MBBR镶嵌氧化沟在某污水处理厂的提标效果分析

Retrofitting Effect of Oxidation Ditch Embedded with MBBR in a Wastewater Treatment Plant

浙江某污水处理厂将MBBR镶嵌于卡鲁塞尔氧化沟进行一级A提标改造,在好氧段设置MBBR区域,投加SPR-Ⅱ型悬浮载体强化脱氮除磷。改造后,系统的抗冲击负荷能力得以强化,生化段出水COD、BOD5、氨氮、TN、TP均值分别为26.04、4.72、2.42、10.46、0.26 mg/L,稳定达到了一级A标准;生化段沿程测试和小试结果显示,好氧区存在稳定的同步硝化反硝化(SND)作用,平均去除了4.29 mg/L的TN,约占进水TN的12.05%,降低了运行能耗和药耗。高通量测序结果显示,悬浮载体对硝化菌的筛选和富集具有重要作用,硝化菌在悬浮载体中的丰度为6.08%,是其在污泥中的6倍;反硝化菌在悬浮载体中的丰度为13.40%,为SND的发生提供了微观保证;系统中超过64%的硝化过程来自悬浮载体生物膜。改造后运行电耗降至0.256 kW·h/m^3,较改造前节约了17%。

A wastewater treatment plant in Zhejiang Province was upgraded to first level A standard by embedding a moving-bed biofilm reactor(MBBR)in the Carrousel oxidation ditch,in which MBBR was set up in the aerobic section and SPR-Ⅱsuspended carrier was added to strengthen the removal effect of nitrogen and phosphorus.After retrofitting,the anti-shock capacity of the system was strengthened.Average effluent COD,B0D5,NH4^+-N,TN and TP of the biochemical section were 26.04 mg/L,4.72 mg/L,2.42 mg/L,10.46 mg/L and 0.26 mg/L,respectively,which stably reached the first level A standard.According to test results along the biochemical section and trial results,it was found that there existed stable simultaneous nitrification and denitrification(SND)in the aerobic zone,and the average removal amount of TN was 4.29 mg/L,accounting for about 12.05%of the influent TN,which eventually reduced the energy consumption and chemicals consumption.The high-throughput sequencing results showed that the suspended carrier played an important role in screening and enrichment of nitrifying bacteria,and the abundance of nitrifying bacteria in the suspended carrier was 6.08%,which was 6 times of that in sludge.The abundance of denitrifying bacteria in the suspended carrier-was 13.40%,which provided a micro-environment for SND.More than 64%of the nitrification process in the system took place in the suspended earner.After retrofitting,the operation power consumption was reduced to 0.256 kW·h/m^3,which was 17%less than before retrofitting.