氯化钠对餐厨垃圾厌氧发酵产沼气影响

Effect of Sodium Chloride on Biogas Generation of Kitchen Waste by Anaerobic Fermentation

摘要:

通过在餐厨垃圾发酵过程中添加不同质量浓度的氯化钠,分析厌氧消化过程中产气量、中间代谢产物、酶活等指标,考察氯化钠对厌氧消化产沼气的影响。结果表明,添加低质量浓度氯化钠对产沼气量影响不大,而添加高质量浓度氯化钠则对产气有较大的抑制作用,添加2 g/L氯化钠对餐厨垃圾厌氧发酵产沼气没有影响,添加5 g/L氯化钠产气量比对照提高7.5%,添加10、20、30 g/L产气量分别比对照减少17%、24%、51%。对不同氯化钠质量浓度下产气的情况进行了动力学拟合,结果表明:添加5 g/L氯化钠时,产甲烷过程与Cheynoweth方程的相关系数R2为0.991,甲烷产量B0为399 mL/g,反应速率常数k为0.114 d-1。高浓度氯化钠影响厌氧代谢过程使得丙酸和总有机酸累积。添加20、30 g/L氯化钠下脱氢酶活性受到严重抑制,添加氯化钠浓度10、20、30 g/L氢酶失活15%、55%、60%。

Abstract:

The effect of NaCl on the fermentation process of kitchen wastes was indicated by adding different concentration of NaCl,gas production yield,intermediate metabolite,enzyme activity were analyzed during the biogas process.The results show that adding low concentration of NaCl had little influence on gas production,but adding high concentration of NaCl had obviously inhibition on the anaerobic fermentation.Biogas production of kitchen waste by anaerobic fermentation remained unchanged in adding concentration of 2 g/L NaCl,while it promoted 7.5% gas production by adding 5 g/L NaCl.Gas production was reduced by 17%,24%,51% by the adding NaCl concentration was 10,20,30 g/L,which compared to the control.The data of fitting parameters by adding NaCl concentration 5 g/L indicated that the correlation coefficient R2of the methanogenic process with Cheynoweth equation was 0.991,the methane production B0 was 399 mL/g VS and the reaction rate of constant k was 0.114 d-1.High NaCl concentration lead to the accumulation of total acid and propionic acid concentration.The experiment found that adding concentration of 20、30 g/L NaCl was severely restrained dehydrogenase enzyme activity.When adding NaCl concentration was 10、 20、30 g/L,dehydrogenase activity lose 15%,55%,60%,respectivly.