Recycled Wool Based Non-Woven Material as Sorbent for Heavy Metals

Abstract

The aim of this study was to investigate the sorption properties of recycled wool based non-woven material for heavy metal ions. To improve sorption properties wool material was treated with air low-temperature plasma (LTP) and/or biopolymer chitosan (CHT). The rate and extent of uptake of various metal cations (Pb+2, Cu+2, Zn+2) by wool, kinetics of adsorption, as well as the influence of concentration, pH and temperature on the sorption process were determined. It was found that wool even as a recycled material efficiently binds metal cations in all investigated cases. Recycled non-woven wool material is good sorbent for Pb+2 ions and it seems that it does not need any modification to improve this property. The modification of the material with LTP and/or CHT does not pass over 5 % of metal uptake improvement. Sorption properties for Cu+2 Ions improve about 10 % with LTP+CHT modification of the sorbent material, but metal salt solution still contains considerable amount of residual metal in solution (>30 %) even alter 24 hours of adsorption. The improvement in Zn+2 ions sorption is the most obvious with sorbent material modification as the LTP+CHT modified wool adsorbs 84 % more Zn+2 Ions than unmodified sorbent after 24 hours. The percentage of Zn+2 ions remaining in the solution is still considerable, but it improves from 72 % to 48 %. The further improvement in lead and copper sorption properties could be obtained by increasing pH and temperature of metal salt solution. The results indicate that the investigated non-woven recycled wool based sorbent material is potentially useful low-cost substrate for removing heavy metals from industrial effluents and other water sources.