NANOBUBBLE TECHNOLOGY FOR SOIL REMEDIATION: CURRENT PROGRESS, MECHANISTIC INSIGHTS, CHALLENGES, AND FUTURE PROSPECTS

Abstract

Nanobubble technology can be a game-changer for the soil remediation sector, which faces significant challenges in combating soil contamination to ensure food security and overall ecosystem health. Nanobubbles are smaller bubbles with a diameter less than one micrometer that have extraordinary properties such as very large specific surface area, high stability, and strong negative surface charge and capacity to produce reactive oxygen species. The present review gives a comprehensive synthesis of nanobubble application technology in soil remediation including understanding the mechanism and their applications in soil remediation of both organic contaminant and inorganic contaminant. Mechanisms include improving gas transfer, oxygenating the soil, contaminant release and mobility, production of reactive oxygen species, soil-microbe-plant interaction with increased soil biodegradation. Enhancements in plant growth of 10-50% and contaminant removal efficiencies of up to 75-98% have been seen for petroleum hydrocarbons, pesticides, heavy metals and emerging persistent contaminants. Synergistic hybrid systems come with integration to bioremediation, phytoremediation, biochar and advanced oxidation. Laboratory to field translation and protocols standardization, ecotoxicological evaluation and economic feasibility are key challenges. Future directions include precision remediation via smart monitoring and adaptive management using AI. The review concludes that nanobubble technology holds potential for sustainable soil remediation for agricultural productivity, while ensuring soil health and environmental quality.