| Activated slud ge process is the most widely used method in bio logica l wastewatertreatment a ll over the world, but there is a disadva ntage during the operation, whic hproduce large qua ntity of waste activated s ludge. S ludge conte nts various k inds ofpolluta nts, handing and disposal of the sludge is a big proble m. On the other hand,adopt the methods of land fill and inc ineratio n to dispose the s ludge will causesecondary pollution. There fore, it ge nerates a new internatio na l tendency o f sludgereduction and resource utilizatio n. The essentia l way to solve this proble m is reduceexcess sludge productio n rate with a ma ximum fro m the source, that’s sludgereduction technolo gies. Hydrolys is is the rate limiting step of s lud ge anaerobicdigestion, enhanc ing sludge hydrolys is is important base and premise to reduce sludge.Compared with the phys ical and chemica l treatme nt, the slud ge reductiontechno logies by additio nal enzyme of bio logica l methods can not only cut downdigesting time, improved sludge digestib ility, but also can be easily contro lled,econo mical and effic ient, and its products are harmless to environme nt. However,additio nal e nzyme treatme nt has some d isadvanta ges such as difficulty to recover andreuse, easily inactivated. Consequently, the researchers pay more attention to mimicenzymes sludge reductio n techno logies.The so-ca lled mimic enzymes s lud ge reduction techno logies is application o f thesynthetic polymer materia l which present a great similar effic iency and selectivitycompared to b io-enzyme into the sludge anaerobic hydrolys is process to realize thesludge reductio n. Metalloporphyrins as the mimic e nzymes models of cytoc hromeP-450mo no-oxygenase in research of the cata lytic oxidation aspect has been receivedwidespread attentio n, it’s one of the most attractive job in bio mimetic che mistry fie ld.This stud y was mainly targeted at ironporphyrin as the biomimetic catalyst model ofthe cytochrome P-450mono-oxyge nase enha nc ing sludge anaerobic hydrolys is andrea lizing sludge reduction made a deep discuss ion.In this investigation, metalloporphyrin [meso-tetrakis (4-a minophe nyl) porphyrin]iron (III) chlorid ize (FeTAPP) is bonded to the Fe3O4-NPs by a silanatio n method.The obta ined supported bio mimetic catalysts were characterized by X-ray diffraction(XRD), scanning electron microscopy (SEM), Fourier trans form infrared spectroscopy(FTIR). The effects of supported bio mimetic catalysts dosage, experiment temperature and reaction time on hydrolys is of excess sludge were eva luated. The results ind icatedthat this supported bio mimic catalysts played a significa nt role in the promotion ofsludge hydro lys is. The optimum conditio ns for bio mimic catalysts enha nc ingeffic ie ncy of WAS hydrolys is in terms of economy and effic ie ncy as follows: dosageof catalysts100mg, e xperime nt te mperature50℃, reaction time7h. Under optima lcond itions, the ratio of SCOD/TCOD and VSS reduction increased fro m13.2%and17.0%(control test) to25.7%and35.3%. Correspondingly, the concentration o fNH4+-N and reducing sugar increased by76.7%and39.2%compared with contro l test.After five times cyc lic tests of this supported bio mimic catalysts, the four para metersof SCOD/TCOD ratio, VSS reduction, concentration o f NH4+-N and reducing sugarjust a little loss, ind icating that bio mimic catalysts could be re-used for several timeswithout any s ignificant cha nges in the catalytic capacity.The effect of pH on WAS hydrolys is in existence o f supported bio mimic catalystswas also investigated. At condition of pH=7, the fo ur parameters of SCOD/TCODratio, VSS reduction, concentratio n of NH4+-N and reducing sugar were increasedfro m10.7%、17.4%、92.1mg/L and105.3mg/L (contro l test) to23.2%、34.6%、172.8mg/L and148.1mg/L. The augmenter of the four parameters at near-neutra l pH va luesis s ignificantly higher than at a lkaline and acidic pH range. That showed the neutra lpH conditio n was benefic ia l to play the best catalytic performa nce for bio mimiccatalysts, and the ac id and alkali e nvironment could cause the inhibition o f thecatalytic performance of the b iomimic cata lysts, but can’t make this s upportedbiomimic cata lysts deactivated complete ly. |
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