Abstract:

To investigate the removal of ammonia nitrogen by microorganism immobilized on bamboo carbon, nitrifying bacteria and denitrifying bacteria were immobilized on bamboocarbon （specific surface area, 365 m²·g^-1; pore volume, 0.34 mL·g^-1） to remove ammonia nitrogen. The effects of various parameters such as initial ammonia nitrogen concentration, immobilized biomass, dissolved oxygen and pH were studied. Meanwhile, the ammonia nitrogen removal kinetics was examined and the comparison experiments between bamboocarbon adsorption and bamboo carbon immobilized microorganism were carried out. The results show that parameters such as initial ammonia nitrogen concentration, immobilized biomass, dissolved oxygen and pH affect the removal of ammonia nitrogen. With the increase of bamboocarbon immobilized microorganism, the nitrogen removal rate and the removal quantity increase; but when the dosage is increased to a certain amount, the nitrogen removal rate and removal quantity begin to increase more slowly. An alkaline environment with pH at 8 is conducive to the removal of ammonia by microorganism immobilized on bamboocarbon. When microorganism immobilized on bamboocarbon is used to purify ammonia water samples, both bamboocarbon adsorption and biological nitrogen removal go into effect. With initial ammonia nitrogen concentration ≤200 mg·L^-1_, nitrification and denitrification happen simultaneously in bamboocarbon immobilized microorganism system under such condition as pH is 8 and dissolved oxygen is 1 mg·L^-1, and ammonia nitrogen removal rate can be more than 70%. The removal process follows first order kinetics.

Key words: bamboo carbon, immobilized, microorganism, ammonia nitrogen