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Emerging Carbon-Based Nanocomposites for Remediation of Heavy Metals and Organic Pollutants from Wastewater
Prasenjit Kar1, Pratyush Jain1, Raju Kumar Gupta1,2* and Kumud Malika Tripathi3†
1 Department of Chemical Engineering, Indian Institute of Technology Kanpur, Uttar Pradesh, India
2 Center for Environmental Science and Engineering, Indian Institute of Technology Kanpur, Uttar Pradesh, India
3 Department of Bionanotechnology, Gachon University, Seongnam-daero, Sujeong-gu, Seongnam-si, Gyeonggi-do, Republic of Korea
Abstract
Nano-carbons are emerging as promising materials for environmental remediation applications. Unique and extraordinary optical, electrical, and surface properties of nano-carbons in all of their forms have substantially and successfully been investigated widely for water remediation for the removal of diverse range of contaminants. Furthermore, revolutions in synthesis of nano-carbons–based composites led to the facile and fast adsorbent technologies for remediation applications. Ease in synthesis along with a wide scope to engineer the surface structure, porosity, electronic and magnetic properties of nano-carbons is the most significant criteria to the rational design of diverse adsorbent. In this chapter, carbon-based nanomaterials, especially graphene oxide (GO) and carbon nanotubes (CNTs) have been explored for their water remediation capabilities via adsorption process. Mechanistic insights and the interactions responsible for the adsorption are highlighted. Structural engineering of these materials into more suitable form for handling purposes has shown their practical application for treatment of water resources. Dyes, toxic metals, and other organic pollutants have been described for their removal via adsorption through GO and CNTs.
Amphiphilic nature of GO helps it to remove pollutants from water easily where most of the adsorption occurs due to the electrostatic interactions between functional group on GO and pollutants present. CNTs have shown very high specific area with tunable functionality, which can be used for removing polar and non-polar pollutants.
Keywords: Graphene oxide, carbon nanotube, organic pollutants, heavy metals, adsorption, water remediation
1.1 Introduction
Water soluble toxic pollutants are one of the vital concerns to both human and environment health worldwide in recent past few decades. Ever increasing world population, expanded use of chemical products and their demands toward the exploitation of natural resources has made it inevitable to develop unique methods and materials for the environmental remediation [1–4]. Hazardous industrial wastes, unethical agricultural practices, and unplanned human waste management have caused intoxication of water resources almost worldwide [5–7]. Although, stronger regulations by governments of various countries have been implemented to curb the unruly contamination of water bodies but recalcitrant nature of pollutants towards treatment in conventional wastewater treatment plants (WWTPs) has necessitated us to approach this grave problem from a new perspective [8, 9].
Widespread occurrence of water soluble pollutants, such as heavy metal ions [Cr(VI), Al(III), Hg(II), Ag(I), Pb(II), Fe(III), As(III) and Co(II)], synthetic organic contaminants like textile dyes, new emerging contaminants such as pharmaceutical and personal care products (PPCPs), microplastic pesticides, endocrine disruptors, nanomaterials textile dyes, and synthetic and natural organic contaminants, have threatens the balance of nature and causing concerns and research interests worldwide [10, 11]. Even these compounds are present at trace levels but could result in adverse effects over human health and aquatic life because of high toxicity and carcinogenic nature. Their resistant nature towards the bio-decomposition led to their gradual accumulation over a period of time in water bodies and their concentration may rise well above the safer limits [12]. Conventional techniques including primary processes like sedimentation, chemical precipitation filtration along with biological treatment as secondary process have been used for the removal of these contaminants. Advance processes for tertiary treatment like adsorption, micro and ultra-filtrations, catalytic wet air oxidation, photocatalysis, and electrocatalysis can be used to improve the efficacy of the treatment processes [13] (Figure 1.1)....
