利用水厂生产废水促进UASB工艺处理低温城市污水启动

为缩短UASB工艺处理低温城市污水的启动周期,开展在原水中添加水厂生产废水强化UASB系统污泥颗粒化可行性研究,并以常规启动方式做为比较,对启动过程中系统运行特性和形成的颗粒污泥特性进行探讨。试验结果表明,在水温为15℃,初始有机负荷为0.25kgCOD/（m3.d）的条件下,采用逐步提高负荷的传统启动方式和添加生产废水的强化启动方式都能实现UASB工艺的低温启动,相应的启动周期分别为120d和95d左右。在整个启动过程中,添加生产废水启动方式对有机负荷提高适应性较强,达到4kgCOD/（m3.d）时较常规方式缩短30d,而且具有较高的COD去除效率和微生物增长速率（分别为0.029g VSS/d和0.043g VSS/d）。与常规启动方式相比,强化启动方式颗粒粒径较大,在第95d内可形成2mm粒径颗粒污泥。采用添加生产废水的启动方式能够缩短UASB工艺的启动周期并强化污泥颗粒化,提高低温城市污水的处理效率和运行稳定性。

Reuse of Waterworks Wastewater to Enhance the Start-up of UASB Process for Low Temperature Municipal Wastewater Treatment

To shorten the start-up period of UASB process for the low temperature municipal wastewater treatment,two lab-scale UASB reactors were employed to study the feasibility of enhanced start-up with addition of waterworks wastewater to raw water.Also the operation and biomass characteristics were investigated with comparison of conventional start-up mode.The results show that,under the water temperature of 15℃ and the initial organic loading rate（OLR） of 0.25 kgCOD/（m3·d）,the UASB system can get stable condition with both the OLR escalating and enhanced mode,and the start-up period is approximate 120 days and 95 days respectively.Throughout the experiment the enhanced start-up processes preferable adaptability,which shorten 30days to achieve the OLR of 4 kgCOD/（m3·d）,and higher COD removal as well as biomass growth rate（0.029 g VSS/d versus 0.043 g VSS/d） correspondingly.Compared to conventional mode,the mean diameter of granular sludge is larger and 2 mm granular sludge can be formed within 95 days by enhanced mode.The experimental results demonstrate that adding waterworks wastewater can shorten the start-up time and enhance granulation,which in turn leads to improvement in organics removal efficiency and stability of the UASB system for low temperature municipal wastewater treatment.