Spent Tea Leaves as an Adsorbent Material: Preparation, Characterization, and Application

The adsorption of Congo Red (CR) on the surface of Spent Tea Leaves (STL) was evaluated in an aqueous system. The study was carried out for the establishment of a standard wastewater treatment method that would remove reactive dyes by employing spent tea leaves as a bio-adsorbent. The effect of various parameters like amount of adsorbent, contact time, concentration of dye, and pH on the adsorption was studied. The adsorption capacity was monitored with a UV-visible spectrophotometer. The maximum adsorption of dye was observed at adsorbent mass of 3.5g /100 mL, at 8×10-5 M CR concentration, at pH = 9.72 and 50 minutes of contact time. The experimental results suggest that the adsorption of CR on the surface of STL is an exothermic process. The adsorption of CR on STL is found to follow pseudo first order kinetics. Based on the findings, it’s feasible to draw the conclusion that spent tea leaves would be a better adsorbent for the removal of reactive dyes from the wastewater.