初始pH值对皂苷强化污泥生产短链挥发性脂肪酸的影响

Effect of initial pH on short chain fatty acid production from sludge anaerobic fermentation enhance by saponin

近年来,应用化学表面活性剂强化污泥厌氧生产短链挥发性脂肪酸得到广泛地关注。相较于化学类的表面活性剂,生物表面活性剂具有能够降解,对环境污染小的优点。报道了一种新型的生物表面活性剂皂苷,并用皂苷强化污泥厌氧发酵。实验结果表明,皂苷的最佳投放量为0.2 g·g-1干污泥,相应的最大产酸量为2 149 mg·L^(-1)此外还探究了初始pH值对皂苷强化污泥产酸的影响,实验表明最佳的初始pH为11。机理研究发现初始pH=11能够加速污泥的水解,抑制甲烷产生进而提高了短链挥发性脂肪酸的含量。

Recently,much attention has been given to the application of chemical surfactants for the production of short chain fatty acid（ SCFA） from sludge anaerobic fermentation. Compared with chemosynthetic surfactants,bio-surfactants are readily biodegradable and therefore have a low negative impact on the environment. In this paper,a novel bio-surfactant-saponin（ SP） is reported,and using SP to enhance the SCFA from sludge anaerobic fermentation is discussed. The experimental results have shown that the optimal SP dosage was 0. 2 g·g- 1dry sludge（ DS）,with the corresponding SFCA production being 2 149 mg·L- 1. In addition,the effect of the initial pH on the SCFA production from sludge anaerobic fermentation,enhanced by SP,was investigated. The results revealed that the optimal initial pH was 11. Mechanisms study has shown that an initial pH 11 could improve hydrolysis and inhibit methanogenesis,thereby enhancing SCFA production.