餐厨垃圾单相厌氧消化系统酸化预警指标

针对餐厨垃圾单相厌氧消化系统极易酸化、缺乏有效预警监控指标的技术瓶颈，在中温条件下利用自行设计的单相厌氧消化反应器，进行了实验室规模的启动、连续式单相厌氧消化系统运行试验，通过深入分析表征系统酸碱抵抗能力指标的变化规律，选取挥发性脂肪酸（VFA）、碳酸氢盐碱度与总碱度的比值（BA／TA）和挥发性脂肪酸总浓度与碳酸氢盐碱度的比值（VFA／BA）作为餐厨垃圾厌氧消化系统酸化抑制的指示性指标。当VFA／BA〉0．8、BA／TA〈0．4或VFA〉3000mg／L时，表明系统缓冲能力极小，应及时采取调控措施预防系统酸化；而当BA／TA≥0．8、VFA／BA〈0．4时系统碱度较高，可以在较高负荷下运行以提高系统的产气效率。

Early-warning Indicators of Acidification in the Single-phase Anaerobic Digestion Process for Food Wastes

The commonly used indicators are often too slow to reflect the operating status in time. Confronted with lacking reliable early-warning indices in the single-phase anaerobic digestion for kitchen waste which is easy to decay, lab-scale experiments of start-up and continuous operation process of anaerobic digestion for kitchen waste were carried out in the single-phase anaerobic reactor which is self- designed under mesophihc conditions. Those values which reflect the capacity of acidity-basicity resistance, including the ratio of bicarbonate alkalinity to total alkalinity （BA/TA）, absolute testing value of volatile fatty acid （VFA） and the ratio of total concentration for volatile fatty acid to bicarbonate alkalinity （VFA/ BA）, are determinated to be the early-warning indices for acidification and imbalance of single-phase anaerobic digestion for kitchen waste. It is considered that,when VFA/BA〉0.8,BA/TA〈0.4 and VFA〉 3000mg/L,buffering capacity of the system is very poor,and the system might be out of control. Therefore, an immediately steps must be taken. While,when BA/TA≥0. 7-0.8 and VFA/BA〈0.4, the alkalinity of system is relatively better and the process can be operated with higher organic volumetric loading,which can raise the biogas-producing efficiency and get economic benefit.