Spent tea leaves: A new non-conventional and low-cost biosorbent for ethylene removal

摘要

This characterizations of the low-cost microsized spent tea leaf powder (MSTLP) and the effectiveness on its use as biosorbent in the removal of ethylene from a gaseous stream was investigated. Microprocessing treatment of used tea leaves significantly enhanced its ethylene removal capability. The effects of MSTLP dosage, initial ethylene concentration, and temperature on the adsorption of ethylene on MSTLP were evaluated. Moreover, the surface area/pore size distribution, functional group, and morphology of MSTLP samples were characterized. The kinetic adsorption data conformed well to a pseudo-second-order equation, and this adsorption was involved in intraparticle diffusion. The negative value of Delta G(0) and the positive value of Delta G(0) indicate that the adsorption of ethylene onto MSTLP was a spontaneous process. The adsorption capacity was found to increase with decreasing temperature and increasing MSTLP dosage. The maximum adsorption capacities varied from 0.68 to 6.93 mu mol/g at 25 degrees C based on the fits of Langmuir isotherm. MSTLP could be regenerated, and reused ten times for ethylene adsorption. The results show that a suitable choice of the microprocessing procedure for agriculture byproducts permits production of cheap biosorbent with high sorption capacity of ethylene. (c) 2015 Elsevier Ltd. All rights reserved.