| With the rapid development of my country’s national economy,energy supply and environmental protection have become the primary issues in today’s social life.Paying attention to environmental protection and alternative energy development,and continuously encouraging the development of biomass energy is an important energy strategy in my country.Anaerobic digestion technology is an effective method to stabilize,reduce and convert sludge into energy,and has great potential to develop biomass energy.The organic matter content of sludge is very high,which is suitable as a substrate for anaerobic digestion,but the sludge composition is complex.Only 40%-50%of the organic matter is converted to methane in anaerobic digestion.The pretreatment method can effectively destroy the flocculent structure of the extracellular polymer,so that the organic matter can be dissolved rapidly,which can provide a substrate for the anaerobic microorganisms in the sludge.However,traditional pretreatment methods have problems such as high energy consumption and secondary pollution,which greatly limit the industrial application of pretreatment methods.Metalloporphyrins are macromolecular heterocyclic conjugated compounds composed of porphyrins with different substituents and a variety of central metals.Metalloporphyrins have been used in the fields of degradation and conversion of organic solid wastes due to their high catalytic oxidation efficiency,mild reaction conditions,and no secondary pollution.In this study,metalloporphyrin was used as a catalyst for pretreatment of sludge anaerobic digestion,and a catalytic oxidation system with metalloporphyrin as catalyst H2O2 as oxidant and CH3OH as solvent was constructed.Influence factors such as strategy are discussed.Furthermore,the influence of water-soluble iron porphyrin FeTSPPCl catalytic oxidation sludge pretreatment process on sludge hydrolysis performance was deeply studied,and the operating parameters were optimized.The results showed that the optimal conditions for FeTSPPCl were as follows:the dosage concentration was 80 mg/L,the hydrolysis temperature was 30℃,and the pH of the mixture was 2.Under the optimized conditions,the soluble protein content in the sludge reached 459.28 mg/g VSS,the soluble carbohydrate content reached 277.99 mg/g VSS,and the ammonia nitrogen content reached 316.38 mg/g VSS,which were increased by 241.2%and 241.2%respectively compared with the control group.367.9%and 211.6%,and the pH of the sludge was significantly reduced,and the conductivity was increased by 52.3%.The results of three-dimensional fluorescence spectrum analysis show that FeTSPPCl catalytic oxidation pretreatment can significantly improve the humification level of sludge.The results of sludge drying curve analysis show that FeTSPPCl catalytic oxidation pretreatment has a certain promotion effect on sludge dewatering performance.The ICP analysis of Fe ions in the sludge showed that the active species generated by FeTSPPCl catalytic oxidation pretreatment were more oxidative than hydroxyl radicals.Finally,the test results of TSS and VSS removal rate of sludge after hydrolysis experiment showed that FeTSPPCl catalytic oxidation pretreatment has a good effect on sludge reduction.In addition,subsequent anaerobic digestion experiments showed that FeTSPPCl catalytic oxidation pretreatment can effectively promote sludge methane production.Although there is a certain lag period,the final biogas production reached 308.11 mL/g VSS,which was 42.0%higher than the control group.more obvious.The results of this study will help to solve the huge amount of sludge problem and provide new ideas for sludge anaerobic digestion. |
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