Efficient phenol removal of wastewater trom phenolic resin plants using crosslinked cyclodextrin particles

Removal of phenolic compounds from a raw industrial wastewater from phenolic resin processing, of which the components are phenol (8.9 wt%), m- and p-cresols (0.33 wt%), and xylenols (0.044 wt%), was carried out by using crosslinked cyclodextrin particles as a sorbent. A series of sorbents was prepared by varying the combination of cyclodextrin (CyD), beta-CyD, gamma-CyD, Mix-CyD (alpha-CyD:beta-CyD:gamma-CyD:dextrin = 30:10:10:SO wt/wt), the crosslinker, hexamethylene diisocyanate (HDI) or toluene-2,6-diisocyanate, and their molar ratio in the reaction batch. The removal of the phenolic compounds from raw industrial wastewater was an instantaneous process and was completed within about 5 min. The best removal efficiency was obtained by the crosslinked beta-CyD with HDI in a 1:8 molar ratio or the crosslinked Mix-CyD with HDI, also in a 1:8 molar ratio. The prepared sorbents were efficiently regenerated by elution of the adsorbed phenols from the crosslinked polymers with methanol. (c) 2006 Society of Chemical Industry.