Air agitated tapered bubble column adsorber for hazardous dye (crystal violet) removal onto activated (ZnCl2) carbon prepared from bamboo leaves

摘要

Abstract Adsorption of crystal violet, a hazardous dye, from aqueous solution on activated carbon prepared from carbonized bamboo leaves powder with ZnCl2 activation is reported in this article using a novel air agitated tapered bubble column adsorber. The adsorbent prepared was characterized by determining the pHPZC, multipoint BET surface area and pore analyses, SEM analysis and FTIR analysis. The pHPZC of the prepared adsorbent was 6.6. The multipoint BET area measured was 291.3m2/g. Batch experiments were conducted as functions of initial concentration (50 to 150mg/L), contact time (1 to 40min), adsorbent dose (0.2 to 0.9g/L) and air flow rate (8.75×10?5 to 70.00×10?5 m3/s). The maximum percentage removal observed was 99.99% at equilibrium time of 20min under optimum conditions. The maximum adsorption capacity observed was 393.16mg/g. Results followed Freundlich isotherm (amongst seven isotherms examined) and pseudo-second order kinetics with intra-particle diffusion. The observed pressure drop was ranging from 2719 to 2837N/m2 and the energy dissipation per unit volume of colored liquid was ranging from 82.75 to 634.51W/m3 in the system studied. Very high removal and adsorption capacity of the prepared adsorbent observed in the novel tapered air agitated bubble column adsorber is the novelty achieved in the present investigation. Graphical abstract Display Omitted Highlights ? Carbonized bamboo leaves powder activated with ZnCl2 used as adsorbent. ? Novel air agitated tapered bubble column adsorber to study removal of crystal violet a hazardous dye. ? Observed higher removal efficiency (99.99%) and adsorption capacity (393.16mg/g)