Application of Aquatic Plants Dead Biomass in Remediation of Heavy Metals Pollution by Adsorption: A Review

Abstract

Objectives: To figure out the sources of heavy metals pollution in water bodies, their toxicity, and utilization of aquatic plants’ dead biomass as adsorbents for heavy metals removal. In addition, this review also explains the adsorption mechanism through adsorption isotherms and kinetics. Methods: Various research papers related to aquatic plant adsorbents from various sources have been compiled to assess the adsorption capacity of heavy metals from synthetic solutions as well as from the wastewater. Findings: The adsorption using aquatic plants as adsorbents were found to be an economic and environment-friendly method for heavy metal adsorption from wastewater as aquatic plants grow rapidly and are found abundantly. The efficacy of these adsorbents has been increased by various researchers by modifying them via chemical treatment and nanotechnology. It was found that adsorbent derived from various aquatic plants like Eichhornia crassipes, Pistia stratiotes, Ceratophyllum demersum, Spirodela polyrhiza, Lemna minor, etc. shows good adsorption potential for heavy metal removal. Novelty: The research data on adsorption shows that the dead biomass of these plants can be capable for elimination of heavy metals from aqueous solutions. As some of the aquatic plants are invasive and compete with the native species, not desirable for the aquatic ecosystem, so utilization of aquatic plants provides double benefits. Keywords: Adsorption; Heavy metal; Aquatic plant; Adsorbent; Adsorption capacity