(255b) Evaluation of Physical and Morphological Alteration of Seaweed Char with Varying Activation Parameters and Corresponding Fate on Cationic Dye Adsorption

Sargassum (brown seaweed) are free floating brown algae found on ocean shores in large quantities littering shorelines causing visual and olfactory nuisances affecting tourism and fishery industries for the affected areas. As Sargassum decomposes warnings have been issued to individuals with asthma or other respiratory illnesses to avoid the affected areas as the produced Hydrogen Sulfide may trigger breathing complications. As a result, the removal of Sargassum is imperative for sustaining the impacted industries. The use of Sargassum as a biomass source has proven to be a simple and wise decision due to the high organic carbon content and low cost. Superactivated hydrochar recently have gained substantial interest in adsorption applications such as gas storage, supercapacitors, dye, and toxin removal owing to the high porosity, and multimodal pore size distribution (macro-, meso-, micropores). Consequently, exploration of physical and chemical properties of the Sargassum derived Seaweed Char was undertaken. Synthesis involved hydrothermal carbonization (HTC) at temperatures 180, 220, and 260 ℃ for 30 min followed by chemical activation with KOH at activation temperature 800℃ and varying KOH to hydrochar ratio (2:1, 3:1, and 4:1). Physical (Thermogravimetric Analysis, Ultimate Analysis), morphological (Brunauer-Emmet-Teller surface area, Scanning Electron Microscopy), and chemical characterization (Fourier Transform Infrared Spectroscopy, Boehm Titration) were performed to study the resulting Seaweed Char based on the varying synthesis conditions. From characterization results selected Seaweed Char were investigated for methylene blue dye adsorption application and as observed with increase in porosity of the Seaweed Char with results in an increase in maximum adsorption capacity.