The present study seeks to investigate the capacity of Polypyrrol/Tannic acid (PPy/TA) nano-adsorbent to adsorb anionic dyes namely congo red (CR), acid yellow42 (AY42) and methyl orange (MO) from aqueous solution. Different variables, including adsorption time and solution pH, were changed, and their effects on dyes adsorption onto nano-adsorbent were investigated. The optimum value of pH for CR, AY42, and MO dyes was obtained 2, 10 and 6, respectively. Results showed that adsorption efficiency for CR, AY42, and MO dyes was increased from 97.9% to 99.6%, 36.95 to 64.25% and 45.67 to 84.18%, respectively, when adsorption time changed from 5 to 60 min. Kinetic studies showed that the adsorption process onto nano-adsorbent for three dyes followed the pseudo-second-order kinetic model, which indicates that the adsorption process is chemisorption-controlled. Moreover, adsorption capacity for all dyes obtained through pseudo-second-order kinetic model was very close to its experimental value.
