Document Type : Original Research Paper
1Department of Chemical and Environmental Engineering, Federico Santa Mar1a Technical University, Ave. España 1680, Valpara1so, Chile
Department of Chemical and Environmental Engineering, Federico Santa Mar1a Technical University, Ave. España 1680, Valpara1so, Chile
Department of Chemical Engineering, Santiago de Chile University, Ave. Lib. Bernardo O’Higgins 3363, Santiago de Chile, Chile
Instituto de la Grasa (CSIC), Avda. Padre García Tejero, 4, 41012-Sevilla, Spain
The general objective of this study was to develop a highly efficient, economical and
integrated technology for the removal of nitrogen compounds through denitrification via nitrite. To
achieve this, a modified UASB reactor was designed, set-up and operated using Chilean zeolite as
microbial support. The results were compared to a conventional UASB reactor used as control. The
volume of each reactor was 2 L. The reactors operated with synthetic wastewater under the same
operating conditions (with superficial velocities, vs, of up to 1 m/h) in the first part of the experiment.
Later, during the second part of the experiment, only the modified UASB was used, with vs of up to
5.5 m/h. In the first part of the experiment, a higher velocity of denitrification in the reactor with
zeolite was obtained. Nitrogen removal at the end of this experimental set for both reactors, with a vs
lower than 1 m/h, was 87%. In the second stage, the modified UASB reactor operated at vs of
between 1.5 and 5.5 m/h. Here, it was observed that the removal of nitrite increased significantly.
Specifically, at vs values of 2.5, 4.0 and 5.5 m/h, a value of the nitrogen loading rate (NLR) of 1.22 kg
N-NO2 -/m3/d was kept constant, achieving nitrogen removal efficiencies of 50%, 65% and 95.5%
respectively. This last value proves how highly effective the modified UASB reactor is when operating with vs as high as 5.5 m/h.