Banca de DEFESA: VALÉRIA RAFASHI

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VALÉRIA RAFASHI
DATE: 23/08/2023
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/wagner-27
TITLE:

REMOVAL OF PHOSPHORUS PRESENT IN DOMESTIC EFFLUENTS BY CHEMICAL PRECIPITATION AS STRUVITE

PAGES: 67
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:

Currently, there are two problems involving phosphorus: (a) the depletion of this resource, which should occur in this century due to the inefficient and predatory extraction of its natural sources; and (b) its presence in excessive amounts in water bodies due to the disposal of untreated or poorly treated sanitary effluents, causing large-scale environmental damage, mainly in water bodies, such as eutrophication. One of the methods of removing phosphorus in the form of phosphate from effluents is its chemical precipitation with the addition of a metal, among which magnesium has been widely used in order to produce struvite, a mineral of great interest for use as a fertilizer. This technology for removing phosphorus from effluents by precipitation such as struvite and with commercial application is not yet being applied in Brazil, but there are already success stories in other countries such as Germany. Furthermore, the literature brings quite controversial data regarding the conditions under which it is possible to precipitate phosphate, particularly as struvite. In this work, the tests were carried out on a laboratory scale, using a synthetic sample and effluent from a Sewage Treatment Station. The challenge of this research was to remove phosphorus by precipitation from samples with low phosphate concentrations. The interference of calcium ions commonly present in domestic effluents was also evaluated. The formed solids were identified by energy dispersive X-ray scanning electron microscopy (SEM-EDS) and X-ray diffraction. It was possible to obtain struvite from phosphorus concentrations as low as 3.4 mmol L-1 (105 mg L-1) and a P:Mg:N molar ratio of 1:1.5:2.6. In the presence of calcium, calcium phosphate was also formed. 91% phosphorus removal was achieved in the synthetic sample and 63% in the real effluent.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1601156 - WAGNER ALVES CARVALHO
Membro Titular - Examinador(a) Interno ao Programa - 2046361 - BRUNO LEMOS BATISTA
Membro Titular - Examinador(a) Externo à Instituição - ANA CLELIA BABETTO FERREIRA
Membro Suplente - Examinador(a) Interno ao Programa - 1762430 - DALMO MANDELLI
Membro Suplente - Examinador(a) Externo à Instituição - PAULO ROBERTO FERREIRA DE BRITO