有机垃圾组分中温厌氧消化产甲烷动力学研究

以土豆、生菜、瘦肉和花生油为原料,采用批式中温厌氧消化产甲烷实验,研究了城市生活有机垃圾中淀粉类、纤维素类、蛋白质类和脂类4种典型组分的厌氧消化产甲烷特性。利用修正Gompertz方程对累积产甲烷量进行拟合,并对厌氧降解过程用一级动力学进行分析。结果表明:土豆、生菜、瘦肉和花生油的最终甲烷产量为260.1、145.7、258.4和757.2mL·gVS~(-1),延滞期分别为0、1.3、1.6和13.1d,累积甲烷产量达到最终甲烷产量80%所需的时间分别为7.2、9.6、8.1和59.7d,可生物降解度分别为74%、31%、51%和85%。从厌氧消化过程中液相的挥发性脂肪酸浓度和气相的氢气浓度以及pH监测结果表明,所有厌氧消化过程均没有中间产物的积累,适合一级动力学方程。土豆、生菜、瘦肉和花生油的厌氧降解速率常数分别为0.183、0.147、0.190和0.020d~(-1)。

KINETIC STUDY OF THE MESOPHILIC ANAEROBIC DIGESTION OF ORGANIC WASTE COMPONENTS

Batch mesophilic anaerobic digestion to produce methane were conducted using potato, lettuce, meat and peanut oil as the typical components of organic fraction of municipal solid wastes (amylaceous, cellulosic, proteinic and lip-idic materials).Modified Gompertz equation were used to fit the cumulative methane production and the anaerobic degradation processes were analyzed with first-order kinetics equation.The results showed that the methane yields of potato, lettuce, meat and peanut oil were 260.1, 145.7, 258.4 and 757.2mL ·gVS~(-1), respectively.Lag phase were 0, 1.3, 1.6 and 13.1 day.The periods which cumulative methane production achieved 80% of methane yield were 7.2, 9.6, 8.1 and 59.7 per day.Biodegradability were 74%, 31%, 51% and 85%, respectively.The determining results of total volatile fatty acids concentrations and pH in liquid phase and hydrogen concentrations in gas phase showed that there is no accumulation of intermediary products during the anaerobic digestion processes.First-order methane production kinetics could be used describing anaerobic degradation rate of organic substrates.The degradation rate constants of potato, lettuce, meat and peanut oil were 0.183, 0.147, 0.190 and 0.020d~(-1).