TiO2 supported layered compounds (SLCs) with different loading amounts of layered compound (LC) were prepared via impregnating TiO2 with a KOH solution and then calcining at high temperature. The photo-reduction of Cr(VI) catalyzed by SLCs and LC was also examined. Results showed that LCs were observed in the surface of SLCs and they were generated by a solid-phase reaction between KOH/K2CO3 and TiO2 at high temperature. At a solution pH of 1.0, the Cr(VI) photo-reduction showed 1/2 order kinetics in the presence or absence of TiO2. However, the Cr(VI) photo-reduction catalyzed by LC fitted zero order kinetics. In the presence of SLC with low loading amount of LC, the Cr(VI) photo-reduction showed the same kinetics as that over TiO2. In contrast, the kinetics of Cr(VI) photo-reduction catalyzed by SLC with high loading amount of LC was similar to that by the unsupported LC. SLC with a certain loading amount of LC exhibited enhanced catalytic activity for Cr(VI) photo-reduction. The enhanced catalytic activity was related to the electron transfer between the support and the LC.

Two hypercrosslinked resins CHA-101 and CHA-111 were used as polymeric adsorbents and their behaviours against the adsorption of four naphthalene derivatives-1-naphthol, 2-naphthol, 1-naphthylamine and 2-naphthylamine were studied. Equilibrium adsorption data were obtained and fitted to the Freundlich isotherms. Results indicated that the CHA series resins were far more superior to macroporous Amberlite XAD-4 in adsorbing naphthalene derivatives, and the CHA-101 resin demonstrated the highest adsorption capacity. The difference in the adsorption property between the hypercrosslinked resins and the conventional macroporous resin was attributed to the large specific surface area, uniform pore structure, appropriate pore size and partial polarity of the network of the hypercrosslinked resins.

The adsorption of I-naphthol, 2-naphthol, I-naphthylamine and 2-naphthylamine from aqueous solutions on macroporous polymeric adsorbents was studied. The equilibrium data were fitted to Freundlich-type isotherms and the equilibrium constauts K, and n were obtained. The values of the adsorption capacity depend on the surface area of adsorbents, the chemical properties of naphthalene derivatives, as well as the polarity of adsorbents. 91997 Elsevier Science Ltd

Porous resins have been used to sorb organic residues in industrial wastewaters for over four decades. A survey of literature revealed that these resins have surface areas up to 1500m2/g, and may be tailor made to selectively sorb certain groups of organic chemicals. Resins may be regenerated, upon saturation, on site at ambient temperature by solvent elution, or by other means such as pH adjustment, microwave, or steam. The organic chemicals are desorbed from the resin, during regeneration, and may be recovered for reuse. This paper reviews literature related to the applications of these porous resin sorbents for the removal and recovery of organic chemicals from wastewater, their syntheses and physicochemical properties, as well as their sorption characteristics and mechanisms. Sorption data scattered in literature are compiled, methods of resin regeneration and recovery of organic chemicals for reuse are discussed, and case studies of full-scale industrial applications in both the United States and China are presented.