Naslov
Heavy metal removal by biomass-derived carbon nanotubes as a greener environmental remediation: A comprehensive review

Autori
Anh Tuan, Hoang ; Nižetić, Sandro ; Chin, Cheng ; Rafael, Luque ; Sabu, Thomas ; Tien Long, Banh ; Van Viet, Pham ; Xuan, Phuong Nguyen

Izvornik
Chemosphere (0045-6535) 287 (2022), 1; 131959-131959

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Adsorbents ; Biomass waste ; Carbon nanotubes ; Functional groups ; Heavy metal ions ; Adsorption mechanism

Sažetak
The concentrations of heavy metal ions found in waterways near industrial zones are often exceed the prescribed limits, posing a continued danger to the environment and public health. Therefore, greater attention has been devoted into finding the efficient solutions for adsorbing heavy metal ions. This review paper focuses on the synthesis of carbon nanotubes (CNTs) from biomass and their application in the removal of heavy metals from aqueous solutions. Techniques to produce CNTs, benefits of modification with various functional groups to enhance sorption uptake, effects of operating parameters, and adsorption mechanisms are reviewed. Adsorption occurs via physical adsorption, electrostatic interaction, surface complexation, and interaction between functional groups and heavy metal ions. Moreover, factors such as pH level, CNTs dosage, duration, temperature, ionic strength, and surface property of adsorbents have been identified as the common factors influencing the adsorption of heavy metals. The oxygenated functional groups initially present on the surface of the modified CNTs are responsible towards the adsorption enhancement of commonlyencountered heavy metals such as Pb 2+ , Cu 2+ , Cd 2+ , Co 2+ , Zn 2+ , Ni 2+ , Hg 2+ , and Cr 6+ . Despite the recent advances in the application of CNTs in environmental clean-up and pollution treatment have been demonstrated, major obstacles of CNTs such as high synthesis cost, the agglomeration in the post-treated solutions and the secondary pollution from chemicals in the surface modification, should be critically addressed in the future studies for successful large-scale applications of CNTs.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne tehničke znanosti

POVEZANOST RADA