碳源类型和温度对BAF脱氮性能影响研究

以某钢铁厂的二级出水为研究对象,研究了曝气生物滤池(BAF)系统的挂膜,不同碳源类型和温度对该系统脱氮的影响。结果表明:利用含有硝化菌与好氧反硝化菌的富集菌液进行挂膜,16d基本完成挂膜,氨氮、硝态氮的去除率分别高达90.2%和92.2%。不同碳源类型对系统的脱氮性能影响存在差异,以葡萄糖和乙醇作为碳源时效果最佳,氨氮和硝态氮的去除率均超过85%,总无机氮去除率分别是93.4%、95.6%。乙酸钠为碳源时亚硝态氮的质量浓度积累最高达5.79mg/L,采用其它碳源时亚硝态氮几乎没有积累;当不投加外部碳源时,通过内源呼吸代谢作用进行硝化反硝化效果最差,总无机氮的去除率仅有20.4%。随着温度的上升,硝化和反硝化效果逐渐升高,其中硝化的最适温度是在27.3℃左右,氨氮的去除率高达91.1%,好氧反硝化过程对温度的耐受性比较好,在17.5～33.1℃时,平均去除率大于90%。

Influences of carbon source and temperature on nitrogen removal performance of BAF

Taking secondary effluent from a steel plant as treatment object,the membrane forming of biological aerated filter(BAF) and the influences of carbon source and temperature on the nitrogen removal performance of the system were studied.The results showed that:the process of membrane forming was completed and the removal rates of ammonia-nitrogen and nitrate-nitrogen were 90.2% and 92.2% respectively after 16 days of cultivation using enrichment culture which containing nitrifying bacteria and aerobic denitrifying bacteria.The use of different carbon source affected the nitrogen removal performance of the system.The best effect was obtained when glucose and ethanol were used as carbon source:the removal rates of ammonia-nitrogen and nitrate-nitrogen were both above 85% and the removal rates of total inorganic nitrogen(TIN) were 93.4% and 95.6% respectively.The accumulation of nitrite was up to 5.79 mg /L when using sodium acetate as carbon source,however,no accumulation of nitrite was measured when other carbon sources were used.The nitrification-denitrification effect by endogenous respiration without carbon source added was the worst,which manifested as the low removal rate of TIN(only 20.4%).The effect of nitrification and denitrification increased with the increasing of temperature,The optimum temperature for nitrification was about 27.3 ℃,the removal rate of ammonia nitrogen was up to 91.1%.The process of aerobic denitrification had a wide temperature endurance area,the average removal rate of nitrate was above 90% at the temperature of 17.5-33.1 ℃.