颗粒/絮体共存的生物除磷系统的特性研究

Characteristics of Biological Phosphorus Removal System with Coexistence of Granules and Flocs

以颗粒/絮体共存的SBR生物除磷系统为研究对象,考察了生物除磷污泥的形成过程、颗粒/絮体共存及各自单独存在下的污泥特性和除污性能。在40 min的沉淀时间下,以厌氧/好氧交替方式运行的SBR反应器中有白色颗粒污泥出现,随着运行则系统处于颗粒和絮体共存的状态。运行至第60天,污泥的平均粒径为553μm,颗粒(粒径>200μm)占污泥总量的比例为67%。颗粒/絮体共存的形式可以提高絮体污泥的沉降性能,同时降低颗粒污泥解体所导致的出水SS浓度的增加。另外,颗粒/絮体共存系统对COD、PO3-4-P、NH+4-N的去除率分别为80%、98.5%、100%。而单独颗粒系统的出水NH+4-N为7.63 mg/L,单独絮体系统的出水PO3-4-P为5.87 mg/L。颗粒与絮体共存更有利于对污染物的去除及污泥沉降性能的改善。

A sequencing batch reactor （SBR） system with coexistence of granules and flocs was used to investigate the formation process of biological phosphorus removal sludge as well as the sludge characteristics and the performance of pollutants removal with coexistence and single existence of granules and floes. There was white granular sludge generated in the SBR which operated under alternatively anaerobic/aerobic conditions after 40 min settling time, and granules and floes coexisted in the system with the operation. On the 60th day, the mean particle size of sludge was 553 μm, and the percentage of gran- ules with particle size larger than 200 μm was 67% of the total amount of sludge. The coexistence of granules and floes could improve the settleability of flocculent sludge and reduce the increase in SS concentration in the effluent caused by the disintegration of granular sludge. In addition, the removal rates of COD, PO4^3- - P and NH4^＋ - N in the system with coexistence of granules and flocs were 80% , 98.5% and 100%, respectively. However, the NH4^＋ -N concentration in the effluent from the system with single existence of granules was 7.63 mg/L, and the PO4^3- - P concentration in the effluent from the system with single existence of flocs was 5.87 mg/L. It indicated that the coexistence of granules and flocs was more beneficial to pollutants removal and sludge settleability improvement.