青岛市菜市场垃圾的高温厌氧消化研究

Study on thermophilic anaerobic digestion of vegetable market waste in Qingdao

在中试规模下进行菜市场垃圾高温厌氧消化试验,通过监测消化过程中的产气情况和消化液的pH、可溶解性COD(SCOD)、挥发性脂肪酸(VFA)、NH3-N、碱度等变化,确定菜市场垃圾厌氧消化的最大有机负荷,并分析对菜市场垃圾进行高温厌氧消化处理的可行性。结果表明,在中试规模下,菜市场垃圾高温厌氧消化的最高有机负荷可达6.23kg/(m3.d)(以挥发性固体计),此时的甲烷产量可保持在较高水平,利用菜市场垃圾高温厌氧消化产甲烷具有一定的技术可行性;高温厌氧消化系统运行44d后,消化液VFA中丙酸最高质量浓度达3 250mg/L,而系统仍稳定运行,说明消化液中丙酸在该浓度下不会对产甲烷菌产生强烈抑制;菜市场垃圾高温厌氧消化过程中,消化液中NH3-N浓度不是主要的产甲烷抑制因素。

The thermophilic anaerobic digestion of vegetable market waste was performed in the pilot scale device.The variation of pH,soluble COD（SCOD）,volatile fatty acid（VFA）,ammonia and alkalinity in digested liquid as well as gas production were monitored to determine the maximum organic load of vegetable market waste anaerobic digestion.The feasibility of thermophilic anaerobic digestion for vegetable market waste treatment was analyzed.The results showed that the maximum organic loading of vegetable market waste digestion system was 6.23 kg/（m3·d）（per kilogram volatile soild） in the pilot scale device.The methane output maintained at comparatively high levels under the maximum organic loading condition.So,thermophilic anaerobic digestion of vegetable market waste was technically feasible in Qingdao.After 44 days of operation,the concentration of propionic acid in digested liquid reached to the highest of 3 250 mg/L,while the system still kept in stable,which indicated that the propionic acid would not inhibit the methanogenic bacteria strongly under that level.Ammonia concentration in digested liquid was not the primary inhibition factor of methane production.