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

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 K2CO3). 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 K2CO3-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 K2CO3 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 R133, WV-A1100 or Centaur HSV were obtained. (C) 2014 Elsevier B.V. All rights reserved.