不同碳源下缺氧/好氧连续流系统生物除磷效果及其机理

为了考察前期发现的以淀粉为唯一碳源、缺氧好氧生物脱氮系统对含多种有机物的废水中磷的脱除,在以淀粉为唯一碳源、已能稳定生物除磷(除磷率达72％)的缺氧好氧连续流生物脱氮系统中,改变进水碳源组成及浓度,测定了系统对磷去除的变化、分析了系统除磷与进水碳源的关系.结果 表明,在进水中淀粉浓度保持为400 mg·L-1(以COD...

Biological phosphorus removal and its mechanism in anoxic/aerobic continuous flow system with different carbon sources

To investigate the phosphate removal from wastewater containing many types of organics by anoxic/aerobic biological denitrification system with starch alone as carbon source, which was observed before, the effects of the constitution and concentration of carbon source on the performance of the continuous flow system, which achieved good phosphorus removal (efficiency of 72%)with starch alone as carbon source, were studied, as well as the change of phosphorus removal and the relationship between the carbon source and phosphorus removal. The results showed that when the concentration of starch in the influent was at 400 mg·L−1, and the COD value of the wastewater increased to 500 mg·L−1 and 600 mg·L−1 with addition of glucose or a mixture of peptone and milk powder, respectively, the glycogen content in the sludge under anoxic period increased from 282.9 mg·g−1 to 312.3 mg·g−1 with addition of glucose, while the amount of lactic acid in the bulk liquid decreased, at last the decrease in phosphorus removal rate occurred. When different mixtures of peptone and milk powder (1∶1) were added, the amount of lactic acid in the bulk liquid of anoxic period and the phosphorus removal by the sludge were almost the same as before. Under the conditions of constant starch content and increased influent COD value, the phosphate removal of the system did not increase with addition of glucose or a mixture of peptone and milk powder. Under the conditions of maintaining the total influent COD of 400 mg·L−1, reducing the amount of starch in the influent to 300, 200 and 100 mg·L−1 , respectively, and increasing glucose or a mixture of peptone and milk powder (1∶1) at the same time, the reduction of starch in influent resulted in the decrease of phosphorus removal efficiency of the system with 6 types of carbon sources. When the glucose concentration was 100 mg·L−1 and starch 300 mg·L−1, phosphorus removal efficiency of the system was the highest, phosphorus intake amount and rate were 2.9 mg·L−1 and 0.95 mg·(g·h)−1, respectively. It implies that the system relied on lactic acid produced by starch fermentation at anoxic stage to achieve excessive phosphorus uptake, while the sludge in the system did not use protein substances to ferment and produce lactic acid, which did not help to remove phosphorus. When the starch was sufficient (COD 400 mg·L−1), glucose addition was not conducive to phosphorus removal. Glucose could be used as a supplementary carbon source when the starch was insufficient.