Chemical Engineering Journal, Vol.280, 248-255, 2015
A feasible strategy for promoting activated sludge hydrolysis by using ironporphyrin modified Fe3O4 nanoparticles as an efficient biomimic catalyst
In this research, a feasible strategy for promoting activated sludge anaerobic hydrolysis is presented. Application of supported ironporphyrin as a biomimic catalyst on anaerobic hydrolysis of excess sludge was explored. The magnetic Fe3O4 nanoparticles (Fe3O4-NPs) modified by ironporphyrin were further synthesized by a silanation method and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FUR). The results indicated that this supported biomimic catalyst exhibited a remarkable performance in the promotion of sludge hydrolysis. Under optimal conditions, the ratio of SCOD/TCOD and VSS reduction increased from initial 13.2% and 17.0% (control test) to 25.7% and 353%, respectively. Furthermore, the concentration of NH4+-N and reducing sugar were respectively increased by 76.7% and 39.2% compared with the control test. The results showed that the hydrolysis of excess sludge in the presence of biomimic catalysts at near-neutral pH values were more efficient than those of performed at alkaline and acidic pH ranges. The recycle studies showed that biomimic catalysts could be re-used for several times without any significant changes in the catalytic capacity. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Activated sludge;Anaerobic hydrolysis;Metalloporphyrin;Magnetite nanoparticles;Biomimic catalyst