Functionalized carbon nanotubes (CNTs) for water and wastewater treatment : preparation to application
As the world human population and industrialization keep growing, the water availability issue has forced scientists, engineers, and legislators of water supply industries to better manage water resources. Pollutant removals from wastewaters are crucial to ensure qualities of available water resources (including natural water bodies or reclaimed waters). Diverse techniques have been developed to deal with water quality concerns. Carbon based nanomaterials, especially carbon nanotubes (CNTs) with their high specific surface area and associated adsorption sites, have drawn a special focus in environmental applications, especially water and wastewater treatment. This critical review summarizes recent developments and adsorption behaviors of CNTs used to remove organics or heavy metal ions from contaminated waters via adsorption and inactivation of biological species associated with CNTs. Foci include CNTs synthesis, purification, and surface modifications or functionalization, followed by their characterization methods and the effect of water chemistry on adsorption capacities and removal mechanisms. Functionalized CNTs have been proven to be promising nanomaterials for the decontamination of waters due to their high adsorption capacity. However, most of the functional CNT applications are limited to lab-scale experiments only. Feasibility of their large-scale/industrial applications with cost-effective ways of synthesis and assessments of their toxicity with better simulating adsorption mechanisms still need to be studied.
Research Council of Texas A&M University San Antonio
Ministry of Science and Technology of R.O.C. (Taiwan)
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The authors gratefully acknowledge the funding support by the Research Council of Texas A&M University San Antonio, and the Ministry of Science and Technology of R.O.C. (Taiwan), 107-2221-E-029-001-MY2. The authors would also like to thank Yu-Ling Wei, Chiung-Fen Chang, and Meng-Hau Sung for providing financial and analytical support to M.M.A.A. We acknowledge support of the Hamburg University of Technology (TUHH) by enabling open access publishing through funding programme Open Access Publishing.