Nanotechnology and soil heavy metal remediation: bridging science and practical solutions

Community health and global stability face significant threats from the prevailing issue of heavy metal (HMs) contamination. Persistent HMs like zinc, chromium, mercury, cobalt, copper etc., invade the food chain, leading to acute health dilemmas. Hence, it is imperative to consistently monitor the presence of HMs traces in surroundings and appropriately mitigate them. Despite ongoing debate about the operational significance of using nanomaterials for decontamination of HMs, there is growing optimism that nanotechnology could emerge as durable method for combating HMs contamination later on. This thorough review begins with a concise overview of HMS rectification approaches, following a precise summary of nanomaterials and critical examination of latest technologies of HMs decontamination comprising techniques like filtration, adsorption, photolysis and more. At identified farming sites, heavy metal deposition exceeded permissible limits by 19.4%, while across the entire cultivable area, the exceedance was 16.1%. In the leaves of Noccaea caerulescens, zinc (Zn) levels exceeded the threshold by 300 g/ha at two-month intervals. Similarly, in the shoots of Pennisetum purpureum, the total quantities of Zn and cadmium (Cd) were found to be 5023.9 g/ha and 197.5 g/ha, respectively. The roots of Atriplex halimus contained 606.51 parts per million (ppm) of Cd, while the shoots contained 217.52 ppm. Hydroponically grown Brassica juncea was able to eliminate approximately 95% of mercury (Hg) through a combination of phytoextraction and volatilization. Additionally, Pteris vittata plants injected with the R507 strain of Cupriavidus basilensis accumulated 170% more arsenic (As) in their tissues. Based on past studies, the present review, offer additional suggestions regarding the functional outcomes of nanotechnology and aiming for enriched and ecofriendly eradication of HMs in the future.