Catalytic activity of biodegradable polymeric colloidal particles in ground water remediation: recent progress and challenges

Applications of colloid science in ground water remediation enable the selective targeting of the contaminants while minimizing the environmental side effects. When the waste reaches the ground water level, the subsurface becomes unreachable for extraction of the contaminants, thereby restricting the efficacy of conventional remediation processes. Particularly hydrophobic contaminants such as non-aqueous phase liquid (NAPLs) accumulate under the subsurface of the aquifer and create a contaminant plume which is very difficult to extract. Pristine nanoparticles show versatile catalytic activities to decontaminate the ground water, but they face difficulty in reaching the targeted zone due to their tendency to form agglomerates, thereby compromising the subsurface mobility. This encourages the study of biodegradable polymeric coating to the active nanoparticles acting as remediation catalyst. Hence, these micro-to-nano-sized polymeric colloid materials are only viable options for the in-situ ground water remediation. This particular study reviews the catalytic activity of various metal and carbonaceous nanoparticles for the removal of contaminants, and their biodegradable polymeric coating, which ensures their environmental compatibility, transportability and enhances the efficacy of nanoparticles to remove chlorinated solvents, dyes and heavy metals from contaminated groundwater. Advances in nanotechnology-integrated eco-friendly formulations are explored to address their limitations, emphasizing the need for further research and development to optimize their deployment in diverse environmental settings.