Abstract
A series of sorbents with mean diameters no greater than φ75μm was prepared by a crosslinking reaction with β-cyclodextrin (βCyD) and diisocyanates followed by ball-milling. The sorbent synthesized with hexamethylene diisocyanate (HDI) as a crosslinker showed better phenol removal efficiency than that with toluene 2,6-diisocyanate (TDI). The greatest removal efficiency was achieved with βCyD/HDI (1/8) sorbent which was obtained by the crosslinking of βCyD with HDI in a 1 : 8 molar ratio. The removal of the phenolic compounds from the raw industrial wastewater was almost instantaneous and the sorbents were efficiently regenerated by the elution of the adsorbed phenols with methanol. The βCyD/HDI (1/8) sorbent effectively removed phenol from phenolic wastewater containing 89 g/L phenol to concentrations as low as 117 mg/L, using five times accumulated batchwise treatments. Adsorption by the use of a liquid-solid fluidized bed was also carried out.
