Abstract: The influence of nitrogen (N), phosphate (P) and N&P deficiency on sludge settleability and filamentous growth was investigated in four sequencing batch reactors. The results showed that P deficiency in influent would cause decrease of polyphosphate-accumulating organisms (PAOs) and inhibit the storage capability of floc-formers. Moreover, the proportion of protein in extracellular polymer substances (EPS) decreased and sludge volume index (SVI) of 200—250 ml·g^-1 was observed. N deficiency in influent had less impact on the growth of PAOs and the storage capability of floc-formers. Protein in EPS was significantly improved, and SVI of less than 100 ml·g^-1 was observed under this condition. The short-term deficiency of N&P in influent would cause deterioration of sludge settleability, but no further deterioration was observed after long-term domestication. No excessive growth of filaments but large numbers of spherical floc-formers existed in the N&P deficiency system, resulting in SVI of around 120 ml·g^-1. The dominant filaments for N, P and N&P deficiency were N. limicola Ⅱ, Type 0092 and N. limicola I, respectively. All of these dominant filaments had limited effect on sludge settleability.

Key words: aerobic, nutrient, nitrogen/phosphate deficiency, sludge bulking, filaments, sedimentation, molecular biology

摘要： 在4个序批式反应器中，分别考察了氮磷正常供给、磷缺乏、氮缺乏及氮磷同时缺乏对污泥沉降性能和丝状菌生长的影响。结果显示：磷缺乏会导致聚磷菌流失，限制菌胶团菌对碳源的贮存和利用，导致胞外聚合物中蛋白质的含量减少，SVI达到200～250 ml·g^-1；氮缺乏对聚磷菌生长及菌胶团菌贮存利用碳源的影响较小，能刺激菌胶团菌大量分泌蛋白质，SVI低于100 ml·g^-1；短期内氮磷同时缺乏会导致污泥沉降性能恶化，但经长期驯化后微生物种群结构会发生较大改变，丝状菌数量减少，且会滋生大量球状菌胶团菌，SVI在120 ml·g^-1左右。进水磷缺乏的优势丝状菌为N. limicola Ⅱ；进水氮缺乏的优势丝状菌为Type 0092；进水氮磷同时缺乏的优势丝状菌为N. limicola I。氮磷缺乏所滋生的丝状菌种类对污泥沉降性能均只能产生有限的影响。

关键词: 需氧, 营养元素, 氮磷缺乏, 污泥膨胀, 丝状菌, 沉降, 分子生物学