VOCs removal by adsorption onto activated carbons from biocollagenic wastes of vegetable tanning

Abstract

Abstract The objective of this work was to obtain low-cost adsorbent materials in order to remove VOC pollutants. Toluene was chosen as a model of volatile organic compounds for this study. Microporous activated carbons were obtained from vegetable-tanned leather wastes (shavings, trimmings and buffing dust) by means of chemical activation with alkaline agents (KOH, NaOH and K 2 CO 3 ). A specific BET surface area, total pore volume ( V TOT ) and total micropore volume ( V tot ) of 2719 m 2 g −1 , 1.184 cm 3 g −1 and 0.829 cm 3 g −1 , respectively, were obtained by KOH-activation, whereas K 2 CO 3 -activation yielded values of 1645 m 2 g −1 , 0.712 cm 3 g −1 and 0.536 cm 3 g −1 , respectively. Low-cost activated carbons with textural properties, chemical functional groups and a capacity for toluene adsorption comparable to that of activated carbons obtained with KOH or NaOH were produced from these wastes by means of K 2 CO 3 chemical activation. Toluene adsorption values at concentrations on the odour threshold-5 ppm (27 mg VOC/g), TLV-TWA-50 ppm (288 mg VOC/g) or TLC-C-100 ppm (700 mg VOC/g) higher than commercial activated carbons such as NORIT RB3, WV-A1100 or Centaur HSV were obtained.