Improvement in nitrification through the use of natural zeolite: influence of the biomass concentration and inoculum source|
Montalvo, S. J.; Guerrero, L. E. & Borja, R.
A batch nitrification process was studied using
synthetic wastewater as substrate and Chilean natural
zeolite as biomass carrier at ambient temperatures (20 °C).
Three groups of experiments were carried out: a first
experimental set (I) with and without added zeolite using
initial biomass concentrations of 1,000 and 2,000 mg VSS/
L; a second set of experiments (II) with added zeolite and
at the same initial biomass concentrations. In these two
experimental sets, biomass from an activated sludge process
located in an urban wastewater treatment plant at La
Farfana, Santiago de Chile, was used as inoculum (1).
Finally, a third set of experiments (III) was carried out with
zeolite at an initial biomass concentration of 1,000 mg
VSS/L using an inoculum derived from an activated sludge
process treating wastewater from a paper mill (inoculum
2). Nitrifying biomass concentration values in the range of
13,000–18,800 mg VSS/L were achieved when initial
biomass concentrations varied between 1,000 and
2,000 mg VSS/L. Inoculum (1) generated higher biomass
concentrations than inoculum (2). Ammonium N removals
higher than 70 % were obtained in experimental sets II and
III when zeolite was used. For both initial biomass
concentrations tested, an exponential biomass growth was
observed up to the second day of operation, and a slight
decrease was evident afterwards, achieving stationary
values after 10–12 days of operation. The third experimental
set (III) revealed that the highest N consumption
took place between days 11 and 16 of digestion.
Batch mode; Inoculum type; Nitrifying biomass carrier; Zeolite