Study on the adsorption performance and competitive mechanism for heavy metal contaminants removal using novel multi-pore activated carbons derived from recyclable long-root Eichhornia crassipes

Long-root Eichhornia crassipes has shown great remediation capacity for eutrophication while the dispose of massive plants reaped is a pressing challenge for its large-scale application. In this study the waste plants were reclaimed and employed to prepare multi-pore activated carbons (MPAC) with high specific surface area through a simple gradient heating method. Owing to the large specific surface area and abundant multiple functional groups, the MPAC exhibited great adsorption performances for heavy metals with great adsorption capacities and rapid rate. Careful adsorption investigation indicated that the adsorption was mainly controlled by a charge transfer complex pattern. In addition, the adsorption impetuses were heterozygous involving electrostatic interaction, electron sharing or electronic-donor-acceptor interaction, etc. Moreover, the competitive adsorption reflected adsorption preference existed in the heavy metal removal using the MPAC as adsorbents due to the imparities in the adsorption affinity, thus resulting in the differences of the adsorption tolerance to exogenous influence.