文摘
This study investigated the treatment performance for aging leachate containing refractory organic pollutants by TiO2-organobentonite photocatalyst combined with polyaluminum chloride (PAC) coagulant. TiO2 was immobilized on organobentonite granules as a supporter modified by cetyltrimethylammonium chloride (CTAC). The prepared catalysts were characterized by ESEM, FTIR, and XRD analysis, which showed that TiO2-organobentonite catalyst had uniform coating of TiO2 on support. Chemical oxygen demand (COD) and NH3-N removal rates by combination of TiO2-CTAC2.0 photocatalysis and PAC coagulation were evaluated, optimized, and compared to that by either treatment alone, with respect to TiO2-CTAC2.0 dose, photocatalytic contact time, pH, and PAC dose. Furthermore, higher removal rates (COD 80 %; NH3-N 46 %) were achieved by response surface methodology (RSM) when TiO2-CTAC2.0 photocatalysis was followed by PAC coagulation at optimized conditions. The optimized experimental conditions were TiO2-CTAC2.0 dosage of 5.09 g/L, at pH 5.53, photocatalytic contact time for 180 min, and PAC dosage of 1062 mg/L.