treatments. Very few researches are carried out using RH compared with the pyrolyzed RHA as an alternative. This paper highlights the various field of RH applications and suggests composting of RH with nitrogen-rich garden waste to obtain an enriched soil stabilizing product with high nutrient and organic value. This approach would restore RH in its the place of generation, thereby improving the economic value of the agricultural mass and sustainable way of living.

In this study, the efficiency of fungal consortia was evaluated on the degradation of rice straw by varying the initial carbon/nitrogen ratio of the compost piles. Consortia of three potent cellulose-degrading fungal strains: Aspergillus fumigatus, Aspergillus terreus and Aspergillus flavus were used as an inoculant to degrade rice straw in a 90-day composting process. The carbon/nitrogen ratio of the composting piles was varied by varying the proportion of bedding material in different treatments. The composts thus achieved were subjected to physic-chemical analysis and phytotoxicity assay using Solanum lycopersicum as test seeds. After 90 days of composting, compost from treatment 4 with initial carbon/nitrogen ratio 34 depicted maximum stability by achieving a final carbon/nitrogen ratio of 16.25. Compost from treatment 4 showed the highest Germination Index (%) followed by treatment 3 and treatment 2 as 94.32%, 88.88% and 79%, respectively on the growth of Solanum lycopersicum seeds. Results concluded that fungal consortia derived agro-waste compost with an initial carbon/nitrogen ratio 34 depicted the earliest maturity which is suggestive of its suitability for agricultural application.