底物浓度对餐厨垃圾厌氧消化的影响

Effect of substrate concentrations on anaerobic digestion of kitchen waste

在中温（37℃）及固定接种比[菌泥∶餐厨=2∶1（挥发性固体质量比,VS）]条件下,考察了底物浓度（6%、9%、12%）对餐厨垃圾厌氧消化的影响。结果表明,底物浓度对累积甲烷产量、底物甲烷得率和容积产气率影响不同。随着底物浓度增加,累积甲烷产量逐渐增加,甲烷得率逐渐降低,容积产气率先增大后减小,相应的最大值及底物浓度分别为3 062 mL（总固体12%）、479 mL CH4/g挥发性固体（总固体6%）和730 mL CH4/（L·d）（总固体9%）。厌氧消化结束后,体系固形物去除率为19.24%-20.20%,挥发性固形物去除率为31.08%-32.63%。发酵结束后,消化液化学需氧量（COD）、碱度和氨氮浓度均随着底物浓度增加而增加,最大值分别为2 344 mg/L、7232 mg CaCO3/L和1 340 mg/L。采用Modified Gompertz模型对餐厨垃圾厌氧消化过程进行拟合,结果表明,总固体为6%时Mmax和Rmax最高,分别为486 mL/g和60.58 mL/（g·d）。

Effect of substrate concentrations（ total solid,TS,6%,9%,and 12%） on anaerobic digestion of kitchen waste was investigated under mesophilic condition（ 37 ℃） with inoculum to substrate ratio of 2∶ 1（ based on volatile solid,VS）. Results showed that effects of substrate concentrations on cumulative methane production,methane yield,and volumetric methane production were different. As increasing substrate concentrations,cumulative methane production increased,methane yield decreased,and volumetric methane production increased first and then decreased. Their maximum values and corresponding TS concentrations were 3 062 mL（ TS 12%）,479 mL CH4/ g VS（ TS 6%） and 730 mL CH4/（ L·d）（ TS 9%）,respectively. After anaerobic digestion,TS and VS degradations of digestion system were 19. 24% - 20. 20% and 31. 08% - 32. 63% under different TS concentrations. COD,alkaline and ammonia nitrogen concentrations of anaerobic effluent increased as increasing substrate concentrations. The maximum concentrations of COD,alkaline and ammonia nitrogen were 2 344 mg / L,7 232 mg Ca CO3/ L,and 1 340 mg / L,respectively. Modified Gompertz model was used to simulate the anaerobic digestion of kitchen waste. Result showed the highest Mmax and Rmax of kitchen waste were 486 mL / g and 60. 58 mL /（ g·d） under substrate concentration of TS 6%.