【摘要】 挥发性脂肪酸(VFAs)是强化生物除磷过程中易于利用的碳源。在污水处理厂内部,将污泥进行厌氧发酵以获取生物除磷所需的易生物降解基质是可行的,同时还能减轻污泥对环境的污染。在影响污泥厌氧发酵的因素中pH是重要的参数之一。因此,在20~22℃的条件下研究了剩余污泥在不同pH下厌氧发酵的产酸情况。结果表明:将剩余污泥的pH值控制为8~11,在20 d的厌氧发酵时间内产生的VFAs量多于pH值为4~7的,特别是pH=10时,第12天的产酸量就达到最大值(256.16 mgCOD/gVSS),是pH=7时最大产酸量的3倍左右。在VFAs中乙酸、丙酸、异丁酸和异戊酸的含量占主导。除此之外,在碱性条件下SCOD的溶出量较多,糖类和蛋白质的溶出量也基本上是碱性条件下的多于酸性条件下的,而且溶解性蛋白质的浓度要大于糖类物质的浓度。更多还原

【Abstract】 Volatile fatty acids(VFAs) are recognized as the carbon sources suitable for enhanced biological phosphorus removal process.It is feasible to utilize the anaerobic fermentation of sludge to acquire biodegradable substrates for biological phosphorus removal in wastewater treatment plant.At the same time,the effect of sludge pollution on environment is reduced.The pH value is an important parameter to affect the anaerobic fermentation.The effect of different pH values on the anaerobic acidogenesis of excess sludge at 20 to 22 ℃ was investigated.The results show that VFAs production at pH 8 to 11 is higher than that at pH 4 to 7 in the fermentation period of 20 days.When the pH is controlled at 10,the maximal VFAs of 256.16 mgCOD/gVSS are achieved on the 12th day,which is almost 3 times of that at pH of 7.The VFAs are mainly composed of acetic acid,propionic acid,iso-butyric acid and iso-valeric acid.Besides,much soluble chemical oxygen demand(SCOD) is released under alkaline conditions.The released amounts of carbohydrates and protein under alkaline conditions are greater than those under acidic conditions,and the concentration of soluble protein is higher than that of carbohydrates.更多还原