A Comprehensive Review on Application of Different Natural and Chemically Modified Nanomaterials Adsorbents for Heavy Metals Removal

Abstract

The present study is a comprehensive review of environmental problems raised by various heavy metal ions. Due to various heavy metal ions such as Cd (II), Pb (II), Cr (VI), Hg (II), Sr (II), and many more in the environment harm people’s health because they are poisonous and persistent. Also, it spreads toxicity and carcinogenicity to ecosystems and living things. Various hazardous effects of heavy metals are such as toxicity, bioaccumulation, and environmental pollution. The heavy metals basically cause the neurological disorders, kidney damage, liver damage, cardiovascular disease and sometimes cancer. To address the issue of heavy metal ions using various nanomaterials and natural resources through efficient and effective ways is reported in the present review. The use of natural zeolites and their derivatives used for heavy metal removal were systematically discussed. The characteristics of the heavy metal after the surface modification were investigated using various analytical techniques such as FTIR, XRD, BET, TEM, AFM, SEM–EDX, Raman spectroscopy, etc. The higher adsorption efficiencies of various inorganic nanomaterials were observed because of their solid and active sites, interactions, complexation, and reduction mechanisms. Natural zeolite and other inorganic nanomaterials such as GO, MXene, MoS₂, hBN, and TiO₂ were found to be effective and efficient adsorbents with surface-modified chemicals for the degradation and removal of heavy metal ions from different industrial wastewater streams.