Assessment of vegetable wastes for basic violet 14 removal: role of sorbent surface chemistry and porosity

ABSTRACTIn this work, two vegetable wastes (i.e. grape stalks and cork bark) have been investigated as potential sorbents for the removal of the dye basic violet 14 or commonly named basic fuchsin from aqueous solution. The physical and chemical properties of grape stalks and cork bark defined by elemental analysis, polarity index, acidic functional groups, FTIR analysis, surface area and porosity were investigated to explain the different sorption behaviour of these two sorbents towards basic fuchsin removal. Effect of solution pH on basic fuchsin sorption onto both vegetable wastes has been investigated and sorption kinetics and isotherms determined. Results have been compared to those obtained using a commercial activated carbon. Langmuir maximum sorption capacity of grape stalks (106.8 mg g−1) estimated by the orthogonal distance regression method was of similar magnitude to that obtained by activated carbon (158.5 mg g−1) but cork bark (29.9 mg g−1) resulted to be about five times less effective than...