Banca de DEFESA: EDILVAN EXPEDITO DE SOUSA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : EDILVAN EXPEDITO DE SOUSA
DATE: 18/07/2023
TIME: 15:00
LOCAL: meet.google.com/zzk-omuh-kej
TITLE:

Adsorption of Polyacrylamide in soil with cohesive character in Pernambuco Coastal Tableland

KEY WORDS:

Solute Dynamics; Environment; Soil Physics; kinetics; Adsorption isotherms.

PAGES: 66
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUMMARY:

Cohesive soils or soils with a cohesive character are soils that present horizons or hardened subsurface layers when dry, they have a generally massive structure, however, when moistened, they quickly return to their friable state. Soils with such characteristics are widely used in agriculture, however, by limiting the deepening of roots, they cause a reduction in the absorption of water and nutrients by plants. To mitigate this problem, artificial polymers, such as polyacrylamide (PAM), have been used as soil conditioners, requiring a better understanding of the movement of these polymers along the soil profile. This work aimed to evaluate and understand the transport parameters and adsorption mechanisms of the PAM molecule in soil with a cohesive horizon, located at the Experimental Station of Itapirema, Goiana – PE. Soil samples were collected, deformed and undisturbed, in a soil profile, in the horizons A, E, BE and Bt. In the laboratory, chemical and physical analyzes of the soil samples were carried out, as well as tests on equilibrium lots, and kinetics and adsorption isotherms. Polyacrylamide was used in the kinetic tests at a concentration of 200 mg L -1 , at different contact times of 5, 15, 30, 60, 120, 360, 720, 1440 and 2880 minutes. Based on the equilibrium times in the kinetic tests, the parameters for the adsorption isotherm tests were defined, in soil samples in the natural field condition and in samples with extraction of cementing agents from the soil (Si, Fe and Al). Soil samples were weighed and placed in contact with PAM solutions at different concentrations within 24 h. The PAM concentrations for the isotherm tests were 10, 20, 30, 50, 70, 90, 120,150 and 200 mg L -1 . The pseudo-first and pseudo-second order kinetic models were adequate, varying the best fit for each horizon. The Sips isothermal model had the best fit for all studied soil layers. The type of adsorption that occurred between polyacrylamide and soil samples showed chemisorption characteristics.

COMMITTEE MEMBERS:
Externo à Instituição - FRANCISCO DIRCEU DUARTE ARRAES
Presidente - FERNANDO CARTAXO ROLIM NETO
Interno - MARCUS METRI CORREA