碳源对反硝化生物滤池系统运行及微生物种群影响

EFFECTS OF CARBON SOURCE TYPES ON THE OPERATION AND NITRIFYING MICROBIAL COMMUNITY OF DENITRIFYING BIOFILTER FOR ADVANCED NITROGEN REMOVAL

采用大型中试反硝化生物滤池系统,针对乙酸钠、乙酸和甲醇3种实际工程中拟选用的碳源的处理效果与种群进行了系统的试验研究。试验发现乙酸钠、乙酸和甲醇为碳源,硝酸盐去除率均可达90%以上,北方冬季更适宜采用甲醇为碳源。与乙酸和乙酸钠相比,甲醇为碳源所用投加量最低,费用最少,反冲洗周期最长,且对出水浊度的影响最小。以乙酸钠、乙酸和甲醇为碳源初期启动出现了大量的亚硝酸盐累积,经驯化后可逐渐消失;但以甲醇为碳源,当碳源投加量不足时,会再次出现亚硝酸盐累积问题。以乙酸钠和乙酸为碳源与以甲醇为碳源DNBF中的微生物种群存在显著差别,可明显观察到甲醇为碳源时滤料表面生物膜几乎全部为杆菌,并由粘性物质连接。

The efficiency and microbial community using three typical carbon sources （sodium acetate, acetate and methanol） applied in real water recycling plant, were systematically studied in large scale pilot denitrifying biofilter （DNBF）. The results indicated that nitrate removal efficiency were higher than 90% in DNBF by using these three carbon sources. Methanol was more suitable for applying in cold winter in south china than sodium acetate and acetate. Compared to acetate and sodium acetate, using methanol as carbon source, the dosage and cost were both very low, the back-wash cycle was long, and the effect of carbon source on the turbidity in the effluent was very small. During the start-up stage, large amount of nitrite were accumulated by using these three carbon sources. Though the phenomenon of nitrite accumulation was disappeared through cultivating for about 1 month, nitrite was re-accumulated using methanol as carbon source when the carbon dosage was insufficient. Microbial communities using methanol as carbon source in DNBF were more distinguish than that using sodium acetate and acetate as carbon sources. Bilfilm attached on the surface of filter media was combined by bacillus, which were binding by slimy growth.