摘要
厌氧发酵技术在有机垃圾处理中的应用越来越广泛,但在工程运行中氨氮的抑制问题比较突出。试验对餐厨垃圾厌氧发酵中的氨氮毒性抑制特性进行了研究,通过设置不同氨氮梯度探讨了氨氮对发酵过程产气量、脂肪酸和碱度的抑制影响。试验证明氨氮可以引起发酵系统脂肪酸的积累,尤其是丙酸的积累会造成发酵过程受到抑制。氨氮浓度较低时,可以刺激厌氧发酵的进行,使发酵产气量增加,当氨氮浓度增高到抑制浓度时,发酵产气量明显减少。反应器的碱度都随着发酵过程逐渐升高,但在高氨氮浓度下,C和D反应器的碱度含量相对较低,不足以缓冲发酵体系的pH值,因此反应器发酵过程不稳定。同时高氨氮污水的产生对后续污水的处理也带来了难度。试验证明发酵系统发生氨氮抑制后很难恢复,运行中应加大对氨氮的监测,通过调节物料进入和注入清水等措施控制氨氮浓度。
Anaerobic fermentation technology has been widely used in the treatment of organic waste,but the inhibition problem of ammonia nitrogen is prominent in engineering operation.In this paper,the toxicity characteristics of ammonia nitrogen in the anaerobic fermentation of kitchen waste were studied.The inhibition effects of ammonia nitrogen on biogas production,fatty acids concentration and alkalinity in the fermentation system were investigated by setting different ammonia nitrogen concentration gradient.It was proved that ammonia nitrogen could cause the accumulation of fatty acids in the fermentation system,especially the accumulation of propionic acid,which would inhibit the fermentation process.When ammonia nitrogen concentration was low,it could stimulate the anaerobic fermentation and increase the biogas production.When ammonia nitrogen concentration was increased to the inhibitory concentration,the biogas production of fermentation was significantly reduced.The alkalinity of the reactor increased gradually along with the fermentation process,but under the high ammonia nitrogen concentration,the alkalinity content of the reactor C and D were relatively low,which were not enough to buffer the pH of the fermentation system,so the fermentation process of the reactor was unstable.At the same time,the production of high ammonia nitrogen wastewater also brings difficulty to the subsequent wastewater treatment.The test showed that it is difficult to recover after ammonia inhibition occurred in the fermentation system.The monitoring of ammonia nitrogen should be increased during operation,and the concentration of ammonia nitrogen should be controlled by adjusting the entry of materials and adding clear water.
作者
徐家英
XU Jia-ying(Qingdao Centre for Environmental Sanitation Development,Qingdao 266003,China)
出处
《中国沼气》
2021年第5期12-16,共5页
China Biogas
关键词
餐厨垃圾厌氧发酵
氨氮
毒性抑制
脂肪酸
anaerobic digestion of kitchen waste
ammonia nitrogen
toxicity
inhibition
fatty acid
