果蔬废弃物厌氧消化特征及固体减量研究

Characteristics of Anaerobic Digestion of Fruit and Vegetable Waste and Solid Decrement

采用两相厌氧消化工艺处理固体果蔬废弃物,反应液在系统内循环使用,研究了果蔬废弃物产酸发酵类型、产甲烷相对消化产物的利用顺序和果蔬固体减量效果。结果表明,在酸化阶段,挥发酸总量最高达5800mg/L,其中丁酸占45%、戊酸占23%、乙酸占20%、丙酸和乙醇占10%左右,属于丁酸型发酵;产甲烷相对挥发酸的利用顺序为乙醇>丁酸>戊酸>丙酸>乙酸,产甲烷阶段体系ORP为-480mV左右;在厌氧消化处理过程中,反应液中COD由开始时的10000mg/L降至反应后期2000mg/L左右,COD去除率达80%以上;同时,果蔬固体物质去除率达到98.6%,果蔬废弃物减量效果明显。

Fermentation type, utilization order of digestion products in methane production phase as well as effectiveness of total solid decrement of fruit and vegetable wastes （FVW） were studied by using a two-phase anaerobic digestion process. Results showed that the maximum total volatile fermentation acids （VFA） was 5800mg/L in the acidification phase, in which the concentration of propionic acid, valeric acid, acetic acid and propionic acid/ethanol were 45%, 23%, 20% and 10% respectively, with fermentation as butyric acid type. Oxidation-reduction potential （ORP） of reactor in the methane production phase was about -480mV. COD in anaerobic treatment process was decreased from 10000mg/L at beginning to about 2000mg/L at end, resulting in 80% of COD removal efficiency. Solid decrement was significantly effective with FVW solid decrement rate up to 98.6%.