December 2025 – Silica has achieved key technological breakthroughs in the fields of agricultural waste recycling and ecological environment governance. Through innovations in resource conversion and material modification, it not only addresses the problem of agricultural solid waste pollution but also provides green and efficient solutions for soil improvement and water pollution control, demonstrating its diverse value in ecological sustainable development.

In terms of agricultural waste recycling, the industrialization technology of rice husk-based silica has been large-scale implemented, establishing a closed-loop industrial chain of "turning waste into treasure." As the main by-product of rice cultivation, rice husks contain up to 25% silica. In the past, most of them were incinerated or discarded, causing environmental pollution and resource waste. Nowadays, through controlled heat treatment, alkaline hydrolysis extraction, sol-gel method and other processes, high-purity silica materials can be efficiently prepared from rice husk ash. This not only solves the problem of agricultural solid waste accumulation but also endows the products with excellent characteristics such as high specific surface area (>470 m²/g) and high porosity (>90%). More notably, the preparation process using carbon dioxide instead of traditional sulfuric acid as a precipitant can achieve a carbon emission reduction of 0.6 tons per ton of bio-based silica product, equivalent to the carbon sequestration effect of planting 120 trees. Certified by life cycle assessment, it achieves carbon footprint reversal, truly realizing "carbon-negative production." Such materials have been widely used in various fields, and the tailings can be simultaneously used to prepare activated carbon, realizing 100% resource conversion of agricultural waste.

In the field of ecological governance, silica materials have shown outstanding efficiency in soil improvement and water pollution remediation. Addressing China's increasingly severe soil salinization problem (salinized land accounts for about one-fifth of the total cultivated land area), functional silicon-based formulations provide an effective solution for crops to resist salt stress. Studies have shown that silicon can alleviate osmotic stress caused by salt through two mechanisms: activating aquaporins in crop roots and forming a physical barrier in cell walls, thereby significantly enhancing crop stress resistance. Under salt stress conditions, the application of silicon-based formulations can increase rice plant height by 6.2%~12.5% and biomass by 6.1%~10.8%, while improving leaf chlorophyll content and photosynthetic efficiency, providing key support for crop yield increase in salinized land. In water pollution control, rice husk-based silica aerogel exhibits high adsorption performance due to its abundant surface functional groups and defect structure. Under neutral pH conditions, its removal rate of antibiotics such as amoxicillin in water can reach up to 90%, providing a low-cost and environmentally friendly new path for the treatment of refractory pollutants in water bodies.

This series of technological innovations not only promotes the green upgrading of silica materials but also constructs a virtuous cycle model of "resource-product-ecology." It provides practical technical support for agricultural sustainable development and ecological environment governance, and its diverse application potential is continuously being released.