Removal of polycyclic aromatic hydrocarbons from aged-contaminated soil using cyclodextrins: experimental study

The removal of polycyclic aromatic hydrocarbons (PAHs) from soil using water as flushing agent is relatively ineffective due to their low aqueous solubility. However, addition of cyclodextrin (CD) in washing solutions has been shown to increase the removal efficiency several times. Herein are investigated the effectiveness of cyclodextrin to remove PAH occurring in industrially aged-contaminated soil. Beta-cyclodextrin (BCD), hydroxypropyl-beta-cyclodextrin (HPCD) and methyl-beta-cyclodextrin (MCD) solutions were used for soil flushing in column test to evaluate some influent parameters that can significantly increase the removal efficiency. The process parameters chosen were CD concentration, ratio of washing solution volume to soil weight, and temperature of washing solution. These parameters were found to have a significant and almost linear effect on PAH removal from the contaminated soil, except the temperature where no significant enhancement in PAH extraction was observed for temperature range from 5 to 35 degrees C. The PAHs extraction enhancement factor compared to water was about 200.     

Construction of MoS2 nanoarrays and MoO3 nanobelts: Two efficient adsorbents for removal of Pb（Ⅱ）, Au（Ⅲ） and Methylene Blue

Toxic heavy metal ions, valuable noble metal ions and organic dyes are significant concerns in wastewater treatment. In this work, MoO₃ nanobelts（MoO₃ NBs） prepared by solvothermal method and MoS₂ nanoarrays（Mo S₂ NAs） constructed using MoO₃NBs precursor were proposed to effectively remove heavy/noble metal ions and organic dyes, such as Pb^（Ⅱ）, Au^（Ⅲ）and Methylene Blue（MB）. The two adsorbents exhibited the excellent adso...