**2. Materials and Methods**

#### *2.1. Materials*

Bituminous coal-based commercial activated carbon (Chemviron CPG-LF) was procured from Calgon Carbon, Brazil, for the preparation of the adsorbent beads. The activated carbon has a surface that is non-polar, which results in an affinity for non-polar adsorbates such as organics. The adsorbent particle sizes were in the range of 1.2–1.4 mm with an iodine number of 950 mg/g. The carbon possessed a specific surface area of 650 m2/g (based on the Brunauer–Emmett–Teller method) with a mean pore radius of 450 nm and total pore volume of 0.18 cm3/g. Epoxy resin (Araldite 506), methyl nadic anhydride (MNA hardener) and phenol were obtained from Sigma Aldrich, India. Ethanol (99% pure) was obtained from Fisher scientific, India. Glass beads (1.76 mm diameter) were provided in gift packs from local industry in Vellore SIPCOT, India. All the chemicals and reagents used in the study were of analytic grade and were used directly for experiments. Double-distilled water (Merck Millipore) was utilized for the solution preparation, dilution and wash applications.

### *2.2. Adsorbent Preparation and Characterizations*

Activated carbon was used to coat the glass beads with a dimension 1.76 mm in diameter. This coating was achieved by using epoxy resin. The resin and MNA hardener were mixed in the

weight ratio of 1:1. The slurry of the glass beads and epoxy resin was made and mixed, such that the resin was distributed evenly on the glass bead surface to ensure uniform binding of the activated carbon. Following this, a known measure of activated carbon was sprinkled into the slurry, and then rolled and sieved to give the resultant activated-carbon glass bead adsorbent.

The morphology and surface chemistry of the synthesized adsorbent beads were analyzed through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) studies. SEM micrographs (Evo-18, Carl Zeiss, Dublin, CA, USA) were used to understand the pore structure of the activated carbon glass bead samples. An IR spectrophotometer (IR Affinity-1, Shimazdu, Kyoto, Japan) was used to conduct the FTIR analysis of the adsorbent through the KBr pellet method. The spectral scan was acquired in the range from 4000 to 400 cm<sup>−</sup>1. SEM and FTIR studies were performed for the fresh, phenol-loaded and regenerated activated-carbon glass bead samples.
