摘要
以蔬菜废弃物为原料的厌氧消化系统,由于原料的易酸化特性,在高负荷条件下易失稳,而低负荷的运行会导致较低的池容产气率。本研究采用自行设计的70-L厌氧发酵罐,在中温35℃条件下进行蔬菜废弃物厌氧消化的连续冲击负荷试验,根据气体成分(CH4)的变化规律,添加微量元素(Fe,Co,Ni)以调控消化过程,使其由失稳状态恢复至稳定状态,旨在提高高负荷厌氧发酵的稳定性。研究结果表明,蔬菜废弃物中温厌氧消化系统的有机负荷率增大至2.0 g VS/(L·d)时,CH4含量由50%降至40%,从第103天开始连续添加5天微量元素(Fe,Co,Ni)后,CH4含量迅速恢复至50%~55%的稳定状态,池容产甲烷率由0.38 L/(L·d)增大至0.6 L/(L·d)左右并保持稳定。停止添加微量元素后,继续增大有机负荷率,厌氧消化系统稳定运行83天。当运行至第195天时(3.0 g VS/(L·d)),CH4含量再次出现下降趋势,由58.9%降至53.4%,添加3天微量元素后,CH4含量再次恢复到55%以上的稳定状态。微量元素的添加可有效提高蔬菜废弃物厌氧消化的稳定性,能够快速恢复失稳的系统。
The anaerobic digestion（AD） system with vegetable waste（VW） as substrate for easy acidification was always operated under low organic loading rate（OLR） with low volumetric methane production rate（VMPR） and then it would result in low efficiency of digester. In this study, continuous AD of VW was carried out in the self-designed 70 L anaerobic reactors under mesophilic conditions（35 oC）. The trace elements（TE） supplementation was based on the decreasing CH4 content in order to stabilize the process of high OLR for long run-length. When the AD process ran at OLR 2.0 g VS/（L·d） with the CH4 content rapidly decreased from 50% to 40%, through the TE supplementation of 5 days, the CH4 content could quickly return to the stable state 50% ~ 55% from 40%, and VMPR increased from 0.38 L/（L·d） to the stable state of 0.6 L/（L·d）. Meanwhile, p H rose from 7.21 to 7.4 and ORP decreased from-509 m V to-530 m V. When the AD process ran at the 20 th day of OLR 3.0 g VS/（L·d） after 83 days of the first TE supplementation, the CH4 content decreased from 58.9% to 53.4% again, and then after the TE supplementation of 3 days, the CH4 content could maintain at above 55%. The TE supplementation can effectively improve the OLR and VMPR and stabilize the AD process to increase the utilization of raw materials.
出处
《新能源进展》
2018年第1期21-25,共5页
Advances in New and Renewable Energy
基金
国家自然科学基金面上项目(21476222)
中国科学院战略生物资源服务网络计划生物资源衍生库项目(ZSYS-009)
中国科学院青年创新促进会资助项目(2017423)
关键词
蔬菜废弃物
厌氧消化
微量元素
有机负荷率
vegetable waste
anaerobic digestion
trace elements
organic loading rate
