Phytoremediation for Heavy Metal Removal

Phytoprevention of Heavy Metal Contamination From Terrestrial Enhanced Weathering: Can Plants Save the Day?

“…While hyperaccumulation has probably evolved as a defense mechanism of plants against herbivores (Rascio and Navari-Izzo, 2011), excluders use one or several separate strategies to either break down contaminants or make them less bioavailable (e.g. phytodegradation, rhizodegradation, and phytostabilization; Etim, 2012;Yadav et al, 2021).…”

“…In phytoremediation, appropriate plants are used to decontaminate soils or water bodies polluted from anthropogenic impacts either by extracting HM or making them less bioavailable. To remove metals from soils, phytoextracting plants that accumulate metals of interest, ideally in the above ground biomass, are particularly useful (Pulford and Watson, 2003;Vara Prasad and de Oliveira Freitas, 2003;Etim, 2012;Yadav et al, 2021). These plants are usually separated into hyperaccumulators having a metal concentration of >1000 ppm of some HM (including Ni and Cr) in their dried biomass (Baker and Brooks, 1989) and non-hyperaccumulators that have lower HM concentrations but may still accumulate HM from soils (called accumulators here).…”

“…In a study of soils contaminated with hydrocarbons and heavy metals, these trees removed on average ∼40% of Ni within three years. Zaranyika and Ndapwadza, 1995;Zhu et al, 1999;Ingole and Bhole, 2003;Mishra and Tripathi, 2009;Fazal et al, are the use of rhizobacteria (Yadav et al, 2021) or mycorrhiza (Coninx et al, 2017) that may encourage plant growth, and increase the bioavailability and uptake efficiency of metals. The latter effect could also be achieved by adding chelating agents like EDTA to soils (Lim et al, 2004;Wu et al, 2004), although this should be viewed with caution and tested meticulously as the increased bioavailability and element mobility might promote runoff of HM into surface and groundwaters (Cooper et al, 1999;Pulford and Watson, 2003;Wu et al, 2004).…”

Ligand-modified eggshells for rapid naked-eye detection and removal of trace level Ni2+ ions

“…Typically, the traditional techniques employed for the identification and removal of this metal ion encompass chemical precipitation, membrane filtration, ion exchange processes, adsorption onto activated carbons, precipitative softening, hydroxide co-precipitation, and coagulation and flocculation. 11–14 Nonetheless, these conventional methods have notable drawbacks, including the use of costly materials, the potential for secondary pollution, limited efficiency, and lack of selectivity, which have hindered their continuous application. Furthermore, traditional instrumental methods like online pre-concentration, voltammetry, polarography and ion-selective electrode potentiometry are characterized by their expensive and time-consuming nature, complexity, and sophistication.…”

Phytoremediation of Secondary Treated Sewage through Constructed Wetland: Lab-Scale Study

“…Contamination of rivers, lakes, ponds, waterways, and groundwater has become a serious concern in developing nations like India. Agricultural run-off, industrial discharges, domestic sewage, and other sources of pollution have badly contaminated the bulk of aquatic habitats (Gupta et al 2020, Yadav et al 2021. In the Indian context, agriculture discharge, industrial effluents and sewage contribute as 65, 25, and 10% towards the quantitative pollution load of the aquatic environment (Kumar et al 2015).…”