碳源对含盐废水短程硝化反硝化的影响

Effect of carbon sources on shortcut nitrification-denitrification in salinity wastewater

分别采用醋酸钠、甘油、乙醇和葡萄糖作为外加碳源,研究不同碳源对含盐废水短程硝化反硝化的影响。结果表明:(1)利用醋酸钠作为碳源,逐步增加NaCl盐度可以实现短程硝化反硝化,TN平均去除率高于95%。当NaCl盐度为14.2 g/L时,采用醋酸钠、甘油、乙醇和葡萄糖作为碳源时,NO-2-N的累积率分别为98.7%、86.5%、58.9%和54.6%。醋酸钠和甘油作为碳源,实现短程硝化反硝化效果较好。(2)采用不同碳源时,实现反硝化所需理论需碳量和理论C/N平均分别为48 g/d和1.03(摩尔比,下同);由于反硝化菌受到盐度的抑制,实际C/N约为理论C/N的2.3倍,实际需碳量约为理论需碳量的2.6倍。(3)醋酸钠、甘油、乙醇和葡萄糖完全反硝化氧化还原电位(ORP)分别为-382、-394、-403、-427 mV。当反硝化过程中碳源充足,反硝化表现为零级动力学方程。

Sodium acetate,glycerol,ethanol and glucose were applied as carbon source respectively to investigate the effect of different carbon sources on shortcut nitrification-denitrification in the salinity wastewater in SBR.The results showed when sodium acetate was used as carbon source,short-cut nitrification and denitrification of SBR can be achieved by gradually increasing the NaCl concentration,and the removal efficiency of total nitrogen was higher than 95%.When NaCl concentration was 14.2 g/L,using sodium acetate,glycerol,ethanol and glucose as carbon source respectively,the corresponding accumulation rate of nitrite in SBR were 98.7%,86.5%,58.9% and 54.6%.So,sodium acetate and glycerol were better carbon source for short-cut nitrification and denitrification process.The theory carbon demand and C/N were 48 g/d and 1.03 respectively,while the actual carbon demand and C/N was respectively 2.6 times and 2.3 times of theory carbon demand and theory C/N because of the inhibition effect of salinity to denitrifying bacteria.Complete denitrification of oxidation-reduction potential（ORP） of sodium acetate,glycerol,ethanol and glucose were-382,-394,-403,-427 mV,respectively.The denitrification process was well fitted by zero-order kinetic equations when carbon source was sufficient.