温度对高氨氮废水单级自养脱氮系统效能的影响

现有单级自养脱氮系统通常在中温(25~35℃)条件下运行,温度控制成为该技术应用的瓶颈。以高氨氮(2 000 mg/L)废水为研究对象,采用序批式生物膜反应器,探究了温度为30、15℃时,高氨氮废水单级自养生物膜脱氮系统的构建方法,以及温度对系统脱氮效能的影响。结果表明,当温度为30℃时,采用逐步提高进水氨氮负荷的方法,反应器运行118 d,进水氮负荷达到0. 50 kgN/(m^3·d),TN去除率达到91. 9%,系统构建成功;在此基础上,采用逐步降低温度(每次降低2. 5℃)至15℃,进水氮负荷降为0. 25 kgN/(m^3·d),经过260 d的运行,低温系统构建成功,TN去除率为87. 0%。温度对单级自养脱氮系统效能的影响显著,在氮负荷为0. 50 kgN/(m^3·d),温度分别为35、30、25、20℃时,TN平均去除率分别为93. 1%、91. 6%、88. 0%、81. 7%;而直接采用15℃运行时系统崩溃。

Effect of Temperature on Performance of Single-stage Autotrophic Nitrogen Removal System for Treating High Ammonia Nitrogen Wastewater

The existing single-stage autotrophic nitrogen removal system is usually operated at medium temperature (25-35℃),and temperature control has become the bottleneck of the application of the technology. High ammonia nitrogen (2 000 mg/L) wastewater was treated by a sequencing batch biofilm reactor,and the construction method of a single-stage autotrophic biofilm nitrogen removal system at temperatures of 30 ℃ and 15 ℃ was discussed. The effect of temperature on the nitrogen removal of the system was explored. The results showed that the system was successfully constructed at 30 ℃ by gradually increasing the influent ammonia nitrogen load to 0. 50 kgN/(m^3·d) after 118 days,and the TN removal rate reached 91. 9%. On this basis,a low temperature system was successfully constructed after 260 days when the temperature was gradually decreased to 15 ℃(decreased by 2. 5 ℃ each time)and the nitrogen load decreased to 0. 25 kgN/(m^3·d),and the TN removal rate reached 87. 0%. The temperature had a significant effect on performance of the single-stage autotrophic nitrogen removal system. When the nitrogen load was 0. 50 kgN/(m^3·d),the average TN removal rates of the system were 93. 1%,91. 6%,88. 0% and 81. 7% at 35 ℃,30 ℃,25 ℃ and 20 ℃. However,the system collapsed when it directly operated at 15 ℃.