Desenvolvimento de nanocompósito (hidroxiapatita/ poliuretano) pela gelação (gelling) de poli ( álcool vinílico) (PVA) para remoção de metais pesados
Removing microcontaminants from effluents is a challenge today, because of its high cost and low efficiency, especially in the treatment of effluents containing heavy metals. An alternative that has emerged is the use of biodegradable nanocomposites, which exhibit good removal and recovery perfor...
Na minha lista:
| Autor principal: | |
|---|---|
| Outros Autores: | |
| Formato: | doctoralThesis |
| Idioma: | por |
| Publicado em: |
Universidade Federal do Rio Grande do Norte
|
| Assuntos: | |
| Endereço do item: | https://repositorio.ufrn.br/jspui/handle/123456789/15605 |
| Tags: |
Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
|
| Resumo: | Removing microcontaminants from effluents is a challenge today, because of its high cost and
low efficiency, especially in the treatment of effluents containing heavy metals. An alternative
that has emerged is the use of biodegradable nanocomposites, which exhibit good removal
and recovery performances, in addition to its low cost. With this in mind, the present study
aimed to develop and characterize a nanocomposite based on hydroxyapatite (HAP),
polyurethane (PU) and polyvinyl alcohol (PVA) for removing heavy metals. Thus, the
research was conducted in several steps: i)- Physico-chemical and microbiological hospital
effluent characterization; ii)- Production of hydroxyapatite by aqueous precipitation
technique, and their characterization; iii)- Production of the nanocomposite in which the
hydroxyapatite was added to the polyurethane prepolymers and then the polyvinyl
alcohol/hydroxyapatite film was produced; iv)- Polyvinyl composite without film PU/HAp
was also produced in the proportions of 20 and 40% HAp; v)- The composites was
characterized by the techniques of XRD, FTIR, SEM / EDS, BET, Zeta Potential and TGA;
vi)- The sisal and coconut fibres were washed and dried for comparative tests of adsorption;
vii)- Adsorption tests for evaluating the removal of heavy metals (nickel and cadmium).
Initial screening adsorption capacity (HAp; PU/HAp - 20 and 40%; PU / HAp / PVA), kinetic
studies of adsorption of Cd (II) by HAp; multifactorial design analysis (factorial design) for
identifying the most important variables in the adsorption of Cd (II) by composite PU/HAp.
Also comparative analysis of adsorption of Cd and Ni by composite PU/HAp were conducted,
as well as comparative tests of adsorption of Cd (coconut fibre) and Ni (sisal fibre). It was
possible to verify that the composite PU/HAp 40% showed better effectiveness for the
removal of Cd (II) and Ni (II), above 80%, equivalent to the lignocellulosic fibre used and
HAp produced. As main conclusion, it can be referred that the composite PU/HAp 40% is an
effective adsorvent to wastewater treatment for heavy metal removal, with low cost and high
efficiency |
|---|