有机负荷对餐厨垃圾厌氧消化性能影响及动力学分析

Effect of Organic Loading Rate on Process Performance of Food Waste and its Kinetic Analysis

为探究有机负荷对餐厨垃圾厌氧消化系统的影响,在50 L全混合式厌氧消化反应器(CSTR)进行进料负荷从0.72增至3.86 kgVS·m^(-3)d^(-1)的梯度实验。同时采用Modified Gompertz模型研究不同进料负荷(1、2、3、4、5 kgVS·m^(-3)d^(-1))产甲烷动力学特性,开展生化产甲烷潜力(BMP)试验。结果表明,日产气量和挥发性脂肪酸(VFA)随着负荷的增加而波动上升,而吨VS产气量和碱度则随之下降;在负荷3.15 kgVS·m^(-3)d^(-1)阶段,VFA为2000 mg·L^(-1)左右,酸碱比在0.13左右,容积产气率在2.25 L·L^(-1)左右,系统稳定性强且厌氧消化效率高,此负荷为最佳负荷。BMP试验显示Modified Gompertz模型适合描述餐厨垃圾厌氧消化过程,最大产甲烷量和最高产甲烷率均随着负荷的增加而提高。

In order to investigate the effect of organic load rate on the anaerobic digestion system of food waste,a gradient experiment was conducted in a 50 L fully mixed anaerobic digestion reactor(CSTR)to increase the feed load from 0.72 to 3.86 kgVS·m^(-3) d^(-1).At the same time,the Modified Gompertz model was used to study the methane production dynamics of different feed loads(1、2、3、4、5 kgVS·m^(-3)d^(-1))were studied,and the biochemical methane production potential(BMP)test was carried out.The results showed that the daily gas production and volatile fatty acid(VFA)increased with the increase of load,while the gas production and alkalinity of VS per ton decreased with the increase of load.At the load stage of 3.15 kgVS·m^(-3)d^(-1),the VFA is about 2000 mg·L^(-1),the acid-base ratio is about 0.13,and the volumetric gas production rate is about 2.25 L·L^(-1).The system has strong stability and high anaerobic digestion efficiency,and this load is the best load.The BMP test showed that Modified Gompertz model is suitable for describing the anaerobic digestion process of restaurant kitchen waste.The maximum methane production and maximum methane production rate both increase with the increase of load.