城市生活有机垃圾各组分的厌氧消化产甲烷能力

通过生化产甲烷能力(BMP)测定实验确定了葡萄糖、大米、蔬菜、纸张、动物油、植物油和瘦肉等7种城市生活有机垃圾(BOFMSW)组分的生化产甲烷能力,并研究了抑制动物油、植物油和瘦肉厌氧消化过程的影响因素.实验结果表明,葡萄糖、大米、蔬菜和纸张在发酵过程中没有消化抑制发生,4种原料的生化产甲烷能力分别为241、210、147和244mL·g-1,相应地占理论产甲烷能力的64.5%、56.3%、32.6%和67.9%.瘦肉的厌氧消化过程停止产气后,消化液的总挥发性脂肪酸(VFAs)浓度为15800mg·L-1,其中丙酸浓度为2509mg·L-1;消化液中氨氮浓度为13892mg.L-1;较高的VFAs和氨氮浓度共同作用形成消化过程的"抑制型稳态",抑制了产甲烷菌的产甲烷代谢,导致酸化率较高而生物气转化率却很低.猪油和花生油等脂类原料的厌氧消化,由于水解和酸化细菌受到长链脂肪酸(LCFAs)的抑制而影响了原料的降解和酸化,酸化率仅分别为11.5%和10.O%.

Anaerobic biochemical methane potential of organic fraction of municipal solid waste

Biochemical methane potential (BMP) tests were conducted on glucose,rice,vegetables,paper,fat,oil and meat,and the digestion inhibitions of fat,oil and meat were studied in a batch reactor.The results showed no inhibitors in the anaerobic digestions of glucose,rice,vegetable and paper,the BMP of which were 241,210,147 and 244 mL·g^-1 respectively,or 64.5%,56.3%,32.6% and 67.9% of the theoretical methane potential (TMP) calculated by elemental analysis.For the digestion of meat,after biogas production,the total volatile fatty acids (VFAs) concentration in the digestion mixture was 15800 mg·L^-1,the propionic acid concentration was 2509 mg·L^-1,and the ammonia concentration was 13892 mg·L^-1.The interaction between high VFAs and ammonia concentration led to an "inhibited steady state",a stable condition with a low methane yield.The methanogens were inhibited in this steady state,and a high acidification rate with a low biogas conversion was observed.In the digestion of lipid materials such as fat and oil,hydrolytic and acidogenic bacteria were inhibited by the long chain fatty acids (LCFAs) and low acidification rates of 11.5% for fat and 10.0% for oil were obtained.