Banca de DEFESA: WANESSA PAULINO NEVES SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : WANESSA PAULINO NEVES SILVA
DATA : 07/12/2016
HORA: 08:00
LOCAL: AUDITÓRIO DO NUPEG
TÍTULO:

"Use of  nonionic surfactants in phenol extraction: equilibrium and modeling"

PALAVRAS-CHAVES:

 surfactant, phenol, cloud point extraction, thermodynamic micellization, experimental design.

PÁGINAS: 136
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
RESUMO:

Environmental sustainability has been the subject of interest and concern in the industry, mainly due to the generation of waste. As the phenolic compounds are toxic to living organisms, the maximum level of 0.5 ppm is considered as concentration limit for releases in freshwater bodies by the Federal CONAMA Resolution no. 430 2011. In the process of treatment of these effluents, liquid-liquid extraction is the most economical process for the recovery of phenol, because it consumes little energy, but most often implements an organic solvent that can cause certain environmental problems. Some studies demonstrate the feasibility of using non-ionic surfactants to replace organic solvents. The main objective of this work was to study the process of wastewater phenol extraction using as extracting agent non-ionic surfactants nonylphenol ethoxylate: R-80, R-95, R-100, R-110 and R-120. They evaluated several properties like the cloud point and miclar concentration critique of surfactants micellization thermodynamic effect of salt concentration (Xsal), surfactant concentration (Xt), phenol concentration (Xf) and degree of ethoxylation molecule surfactant (EO) as well as the parameters of the extraction process. The results showed that the cloud point (NP) of the surfactants is directly affected by the amount of phenol and salts present in the effluent. The experimental design technique was efficient in the development of mathematical models capable of predicting the PN of surfactants and optimization of variables aimed at energy cost (reduction of PN). The conditions to obtain the lowest value PN is Xsal = 0.2%, Xt = 0.5 and EO = 10. Assays for determining the c.m.c and micellization thermodynamic analysis allowed to verify that the increase in temperature tends to decrease c.m.c of surfactants, the micellization is spontaneous and exothermic process for all temperatures studied and surfactants. The phenol removal efficiency of the systems was satisfactory and in some cases greater than 95%, despite the high percentage of the volume of coacervata phase. The modeling and statistical analysis of experimental data generated models capable of describing and predicting the removal efficiency and the process parameters depending on the composition of the system. Therefore, the proposed use of non-ionic surfactants nonylphenol ethoxylate represent a practical alternative for phenol removal from wastewater, less environmental risks than conventional systems used in industry.

MEMBROS DA BANCA:
Interno - 347289 - AFONSO AVELINO DANTAS NETO
Externo à Instituição - ALESSANDRO ALISSON DE LEMOS ARAÚJO - UFERSA
Externo à Instituição - ANDRE EZEQUIEL GOMES DO NASCIMENTO - UFRN
Presidente - 1308273 - EDUARDO LINS DE BARROS NETO
Externo ao Programa - 1670497 - HUMBERTO NEVES MAIA DE OLIVEIRA
Externo à Instituição - LUIS FERREIRA DE LIMA - UFRN
Externo à Instituição - RICARDO PAULO FONSECA MELO - UFERSA