NaCl对餐厨垃圾厌氧发酵产VFA浓度及组分的影响

通过间歇实验研究了最适反应条件(pH值为6.0、温度为35℃)下NaCl含量对餐厨垃圾厌氧发酵产挥发性脂肪酸(VFA)的影响.考察了NaCl含量为0.0,3.0,6.0,9.0,12.0g/L下的有机酸浓度及组成情况.结果表明,NaCl对厌氧发酵液中VFA浓度影响显著,随NaCl含量提高VFA浓度呈下降趋势,当NaCl含量达到12.0g/L时,VFA浓度在第114h达到最大值4.14g/L,仅为未添加NaCl条件下的10.1%.发酵液中各组分变化经历丁酸积累、乙酸积累与乙酸消耗3个阶段,NaCl对厌氧发酵类型影响不显著,各批次发酵均为丁酸型发酵,仅当NaCl含量超过6.0g/L时丁酸积累阶段时间延长.

Effect of NaCl content on VFA concentration and composition during anaerobic fermentation of kitchen waste

Under the optimum reaction conditions (pH 6.0, the temperature of 35℃), sequencing batch experiments were carried out to determine the effect of NaCl content on volatile fatty acid (VFA) concentration and composition during anaerobic acidogenesis kitchen wastes. The NaCl content was controlled at 0.0g/L, 3.0g/L, 6.0g/L, 9.0g/L, 12.0g/L. The results showed that, the effect of NaCl on VFA concentration was significant, and VFA concentration decreased with the amount of NaCl increased. When the amount reached 12.0g/L, VFA maximum concentration reached 4.14g/L at 114h, which was only 10.1percent of that of not adding. We also found the fermentation reactions included three stages: butyric acid accumulation, acetic acid accumulation and acetic acid consumption. The product composition in the acid reactor was less depended on NaCl. Each experiment was butyric-acid-type fermentation. When NaCl exceeded more than 6.0g/L, butyric acid accumulation stage was prolonged.