Banca de DEFESA: ALINE RAMOS PORTELLA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALINE RAMOS PORTELLA
DATE: 29/08/2022
TIME: 09:00
LOCAL: Online via Google Meet
TITLE:

Fixed bed column with Lithothamnium calcareum as municipal wastewater post-treatment aiming at nutrient removal

KEY WORDS:

marine bioclastic granulate, adsorption, phosphorus, eutrophication.

PAGES: 80
BIG AREA: Ciências Agrárias
AREA: Engenharia Agrícola
SUMMARY:

Conventional sewage treatment technologies, in general, do not satisfactorily remove nitrogen and phosphorus, nutrients responsible for the eutrophication of lakes, ponds and reservoirs. Bioclastic granules such as Lithothamnium calcareum have been widely used in rural areas and, due to their high porosity and high surface area, they have aroused interest in their use as an adsorbent in the treatment of effluents. The present work aimed to evaluate the removal of nitrogen and phosphorus from liquid effluents, using filters of this type of bioclastic granulate on a bench scale. Effluent samples from the ETE Piraí I, located upstream of the Vigário Reservoir, and from the lake of the Agronomy Institute, Universidade Federal Rural do Rio de Janeiro, were evaluated to quantify the presence of nitrate, nitrite and phosphorus. After performing the grinding and granulometric analysis of the adsorbent material, batch tests were carried out using the material in the granulometric range from 0.3 to 0.6 mm of particle size at a concentration of 40 g.L-1, analyzing the removal of nitrate, nitrite and phosphorus. The initial concentrations used were 1, 5 and 10 mg.L-1 for nitrate and nitrite and 1, 8, 15, 25 and 50 mg.L-1 for phosphorus. The removal of the same parameters for the effluent collected in the ETE was also analyzed. No significant removal of nitrate and nitrite was observed for any of the assays. Phosphorus removal was very effective, mainly at concentrations of 1 (84%), 8 (97.75%) and 15 (94.46%) mg.L-1. In the tests with ETE effluent, the maximum phosphorus removal was 88.97%. The results of these tests were better adjusted to the Temkin model and presented kinetics compatible with the pseudo-second order model. In the second stage, continuous experiments in columns filled with Lithothamnium were carried out, operating with a flow rate of 46.3 mL.min-1 and a bed height of 2 cm, receiving samples of the treated effluent from the ETE and the lake studied as feed. The maximum efficiencies achieved for phosphorus removal in the tests with real effluents were 56.85% and 32.99% for the lake effluent and the ETE treated, respectively. For comparison with the results obtained for the real effluents, the columns were also operated varying the flow parameters (27.3, 46.3 and 74.6 mL.min-1), bed height (1.2 and 3 cm) and initial phosphorus concentration (1, 8, 15 mg.L-1). The most significant removal efficiencies obtained in these tests were 58.66% and 54.8%, for initial concentrations of 15 and 1 mg.L-1, respectively, in both cases operating with a flow rate of 27.3 mL.min-1 and bed height of 3 cm. The maximum operating time observed until the complete depletion of the column's adsorptive capacity was 120 minutes, under the conditions of lower flow, bed height and concentration studied. Thus, it was found that Lithothamnium calcareum is efficient in removing phosphorus from both treated effluents and lakes with a certain level of eutrophication, using a methodology of continuous operation in fixed bed columns.

BANKING MEMBERS:
Presidente - 1759225 - ALEXANDRE LIOI NASCENTES
Externo ao Programa - 2324368 - FILIPE ARANTES FURTADO - UFRRJExterna à Instituição - DANIELE MAIA BILA - UERJ