(538g) Removal of Organic Compounds from Aqueous Systems Using Carbon Nanomaterial-Based Aerogels

Continued efforts are underway to develop new and improved techniques for removing contaminants from aqueous environments.  Contaminants vary and include organic, metal, and biological compounds.  The use of organic compounds (e.g. fertilizers) in agricultural settings continued to cause concern due to the runoff and buildup in downstream environments.  Buildup of high concentrations of these compounds can potentially lead to adverse health effects in humans and animals.  Adsorbents, such as activated carbon, are well known given their ability to adsorb various contaminants.  However, activated carbon is limited in its effectiveness when introduced in environments where pH and temperature swings reduced activated carbon’s uptake capacity.  Therefore, alternatives to current state-of-the-art adsorbents are desired.  In this work, the adsorption capability of a lightweight, carbon-based aerogel is presented.  The aerogel is composed of 0 to 2 wt% graphene nanoplatelets and single-walled carbon nanotubes (SWCNT).  Two organic compounds, 2,4-dichlorophenoxyacetic acid and 1-pyrenebutyric acid, served as the contaminants.  A design of experiment approach was taken to optimize the aerogel for maximum performance.  Results show that the aerogel containing 0.2 wt% GnP-SWCNT achieved an uptake capacity of 0.22 mg 2,4-D/mg aerogel and 0.083 mg PBA/mg aerogel.  Compared to activated carbon, the aerogels produced in this work demonstrated 39 times higher adsorption of 2,4-D and 5 times higher adsorption of PBA making them a viable candidate as a next generation adsorbent.