基于玉米芯的固相反硝化柱实验研究

Corncob, a typical agricultural waste, is studied as the carbon source for solid phase denitrification under dynamic flow conditions by using 1-D column experiment. The results show that the hydraulic retention time has significant effect on the denitrification rate and transformation between the nitrogen species. The increase of hydraulic retention time can improve the denitrification rate, however, it can cause the accumulation of nitrite when it is in a proper range or ammonium if it is too large. C/N ratio is also an important factor affecting the solid phase denitrification. Appropriate C/N ratio can improve the nitrate removal rate and inhibit the production of nitrite and ammonium. The results show that the optimal hydraulic retention time of the system is 16 h, and the proper nitrate concentration for the system to treat is 50 mg• L^-1. Corncob has good application potential as the packing material of permeable reactive barrier for solid phase denitrification, as it can steadily release the water-soluble TOC to provide electron donor and its surface structure also favors microbial adhesion and growth. The result indicates that Pseudomonas sp is the main bacteria in the corncob-based denitrification system.